Faculty Profiles - NAKANISHI Kazuki

Papers - NAKANISHI Kazuki

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Double-Layered Perovskite Oxyfluoride Cathodes with High Capacity Involving O-O Bond Formation for Fluoride-Ion Batteries Reviewed

Miki H., Yamamoto K., Nakaki H., Yoshinari T., Nakanishi K., Nakanishi S., Iba H., Miyawaki J., Harada Y., Kuwabara A., Wang Y., Watanabe T., Matsunaga T., Maeda K., Kageyama H., Uchimoto Y.

Journal of the American Chemical Society Vol. 146 ( 6 ) page： 3844 - 3853 2024.2

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of the American Chemical Society

Developing electrochemical high-energy storage systems is of crucial importance toward a green and sustainable energy supply. A promising candidate is fluoride-ion batteries (FIBs), which can deliver a much higher volumetric energy density than lithium-ion batteries. However, typical metal fluoride cathodes with conversion-type reactions cause a low-rate capability. Recently, layered perovskite oxides and oxyfluorides, such as LaSrMnO4 and Sr3Fe2O5F2, have been reported to exhibit relatively high rate performance and cycle stability compared to typical metal fluoride cathodes with conversion-type reactions, but their discharge capacities (∼118 mA h/g) are lower than those of typical cathodes used in lithium-ion batteries. Here, we show that double-layered perovskite oxyfluoride La1.2Sr1.8Mn2O7−δF2 exhibits (de) intercalation of two fluoride ions to rock-salt slabs and further (de) intercalation of excess fluoride ions to the perovskite layer, leading to a reversible capacity of 200 mA h/g. The additional fluoride-ion intercalation leads to the formation of O-O bond in the structure for charge compensation (i.e., anion redox). These results highlight the layered perovskite oxyfluorides as a new class of active materials for the construction of high-performance FIBs.

DOI： 10.1021/jacs.3c10871

Unusual flexibility of transparent poly(methylsilsesquioxane) aerogels by surfactant-induced mesoscopic fiber-like assembly Reviewed

Ryota Ueoka, Yosuke Hara, Ayaka Maeno, Hironori Kaji, Kazuki Nakanishi, Kazuyoshi Kanamori

Nature Communications Vol. 15 ( 1 ) page： 461 2024.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer Science and Business Media LLC

Abstract

High-performance thermal insulators represented by aerogels are regarded as one of the most promising materials for energy savings. However, significantly low mechanical strength has been a barrier for aerogels to be utilized in various social domains such as houses, buildings, and industrial plants. Here, we report a synthetic strategy to realize highly transparent aerogels with unusually high bending flexibility based on poly(methylsilsesquioxane) (PMSQ) network. We have constructed mesoscopic fine fiber-like structures of various sizes in PMSQ gels by the combination of phase separation suppression by tetramethylammonium hydroxide (TMAOH) and mesoscopic fiber-like assembly by nonionic poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-b-PPO-b-PEO) type surfactant. The optimized mesoscale structures of PMSQ gels have realized highly transparent and resilient monolithic aerogels with much high bendability compared to those reported in previous works. This work will provide a way to highly insulating materials with glasslike transparency and high mechanical flexibility.

DOI： 10.1038/s41467-024-44713-5

Other Link： https://www.nature.com/articles/s41467-024-44713-5

Preparation of monolithic silica HPLC columns with truss-structured skeletons and embedded surfactant-templated mesopores Reviewed

Detani T., Morisato K., Ohira M., Nakanishi K.

Journal of Sol-Gel Science and Technology 2024

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Sol-Gel Science and Technology

Monolithic macro/mesoporous silica gels have been prepared via a sol-gel process using triblock copolymer Pluronic P123 (EO20PO70EO20) as a structure-directing agent. In this synthesis, P123 not only induces phase separation to form macroporous structure but also acts as a supramolecular template to form mesopores with precisely controlled shape and size. Obtained was a monolithic silica composed of continuous truss-like columnar skeletons in which cylindrical mesopores are arranged in a 2D-hexagonal symmetry. These monolithic silica gels have extremely high porosity approaching 90% and exhibited high specific surface area and sharp pore size distribution as revealed by N2 sorption measurements. Combinations of the initial composition and the post-gelation treatment on wet gels allowed the control of physical properties of meso- and macropore structures. The monolithic HPLC columns prepared using these silica gels surface-modified by ODS (octadecylsilyl) ligands gave as many as 140,000 theoretical plates/m for the separation of alkylbenzenes in a reversed-phase mode. Very weak dependence of height equivalent to theoretical plate, H, on the mobile phase velocity was also recognized in comparison with conventional particle-packed columns. Graphical Abstract: (Figure presented.)

DOI： 10.1007/s10971-024-06595-3

The Role of Nanoporous Adsorbents in the Circular Economy—Closing the Loop of Critical Materials Recovery Reviewed

Florek J., Negoro M., Hu Y., Kanamori K., Nakanishi K., Kleitz F.

Advanced Functional Materials 2024

Language：English Publishing type：Research paper (scientific journal) Publisher：Advanced Functional Materials

Due to the increase in the global population, industrialization, and the transition to climate neutrality through low-emission technologies, the pressure on critical materials (CMs) continues to grow. CMs are defined as materials with a significant risk of supply chain disruption and limited substitutability. In this context, rare-earth elements, platinum group metals, lithium, and cobalt are particularly crucial for the shift to carbon-free economy and sustainability. One of the important strategies to endorse the goal of carbon reduction is to promote the recycling of resources. As a solution, effective recovery strategies have been developed, such as solid-phase separation technologies based on advanced functional sorbents. This perspective article aims to provide a general assessment of the role of porous materials in closing the loop of critical materials recycling. Here, comprehensive insights are provided into recent development, design, and application of porous adsorbents commonly applied in solid-phase extraction systems. Their current research status and problems related to their future application are also highlighted. This review covers recent advances in porous and hierarchical silica-based materials, aerogels, covalent organic frameworks, metal–organic frameworks, and carbon-based adsorbents.

DOI： 10.1002/adfm.202409462

Powdered Hierarchically Porous Silica Monoliths for the Selective Extraction of Scandium Reviewed

Brewer A., Reicher C., Manatschal O., Bai H., Nakanishi K., Kleitz F.

ACS Sustainable Chemistry and Engineering Vol. 11 ( 42 ) page： 15432 - 15439 2023.10

Language：English Publishing type：Research paper (scientific journal) Publisher：ACS Sustainable Chemistry and Engineering

Scandium (Sc) is a high value Critical Material that is most commonly used in advanced alloys. Due to current and potential supply limitations, there has been an international effort to find new and improved ways to extract Sc from existing and novel resources. Solid-phase extraction (SPE) is one promising approach for Sc recovery, particularly for use with low-grade feedstocks. Here, unfunctionalized, powdered hierarchically porous silica monoliths from DPS Inc. (DPS) are used for Sc extraction in batch and semicontinuous flow systems at model conditions. The sorbent exhibits excellent mass transfer properties, much like the whole monoliths, which should permit Sc to be rapidly recovered from large volumes of feedstock. The Sc adsorption capacity of the material is ∼142.7 mg/g at pH 6, dropping to ∼12.0 mg/g at pH 3, and adsorption is furthermore highly selective for Sc compared with the other rare earth elements (REEs). Under semicontinuous flow conditions, recovery efficiency is limited by a kinetic process. The primary mechanism responsible for the system’s slow approach to equilibrium is the Sc adsorption reaction kinetics rather than inter- or intraparticle diffusion. Overall, this unmodified hierarchically porous silica powder from DPS shows great promise for the selective extraction of Sc from various feedstocks.

DOI： 10.1021/acssuschemeng.3c04672

Dedicated to Professor Sumio Sakka, Founding Editor of Journal of Sol-Gel Science and Technology Reviewed

Nakanishi, K; Kozuka, H

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 104 ( 3 ) page： 447 - 448 2022.12

Porous polymer-derived ceramics: Flexible morphological and compositional controls through sol-gel chemistry Reviewed

George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi

JOURNAL OF THE AMERICAN CERAMIC SOCIETY Vol. 105 ( 1 ) page： 5 - 34 2022.1

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY

Porous nonoxide ceramics have exhibited impressive progress in terms of synthesis and applications over the past few decades because of their unique characteristics distinguished from the oxide counterparts. From the synthetic aspect, the preceramic polymer route, where nonoxide ceramics such as carbides and nitrides are produced from molecular precursors, offers exceptional opportunities to elaborate and control the material shape as well as the micro- and nanostructures in concert with various techniques. This review presents monolithic ceramic materials based on various reduced phases bearing hierarchical porosity with a focus on those obtained from macroporous preceramic monoliths prepared via the one-pot sol-gel process accompanied by spinodal decomposition. Here, we highlight two classes of preceramic inorganic-organic hybrid gels: organometallic crosslinked polymers based on poly(silsesquioxane)s and nonorganometallic hybrid networks related to Ti without Ti-C bonds. The polymer-to-ceramic conversion processes are discussed with concern for the crystal transition behaviors and the variation of pore properties in different length scales upon heating. In addition, although out of the preceramic polymer category, some examples of inorganic-organic nanocomposite gels with a carbonizable polymer and/or urea for yielding porous metal carbides and nitrides in a monolithic form are introduced as well, which provides extended versatility toward a variety of transition metal systems.

DOI： 10.1111/jace.18130

Synthesis of Hierarchically Porous Metal Oxide Monoliths <i>via</i> Sol-Gel Process Accompanied by Phase Separation From Divalent Metal Salts: A Short Review Reviewed

Lu, XM; Nakanishi, K

FRONTIERS IN CHEMICAL ENGINEERING Vol. 3 2021.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Frontiers in Chemical Engineering

The sol–gel process accompanied by phase separation is one of the methods to prepare hierarchically porous monoliths, hierarchically porous monolith, which is applicable not only to oxides but also to various materials compositions such as metal phosphates, organic-polymers/carbons, metal-organic frameworks. It is not until recently, however, that progress has been made in the preparation of low-valence metal oxide HPMs, such as those of magnesium, manganese, cobalt, nickel, etc. Due to the difficulty of divalent metal precursors to form homogeneous gels, different approaches from those established for trivalent and tetravalent counterparts have been attempted. This short review introduces the methods and trials in the preparation of metal oxide HPMs from divalent metal salts.

DOI： 10.3389/fceng.2021.787788

Variation of meso- and macroporous morphologies in resorcinol-formaldehyde (RF) gels tailored via a sol-gel process combined with soft-templating and phase separation Reviewed

George Hasegawa, Takaya Yano, Hirofumi Akamatsu, Katsuro Hayashi, Kazuki Nakanishi

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 95 ( 3 ) page： 801 - 812 2020.9

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

A wide-range control over multimodal pore systems in porous monoliths is a key technology for developing functional materials, as the favorable pore structures in different length scales are required to be tailored depending on their application fields. In the alkoxy-derived sol-gel systems of silica and organosilicates, the synthetic methodology of meso- and macroporous monoliths with tunable pore properties has been developed by combining the supramolecular self-assembly of a Pluronic surfactant and polymerization-induced phase-separation techniques. This strategy has been applied to the sol-gel process of phenolic resins, giving rise to the hierarchically porous polymer gels with ordered mesoporosity and the corresponding carbon monoliths after carbonization. However, the controllable size range has been limited so far. This study has explored the relationship between the starting composition and the bimodal pore properties in further detail aiming at a better control of pore properties in phenolic resins. The enlargement of mesopore size has been achieved, yet associated with broadening the mesopore size distribution and coarsening the macropore morphology, resulting in the particle aggregates. The systematical investigation also reveals that the addition of KCl can improve the micelle arrangement in macroframework and provide the narrower mesopore size distribution.

DOI： 10.1007/s10971-020-05236-9

Self‐Assembly of Metal–Organic Frameworks into Monolithic Materials with Highly Controlled Trimodal Pore Structures Reviewed

Yosuke Hara, Kazuyoshi Kanamori, Kazuki Nakanishi

Angewandte Chemie Vol. 131 ( 52 ) page： 19223 - 19229 2019.12

Thermogravimetric Evolved Gas Analysis and Microscopic Elemental Mapping of the Solid Electrolyte Interphase on Silicon Incorporated in Free-Standing Porous Carbon Electrodes Reviewed

Hasegawa, G; Kanamori, K; Nakanishi, K; Hayashi, K

LANGMUIR Vol. 35 ( 39 ) page： 12680 - 12688 2019.10

Language：English Publishing type：Research paper (scientific journal) Publisher：Langmuir

Free-standing electrodes, which are free from additives (binders and conductive agents) and even current collectors, are useful in terms of both application research and fundamental study. Here, we demonstrate the preparation of binder-free monolithic carbon electrodes embracing Si nanoparticles in their well-defined porous scaffolds via the one-pot sol-gel reaction followed by carbonization. The free-standing electrodes with a thickness of 150 μm work out as a high-areal-density anode for Li-ion batteries, delivering up to ca. 7 mA h cm-2. As the Si content increases, the capacity decay on cycling becomes pronounced, which is likely to associate with the fracturing and pulverization of Si nanoparticles even with the size smaller than 100 nm after long-term cycles. The thermogravimetry-mass spectrometry profile of the cycled electrode corroborates the successive electrolyte decomposition to grow solid electrolyte interphase (SEI) mainly composed of lithium alkylcarbonates, polymeric species, and LiF, rendering the electrode mass nearly double of its original state after 200 cycles. The elemental mapping analysis reveals that LiF is generated inhomogeneously in the monolithic electrodes unlike the other SEI components, resulting in the concentration gradient depending on the distance from a Li counter electrode.

DOI： 10.1021/acs.langmuir.9b02085

Superflexible Multifunctional Polyvinylpolydimethylsiloxane-Based Aerogels as Efficient Absorbents, Thermal Superinsulators, and Strain Sensors Reviewed

Zu, Guoqing, Kanamori, Kazuyoshi, Maeno, Ayaka, Kaji, Hironori, Nakanishi, Kazuki

Angewandte Chemie-International Edition Vol. 57 ( 31 ) page： 9722 - 9727 2018.7

Language：English Publishing type：Research paper (scientific journal) Publisher：Wiley

Aerogels are porous materials but show poor mechanical properties and limited functionality, which significantly restrict their practical applications. Preparation of highly bendable and processable aerogels with multifunctionality remains a challenge. Herein we report unprecedented superflexible aerogels based on polyvinylpolydimethylsiloxane (PVPDMS) networks, PVPDMS/polyvinylpolymethylsiloxane (PVPMS) copolymer networks, and PVPDMS/PVPMS/graphene nanocomposites by a facile radical polymerization/hydrolytic polycondensation strategy and ambient pressure drying or freeze drying. The aerogels have a doubly cross-linked organic-inorganic network structure consisting of flexible polydimethylsiloxanes and hydrocarbon chains with tunable cross-linking density, tunable pore size and bulk density. They have a high hydrophobicity and superflexibility and combine selective absorption, efficient separation of oil and water, thermal superinsulation, and strain sensing.

DOI： 10.1002/anie.201804559

Superflexible Multifunctional Polyvinylpolydimethylsiloxane‐Based Aerogels as Efficient Absorbents, Thermal Superinsulators, and Strain Sensors Reviewed

Guoqing Zu, Kazuyoshi Kanamori, Ayaka Maeno, Hironori Kaji, Kazuki Nakanishi

Angewandte Chemie Vol. 130 ( 31 ) page： 9870 - 9875 2018.7

Dynamic spring-back behavior in evaporative drying of polymethylsilsesquioxane monolithic gels for low-density transparent thermal superinsulators Reviewed

Hayase, Gen, Kanamori, Kazuyoshi, Maeno, Ayaka, Kaji, Hironori, Nakanishi, Kazuki

Journal of Non-Crystalline Solids Vol. 434 page： 115 - 119 2016.2

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Ambient pressure drying of polymethylsilsesquioxane gels via dynamic shrinkage-reexpansion has been investigated for preparation of aerogel-like xerogels and their application to thermal superinsulators. An extended aging of wet gels in aqueous solution containing precursor-derived species is found to be crucial in obtaining crack-free, monolithic xerogels with sufficiently low thermal conductivity (13.7 mW m(-1) K-1) at bulk density of 0.140 g cm(-3) (porosity similar to 90%). (C) 2015 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jnoncrysol.2015.12.016

Surface Functionalization of Silica by Si-H Activation of Hydrosilanes Reviewed

Nirmalya Moitra, Shun Ichii, Toshiyuki Kamei, Kazuyoshi Kanamori, Yang Zhu, Kazuyuki Takeda, Kazuki Nakanishi, Toyoshi Shimada

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Vol. 136 ( 33 ) page： 11570 - 11573 2014.8

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Inspired by homogeneous borane catalysts that promote Si-H bond activation, we herein describe an innovative method for surface modification of silica using hydrosilanes as the modification precursor and tris(pentafluorophenyl)borane (B(C6F5)(3)) as the catalyst. Since the surface modification reaction between surface silanol and hydrosilane is dehydrogenative, progress and termination of the reaction can easily be confirmed by the naked eye. This new metal-free process can be performed at room temperature and requires less than 5 min to complete. Hydrosilanes bearing a range of functional groups, including alcohols and carboxylic acids, have been immobilized by this method. An excellent preservation of delicate functional groups, which are otherwise decomposed in other methods, makes this methodology appealing for versatile applications.

DOI： 10.1021/ja504115d

Other Link： http://orcid.org/0000-0002-8069-4780

A Superamphiphobic Macroporous Silicone Monolith with Marshmallow-like Flexibility Reviewed

Gen Hayase, Kazuyoshi Kanamori, George Hasegawa, Ayaka Maeno, Hironori Kaji, Kazuki Nakanishi

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION Vol. 52 ( 41 ) page： 10788 - 10791 2013.10

Facile Synthesis of Marshmallow-like Macroporous Gels Usable under Harsh Conditions for the Separation of Oil and Water Reviewed

Gen Hayase, Kazuyoshi Kanamori, Masashi Fukuchi, Hironori Kaji, Kazuki Nakanishi

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION Vol. 52 ( 7 ) page： 1986 - 1989 2013

Hierarchically Porous Monoliths of Oxygen-deficient Anatase TiO<sub>2-x</sub> with Electronic Conductivity (vol 3, pg 7205, 2013) Reviewed

Kitada, A; Hasegawa, G; Kobayashi, Y; Miyazaki, K; Abe, T; Kanamori, K; Nakanishi, K; Kageyama, H

RSC ADVANCES Vol. 3 ( 48 ) page： 26475 - 26475 2013

Selective Preparation of Macroporous Monoliths of Conductive Titanium Oxides TinO2n-1 (n=2, 3, 4, 6) Reviewed

Atsushi Kitada, George Hasegawa, Yoji Kobayashi, Kazuyoshi Kanamori, Kazuki Nakanishi, Hiroshi Kageyama

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY Vol. 134 ( 26 ) page： 10894 - 10898 2012.7

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Monolithic conductive titanium oxides TinO2n-1 (n = 2, 3, 4, 6) with well-defined macropores have been successfully prepared as a single phase, via reduction of a macroporous TiO2 precursor monolith using zirconium getter. Despite substantial removal of oxide ions, all the reduced monoliths retain the macropore properties of the precursor, i.e., uniform pore size distribution and pore volume. Furthermore, compared to commercial porous Ebonex (shaped conductive TinO2n-1), the bulk densities (1.8 g cm(-3)) are half, and the porosities (60%) are about 3 times higher. The obtained TinO2n-1 (n = 2, 3, 4, 6) macroporous monoliths could find applications as electrodes for many electrochemical reactions.

DOI： 10.1021/ja302083n

Hierarchically Porous Materials by Phase Separation: Monoliths Reviewed

Nakanishi, K

HIERARCHICALLY STRUCTURED POROUS MATERIALS: FROM NANOSCIENCE TO CATALYSIS, SEPARATION, OPTICS, ENERGY, AND LIFE SCIENCE page： 241 - 267 2012

Hierarchically Structured Porous Materials: Application to Separation Sciences Reviewed

Nakanishi, K

HIERARCHICALLY STRUCTURED POROUS MATERIALS: FROM NANOSCIENCE TO CATALYSIS, SEPARATION, OPTICS, ENERGY, AND LIFE SCIENCE page： 517 - 529 2012

Controlled pore formation in organotrialkoxysilane-derived hybrids: from aerogels to hierarchically porous monoliths Reviewed

Kazuyoshi Kanamori, Kazuki Nakanishi

CHEMICAL SOCIETY REVIEWS Vol. 40 ( 2 ) page： 754 - 770 2011

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Porous polysilsesquioxane gels derived from sol-gel systems based on trifunctional silanes are reviewed. Although it is well known that trifunctional silanes possess inherent difficulties in forming homogeneous gels, increasing attention is being paid on these precursors and resultant porous polysilsesquioxanes because of hydrophobicity, functionality, and versatile mechanical properties. Much effort has been made to overcome the difficulties for homogeneous gelation, and a number of excellent porous materials with various pore properties have been explored. In this critical review, we put special emphasis on the formation of a well-defined macroporous structure by making use of phase separation, which in turn is a serious problem in obtaining homogeneous gels though. Porous polysilsesquioxane monoliths with the hierarchical structure and transparent aerogels with high mechanical durability are particularly highlighted (169 references).

DOI： 10.1039/c0cs00068j

Facile Preparation of Hierarchically Porous TiO2 Monoliths Reviewed

George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada

JOURNAL OF THE AMERICAN CERAMIC SOCIETY Vol. 93 ( 10 ) page： 3110 - 3115 2010.10

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-BLACKWELL

Monolithic titania (TiO2) with multiscale porous structures have been successfully prepared via the sol-gel route accompanied by phase separation utilizing a chelating agent and mineral salt. The TiO2 gels obtained possess well-defined macropores derived from spinodal decomposition and mesopores as interstices of anatase TiO2 nanocrystallites. Most of the chelating agent were removed by hydrolysis and subsequent decarbonation through the gradual solvent exchange from ethanol to water. The TiO2 particles comprising TiO2 gel skeletons spontaneously converted from amorphous to anatase through the solvent exchange process in a mild condition at 60 degrees C. The present method of the fabrication of porous TiO2 monoliths is advantageous for widespread applications because the reaction occurs under an almost neutral condition and does not require a hydrothermal process, which was indispensable to strengthen the monolith in the method previously reported.

DOI： 10.1111/j.1551-2916.2010.03831.x

Elastic Aerogels and Xerogels Synthesized From Methyltrimethoxysilane (MTMS) Reviewed

Kanamori Kazuyoshi, Nakanishi Kazuki, Hanada Teiichi

POLYMER-BASED SMART MATERIALS - PROCESSES, PROPERTIES AND APPLICATION Vol. 1134 page： 173 - + 2009

Preparation of Macroporous Poly(divinylbenzene) Gels Via Living Radical Polymerization Reviewed

Hasegawa, J; Kanamori, K; Nakanishi, K; Hanada, T; Yamago, S

POLYMER-BASED SMART MATERIALS - PROCESSES, PROPERTIES AND APPLICATION Vol. 1134 page： 139 - + 2009

Hierarchically porous oxides, hybrids and polymers via sol-gel accompanied by phase separation Reviewed

Kazuki Nakanishi

ORGANIC/INORGANIC HYBRID MATERIALS - 2007 Vol. 1007 page： 51 - 62 2008.9

Language：English Publishing type：Research paper (scientific journal) Publisher：MATERIALS RESEARCH SOCIETY

In various crosslinking systems containing metal oxides, organo-siloxane polymers and pure hydrocarbons, monolithic materials with hierarchical well-defined macropores and controlled mesopores have been synthesized. Synthetic progress in alkoxy-derived macroporous silica lead to the preparation of long-range ordered mesoporous skeletons in well-defined. macroporous framework. Alkylene-bridged silicon alkoxides can also be prepared into similarly hierarchical porous structures with broadened variations in framework morphology. Macro-mesoporous alkoxy-derived pure titania and zirconia have been prepared using hydrochloric acid - mediated processes. Compared with those prepared from colloidal dispersions, alkoxy-derived macroporous titania exhibited much higher mechanical strength. Titania monolith is a promising candidate as a separation medium to discriminate phosphorylated compounds in a liquid chromatography mode. Pure alumina macroporous monolith has been first synthesized from aluminum salt using propylene glycol as a proton scavenger to thrust the solution pH from acidic into neutral conditions. Alumina-based complex oxides such as garnets and spinels can also be prepared in pure phases. Polymerization and phase separation in organic crosslinker system was also controlled to obtain well-defined co-continuous macro-frameworks instead of those composed of aggregated particles. These examples demonstrate the versatility of using phase-separation in gelling systems to obtain well-defined macroporous structures.

Phase separation in alkoxy-derived silica system containing polyacrylamide Reviewed

Kousuke Kawamoto, Kazuki Nakanishi, Teiichi Hanada

ORGANIC/INORGANIC HYBRID MATERIALS - 2007 Vol. 1007 page： 63 - 68 2008.9

Language：English Publishing type：Research paper (scientific journal) Publisher：MATERIALS RESEARCH SOCIETY

By inducing phase separation parallel to the sol-gel transition of alkoxy-derived silica systems, gels having both macroporous and mesoporous structures can be obtained. Using poly(acrylamide) (PAAm) as a phase-separation inducer, macro/mesoporous silica gels were synthesized. After solvent exchange by water, the size distribution of mesopores of wet gels was evaluated by thermoporometry using a differential scanning calorimetry (DSC). Alternatively, gels were evaporation-dried after solvent exchange by ethanol or water/ethanol, followed by heat-treatment to completely remove volatile and organic components. Characterization of the dried or heat-treated samples was carried out using a scanning electron microscope (SEM) and by nitrogen adsorption measurements. Experimental results showed that the interaction between PAAm and silica is not so strong as the case of polymers having poly(oxyethylene) chains. The contribution of the secondary phase separation within the crosslinking silica-rich phase was suggested to be responsible for the mesopore formation in the PAAm-silica system.

Phase separation in Al2O3 sol-gel system incorporated with high molecular weight poly(ethylene oxide) Reviewed

Yasuaki Tokudome, Kazuki Nakanishi, Koji Fujita, Kiyotaka Miura, Kazuyuki Hirao

ORGANIC/INORGANIC HYBRID MATERIALS - 2007 Vol. 1007 page： 69 - 74 2008.9

Language：English Publishing type：Research paper (scientific journal) Publisher：MATERIALS RESEARCH SOCIETY

Pure alumina monoliths with well-defined macropores and mesostructured skeleton have been synthesized via a spontaneous route from the aqueous and ethanolic solution of aluminum salts in the presence of propylene oxide and high molecular weight poly(ethylene oxide)(PEO). The addition of propylene oxide to the starting solution controls the gelation, while the addition of PEO induces the phase separation. Appropriate choice of the starting composition, with which the phase separation and gelation concur, produces large-dimension (10mmx10mmx10mm), bicontinuous macroporous Al2O3 monoliths. The mean size of the continuously connected pores is controlled in the micrometer range, depending on the PEO concentration and polarity of the solution. On the other hand, micropores and mesopores, originated from the interstices among primary particles, exhibit median pore size of about 2.6 mn and the BET surface area as high as 396 m(2)/g after dried temperature at 40 degrees C.

Preparation of Macroporous Poly(divinylbenzene) Gels Via Living Radical Polymerization Reviewed

Joji Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada, Shigeru Yamago

POLYMER-BASED SMART MATERIALS - PROCESSES, PROPERTIES AND APPLICATION Vol. 1134 page： 139 - 144 2008.9

Language：English Publishing type：Research paper (scientific journal) Publisher：MATERIALS RESEARCH SOC

Macroporous cross-linked polymeric dried gels have been obtained by inducing phase separation in a homogeneous poly(divinylbenzene) (PDVB) network formed by organotellurium-mediated living radical polymerization (TERP). The living polymerization reaction of DVB with the coexistence of a non-reactive polymeric agent, poly(dimethylsiloxane) (PDMS), in solvent 1,3,5-trimethylbenzene (TMB) resulted in polymerization-induced phase separation (spinodal decomposition), and the transient structure of spinodal decomposition has been frozen by gelation. Well-defined macroporous monolithic dried gels with bicontinuous structure in the micrometer scale are obtained after removing PDMS and TMB by simple washing and drying. The properties of the macropores have been controlled by changing starting composition.

Elastic aerogels and xerogels synthesized from methyltrimethoxysilane (MTMS) Reviewed

Kanamori K., Nakanishi K., Hanada T.

Materials Research Society Symposium Proceedings Vol. 1134 page： 173 - 178 2008.9

Language：English Publishing type：Research paper (scientific journal) Publisher：Materials Research Society Symposium Proceedings

Transparent organic-inorganic hybrid aerogels and aerogel-like xerogels have been prepared from methyltrimethoxysilane (MTMS) respectively by supercritical drying (SCD) and ambient pressure drying (APD). The new aerogels and xerogels significantly deform without collapsing on uniaxial compression and almost fully relax when unloaded. This elastic behavior, termed as "spring-back", allows APD without noticeable shrinkage and cracking. The flexible network composed of lower cross-linking density (up to three bonds per every silicon atom) compared to silica gels (up to four bonds) and repulsion between hydrophobic methyl groups bonded to every silicon atom largely contributes to the pronounced deformability and relaxing, respectively. Lower surface silanol group density also plays a crucial role for the "spring-back" behavior. © 2009 Materials Research Society.

Multiscale templating of siloxane gels via polymerization-induced phase separation Reviewed

Kazuki Nakanishi, Tomohiko Amatani, Seiji Yano, Tetsuya Kodaira

CHEMISTRY OF MATERIALS Vol. 20 ( 3 ) page： 1108 - 1115 2008.2

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

By combining the micellar templating in nanometer-scale with the polymerization-induced phase separation in micrometer-scale, we can synthesize monolithic silica or silsesquioxane gel materials with hierarchical well-defined macropores and shape-controlled mesopores. Depending on the mechanism of enhancing micellar-templating of siloxane oligomers, macroframeworks containing long-range-ordered cylindrical mesopores with different degrees of order have been produced. Alkylene-bridged silicon alkoxides can also be prepared into similarly hierarchical porous structures with broadened variations in framework morphology. These examples demonstrate the versatility of using phase-separation in micellar-templated gelling systems to obtain well-defined macroporous structures.

DOI： 10.1021/cm702486b

Hierarchically porous oxides, hybrids and polymers via sol-gel accompanied by phase separation Reviewed

Nakanishi Kazuki

ORGANIC/INORGANIC HYBRID MATERIALS - 2007 Vol. 1007 page： 51 - 62 2008

Phase separation in alkoxy-derived silica system containing polyacrylamide Reviewed

Kawamoto, K; Nakanishi, K; Hanada, T

ORGANIC/INORGANIC HYBRID MATERIALS - 2007 Vol. 1007 page： 63 - 68 2008

Phase separation in Al<sub>2</sub>O<sub>3</sub> sol-gel system incorporated with high molecular weight poly(ethylene oxide) Reviewed

Tokudome, Y; Nakanishi, K; Fujita, K; Miura, K; Hirao, K

ORGANIC/INORGANIC HYBRID MATERIALS - 2007 Vol. 1007 page： 69 - 74 2008

Sol-gel with phase separation. Hierarchically porous materials optimized for high-performance liquid chromatography separations Reviewed

Kazuki Nakanishi, Nobuo Tanaka

ACCOUNTS OF CHEMICAL RESEARCH Vol. 40 ( 9 ) page： 863 - 873 2007.9

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Sol-gel processes for fabricating oxides or metalloxane polymers with controlled porous structures have been reviewed. Gel materials having controlled macropores are synthesized by polymerization-induced phase separation and concurrent sol-gel transition in a variety of chemical compositions. Several variations of tailoring mesopore structures within the macroporous materials are introduced, which enable one to design hierarchically porous metal oxide and metalloxane polymer materials. Applications of monolithic silica gels having hierarchical macro/mesoporous structure to the separation media of high-performance liquid chromatography, HPLC, are described.

DOI： 10.1021/ar600034p

New transparent methylsilsesquioxane aerogels and xerogels with improved mechanical properties Reviewed

Kazuyoshi Kanamori, Mamoru Aizawa, Kazuki Nakanishi, Teiichi Hanada

ADVANCED MATERIALS Vol. 19 ( 12 ) page： 1589 - + 2007.6

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Transparent organic-inorganic hybrid aerogels and xerogels are prepared by using a sol-gel synthesis from a single trifunctional precursor, methyltrimethoxysilane (see figure). Obtained aerogels show a reversible shrinkage-recovery response against uniaxial compression. Aerogel-like xerogels are successfully obtained by evaporation drying under ambient pressure because the gels recover from the temporal shrinkage caused by the capillary force of a drying solvent. Pore properties and nanotextures are well-preserved in the resultant xerogels.

DOI： 10.1002/adma.200602457

Performance of monolithic silica capillary columns with increased phase ratios and small-sized domains Reviewed

Takeshi Hara, Hiroshi Kobayashi, Tohru Ikegami, Kazuki Nakanishi, Nobuo Tanaka

ANALYTICAL CHEMISTRY Vol. 78 ( 22 ) page： 7632 - 7642 2006.11

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Monolithic silica capillary columns for HPLC were prepared from tetramethoxysilane to have smaller sized domains and increased phase ratios as compared to previous materials, and their performance was evaluated. The monolithic silica columns possessed an external porosity of 0.65-0.76 and a total porosity of 0.92-0.95 and showed considerably higher performance and greater retention factors in a reversed-phase mode after chemical modification than columns previously reported. An octadecylsilylated monolithic silica column with the smallest domain size (through-pores of similar to 1.3 mu m and silica skeletons of similar to 0.9 mu m) showed a plate height of less than 5 mu m at optimum linear velocities (u) of 2- 3 mm/s in 80% acetonitrile for a solute having retention factors of similar to 1, and similar to 7 mu m at u) 8 mm/s. With a permeability similar to that of a column packed with 5-mu m particles, the monolithic silica columns were able to attain column efficiencies comparable to that of particulate columns packed with 2- 2.5-mu m particles, and showed performance in the "forbidden region" for the previous columns. The performance of the monolithic column can be compared favorably with that of a particle-packed column when 15 00030 000 or more theoretical plates are desired at a pressure drop of 20-40 MPa or lower. The increased homogeneity of the co-continuous structures, in addition to the small-sized domains, contributed to the higher performance as compared to previous monolithic silica columns.

DOI： 10.1021/ac060770e

Living radical polymerization in size-exclusion silica gel column reactors Reviewed

Katsube M., Ouchi M., Ando T., Sawamoto M., Nakanishi K., Ishizuka N.

Polymer Preprints, Japan Vol. 55 ( 1 ) 2006.10

Language：English Publishing type：Research paper (scientific journal) Publisher：Polymer Preprints, Japan

This work was aimed to development of continuous-flow living radical polymerization in a silica-gel column, "Chromolith", focusing its separation function by combination of surface chemical absorption and size-exclusion via uniquely shaped mesopores, Thus, living radical copolymerization of two monomers with different polarities, methyl methacrylate (MMA) and 2(dimethylamino)ethyl methacrylate (DMAEMA) was performed with a catalyst [2; Ru(Ind)Cl(PPh3)2] coupled with an initiator (1). Copolymers were continuously produced, and molecular weight distributions were narrower than that in the corresponding batch process.

Preparation of novel macroporous polymer monoliths using polymerization-induced phase separation Reviewed

Kanamori K., Nakanishi K.

Polymer Preprints, Japan Vol. 55 ( 1 ) 2006.10

Language：English Publishing type：Research paper (scientific journal) Publisher：Polymer Preprints, Japan

Macroporous polymer monoliths with rigid three-dimensional networks have been prepared via living radical polymerization of multi-functional vinyl crosslinkers. By incorporating a polymeric agent to effectively induce phase separation, well-defined macroporous morphology with highly interconnected gel skeletons and macropores has been formed presumably by spinodal decomposition. The pore size and volume are found to be controlled simply by changing starting compositions.

Rigid macroporous poly(divinylbenzene) monoliths with a well-defined bicontinuous morphology prepared by living radical polymerization Reviewed

Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada

ADVANCED MATERIALS Vol. 18 ( 18 ) page： 2407 - + 2006.9

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-BLACKWELL

Rigid macroporous poly(divinylbenzene) monoliths with good mechanical and thermal stability and possessing a well-defined bicontinuous structure (see figure) are synthesized using living radical polymerization and a polymeric phase separator. The macropore size and volume can be independently tuned by varying the starting compositions of the mixtures. Scale bars represent 20 m, a-d show increasing polydimethylsiloxane concentration

DOI： 10.1002/adma.200601026

Porous methylsiloxane gel thick film for millimeter-wave antenna substrate prepared by gap filling method Reviewed

Tanaka T., Kawakami N., Hirano T., Fukumoto Y., Suzuki T., Kanamori K., Nakanishi K.

Materials Research Society Symposium Proceedings Vol. 888 page： 251 - 256 2006.5

Language：English Publishing type：Research paper (scientific journal) Publisher：Materials Research Society Symposium Proceedings

A novel process to fabricate a thick silica gel film on an aluminum substrate, named the "gap filling method", has been developed. The process is based on a sol-gel method accompanied by phase separation in a submillimeter thick space defined by two facing substrates. Dielectric thick film integrated on a metal ground plate is successfully formed by using a SiO2 coated aluminum substrate and a cap plate covered with an amorphous carbon thin film, which control the hydrophilicity and the hydrophobicity of the plates, respectively. A thin continuous layer of less than 0. 5n thick is formed at the interface between the porous film and the cap plate, which gives the film a smooth surface preferable for patterning metal circuits of an antenna. The observed dielectric constants (εr) at 60 GHz measured by the Fabry-Perot resonator method are in the range between 1.4 and 1.6. Methyl groups homogeneously distributed in the siloxane network give a hydrophobic siloxane gel film, thus the obtained films have enough environmental stability. These results show that the gap filling method is applicable to the preparation of the porous thick film that is needed for antenna applications. © 2006 Materials Research Society.

New macroporous crosslinked polymer gels prepared via living radical polymerization Reviewed

Kanamori K., Nakanishi K., Hanada T.

Materials Research Society Symposium Proceedings Vol. 947 page： 66 - 71 2006

Language：English Publishing type：Research paper (scientific journal) Publisher：Materials Research Society Symposium Proceedings

Macroporous crosslinked polymer gels have been prepared via TEMPO-mediated living radical polymerization of divinylbenzene (DVB) in a solvent with a counter polymer. Incorporating a counter polymer, poly(dimethylsiloxane) (PDMS), induced macroscopic spinodal-type phase separation during the course of polymerization of DVB while suppressing the segregation of DVB-derived particles from the solution by living polymerization. Well-defined macroporous morphologies comprising continuous DVB-derived skeletons have thus obtained. Macropore volume and diameter were independently controlled by altering the concentrations of PDMS and the solvent. Since the present polymer gels are prepared using only the multifunctional "crosslinker", mechanical durability against bending and compression was found to be as high as inorganic ceramics with similar morphologies and porosities. © 2007 Materials Research Society.

DOI： 10.1557/proc-0947-a03-27

Monolithic O/I-hybrids with hierarchically ordered meso- And macropores Reviewed

Nakanishi K., Kobayashi Y., Amatani T., Hirao K., Kodaira T.

Materials Research Society Symposium Proceedings Vol. 847 page： 147 - 157 2005.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Materials Research Society Symposium Proceedings

Organic-Inorganic hybrid gels with hierarchical well-defined macropores and supramolecularly templated mesopores with long-range orders have been synthesized in the systems of bridged poly(silsesquioxane) systems. Nonionic surfactants such as poly(ethyleneglycol)-poly(propyleneglycol)- poly(ethyleneglycol) triblock copolymers, EOPOEOs, were found to be effective both in inducing the phase separation to give macroporous morphology and in templating the mesopores with narrow size distribution. The number of methylene units in the bridge, changed from 1 to 6 in the present experiments, affected both the phase separation tendency and template strength. In the system containing 1,2-bis(trimethoxysilyl)ethane, 2D-hexagonal arrangement of mesopores have been prepared in the gel skeleton comprising the well-defined continuous macroporous network with an aid of micelle-stabilizing agent. © 2005 Materials Research Society.

Hierarchical macro-mesoporous silica monolith Reviewed

Amatani T., Nakanishi K., Hirao K., Kodaira T.

Materials Research Society Symposium Proceedings Vol. 847 page： 121 - 126 2005.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Materials Research Society Symposium Proceedings

Monolithic pure silica gels with hierarchical macro-mesoporous structure have been synthesized via spontaneous sol-gel process from silicon alkoxidc using a structure-directing agent and a micelle-swelling agent. Monolithic body with well-defined co-continuous macropores is a result of concurrent phase separation and sol-gel transition induced by the polymerization reaction, whereas the mesopores are templated by the cooperative self-assembly of inorganic species, a structure-directing agent and a micelle-swelling agent. The following removal of surfactants by heat-treatment gives silica gels with hierarchical and fully accessible pores in discrete size ranges of micrometers and nanometers. The highly ordered 2D-hexagonal arrays of mesopores have been confirmed by X-ray diffraction measurements and FE-SEM observations. Furthermore, by further additions of the micelle-swelling agent, the mesostructural transition from well-ordered 2D-hexagonal arrays to mesostructured cellular foams (MCF) have been induced accompanied by minor modifications of the micrometer-range structure. © 2005 Materials Research Society.

Three dimensional structure and liquid transport behavior or siloxane gels with co-continuous macropores Reviewed

Saito H., Nakanishi K., Hirao K., Jinnai H., Morisato K., Minakuchi H.

Materials Research Society Symposium Proceedings Vol. 847 page： 203 - 208 2005.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Materials Research Society Symposium Proceedings

The geometrical properties of co-continuous macroporous silica monoliths have been studied by laser scanning confocal microscopy (LSCM) and a comparison with mercury intrusion method has been made. From three-dimensional images obtained by LSCM observation, probability density distributions of curvatures have been calculated on gel skeleton surface by the "sectioning and fitting method". Measured liquid transport behavior in macroporous siloxane gels has been related to the obtained curvature distributions. © 2005 Materials Research Society.

Living radical polymerization in ruthenium-bearing size-exclusion silica gel column reactors Reviewed

Katsube M., Ando T., Ouchi M., Sawamoto M., Nakanishi K., Ishizuka N.

Polymer Preprints, Japan Vol. 54 ( 2 ) 2005.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Polymer Preprints, Japan

A catalyst corresponding to Ru(Ind)Cl(PPh3)2 was covalently supported onto a mesopore and silica-gel (Chromolith™) to construct a "size-exclusion column reactor" in which "physical control" of polymer molecular weight is expected by the retention-time difference of each mobile substrate according to its size exclusion (Scheme 2). With Ru(II)-catalyzed living radical polymerization continuously performed in this column, better reaction control is expected by not only the supported catalyst but by this column separation (Fig. 1). The Ru-bearing column 5 (powder form) in fact induced living radical polymerization of methyl methacrylate with initiator 6 and an additive (n-Bu2NH) in toluene at 80°C (Fig. 2). Continuous flow polymerization in the column reactor will be discussed and compared with those in batch systems.

Real space observation of phase separating structure in a sol-gel system Reviewed

Saito H., Kanamori K., Nakanishi K., Hirao K., Nishikawa Y., Jinnai H.

Polymer Preprints, Japan Vol. 54 ( 1 ) 2005.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Polymer Preprints, Japan

In a sol-gel system accompanied by phase separation, co-continuous macroporous silica gels have been obtained with interconnected gel skeleton and well-defined macropores. The exact formation mechanism of the co-continuous structure, however, has not been sufficiently elucidated in a silica sol-gel system, due to the difficulty of observation in real space. After a device for preferential distribution of marker dye in gel phase and an adjustment of refractive indices between gel and solvent phases, time evolution of phase separating structure has been observed by laser scanning confocal microscopy and the detailed examination of the phase separation mechanism in a sol-gel system has been attempted.

Real space observation of phase separating structure in a sol-gel system Reviewed

Saito H., Kanamori K., Nakanishi K., Hirao K., Nishikawa Y., Jinnai H.

Polymer Preprints, Japan Vol. 54 ( 2 ) page： 3512 - 3513 2005.12

Language：English Publishing type：Research paper (scientific journal) Publisher：Polymer Preprints, Japan

In a sol-gel system accompanied by phase separation, co-continuous macroporous silica has been obtained, and it has been attracting attention as an efficient separation medium in a field of high performance liquid chromatography. The exact formation mechanism of the co-continuous structure, on the other hand, has been still poorly understood due to the difficulty of observation in real space. After the introduction of preferentially distributing marker dye in gel phase and the adjustment of refractive index between gel and solvent phases, time evolution of phase separating structure in a sol-gel system was observed by laser scanning confocal microscope and detailed examination of competitive kinetics between phase separation and sol-gel transition was attempted.

Experimental validation of the tetrahedral skeleton model pressure drop correlation for silica monoliths and the influence of column heterogeneity Reviewed

N Vervoort, H Saito, K Nakanishi, G Desmet

ANALYTICAL CHEMISTRY Vol. 77 ( 13 ) page： 3986 - 3992 2005.7

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

This paper describes the use of computational fluid dynamics for the calculation of the flow resistance through computer-generated models resembling silica monoliths. This study was undertaken to determine the effect of skeleton heterogeneity on the flow resistance and, more precisely, to test the hypothesis that increased skeleton heterogeneity decreases the flow resistance. To evaluate the proposed model, 24 real silica monoliths have been prepared using the same method, covering a wide range of skeleton sizes (2.2 mu m < d(s) < 8 mu m) and porosities (0.47 < epsilon < 0.66). The permeability of these monoliths was determined by pressure drop measurements, and structural information was obtained by image analysis of laser scanning confocal microscopy-generated 3D images of the skeleton structure. The results indicate that the presence of preferential flow paths due to an increased heterogeneity of the flow through pore space reduces the flow resistance of monolithic media. It is also shown that the pore size is hence a much better suited scaling dimension than the skeleton size to reduce the permeability of monolithic columns.

DOI： 10.1021/ac0502798

Three dimensional structure and liquid transport behavior of siloxane gels with co-continuous macropores Reviewed

H Saito, K Nakanishi, K Hirao, H Jinnai, K Morisato, H Minakuchi

Organic/Inorganic Hybrid Materials-2004 Vol. 847 page： 203 - 208 2005

Language：English Publishing type：Research paper (scientific journal) Publisher：MATERIALS RESEARCH SOCIETY

The geometrical properties of co-continuous macroporous silica monoliths have been studied by laser scanning confocal microscopy (LSCM) and a comparison with mercury intrusion method has been made. From three-dimensional images obtained by LSCM observation, probability density distributions of curvatures have been calculated on gel skeleton surface by the "sectioning and fitting method". Measured liquid transport behavior in macroporous siloxane gels has been related to the obtained curvature distributions.

Morphological Control and Mechanical Properties of Porous Phenolic Resins Derived from Poly(4‐Vinylphenol): Effects of Molecular Weight and Polydispersity of Prepolymer Reviewed

George Hasegawa, Atsushi Takano, Chika Hiei, Kyoka Kusano, Kazuki Nakanishi

Advanced Engineering Materials Vol. 26 ( 21 ) 2024.11

Crystalline organic monoliths with bicontinuous porosity Reviewed

Naoto Matsumoto, Sakura Nakagawa, Kei Morisato, Kazuyoshi Kanamori, Kazuki Nakanishi, Nobuhiro Yanai

Chemical Science Vol. 15 ( 29 ) page： 11500 - 11506 2024.7

Language：English Publishing type：Research paper (scientific journal) Publisher：Royal Society of Chemistry (RSC)

Crystalline organic monoliths (COMs) are a novel class of monolithic materials with a bicontinuous porous structure composed of photo-functional molecular crystals.

DOI： 10.1039/d4sc01650e

Hydrogarnet-Derived Porous Polyhedral Particles of SrFeO<sub>3-δ</sub> Perovskite Reviewed

Hikaru Otaguro, Tomoki Takeno, Ryosuke Sugimoto, Saburo Hosokawa, Hirofumi Akamatsu, Takahisa Yamamoto, Kazuki Nakanishi, Katsuro Hayashi, George Hasegawa

Chemistry of Materials Vol. 35 ( 16 ) page： 6423 - 6436 2023.8

Preparation of Hierarchically Porous Niobium(V) Oxide and Alkaline Niobate Monoliths via Sol–Gel Accompanied by Phase Separation Reviewed

Yuji Sato, Kazuyoshi Kanamori, Kazuki Nakanishi

Chemistry of Materials Vol. 35 ( 13 ) page： 5177 - 5184 2023.6

Fabrication process development and basic evaluation of eggshell-based column packing material for reversed-phase preparative separation Reviewed

Tomoka Yoshii, Akihiro Sakama, Kazuyoshi Kanamori, Kazuki Nakanishi, Hiroaki Imai, Daniel Citterio, Yuki Hiruta

Journal of Chromatography A Vol. 1688 page： 463722 2023.1

Mechanical and thermal properties of porous polyimide monoliths crosslinked with aromatic and aliphatic triamines Reviewed

Mitsuhiro Ishida, Yutaro Sashiyama, Hirofumi Akamatsu, Katsuro Hayashi, Kazuki Nakanishi, George Hasegawa

Journal of Sol-Gel Science and Technology Vol. 104 ( 3 ) page： 526 - 535 2022.12

Amphiphilic Copolymer-Modified Eggshell-Based Column Packing Materials for the Preparative Separation of Basic Drugs Reviewed

Yoshii T., Mochida M., Kaizu K., Soda Y., Kanamori K., Nakanishi K., Sato T., Imai H., Citterio D., Hiruta Y.

ACS Applied Polymer Materials Vol. 4 ( 10 ) page： 6949 - 6957 2022.10

Language：English Publishing type：Research paper (scientific journal) Publisher：ACS Applied Polymer Materials

A way to utilize eggshells is desired because most of the eggshell waste is disposed of in landfills. Despite eggshells having attractive features such as a thermodynamically stable porous crystalline structure, their effective utilization as a functional material has yet to be demonstrated. Herein, we developed an alkali-stable column packing material for reversed-phase preparative high-performance liquid chromatography (HPLC) based on eggshells. Nanocrystals and biopolymers present on eggshell powder were removed by surface treatment with buffered ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite solutions, resulting in bare calcium carbonate with a uniform porous surface. The obtained particles were modified with poly(maleic acid-alt-1-octadecene) (PMAcO) having hydrophobic alkyl chains and anionic carboxylate groups. The prepared PMAcO-modified eggshell-based material was applied to an HPLC column, and its performance is evaluated. The column succeeded in the separation of alkylbenzenes, steroids, and diastereomers. It was also used for the separation of basic tricyclic antidepressants in an alkaline mobile phase, showing excellent retention capacity and alkali stability. This study demonstrates the potential of eggshell utilization, providing not only a practical stationary phase for HPLC but also a solution for recycling calcium carbonate-based biomineral waste.

DOI： 10.1021/acsapm.2c00866

Oxide-on-Oxide Porous Electrodes Revealing Superior Reversible Li<sup>+</sup>-Coupled Electron-Transfer Properties by Unconventional Heterojunction Effects Reviewed

Yosuke Hara, Rikuo Shigetake, Kazuki Nakanishi, Kazuyoshi Kanamori, Ken Sakaushi

ACS Applied Materials & Interfaces Vol. 14 ( 31 ) page： 35883 - 35893 2022.7

Designing hierarchical porosity in tin oxide monoliths and their application as a solid acid catalyst Reviewed

Yoshinao Suzuki, George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi

New Journal of Chemistry Vol. 45 ( 37 ) page： 17558 - 17565 2021.10

Sol–gel based structural designs of macropores and material shapes of metal–organic framework gels Reviewed

Yosuke Hara, Kohei Manabe, Kazuki Nakanishi, Kazuyoshi Kanamori

Materials Advances Vol. 2 ( 13 ) page： 4235 - 4239 2021.7

Utility of glomerular Gd-IgA1 staining for indistinguishable cases of IgA nephropathy or Alport syndrome Reviewed

Ishiko S., Tanaka A., Takeda A., Hara M., Hamano N., Koizumi M., Ueno T., Hayashi H., Kondo A., Nagai S., Aoto Y., Sakakibara N., Nagano C., Horinouchi T., Yamamura T., Ninchoji T., Shima Y., Nakanishi K., Yoshikawa N., Iijima K., Nozu K.

Clinical and Experimental Nephrology Vol. 25 ( 7 ) page： 779 - 787 2021.7

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Clinical and Experimental Nephrology

Background: Pathological findings in Alport syndrome frequently show mesangial proliferation and sometimes incidental IgA deposition, in addition to unique glomerular basement membrane (GBM) changes including thin basement membrane and/or lamellation. However, similar GBM abnormalities are also often observed in IgA nephropathy. Both diseases are also known to show hematuria, proteinuria, and sometimes macrohematuria when associated with viral infection. Therefore, it can be difficult to make a differential diagnosis, even based on clinical and pathological findings. Some recent articles demonstrated that galactose-deficient IgA1 (Gd-IgA1)-specific monoclonal antibody (KM55) could potentially enable incidental IgA deposition to be distinguished from IgA nephropathy. Methods: We performed comprehensive gene screening and glomerular Gd-IgA1 and type IV collagen α5 chain immunostaining for five cases with both IgA deposition and GBM changes to confirm that Gd-IgA1 can help to distinguish these two diseases. Results: Four of the cases were genetically diagnosed with Alport syndrome (Cases 1–4) and one was IgA nephropathy with massive GBM changes, which had a negative gene test result (Case 5). In Cases 1–4, glomerular Gd-IgA1 deposition was not detected, although there was positivity for IgA in the mesangial area. In Case 5, glomerular Gd-IgA1 deposition was observed. Conclusion: Gd-IgA1 expression analysis could clearly differentiate these two disorders. This approach can be applied to identify these two diseases showing identical clinical and pathological findings.

DOI： 10.1007/s10157-021-02054-3

Global wellposedness for the energy-critical Zakharov system below the ground state Reviewed

Candy T., Herr S., Nakanishi K.

Advances in Mathematics Vol. 384 2021.6

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Advances in Mathematics

The Cauchy problem for the Zakharov system in the energy-critical dimension d=4 is considered. We prove that global well-posedness holds in the full (non-radial) energy space for any initial data with energy and wave mass below the ground state threshold. The result is based on a Strichartz estimate for the Schrödinger equation with a potential. More precisely, a Strichartz estimate is proved to hold uniformly for any potential solving the free wave equation with mass below the ground state constraint. The key new ingredient is a bilinear (adjoint) Fourier restriction estimate for solutions of the inhomogeneous Schrödinger equation with forcing in dual endpoint Strichartz spaces.

DOI： 10.1016/j.aim.2021.107746

The Correlation between Fluid Distribution and Swelling or Subjective Symptoms of the Trunk in Lymphedema Patients: A Preliminary Observational Study Reviewed

Hisano F., Niwa S., Nakanishi K., Mawaki A., Murota K., Fukuyama A., Takeno Y., Watanabe S., Fujimoto E., Oshima C.

Lymphatic Research and Biology Vol. 19 ( 3 ) page： 269 - 273 2021.6

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Lymphatic Research and Biology

Background: Manual lymph drainage (MLD) is one of the common treatments for breast cancer-related lymphedema (BCRL). Although the primary goal of MLD is to drain the excessive fluid accumulated in the affected upper limb and trunk to an area of the body that drains usually, the use of MLD is decided based on swelling and subjective symptoms, without assessing whether there is fluid accumulated in the affected region. The purpose of this study was to examine truncal fluid distribution in a sample of BCRL patients and investigate any correlation between such fluid distribution and swelling or subjective symptoms. Methods and Results: An observational study was conducted with 13 women who had unilateral, upper extremity BCRL. Fluid distribution was evaluated by using two magnetic resonance imaging (MRI) sequences: half-Fourier acquisition single-shot turbo spin echo and three-dimensional double-echo steady-state. The presence of swelling was determined by lymphedema therapists, and subjective symptoms were measured by using a visual analog scale. On MRI, no participants had any free water signals in the trunk. However, seven had swelling and all 13 had some kind of subjective symptoms on the affected side of their trunk. Conclusions: These results suggest that swelling and subjective symptoms do not correlate with the presence of truncal fluid. For such cases, a different approach than MLD may be needed to address truncal swelling and related subjective symptoms. Checking for the presence of fluid in the truncal region may help MLD be used more appropriately.

DOI： 10.1089/lrb.2020.0075

Preparation of hierarchically porous spinel CoMn2O4 monoliths via sol-gel process accompanied by phase separation Reviewed

Xuanming Lu, Kazuyoshi Kanamori, George Hasegawa, Kazuki Nakanishi

JOURNAL OF THE AMERICAN CERAMIC SOCIETY Vol. 104 ( 6 ) page： 2449 - 2459 2021.6

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY

Cobalt manganite-based hierarchically porous monoliths (HPMs) with three-dimensionally (3D) interconnected macropores and open nanopores have been prepared via the sol-gel process accompanied by phase separation. The controlled hydrolysis and polycondensation of the brominated metal alkoxides, which are generated from an incomplete reaction between epichlorohydrin and MBr2 (M = Co and Mn) in N,N-dimethylformamide (DMF), form a monolithic gel based on the two divalent metal cations. The dual-polymer strategy using polyvinylpyrrolidone (PVP) and poly(ethylene oxide) (PEO) effectively induces the spinodal decomposition, where PVP and PEO are preferentially distributed to the gel phase and fluid phase, respectively, resulting in a porous gel characterized by the co-continuous structure. The effects of DMF and PVP on the porous morphology derived from the phase separation have been systematically studied. Calcination of the as-dried gels allows for the crystallization into the spinel phase yielding hierarchically porous CoMn2O4 monoliths, which have been examined in detail by the structural and compositional analyses.

DOI： 10.1111/jace.17662

Highly porous melamine-formaldehyde monoliths with controlled hierarchical porosity toward application as a metal scavenger Reviewed

Yuki Nakanishi, Yosuke Hara, Riichi Miyamoto, Kazuki Nakanishi, Kazuyoshi Kanamori

Materials Advances Vol. 2 ( 8 ) page： 2604 - 2608 2021.4

Language：English Publishing type：Research paper (scientific journal) Publisher：Royal Society of Chemistry (RSC)

<p>Hierarchically porous melamine-formaldehyde monoliths were prepared <italic>via</italic> sol–gel accompanied by phase separation, followed by a hydrothermal process. The obtained monoliths showed efficient adsorption of precious metal ions.</p>

DOI： 10.1039/d1ma00034a

Tunable and Well-Defined Bimodal Porous Model Electrodes for Revealing Multiscale Structural Effects in the Nonaqueous Li–O2 Electrode Process Reviewed

Yosuke Hara, Manai Ono, Shoichi Matsuda, Kazuki Nakanishi, Kazuyoshi Kanamori, Ken Sakaushi

The Journal of Physical Chemistry C Vol. 125 ( 2 ) page： 1403 - 1413 2021.1

Hierarchically porous monoliths based on low-valence transition metal (Cu, Co, Mn) oxides: Gelation and phase separation Reviewed

Lu, X., Kanamori, K., Nakanishi, K.

National Science Review Vol. 7 ( 11 ) page： 1656 - 1666 2020.11

Hierarchically porous monoliths prepared via sol–gel process accompanied by spinodal decomposition Reviewed

Xuanming Lu, George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi

Journal of Sol-Gel Science and Technology Vol. 95 ( 3 ) page： 530 - 550 2020.9

On-site formation of small Ag nanoparticles on superhydrophobic mesoporous silica for antibacterial application Reviewed

Zhu Yang, Chunhua Wu, Kazuyoshi Kanamori, Toshiyuki Kamei, Toyoshi Shimada, Kazuki Nakanishi

New Journal of Chemistry Vol. 44 ( 32 ) page： 13553 - 13556 2020.8

Superhydrophobic highly flexible doubly cross-linked aerogel/carbon nanotube composites as strain/pressure sensors Reviewed

Guoqing Zu, Xiaodong Wang, Kazuyoshi Kanamori, Kazuki Nakanishi

JOURNAL OF MATERIALS CHEMISTRY B Vol. 8 ( 22 ) page： 4883 - 4889 2020.6

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

We report novel superhydrophobic highly flexible composites based on a doubly cross-linked (DCL) aerogel and carbon nanotubes (CNTs) for strain/pressure sensing. The DCL aerogel/CNT composite is prepared by radical polymerization of vinylmethyldimethoxysilane and vinyldimethylmethoxysilane, respectively, followed by hydrolytic co-polycondensation of the obtained polyvinylmethyldimethoxysilane and polyvinyldimethylmethoxysilane, combined with the incorporation of CNTs. Benefiting from the flexible methyl-rich DCL structure of the aerogel and conductive CNTs, the resultant DCL aerogel/CNT composite combines superhydrophobicity, high compressibility, high bendability, high elasticity, and strain- and pressure-sensitive conductivity. We demonstrate that the composite can be applied as a high-performance strain/pressure sensor for the detection of arterial pulse waves and joint bending with high sensitivity and high durability against humidity.

DOI： 10.1039/c9tb02953b

Superelastic Triple-Network Polyorganosiloxane-Based Aerogels as Transparent Thermal Superinsulators and Efficient Separators Reviewed

Guoqing Zu, Kazuyoshi Kanamori, Xiaodong Wang, Kazuki Nakanishi, Jun Shen

CHEMISTRY OF MATERIALS Vol. 32 ( 4 ) page： 1595 - 1604 2020.2

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

We report new polyorganosiloxane aerogels with superhydrophobicity, high elasticity, and high bendability based on polyvinyl-poly(dimethylsiloxane) (PVPDMS)/polymethylsilsesquioxane (PMSQ). They are synthesized by a radical polymerization/co-polycondensation strategy that involves radical polymerization of vinyldimethylmethoxysilane to obtain chainlike polyvinyldimethylmethoxysilane (PVDMMS) polymers followed by hydrolytic co-polycondensation of PVDMMS polymers and methyltrimethoxysilane combined with ambient pressure drying without any post-gelation modifications. The resultant PVPDMS/PMSQ aerogels exhibit a highly tunable triple-network structure consisting of flexible inter-cross-linked hydrocarbon polymers, poly(dimethylsiloxane), and PMSQ The aerogels with a low content of PVPDMS exhibit small pore sizes (2-80 nm), good transparency, high surface areas, and thermal superinsulation (lambda = 0.0148 W m(-1) K-1), while those with a high content of PVPDMS exhibit large pore sizes (100 nm-3 mu m) and excellent selective absorption for organic liquids. In addition, incorporation of graphene oxide (GO) in PVPDMS/PMSQ aerogels can afford highly flexible PVPDMS/PMSQ/GO composite aerogels, which show efficient separation of three-component water/oil/dye mixtures. These aerogels are promising in the practical applications of thermal insulation, absorption/adsorption, and separation.

DOI： 10.1021/acs.chemmater.9b04877

Colorless Transparent Melamine-Formaldehyde Aerogels for Thermal Insulation Reviewed

Nakanishi, Y., Hara, Y., Sakuma, W., Saito, T., Nakanishi, K., Kanamori, K.

ACS Applied Nano Materials Vol. 3 ( 1 ) page： 49 - 54 2020.1

Self‐Assembly of Metal–Organic Frameworks into Monolithic Materials with Highly Controlled Trimodal Pore Structures Reviewed

Yosuke Hara, Kazuyoshi Kanamori, Kazuki Nakanishi

Angewandte Chemie International Edition Vol. 58 ( 52 ) page： 19047 - 19053 2019.12

Resilient, fire-retardant and mechanically strong polyimide-polyvinylpolymethylsiloxane composite aerogel prepared via stepwise chemical liquid deposition Reviewed

Ze Zhang, Xiaodong Wang, Guoqing Zu, Kazuyoshi Kanamori, Kazuki Nakanishi, Jun Shen

MATERIALS & DESIGN Vol. 183 2019.12

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCI LTD

Resilient, fire-retardant and mechanically strong polyimide-polyvinylpolymethylsiloxane (PI-PVPMS) composite aerogels have been prepared via stepwise chemical liquid deposition (SCLD). The synthesis is based on the formation of PI-PVPMS crosslinked network structure with (3-aminopropyl)trimethoxysilane (APTMS) as a coupling agent to provide reactive sites on the backbone. We successfully realize the PI in-situ growth on the whole super-flexible PVPMS gel skeleton with this simple method. The effect of APTMS amount and deposition time on the properties of final samples is deeply investigated. The resultant PI-PVPMS composite aerogels show excellent mechanical and thermal properties. They can support at least 10,000 times of their own weight and can recover 20% from a 60% of compressive strain, with an elastic modulus of 32 MPa. For thermal performance, they can maintain their structural integrity after being subjected to the alcohol lamp outer flame of around 650 degrees C for 30 min. These results together with the simple synthesis process demonstrate the potential for construction materials using PI-PVPMS composite aerogels. Furthermore, the SCLD synthesis method could also be applied to prepare other composite aerogels, especially for those containing complex polymer. (C) 2019 The Authors. Published by Elsevier Ltd.

DOI： 10.1016/j.matdes.2019.108096

Superelastic Multifunctional Aminosilane-Crosslinked Graphene Aerogels for High Thermal Insulation, Three-Component Separation, and Strain/Pressure-Sensing Arrays Reviewed

Guoqing Zu, Kazuyoshi Kanamori, Kazuki Nakanishi, Xuanming Lu, Kunhua Yu, Jia Huang, Hiroyuki Sugimura

ACS APPLIED MATERIALS & INTERFACES Vol. 11 ( 46 ) page： 43533 - 43542 2019.11

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Aerogels have attracted great interest for their unique properties, but their mechanical brittleness and poor functionality highly limit their practical applications. Herein, we report unprecedented superelastic multifunctional aminosilane-crosslinked reduced graphene oxide (AC-rGO) aerogels that are prepared via a facile and scalable strategy involving simultaneous crosslinking and reducing of graphene oxide nanosheets with different kinds of aminosilanes via C-N coupling and hydrolytic polycondensation reactions. It is found that 3-aminopropyl(diethoxy)methylsilane (APDEMS) is the better choice to enhance hydrophobicity, elasticity, and other properties of the resulting aerogels compared with (3-aminopropyl)triethoxysilane. One APDEMS molecule plays three roles as a crosslinker, a reductant, and a hydrophobizing agent. An outstanding combination of high surface area, ultralow density, superhydrophobicity, supercompressibility, superelasticity, low thermal conductivity, ultrahigh absorption capacity for organic liquids, efficient three-component separation, and strain/pressure sensing has been achieved in a single APDEMS-crosslinked rGO the first time. In addition, a flexible, highly sensitive, and moisture-resistant AC-rGO aerogel-based strain/pressure-sensing array for the effective detection of strain (0-80%)/pressure (10 Pa to 10 kPa) distributions and object shapes has been demonstrated.

DOI： 10.1021/acsami.9b16746

Thermogravimetric evolved gas analysis and microscopic elemental mapping of the solid electrolyte interphase on silicon incorporated in free-standing porous carbon electrodes Reviewed

George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi, Katsuro Hayashi

Langmuir 2019.10

Ambient-dried highly flexible copolymer aerogels and their nanocomposites with polypyrrole for thermal insulation, separation, and pressure sensing Reviewed

Guoqing Zu, Kazuyoshi Kanamori, Ayaka Maeno, Hironori Kaji, Kazuki Nakanishi, Jun Shen

Polymer Chemistry Vol. 10 ( 36 ) page： 4980 - 4990 2019.9

Language：English Publishing type：Research paper (scientific journal) Publisher：Royal Society of Chemistry ({RSC})

Aerogels exhibit unique properties, but their practical applications have been restricted by low mechanical strength and costly supercritical drying; it remains difficult to obtain highly flexible aerogels with good thermal insulation and absorption by ambient pressure drying (APD). Here, we report novel highly flexible aerogels based on the polyvinylpolymethylsiloxane (PVPMS)/polyvinyltrimethylsilane (PVTMS) co-network, which consists of inter-cross-linked hydrocarbon and siloxane polymers with dangling trimethylsilyl groups, and its nanocomposite with polypyrrole (PPy). The PVPMS/PVTMS copolymer aerogels are facilely synthesized by a consecutive radical co-polymerization and hydrolytic polycondensation strategy from two monomers vinylmethyldimethoxysilane and trimethylvinylsilane without additional cross-linkers, followed by APD without any post-gelation modification. The PPy nanocomposite aerogels are synthesized by an in situ oxidation polymerization of pyrrole in the copolymer aerogel networks, followed by APD. The resulting aerogels consist of meso- to macro-scaled pore structures with tunable skeleton and pore sizes with variable cross-linking density and bulk density. In addition, these aerogels show good hydrophobicity and high flexibility in both compression and bending. Moreover, different functionalities such as excellent thermal insulation, oil-water separation, and pressure sensing can be imparted, allowing them to exhibit potential applications in thermal insulation, separation, and sensing.

DOI： 10.1039/c9py00751b

Superhydrophobic Ultraflexible Triple-Network Graphene/Polyorganosiloxane Aerogels for a High-Performance Multifunctional Temperature/Strain/Pressure Sensing Array Reviewed

Guoqing Zu, Kazuyoshi Kanamori, Kazuki Nakanishi, Jia Huang

CHEMISTRY OF MATERIALS Vol. 31 ( 16 ) page： 6276 - 6285 2019.8

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Recently, many efforts have been made to develop various smart sensors. However, achieving flexible multifunctional sensors combining excellent sensing of temperature, strain, and pressure with a single material is still challenging. Here, we report unprecedented superhydrophobic ultraflexible reduced graphene oxide (rGO)/polyorganosiloxane aerogels and high-performance multifunctional temperature/strain/pressure sensors based on these aerogels. GO nanosheets are first cross-linked and reduced with (3-aminopropyl)triethoxysilane (APTES) to obtain APTES-modified rGO aerogels, which are then further covalently cross-linked with polyvinylmethyldimethoxysilane polymers and vinylmethyldimethoxysilane via copolycondensation to afford rGO/polyorganosiloxane aerogels. The resulting aerogels exhibit a coralline-like triple-network nanostructure consisting of rGO nanosheets, polyvinyl-poly(methylsiloxane), and poly- (vinylmethylsiloxane) that are cross-linked with each other. The aerogels combine superhydrophobicity, high compressibility, high bendability, superelasticity, excellent machinability, and temperature-, strain-, and pressure-sensitive conductivity, which is a combination not observed with traditional materials. In addition, an rGO/polyorganosiloxane aerogel-based flexible multifunctional sensing array combining sensing of temperature (20-100 degrees C), strain (in the wide range of 0.1-80%), and pressure (in the wide range of 10 Pa to 110 kPa) with high sensitivity and high durability against compression, bending, and humidity has been demonstrated for the first time.

DOI： 10.1021/acs.chemmater.9b02437

Preparation of zinc oxide with a three-dimensionally interconnected macroporous structure via a sol–gel method accompanied by phase separation Reviewed

Xuanming Lu, Kazuyoshi Kanamori, Kazuki Nakanishi

New Journal of Chemistry Vol. 43 ( 29 ) page： 11720 - 11726 2019.8

Macroporous Niobium Phosphate-Supported Magnesia Catalysts for Isomerization of Glucose-to-Fructose Reviewed

Da-Ming Gao, Yong-Bing Shen, Bohan Zhao, Qian Liu, Kazuki Nakanishi, Jie Chen, Kazuyoshi Kanamori, Huaping Wu, Zhiyong He, Maomao Zeng, Haichao Liu

ACS Sustainable Chemistry and Engineering Vol. 7 ( 9 ) page： 8512 - 8521 2019.5

Language：English Publishing type：Research paper (scientific journal) Publisher：American Chemical Society

The catalytic performance of hierarchically porous niobium phosphate (NbP) supported magnesia for the glucose isomerization to fructose, was investigated under atmospheric air atmosphere. Porous NbP showed improved support effects on MgO in comparison to other metal oxides tested for glucose isomerization. Also, the amount and distribution of basic sites were largely changed by supporting magnesia on NbP. Although the textural properties were reduced and solid acids formed on the MgO/NbP catalysts, glucose isomerization was promoted by increasing magnesium content. The maximum yield of fructose reached ∼24.6% over 40%MgO/NbP-500 with selectivity of 65.7% for 1.0 wt % glucose at 120 °C. The fructose productivity peaked as high as 13.6 g g catalyst -1 h -1 over 40%MgO/NbP-700 catalyst. The leaching of cations and anions resulted in a homogeneous system for glucose isomerization. Regeneration almost fully reactivated the catalyst to its initial activity. The MgO/NbP showed high stability under air atmosphere for 15 days, and high potential use for glucose isomerization.

DOI： 10.1021/acssuschemeng.9b00292

Preparation of surface-coated macroporous silica (core-shell silica monolith) for HPLC separations Reviewed

Risako Ito, Kei Morisato, Kazuyoshi Kanamori, Kazuki Nakanishi

Journal of Sol-Gel Science and Technology Vol. 90 ( 1 ) page： 105 - 112 2019.4

Hybrid silicone aerogels toward unusual flexibility, functionality, and extended applications Reviewed

Kazuyoshi Kanamori, Ryota Ueoka, Takayuki Kakegawa, Taiyo Shimizu, Kazuki Nakanishi

Journal of Sol-Gel Science and Technology Vol. 89 ( 1 ) page： 166 - 175 2019.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer New York LLC

Abstract: Here, we overview the developments in the past decade made on organic–inorganic hybrid aerogels and xerogels based on silicone (polyorganosiloxanes) through persistent works by the authors to increase the mechanical strength and flexibility and add functionality. Polymethylsilsesquioxane (PMSQ, CH3SiO3/2) has been found to show unusual strength and flexibility against compression, and their bending properties can also be improved by several strategies. Silicone-based networks with organic bridges between inorganic moieties are also beneficial for these improvements. In particular, organic bridges with a higher fraction and more extended length have been found to allow higher durability against large deformations. In addition, functional groups such as vinyl, chloromethyl, and amino can readily be introduced by starting from organoalkoxysilanes with these functional substituents (e.g., FG−Si(OR)3 or (RO)3Si−FG−Si(OR)3, where FG shows an organic substituent containing functional groups and R is typically methyl or ethyl), and other functional groups such as carboxyl can be introduced by post-gelation modifications on the pre-installed FG in the network. Possibilities in applications such as thermal insulators, photoluminescent media, and photocatalysts are also discussed. [Figure not available: see fulltext.].

DOI： 10.1007/s10971-018-4804-x

Synthesis of hierarchically porous MgO monoliths with continuous structure via sol–gel process accompanied by phase separation Reviewed

Xuanming Lu, Kazuyoshi Kanamori, Kazuki Nakanishi

Journal of Sol-Gel Science and Technology Vol. 89 ( 1 ) page： 29 - 36 2019.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Springer New York LLC

Hierarchically porous magnesium oxide, MgO, monoliths with a well-defined continuous macroporous structure have been synthesized via the sol–gel route accompanied by phase separation. Magnesium chloride hexahydrate was used as a precursor, and propylene oxide was used as an acid scavenger to raise the pH of a reaction solution homogenously. In order to obtain a crack-free monolith after heating in air, poly(vinylpyrrolidone), PVP, was employed as a scaffold of the skeleton as well as a phase separation controller to form the continuous macropores with higher homogeneity. Due to the moderate hydrogen-bonding interaction with magnesium hydroxide, PVP reinforces the gel network essentially composed of fine grained magnesium hydroxide. Even after the removal of all organic components by calcination, the porous gel samples maintained their monolithic form. On the other hand, an additional incorporation of 1,3,5-benzenetricarboxylic acid, H3BTC, was found to be effective in suppressing the oriented growth of the micrometer-sized crystalline phase. The polycrystalline MgO monoliths with specific surface area of 185, 64, and 48 m2 g−1 were prepared after heating at 400, 500, and 600 °C in air, respectively. [Figure not available: see fulltext.]

DOI： 10.1007/s10971-018-4682-2

Uric acid enhances alteplase-mediated thrombolysis as an antioxidant. Reviewed

Kikuchi K, Setoyama K, Tanaka E, Otsuka S, Terashi T, Nakanishi K, Takada S, Sakakima H, Ampawong S, Kawahara KI, Nagasato T, Hosokawa K, Harada Y, Yamamoto M, Kamikokuryo C, Kiyama R, Morioka M, Ito T, Maruyama I, Tancharoen S

Scientific reports Vol. 8 ( 1 ) page： 15844 2018.10

Sol-gel preparation of hierarchically porous magnesium aluminate (MgAl2O4) spinel monoliths for dye adsorption Reviewed

Guo, Xingzhong, Yin, Pengan, Kanamori, Kazuyoshi, Nakanishi, Kazuki, Yang, Hui

Journal of Sol-Gel Science and Technology Vol. 88 ( 1 ) page： 114 - 128 2018.10

The gravitationally unstable gas disk of a starburst galaxy 12 billion years ago Reviewed

Tadaki K., Iono D., Yun M.S., Aretxaga I., Hatsukade B., Hughes D.H., Ikarashi S., Izumi T., Kawabe R., Kohno K., Lee M., Matsuda Y., Nakanishi K., Saito T., Tamura Y., Ueda J., Umehata H., Wilson G.W., Michiyama T., Ando M., Kamieneski P.

Nature Vol. 560 ( 7720 ) page： 613 - 616 2018.8

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Nature

Galaxies in the early Universe that are bright at submillimetre wavelengths (submillimetre-bright galaxies) are forming stars at a rate roughly 1,000 times higher than the Milky Way. A large fraction of the new stars form in the central kiloparsec of the galaxy1–3, a region that is comparable in size to the massive, quiescent galaxies found at the peak of cosmic star-formation history4 and the cores of present-day giant elliptical galaxies. The physical and kinematic properties inside these compact starburst cores are poorly understood because probing them at relevant spatial scales requires extremely high angular resolution. Here we report observations with a linear resolution of 550 parsecs of gas and dust in an unlensed, submillimetre-bright galaxy at a redshift of z = 4.3, when the Universe was less than two billion years old. We resolve the spatial and kinematic structure of the molecular gas inside the heavily dust-obscured core and show that the underlying gas disk is clumpy and rotationally supported (that is, its rotation velocity is larger than the velocity dispersion). Our analysis of the molecular gas mass per unit area suggests that the starburst disk is gravitationally unstable, which implies that the self-gravity of the gas is stronger than the differential rotation of the disk and the internal pressure due to stellar-radiation feedback. As a result of the gravitational instability in the disk, the molecular gas would be consumed by star formation on a timescale of 100 million years, which is comparable to gas depletion times in merging starburst galaxies5.

DOI： 10.1038/s41586-018-0443-1

On-line Redox Derivatization Liquid Chromatography Using a Carbon Monolithic Column Reviewed

Miyashita Ken, Tanaka Ryo, Hasegawa George, Nakanishi Kazuki, Morioka Kazuhiro, Zeng Hulie, Kato Shungo, Uchiyama Katsumi, Saitoh Kazunori, Shibukawa Masami, Nakajima Hizuru

BUNSEKI KAGAKU Vol. 67 ( 8 ) page： 469 - 478 2018.8

Synthesis of a hierarchically porous niobium phosphate monolith by a sol-gel method for fructose dehydration to 5-hydroxymethylfurfural Reviewed

Gao, Da-Ming, Zhao, Bohan, Liu, Haichao, Morisato, Kei, Kanamori, Kazuyoshi, He, Zhiyong, Zeng, Maomao, Wu, Huaping, Chen, Jie, Nakanishi, Kazuki

Catalysis Science & Technology Vol. 8 ( 14 ) page： 3675 - 3685 2018.7

Comprehensive studies on phosphoric acid treatment of porous titania toward titanium phosphate and pyrophosphate monoliths with pore hierarchy and a nanostructured pore surface Reviewed

Zhu Y., Hasegawa G., Kanamori K., Nakanishi K.

Inorganic Chemistry Frontiers Vol. 5 ( 6 ) page： 1397 - 1404 2018.6

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Inorganic Chemistry Frontiers

Simple post-treatments of the porous titania monolith in varied concentrations of phosphoric acid solution provide a series of monolithic titanium phosphates (TiPs) with a hierarchically porous structure together with an exquisite macropore surface. Depending on the reaction conditions, platy crystallites composed of either Ti2O3(H2PO4)2·2H2O, Ti(HPO4)2·H2O (α-TiP), or Ti2O(PO4)2·2H2O (π-TiP) are generated on the macropore skeleton via a dissolution and reprecipitation process, which forms distinct wrinkled surface morphologies. In addition, the treatments effectively suppress the shrinkage during drying, leading to lower bulk density. Post-calcination in air yields porous titanium pyrophosphates preserving the intricate porous architecture in some cases. Notably, the hierarchically porous TiP2O7 monoliths prepared from the α-TiP precursors have a good thermal robustness related to bulk density.

DOI： 10.1039/c8qi00146d

Iron(III) oxyhydroxide and oxide monoliths with controlled multiscale porosity: synthesis and their adsorption performance Reviewed

Hara, Yosuke, Kanamori, Kazuyoshi, Morisato, Kei, Miyamoto, Riichi, Nakanishi, Kazuki

Journal of Materials Chemistry a Vol. 6 ( 19 ) page： 9041 - 9048 2018.5

Language：English Publishing type：Research paper (scientific journal) Publisher：Royal Society of Chemistry

Iron(iii) oxyhydroxide and oxide monoliths with controlled multiscale porosity have been successfully fabricated via the sol-gel process accompanied by phase separation. The size of macropores was controlled by synthesis parameters such as starting compositions. The as-dried iron(iii) oxyhydroxide monoliths were amorphous and possessed surface areas over 340 m2 g-1, of which mesostructures could be further controlled by a heat-treatment at 250-350 °C without collapse of macrostructures and monolithic forms. When the as-dried gel was heated at 300 °C, the resultant gel transformed to crystalline α-Fe2O3 and exhibited a specific surface area of 124 m2 g-1. Heat-treatment at 350 °C resulted in the broadened size distribution of mesopores. The adsorption behavior of Congo red has revealed that the interconnected macroporous structure contributed to faster diffusion and better accessibility in a continuous flow-through set up, and the crack-free monolithic forms accounted for an advantageous use of the flow-through adsorbents.

DOI： 10.1039/c8ta01691g

Versatile Double-Cross-Linking Approach to Transparent, Machinable, Supercompressible, Highly Bendable Aerogel Thermal Superinsulators Reviewed

Zu, Guoqing, Kanamori, Kazuyoshi, Shimizu, Taiyo, Zhu, Yang, Maeno, Ayaka, Kaji, Hironori, Nakanishi, Kazuki, Shen, Jun

Chemistry of Materials Vol. 30 ( 8 ) page： 2759 - 2770 2018.4

Language：English Publishing type：Research paper (scientific journal) Publisher：American Chemical Society

A facile yet versatile approach to transparent, highly flexible, machinable, superinsulating organic-inorganic hybrid aerogels is presented. This method involves radical polymerization of a single alkenylalkoxysilane to obtain polyalkenylalkoxysilane, and subsequent hydrolytic polycondensation to afford a homogeneous, doubly cross-linked nanostructure consisting of polysiloxanes and hydrocarbon polymer units. Here we demonstrate that novel aerogels based on polyvinylpolysilsesquioxane (PVPSQ), polyallylpolysilsesquioxane (PAPSQ), polyvinylpolymethylsiloxane (PVPMS), and polyallylpolymethylsiloxane (PAPMS) are facilely prepared via this approach from vinyltrimethoxysilane (VTMS
or vinyltriethoxysilane, VTES), allyltrimethoxysilane (ATMS
or allyltriethoxysilane, ATES), vinylmethyldimethoxysilane (VMDMS), and allylmethyldimethoxysilane (AMDMS), respectively. These aerogels combine low density, uniform nanopores, high transparency, supercompressibility, high bendability, excellent machinability, and thermal superinsulation (λ = 14.5-16.4 mW m-1 K-1). More importantly, transparent, superflexible, superinsulating aerogels are obtained with PVPMS and PAPMS via highly scalable ambient pressure drying without any solvent-exchange and modifications for the first time. This work will open a new way to transparent, highly flexible porous materials, promising in the practical applications of thermal superinsulators, adsorbents, sensors, etc.

DOI： 10.1021/acs.chemmater.8b00563

Transparent, Superflexible Doubly Cross-Linked Polyvinylpolymethylsiloxane Aerogel Superinsulators via Ambient Pressure Drying Reviewed

Zu, Guoqing, Shimizu, Taiyo, Kanamori, Kazuyoshi, Zhu, Yang, Maeno, Ayaka, Kaji, Hironori, Shen, Jun, Nakanishi, Kazuki

Acs Nano Vol. 12 ( 1 ) page： 521 - 532 2018.1

Language：English Publishing type：Research paper (scientific journal) Publisher：American Chemical Society

Aerogels have many attractive properties but are usually costly and mechanically brittle, which always limit their practical applications. While many efforts have been made to reinforce the aerogels, most of the reinforcement efforts sacrifice the transparency or superinsulating properties. Here we report superflexible polyvinylpolymethylsiloxane, (CH2CH(Si(CH3)O2/2))n, aerogels that are facilely prepared from a single precursor vinylmethyldimethoxysilane or vinylmethyldiethoxysilane without organic cross-linkers. The method is based on consecutive processes involving radical polymerization and hydrolytic polycondensation, followed by ultralow-cost, highly scalable, ambient-pressure drying directly from alcohol as a drying medium without any modification or additional solvent exchange. The resulting aerogels and xerogels show a homogeneous, tunable, highly porous, doubly cross-linked nanostructure with the elastic polymethylsiloxane network cross-linked with flexible hydrocarbon chains. An outstanding combination of ultralow cost, high scalability, uniform pore size, high surface area, high transparency, high hydrophobicity, excellent machinability, superflexibility in compression, superflexibility in bending, and superinsulating properties has been achieved in a single aerogel or xerogel. This study represents a significant progress of porous materials and makes the practical applications of transparent flexible aerogel-based superinsulators realistic.

DOI： 10.1021/acsnano.7b07117

On-line redox derivatization liquid chromatography using a carbon monolithic column Reviewed

Miyashita K., Tanaka R., Hasegawa G., Nakanishi K., Morioka K., Zeng H., Kato S., Uchiyama K., Saitoh K., Shibukawa M., Nakajima H.

Bunseki Kagaku Vol. 67 ( 8 ) page： 469 - 478 2018

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Bunseki Kagaku

A macroporous resorcinol-formaldehyde (RF) xerogel was synthesized via sol–gel reaction, accompanied by phase separation; a graphitized carbon monolith was then prepared by calcining the RF xerogel at a relatively low temperature (1200 °C) utilizing catalytic graphitization. The retention behaviors of metal-EDTA complexes on the carbon monolithic column were investigated. The carbon monolith exhibited catalytic activity for redox reactions, like porous graphitic carbon packing materials do; they oxidized Co(II)-EDTA to Co(III)-EDTA during elution. Their redox activity could be modified by treating with an eluent containing an oxidizing or reducing agent. A novel on-line redox derivatization HPLC system using a carbon monolithic column was developed for enhancing the separation selectivity. This on-line redox derivatization HPLC system consisted of two ODS columns as a separation column and one carbon monolithic column as redox derivatization unit placed between them. The Co(II)-EDTA migrated as its original oxidation state in the first ODS column, while it migrated as Co(III)-EDTA in the second ODS column, since Co(II)-EDTA was rapidly oxidized to Co(III)-EDTA in the carbon monolithic column. On the other hand, other metal-EDTA complexes migrated as their original oxidation states in these columns. Therefore, the Co-EDTA could be separated from the other metal-EDTA complexes. This on-line redox derivatization HPLC system was successfully used for determining the trace amount of cobalt in a reference copper alloy.

DOI： 10.2116/bunsekikagaku.67.469

The effect of exercise frequency on neuropathic pain and pain-related cellular reactions in the spinal cord and midbrain in a rat sciatic nerve injury model. Reviewed

Sumizono M, Sakakima H, Otsuka S, Terashi T, Nakanishi K, Ueda K, Takada S, Kikuchi K

Journal of pain research Vol. 11 page： 281 - 291 2018

Synthesis and characterization of monolithic ZnAl2O4 spinel with well-defined hierarchical pore structures via a sol-gel route Reviewed

Guo, Xingzhong, Yin, Pengan, Lei, Wei, Yang, Hui, Kanamori, Kazuyoshi, Nakanishi, Kazuki

Journal of Alloys and Compounds Vol. 727 page： 763 - 770 2017.12

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE SA

Hierarchically porous ZnAl2O4 spinel monolith derived from ionic precursors has been successfully prepared via the sol-gel route accompanied by phase separation in the presence of poly (ethylene oxide) (PEO) and propylene oxide (PO). Appropriate amounts of PEO as a phase-separation inducer and PO as a gelation mediator allow the formation of the xerogel with bicontinuous macrostructure and a monolithic shape. The macropore size of the resultant dried gel is mainly distributed in the range of 0.2-1 mu m, and the whole porosity is about 65%. The dried gel is constructed by crystalline Zn-Al hydrotalcite, becoming amorphous after heat-treated at 300-500 degrees C in air, and is further transformed into single phase ZnAl2O4 spinel with plate-like shape at 600 degrees C. The macroporous structure is well maintained while the porosity increases to 75% and the surface area rises to 109 m(2) g(-1) after heat-treatment. (C) 2017 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jallcom.2017.08.172

Aerogels from Chloromethyltrimethoxysilane and Their Functionalizations Reviewed

Kimura, Tomoki, Shimizu, Taiyo, Kanamori, Kazuyoshi, Maeno, Ayaka, Kaji, Hironori, Nakanishi, Kazuki

Langmuir Vol. 33 ( 48 ) page： 13841 - 13848 2017.12

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Reactions of "chloromethyltriinethoxysilane (CMTMS) and its derived colloidal network polychlorome-thylsilsesquioxane (PCMSQ) have been investigated to extend the material design strategy toward functionalized and mechanically reinforced aerogels. In a carefully designed sol gel system, CMTMS has afforded transparent aerogels in the presence of cationic surfactant. The surface chloromethyl groups with polarity and reactivity are shown to be useful for supporting nanostructures, with photoluminescent carbon dots (C-dots) prepared from polyethylenimine and citric acid as an example. Furthermore, since nucleophilic substitution (S(N)2) reactions on the surface chloromethyl groups are found to control the equilibrium of formation/dissociation of siloxane bonds, a new gelation strategy triggered by S(N)2 reactions in sol-gel has been developed. In the presence of nucleophilic organic species such as polyamines, a hybrid network consisting of PCMSQ cross-linked with a polyamine nucleophile can be prepared to enhance mechanical properties of aerogel.

DOI： 10.1021/acs.langmuir.7b03013

Polymer-assisted shapeable synthesis of porous frameworks consisting of silica nanoparticles with mechanical property tuning Reviewed

Sato, Kanako, Ishii, Kanji, Oaki, Yuya, Nakanishi, Kazuki, Imai, Hiroaki

Polymer Journal Vol. 49 ( 12 ) page： 825 - 830 2017.12

Language：English Publishing type：Research paper (scientific journal) Publisher：NATURE PUBLISHING GROUP

We report the shapeable synthesis of porous silica frameworks using polyacrylamide (PAAm) gel as an organic template and hydrolyzed silicon alkoxide as a silica source. Macroscopically shaped porous frameworks-such as plates, tablets and sheets-comprised of 20- to 40-nm diameter silica particles are obtained via PAAm-silica precursor gels. The mechanical properties (i.e., hardness and Young's modulus) of the silica frameworks depend on the packing density and are controlled by changing the silica content in PAAm gels.

DOI： 10.1038/pj.2017.62

Very Compact Millimeter Sizes for Composite Star-forming/AGN Submillimeter Galaxies Reviewed

Ikarashi S., Caputi K.I., Ohta K., Ivison R.J., Lagos C.D.P., Bisigello L., Hatsukade B., Aretxaga I., Dunlop J.S., Hughes D.H., Iono D., Izumi T., Kashikawa N., Koyama Y., Kawabe R., Kohno K., Motohara K., Nakanishi K., Tamura Y., Umehata H., Wilson G.W., Yabe K., Yun M.S.

Astrophysical Journal Letters Vol. 849 ( 2 ) 2017.11

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：Astrophysical Journal Letters

We report the study of the far-infrared (IR) sizes of submillimeter galaxies (SMGs) in relation to their dustobscured star formation rate (SFR) and active galactic nuclei (AGN) presence, determined using mid-IR photometry. We determined the millimeter-wave (λobs = 1100 μm) sizes of 69 Atacama Large Millimeter/ submillimeter Array (ALMA)-identified SMGs, selected with ≥10 δ confidence on ALMA images (F1100 μm = 1.7-7.4 mJy). We found that all of the SMGs are located above an avoidance region in the sizeflux plane, as expected by the Eddington limit for star formation. In order to understand what drives the different millimeter-wave sizes in SMGs, we investigated the relation between millimeter-wave size and AGN fraction for 25 of our SMGs at z=1-3. We found that the SMGs for which the mid-IR emission is dominated by star formation or AGN have extended millimeter-sizes, with respective median Rc,e = 1.6-0.21+0.34 and 1.5 -0.24+0.93 kpc. Instead, the SMGs for which the mid-IR emission corresponds to star-forming/AGN composites have more compact millimeter-wave sizes, with median Rc,e1.0 -0.20+0.20kpc. The relation between millimeter-wave size and AGN fraction suggests that this size may be related to the evolutionary stage of the SMG. The very compact sizes for composite star-forming/AGN systems could be explained by supermassive black holes growing rapidly during the SMG coalescing, star-formation phase.

DOI： 10.3847/2041-8213/aa9572

Synthesis, Reduction, and Electrical Properties of Macroporous Monolithic Mayenite Electrides with High Porosity Reviewed

Wang, Rui, Yang, Hui, Lu, Yunhao, Kanamori, Kazuyoshi, Nakanishi, Kazuki, Guo, Xingzhong

Acs Omega Vol. 2 ( 11 ) page： 8148 - 8155 2017.11

Aerogels from chloromethyltrimethoxysilane and their functionalizations Reviewed

Tomoki KIMURA, Taiyo SHIMIZU, Kazuyoshi KANAMORI, Ayaka MAENO, Hironori KAJI, Kazuki NAKANISHI

Langumuir 2017.11

Nanostructured titanium phosphates prepared via hydrothermal reaction and their electrochemical Li- and Na-ion intercalation properties Reviewed

Zhu, Y., Hasegawa, G., Kanamori, K., Kiyomura, T., Kurata, H., Hayashi, K., Nakanishi, K.

Crystengcomm Vol. 19 ( 31 ) page： 4551 - 4560 2017.8

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

In this report, we demonstrate a facile and versatile methodology for synthesizing a series of titanium phosphates (TiPs) with various morphologies. The hydrothermal reactions of TiO2 in different concentrations of H3PO4 aq. yield 4 types of crystal structures with diverse shapes, such as nanoparticles, nanorods and nanosheets, which are assembled into a variety of flower-like morphologies. The dependence of the crystal phases and morphologies of TiPs on the synthesis conditions have been comprehensively investigated. This synthetic process can be further extended to other TiP derivatives incorporated with guest cations (e.g. NH4+ and Na+) simply by adding the corresponding phosphate salts to the starting composition, which leads to the morphological variation associated with the change of the crystal phase. The mechanism for the formation of the TiPs is discussed in terms of the stable Ti-based ion species relying on the pH value of the reaction solution. In addition, the correlation between the crystal structures and morphologies of TiPs and their electrochemical Li- and Na-ion storage behaviors are demonstrated as well, which discloses the different tendencies of morphological effects between the Li- and Na-ion systems.

DOI： 10.1039/c7ce01123g

Ultralow-Density, Transparent, Superamphiphobic Boehmite Nanofiber Aerogels and Their Alumina Derivatives (vol 27, pg 3, 2015) Reviewed

Gen D Hayase, Kazuya Nonomura, George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi

CHEMISTRY OF MATERIALS Vol. 29 ( 12 ) page： 5413 - 5413 2017.6

Fabrication of hydrophobic polymethylsilsesquioxane aerogels by a surfactant-free method using alkoxysilane with ionic group Reviewed

Hayase, Gen, Nagayama, Shuya, Nonomura, Kazuya, Kanamori, Kazuyoshi, Maeno, Ayaka, Kaji, Hironori, Nakanishi, Kazuki

Journal of Asian Ceramic Societies Vol. 5 ( 2 ) page： 104 - 108 2017.6

Language：English Publishing type：Research paper (scientific journal) Publisher：Elsevier B.V.

Phase separation control is an important factor to prepare a porous monolith by an aqueous sol–gel reaction. Here, we report a surfactant-free synthesis method to obtain hydrophobic polymethylsilsesquioxane aerogels by copolymerizing a cationic-functionalized alkoxysilane N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride. The resultant materials have low-density, high visible-light transmittance, and high thermal insulating equivalent to those of prepared under the presence of surfactant.

DOI： 10.1016/j.jascer.2017.02.003

Functionalization of hierarchically porous silica monoliths with polyethyleneimine (PEI) for CO2 adsorption Reviewed

Guo, Xingzhong, Ding, Li, Kanamori, Kazuyoshi, Nakanishi, Kazuki, Yang, Hui

Microporous and Mesoporous Materials Vol. 245 page： 51 - 57 2017.6

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

A novel CO2 sorbent was prepared by modifying polyethyleneimine (PEI) on hierarchically porous silica (HPS) monoliths with well-defined macro-mesopores through wet impregnation method. HPS monoliths before and after functionalization were characterized by scanning electron microscopy (SEM), differential thermal analysis/thermogravimetry (DTA/TG), fourier transform infrared spectroscopy (FT-IR) and nitrogen adsorption/desorption analysis (BET), and the CO2 adsorption-regeneration properties of as synthesized sorbents were investigated by thermogravimetric analysis (TG). The effects of loaded PEI amount as well as adsorption temperature and CO2 partial pressure on the CO2 adsorption performance of the as-prepared sorbents were also studied. The results showed that the porous structure of HPS-PEI sorbents was preserved after functionalization, while the specific surface area and pore volume decreased with increasing amount of amines to some extent. The use of PEI had a remarkable improvement on the CO2 adsorption capacity. With the increasing amount of PEI loaded, the CO2 adsorption capacity improved significantly. The highest CO2 adsorption capacity of 2.44 mmol (g sorbent)-1 was obtained at 75 degrees C in the CO2 partial pressure of 100 kPa for the HPS loaded with 60 wt% PEI. Adsorption/desorption cycles indicated that the PEI-modified HPS sorbents had a good stability and regeneration. (C) 2017 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.micromeso.2017.02.076

Transparent Ethenylene-Bridged Polymethylsiloxane Aerogels: Mechanical Flexibility and Strength and Availability for Addition Reaction Reviewed

Shimizu, Taiyo, Kanamori, Kazuyoshi, Maeno, Ayaka, Kaji, Hironori, Doherty, Cara M., Nakanishi, Kazuki

Langmuir Vol. 33 ( 18 ) page： 4543 - 4550 2017.5

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Transparent, low-density ethenylene-bridged polymethylsiloxane [Ethe-BPMS, O-2/2(CH3)Si-CH=CH-Si(CH3)O-2/2] aerogels from 1,2-bis(methyldiethoxysilyl)ethene have successfully been synthesized via a sol-gel process. A two-step sol-gel process composed of hydrolysis under acidic conditions and polycondensation under basic conditions in a liquid surfactant produces a homogeneous pore structure based on cross-linked nanosized colloidal particles. Visible-light transmittance of the aerogels varies with the concentration of the base catalyst and reaches as high as 87% (at a wavelength of 550 nm for a 10 mm thick sample). Gelation and aging temperature strongly affect the deformation behavior of the resultant aerogels against uniaxial compression, and the obtained aerogels prepared at 80 C-circle show high elasticity after being unloaded. This highly resilient behavior is primarily derived from the rigidity of ethenylene groups, which is confirmed by a comparison with other aerogels with similar molecular structures, ethylene-bridged polymethylsiloxane and polymethylsilsesquioxane. Applicability of the addition reaction using a Diels-Alder reaction of benzocyclobutene has also been investigated, revealing that a successful addition takes place on the ethenylene linkings, which is verified using Raman and solid-state NMR spectroscopies. Insights into the effect of molecular structure on mechanical properties and the availability of surface functionalization provided in this study are important for realizing transparent aerogels with the desired functionality.

DOI： 10.1021/acs.langmuir.7b00434

Silicone-Based Organic-Inorganic Hybrid Aerogels and Xerogels. Reviewed

Shimizu, Taiyo, Kanamori, Kazuyoshi, Nakanishi, Kazuki

Chemistry (Weinheim an der Bergstrasse, Germany) Vol. 23 ( 22 ) page： 5176 - 5187 2017.4

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Aerogels are attracting increasing attention due to their high thermal insulation ability as well as unique properties such as high porosity, surface area, and transparency. However, low mechanical strengths, originating from their unique porous structure, impede handling, formability, mass production, and extended applications. This minireview focuses on the strengthening of aerogels by several organic-inorganic hybridization strategies. In particular, successful strengthening methodologies, which employ organo-substituted alkoxysilanes as the single precursor for the sol-gel preparations, developed by the authors are highlighted. Moreover, improvements in compressive strength and elasticity lead to monolithic aerogel-like xerogels through ambient pressure drying. Correlations between structures in different length scales (e.g., molecular, network, and pore structure levels) and resultant mechanical properties are discussed for further understandings and better design toward mechanically improved aerogels/xerogels and their applications.

DOI： 10.1002/chem.201603680

Transparent polyvinylsilsesquioxane aerogels: investigations on synthetic parameters and surface modification Reviewed

Shimizu, Taiyo, Kanamori, Kazuyoshi, Nakanishi, Kazuki

Journal of Sol-Gel Science and Technology Vol. 82 ( 1 ) page： 2 - 14 2017.4

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Systematic investigations on the effect of synthetic conditions onto the properties of polyvinylsilsesquioxane (CH2=CHSiO3/2) aerogels have been conducted. As previously reported, transparent polyvinylsilsesquioxane aerogels can be obtained by utilizing a liquid surfactant as a solvent and a two-step sol-gel reaction involving hydrolysis catalyzed by a strong acid and subsequent polycondensation by a strong base. In this study, effects of base catalyst, gelation and aging conditions, amount of surfactant and concentration of acid catalyst have been investigated. With the optimized synthetic condition, the value of light transmittance reaches as high as 70% (at the wavelength of 550 nm for a 10-mm thick sample). Applicability of addition reactions utilizing thiol-ene reactions and hydrosilylation has also been surveyed. Thiol-ene reactions are relatively effective and can modify surface hydrophobicity and mechanical properties of polyvinylsilsesquioxane aerogels. In the case of hydrosilylation, a partial addition of a hydrosilane compound onto the polyvinylsilsesquioxane gel surface can be observed. Addition reactions, in particular thiol-ene reactions, are found to be profitable for implementing chemical functionality on the transparent aerogels.

DOI： 10.1007/s10971-017-4339-6

Highly Flexible Hybrid Polymer Aerogels and Xerogels Based on Resorcinol-Formaldehyde with Enhanced Elastic Stiffness and Recoverability: Insights into the Origin of Their Mechanical Properties Reviewed

Hasegawa, George, Shimizu, Taiyo, Kanamori, Kazuyoshi, Maeno, Ayaka, Kaji, Hironori, Nakanishi, Kazuki

Chemistry of Materials Vol. 29 ( 5 ) page： 2122 - 2134 2017.3

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Flexible low-density materials, such as aerogels and polymer foams, have received increasing attention as energy absorbers and cushions that protect artificial products and human bodies. Microscopic geometry is a crucial factor determining their mechanical functions, i.e. strength and toughness (flexibility). However, it is a formidable challenge to combine these two properties because they are mutually elusive in general; stiff materials are brittle, while flexible ones are soft. Here, we demonstrate lightweight porous polymeric materials based on a common phenolic resin, resorcinol-formaldehyde (RF) gels, with salient combinatorial properties of high stiffness (up to 100 MPa) and good recoverable compressibility (against 80-90% strain), which can deliver remarkable energy absorption and dissipation performances repetitively. The detailed investigation reveals that the unique mechanical features originate from the synergetic effect of interdigitated hard and soft components in polymer matrices as well as exquisitely designed highly branched microstructures both generated through the spontaneous supramolecular self-assembly of the nonionic block copolymer (F127) and RF oligomer, which is essentially analogous to how natural organisms create biological structural materials, e.g. nacre and bone.

DOI： 10.1021/acs.chemmater.6b04706

Amine/Hydrido Bifunctional Nanoporous Silica with Small Metal Nanoparticles Made Onsite: Efficient Dehydrogenation Catalyst Reviewed

Zhu, Yang, Nakanishi, Takahiro, Kanamori, Kazuyoshi, Nakanishi, Kazuki, Ichii, Shun, Iwaida, Kohji, Masui, Yu, Kamei, Toshiyuki, Shimada, Toyoshi, Kumamoto, Akihito, Ikuhara, Yumi H., Jeon, Mina, Hasegawa, George, Tafu, Masamoto, Yoon, Chang Won, Asefa, Tewodros

Acs Applied Materials & Interfaces Vol. 9 ( 1 ) page： 36 - 41 2017.1

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Multifunctional catalysts are of great interest in catalysis because their multiple types of catalytic or functional groups can cooperatively promote catalytic transformations better than their constituents do individually. Herein we report a new synthetic route involving the surface functionalization of nanoporous silica with a rationally designed and synthesized dihydrosilane (3-aminopropylmethylsilane) that leads to the introduction of catalytically active grafted organoamine as well as single metal atoms and ultrasmall Pd or Ag-doped Pd nanoparticles via on-site reduction of metal ions. The resulting nanomaterials serve as highly effective bifunctional dehydrogenative catalysts for generation of H-2 from formic acid.

DOI： 10.1021/acsami.6b12972

Grafted Polymethylhydrosiloxane on Hierarchically Porous Silica Monoliths: A New Path to Monolith-Supported Palladium Nanoparticles for Continuous Flow Catalysis Applications Reviewed

Pelisson, Carl-Hugo, Nakanishi, Takahiro, Zhu, Yang, Morisato, Kei, Kamei, Toshiyuki, Maeno, Ayaka, Kaji, Hironori, Muroyama, Shunki, Tafu, Masamoto, Kanamori, Kazuyoshi, Shimada, Toyoshi, Nakanishi, Kazuki

Acs Applied Materials & Interfaces Vol. 9 ( 1 ) page： 406 - 412 2017.1

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Polyrnethylhydrosiloxane has been grafted on the surface of a hierarchically porous silica monolith using a facile catalytic reaction between Si-H and silanol to anchor the polymer. This easy methodology leads to the functionalization of the surface of a silica monolith, where a large amount of free Si-H bonds remain available for reducing metal ions in solution. Palladium nanoparticles of 15 nm have been synthesized homogeneously inside the mesopores of the monolith without any stabilizers, using a flow of a solution containing Pd2+. This monolith was used as column-type fixed bed catalyst for continuous flow hydrogenation of styrene and selective hydrogenation of 3-hexyn-1-ol, in each case without a significant decrease of the catalytic activity after several hours or days. Conversion, selectivity, and stereoselectivity of the alkyne hydrogenation can be tuned by flow rates of hydrogen and the substrate solution, leading to high productivity (1.57 mol g(Pd)(-1) h(-1)) of the corresponding cis-alkene.

DOI： 10.1021/acsami.6b12653

Low-density, transparent aerogels and xerogels based on hexylene-bridged polysilsesquioxane with bendability Reviewed

Aoki, Yosuke, Shimizu, Taiyo, Kanamori, Kazuyoshi, Maeno, Ayaka, Kaji, Hironori, Nakanishi, Kazuki

Journal of Sol-Gel Science and Technology Vol. 81 ( 1 ) page： 42 - 51 2017.1

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Low-density, transparent aerogels based on a hexylene-bridged polysilsesquioxane ([O1.5Si-(CH2)(6)SiO1.5](n)) network have been prepared for the first time via a simple sol-gel process. An optimized base-catalyzed onestep hydrolysis-polycondensation process of a bridged alkoxysilane precursor 1,6-bis(trimethoxysilyl) hexane in a low-polarity solvent N,N-dimethylformamide allows for the formation of a pore structure of a length scale of several tens nanometers, resulting in low-density, transparent aerogels after supercritical drying. Because of the incorporated organic moiety that bridges the silicon atoms in the network, these aerogels show higher flexibility and strength against compression and bending as compared to silica aerogel counterparts. In addition, minimizing the residual silanol groups in the network by a surface modification with hexamethyldisilazane has further improved resilience after compression and bending flexibility and strength, due to the decreased chance of the irreversible formation of the siloxane bonds upon compression. The resulting trimethylsilylated hydrophobic gels have been subjected to ambient pressure drying to obtain xerogels, resulting in low-density (0.13 g cm(-3), 90 % porosity), transparent (71 % transmittance) xerogels. These results are promising for the development of transparent thermal superinsulators applicable to window insulating systems that manage heat transfer in a more efficient way.

DOI： 10.1007/s10971-016-4077-1

Effects of nanostructured biosilica on rice plant mechanics Reviewed

Sato, Kanako, Ozaki, Noriaki, Nakanishi, Kazuki, Sugahara, Yoshiyuki, Oaki, Yuya, Salinas, Christopher, Herrera, Steven, Kisailus, David, Imai, Hiroaki

Rsc Advances Vol. 7 ( 22 ) page： 13065 - 13071 2017

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Nanostructured amorphous silica in rice plants (biosilica or plant opal) plays an important role in plant growth related to food production. However, the same silica has a structural supporting role as well that has not been uncovered. The current study focuses on the structural design of the two main types of biosilicas in rice plants for the improvement of their mechanical properties. One structural motif is platelike silicas, which cover most of the surfaces of leaf blades. Another is fan-shaped silicas, which are aligned inside leaf blades, providing a stiff backbone. These biosilica structures consist of 10-100 nm diameter nanoparticles. The mechanical properties, such as hardness and Young's modulus, of the biosilicas are associated with their relative density. Thus, the rice plant mechanics is inferred to be designed by changing the packing of the nanoparticles. Silica plates consisting of loosely packed particles have relatively low density and high flexibility enabling coverage of leaf blade surfaces, while fan-shaped silicas, which consist of tightly packed nanoparticles, are rigid to support the leaf blades as a backbone.

DOI： 10.1039/c6ra27317c

Highly Efficient Encapsulation of Ingredients in Poly(methyl methacrylate) Capsules Using a Superoleophobic Material Reviewed

Takei, Takayuki, Araki, Kiyotaka, Terazono, Keita, Ozuno, Yoshihiro, Hayase, Gen, Kanamori, Kazuyoshi, Nakanishi, Kazuki, Yoshida, Masahiro

Polymers & Polymer Composites Vol. 25 ( 2 ) page： 129 - 134 2017

Language：English Publishing type：Research paper (scientific journal) Publisher：ISMITHERS

Increasing the efficiency of encapsulation of ingredients into spherical capsules can decrease the manufacturing costs of the capsules. Ingredients can be encapsulated with high efficiency (>99%) into nondegradable hard resin capsules prepared by polymerization of spherical droplets of trimethylolpropane trimethacrylate (TRIM) monomer placed on a superoleophobic material. Poly(methyl methacrylate) (PMMA) resin is a more versatile capsule material than poly-TRIM resin. In this study, the efficiency of encapsulation in PMMA resin capsules prepared from methyl methacrylate (MMA) monomer was investigated. To reduce the volatility of the MMA monomer, pre-polymerized MMA was used for capsule preparation. Although non-volatile a-tocopherol and doxorubicin could be encapsulated in the capsules with high efficiency by heat polymerization at 60 degrees C for 3 h, the efficiency for volatile tetradecane was much lower (approximately 60%) because it evaporated. Furthermore, even when using pre-polymerized MMA, more than 70% of the prepolymer evaporated during polymerization. To prevent the evaporation of tetradecane and the prepolymer, ultraviolet photopolymerization was adopted because it was faster and could be conducted at a lower temperature. The photopolymerization prevented the evaporation of the prepolymer and increased the efficiency of encapsulation of tetradecane (approximately 90% efficiency). This polymerization system is effective for encapsulation of ingredients in PMMA capsules with high efficiency.

DOI： 10.1177/096739111702500202

Transparent Ethylene-Bridged Polymethylsiloxane Aerogels and Xerogels with Improved Bending Flexibility Reviewed

Taiyo Shimizu, Kazuyoshi Kanamori, Ayaka Maeno, Hironori Kaji, Kazuki Nakanishi

LANGMUIR Vol. 32 ( 50 ) page： 13427 - 13434 2016.12

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Transparent, monolithic aerogels with nano sized colloidal skeletons have been obtained from a single precursor of 1,2-bis(methyldiethoxysilyl)ethane (BMDEE) by adopting a liquid surfactant and a two-step process involving strong-acid, followed by strong-base, sol gel reactions. This precursor BMDEE forms the ethylene-bridged polymethylsiloxane (EBPMS, O-2/2(CH3)Si-CH2CH2-Si(CH3)O-2/2) network, in which each silicon has one methyl, two bridging oxygens, and one bridging ethylene, exhibiting an analogous structure to that of the previously reported polymethylsilsesquioxane (PMSQ CH3SiO3/2) aerogels having one methyl and three bridging oxygen atoms. Obtained aerogels consist of fine colloidal skeletons and show high visible-light transparency and a flexible deformation behavior against compression without collapse. Similar to the PMSQ aerogels, a careful tuning of synthetic conditions can produce low-density (0.19 g cm(-3)) and highly transparent (76% at 550 nm, corresponding to 10 mm thick samples) xerogels via ambient pressure drying by solvent evaporation due to their high strength and resilience against compression. Moreover, EBPMS aerogels exhibit higher bending strength and bending strain at break against the three-point bending mode compared to PMSQ aerogels. This improved bendability is presumably derived from the introduced ethylene-bridging parts, suggesting the potential for realizing transparent and bendable aerogels in such polysiloxane materials with organic linking units.

DOI： 10.1021/acs.langmuir.6b03249

Monolithic acidic catalysts for the dehydration of xylose into furfural Reviewed

Yang Zhu, Kazuyoshi Kanamori, Nicolas Brun, Carl-Hugo Pelisson, Nirmalya Moitra, Francois Fajula, Vasile Hulea, Anne Galarneau, Kazuyuki Takeda, Kazuki Nakanishi

CATALYSIS COMMUNICATIONS Vol. 87 page： 112 - 115 2016.12

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

We report the application of hierarchically porous zirconium phosphate monoliths with high surface area as acidic heterogeneous catalysts for the dehydration of xylose into furfural. Analyses by NH3-temperature programmed desorption and P-31 solid state NMR reveal the presence of both Lewis and Bronsted acid sites in the as-synthesized zirconium phosphate monolith and that calcined at 600 degrees C. High accessibility and availability of the acidic sites and easy separation of the monolith from the liquid medium result in good catalytic activity (initial reaction rate for furfural production as 8.7 mmol g(cat)(-1) h(-1)) with easy handling of the catalyst. (C) 2016 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.catcom.2016.09.014

Transparent, Highly Insulating Polyethyl- and Polyvinylsilsesquioxane Aerogels: Mechanical Improvements by Vulcanization for Ambient Pressure Drying Reviewed

Taiyo Shimizu, Kazuyoshi Kanamori, Ayaka Maeno, Hironori Kaji, Cara M. Doherty, Paolo Falcaro, Kazuki Nakanishi

CHEMISTRY OF MATERIALS Vol. 28 ( 19 ) page： 6860 - 6868 2016.10

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Silica aerogels are unique porous materials possessing high visible-light transparency and low thermal conductivity. However, the practical applications are limited due to the native fragility of silica, and a lot of research focuses on the improvement of mechanical properties by organic inorganic hybridization, and so forth. Here, the first synthesis of polyethylsilsesquioxane (PESQ CH3CH2SiO1.5) and polyvinylsilsesquioxane (PVSQ CH2=CHSiO1.5) aerogels is reported. The resultant PESQand PVSQ aerogels obtained through a two-step acid-base sol-gel reaction in a surfactant-based solution exhibit visible-light transmittance and flexibility against compression without collapsing. The microstructural variations of these aerogels are systematically investigated by positron annihilation lifetime spectroscopy (PALS) in order to clarify the differences in properties derived from substituent groups. Furthermore, a post cure on the PVSQ wet gel using a radical initiator induces polymerization of vinyl groups in the solid network, resulting in mechanically reinforced aerogels with higher compressive modulus and resilience. This chemical modification, similar to vulcanization in silicone rubber materials, helps to produce xerogels with comparable properties to those of aerogels via ambient pressure drying. Since the resultant xerogel obtained from the vulcanization of PVSQ shows sufficiently low thermal conductivity of 15.3 m(-1) K-1, these novel polysilsesquioxane materials are promising for transparent aerogels/xerogels superinsulators.

DOI： 10.1021/acs.chemmater.6b01936

The XVIII International Sol-Gel Conference: Sol-Gel 2015 was held in Kyoto, Japan, September 6-11, 2015 Reviewed

Kazuki Nakanishi

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 79 ( 2 ) page： 241 - 241 2016.8

Facile preparation of well-defined macroporous yttria-stabilized zirconia monoliths via sol-gel process accompanied by phase separation Reviewed

Guo, Xingzhong, Song, Jie, Ren, Jing, Yang, Fanger, Kanamori, Kazuyoshi, Nakanishi, Kazuki

Journal of Porous Materials Vol. 23 ( 4 ) page： 867 - 875 2016.8

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Yttria-stabilized zirconia monoliths with well-defined macropores and high porosity have been successfully fabricated via sol-gel process accompanied by phase separation. Propylene oxide acts as an acid consumer to mediate sol-gel process, and poly (ethylene oxide) is used to induce phase separation. Ethylene glycol is applied as chelating agent, and formamide serves as drying control chemical additive to inhibit cracking during drying stage. Proper proportion of the starting compositions allows the generation of well-defined macroporous YSZ monoliths with co-continuous skeletons and porosity as high as more than 60 %. The dried gels are amorphous and crystalline of ZrO2 precipitates after heat treatment between 400 and 1200 A degrees C without formation of monoclinic ZrO2, which indicating a wide application prospects.

DOI： 10.1007/s10934-016-0143-x

Studies on electrochemical sodium storage into hard carbons with binder-free monolithic electrodes Reviewed

George Hasegawa, Kazuyoshi Kanamori, Naokatsu Kannari, Jun-ichi Ozaki, Kazuki Nakanishi, Takeshi Abe

JOURNAL OF POWER SOURCES Vol. 318 page： 41 - 48 2016.6

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Hard carbons emerge as one of the most promising candidate for an anode of Na-ion batteries. This research focuses on the carbon monolith derived from resorcinol-formaldehyde (RF) gels as a model hard carbon electrode. A series of binder-free monolithic carbon electrodes heat-treated at varied temperatures allow the comparative investigation of the correlation between carbon nanotexture and electrochemical Na+-ion storage. The increase in carbonization temperature exerts a favorable influence on electrode performance, especially in the range between 1600 degrees C and 2500 degrees C. The comparison between Li+- and Na+-storage behaviors in the carbon electrodes discloses that the Na+-trapping in nanovoids is negligible when the carbonization temperature is higher than 1600 degrees C. On the other hand, the high temperature sintering at 2500-3000 degrees C enlarges the resistance for Na+-insertion into interlayer spacing as well as Na+-filling into nanovoids. In addition, the study on the effect of pore size clearly demonstrates that not the BET surface area but the surface area related to meso- and macropores is a predominant factor for the initial irreversible capacity. The outcomes of this work are expected to become a benchmark for other hard carbon electrodes prepared from various precursors. (C) 2016 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jpowsour.2016.04.013

Hierarchically Porous Carbon Monoliths Comprising Ordered Mesoporous Nanorod Assemblies for High-Voltage Aqueous Supercapacitors Reviewed

George Hasegawa, Kazuyoshi Kanamori, Tsutomu Kiyomura, Hiroki Kurata, Takeshi Abe, Kazuki Nakanishi

CHEMISTRY OF MATERIALS Vol. 28 ( 11 ) page： 3944 - 3950 2016.6

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

This report demonstrates a facile one-pot synthesis of hierarchically porous resorcinol-formaldehyde (RF) gels comprising mesoporous nanorod assemblies with two-dimensional (2D) hexagonal ordering by combining a supramolecular self-assembly strategy in the nanometer scale and phase separation in the micrometer scale. The tailored multilevel pore system in the polymer scaffolds can be preserved through carbonization and thermal activation, yielding the multimodal porous carbon and activated carbon (AC) monoliths. The thin columnar macroframeworks are beneficial for electrode materials due to the short mass diffusion length through small pores (micro- and mesopores). By employing the nanostructured AC monolith as a binder-free electrode for supercapacitors, we have also explored the capability of "water-in-salt" electrolytes, aiming at high-voltage aqueous supercapacitors. Despite that the carbon electrode surface is supposed to be covered with salt-derived decomposition products that hinder the water reduction, the effective surface area contributing to electric double-layer capacitance in 5 M bis(trifluoromethane sulfonyl)imide (LiTFSI) is found to be comparable to that in a conventional neutral aqueous electrolyte. The expanded stability potential window of the superconcentrated electrolyte allows for a 2.4 V-class aqueous AC/AC symmetric supercapacitor with good cycle performance.

DOI： 10.1021/acs.chemmater.6b01261

Other Link： http://orcid.org/0000-0002-8069-4780

Boehmite Nanofiber-Polymethylsilsesquioxane Core-Shell Porous Monoliths for a Thermal Insulator under Low Vacuum Conditions Reviewed

Hayase, Gen, Nonomura, Kazuya, Kanamori, Kazuyoshi, Maeno, Ayaka, Kaji, Hironori, Nakanishi, Kazuki

Chemistry of Materials Vol. 28 ( 10 ) page： 3237 - 3240 2016.5

Metal zirconium phosphate macroporous monoliths: Versatile synthesis, thermal expansion and mechanical properties Reviewed

Yang Zhu, Kazuyoshi Kanamori, Nirmalya Moitra, Kohei Kadono, Shugo Ohi, Norimasa Shimobayashi, Kazuki Nakanishi

MICROPOROUS AND MESOPOROUS MATERIALS Vol. 225 page： 122 - 127 2016.5

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

A versatile synthetic method has been developed for the fabrication of metal zirconium phosphate (MZP) macroporous monoliths via a sol-gel process accompanied by phase separation. More than 30 kinds of MZP monolithic polycrystalline monoliths with co-continuous macroporous structure have been synthesized by simply adding the target metal salt in the starting solution with optimized compositions. Glycerol, due to its high boiling point, plays the key role as the solvent to prevent metal salt from recrystallization, allowing a homogeneous distribution of metal salts over the polymerizing zirconium phosphate network. Hierarchically porous polycrystalline strontium zirconium phosphate (SrZrP) monolith has been obtained when the dried gel was calcined at 1000 degrees C. Very low thermal expansion (coefficient of thermal expansion (CTE) as 1.4 x 10(-6) K-1) over a wide temperature range (38 degrees C-1000 degrees C) together with good mechanical properties (flexural modulus as 8.0 GPa from 3 point bending test and Young's modulus as 1.9 GPa from uniaxial compression test) has been demonstrated, while high porosity (43%) due to the presence of macropores reduces bulk density. As compared with dense ceramics of the same composition, the CTE value is lower and can be attributed to the presence of nanometer-sized small pores, which absorbs the anisotropic thermal expansion of each crystallite in the macropore skeletons at elevated temperatures. (C) 2015 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.micromeso.2015.12.002

Encapsulation of hydrophobic ingredients in hard resin capsules with ultrahigh efficiency using a superoleophobic material Reviewed

Takei, Takayuki, Terazono, Keita, Araki, Kiyotaka, Ozuno, Yoshihiro, Hayase, Gen, Kanamori, Kazuyoshi, Nakanishi, Kazuki, Yoshida, Masahiro

Polymer Bulletin Vol. 73 ( 2 ) page： 409 - 417 2016.2

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Spherical capsules have been used in various fields because of their many advantages. In many industrial applications, hydrophobic hard resins (e.g., polyacrylate, epoxy and polystyrene) are used as a shell material for stable packaging of ingredients within capsules. However, it is difficult to encapsulate ingredients in such capsules without loss by conventional techniques. The purpose of this study was to encapsulate hydrophobic ingredients within polyacrylate resin capsules with ultrahigh efficiency. In our methodology, a small volume of resin monomer solution containing the ingredients was first placed on a superoleophobic material and the resulting spherical droplets were then solidified by polymerization of the monomer. Doxorubicin (an anticancer drug), a-tocopherol (an antioxidant) and tetradecane (a phase change material used for heat storage) could be encapsulated in spherical hard capsules with almost no loss by heat and photopolymerization. We showed that tetradecane in the capsules had almost identical thermal properties to pure tetradecane. These results demonstrate that our technique is promising for encapsulation of hydrophobic ingredients in hard resin capsules.

DOI： 10.1007/s00289-015-1497-y

The chromatographic performance of flow-through particles: A computational fluid dynamics study Reviewed

Wim Smits, Kazuki Nakanishi, Gert Desmet

JOURNAL OF CHROMATOGRAPHY A Vol. 1429 page： 166 - 174 2016.1

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

The performance of flow-through particles has been studied by computational fluid dynamics. Computational fluid dynamics simulations was used to calculate the flow behaviour around and inside the particles rather than estimate it. The obtained flow field has been used to accurately simulate plate heights generated by flow-through particles and compare them to standard fully porous particles. The effects of particle size, particle porosity and microparticle size on the intra-particle flow and plate heights is investigated. It is shown that the intra-particle flow generates mass transfer enhancement which lowers the total plate height. An empirical model is proposed for the mass transfer enhancement and it is compared to previously proposed models. Kinetic plots are constructed for the flow-through particles. Counter-intuitively, columns packed with flow-through particles have a higher flow resistance which counters the advantages of lower plate heights. Flow-through particles offer no significant gain in kinetic performance over fully porous particles. (C) 2015 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.chroma.2015.12.019

Hierarchically porous titanium phosphate monoliths and their crystallization behavior in ethylene glycol Reviewed

Yang Zhu, Koji Yoneda, Kazuyoshi Kanamori, Kazuyuki Takeda, Tsutomu Kiyomura, Hiroki Kurata, Kazuki Nakanishi

NEW JOURNAL OF CHEMISTRY Vol. 40 ( 5 ) page： 4153 - 4159 2016

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Hierarchically porous titanium phosphate monoliths combining well-defined co-continuous macropores and accessible large mesopores have been synthesized for the first time via a sol-gel process accompanied by phase separation using titanium oxysulfate and phosphoric acid as precursors. The macropore size was tunable over a broad range from 0.6 mu m to 10 mu m by changing the starting composition, while the mesopore size and the specific surface area of the as-synthesized amorphous monoliths are 21 nm and 320 m(2) g (1), respectively. Crystallization of the gel network can be induced in two different ways. Calcination at elevated temperature (800 degrees C) leads to the formation of TiP2O7 and the collapse of both the macro- and meso-structures, while the solvothermal treatment of the as-synthesized gel in ethylene glycol leads to the formation of platy crystals of titanium phosphate with a layered structure at relatively low temperature. The titanium phosphate monoliths with a hierarchically porous structure are expected to be useful in various applications such as continuous-flow catalysis, water remediation and ion batteries.

DOI： 10.1039/c5nj02820e

Hard Carbon Anodes for Na-Ion Batteries: Toward a Practical Use Reviewed

George Hasegawa, Kazuyoshi Kanamori, Naokatsu Kannari, Jun-ichi Ozaki, Kazuki Nakanishi, Takeshi Abe

CHEMELECTROCHEM Vol. 2 ( 12 ) page： 1917 - 1920 2015.12

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Hard carbons have immense potential as anode materials for Na-ion batteries, because the expanded graphene interlayers and nanovoids between randomly stacked aromatic fragments can accommodate a substantial amount of sodium. However, the large irreversible capacity in the first cycle still remains as a significant issue in terms of a practicable battery technology. Here, we show that hard carbon electrodes derived from a common phenol resin deliver a high reversible capacity within the narrow potential range of 0.1-0.005V (vs. Na+/Na) and an excellent initial coulombic efficiency up to 95%. The former allows the sustainable high voltage, whereas the latter minimizes the amount of unavailable Na+ in a closed cell. The findings in this work put forward a guideline for manufacturing hard carbon electrodes, which goes against the current trend of nanostructuring and downsizing.

DOI： 10.1002/celc.201500412

Synthesis of hierarchically porous polymethylsilsesquioxane monoliths with controlled mesopores for HPLC separation Reviewed

Yang Zhu, Yoshie Morimoto, Taiyo Shimizu, Kei Morisato, Kazuyuki Takeda, Kazuyoshi Kanamori, Kazuki Nakanishi

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN Vol. 123 ( 1441 ) page： 770 - 778 2015.9

Language：English Publishing type：Research paper (scientific journal) Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

Sol-gel synthesis of macroporous polymethylsilsesquioxane (PMSQ) monoliths has been successful over the past decade, and applications to separation media have been investigated. However, the control of mesopores to tailor hierarchical porosity, which is promising for improvement of the separation efficiency, remains challenging. In particular, an independent control of meso- and macropores has not been achieved in PMSQ. Herein we present a method to synthesize PMSQ monoliths with well-defined macropores and controlled mesostructure (pore size ranging from 10 to 60 nm, total pore volume from 0.2 to 0.6 cm(3) g(-1)) via sol-gel accompanied by phase separation. Different Pluronic-type nonionic surfactants were used to control phase separation of the hydrophobic PMSQ network in aqueous media. Due to different packing density of the colloidal PMSQ constituents in the continuous skeletons in the micrometer-scale (termed as macropore skeletons) and their rearrangements through the hydrothermal post-treatment under basic conditions, mesopore characteristics have been successfully controlled independently of the preformed macropore structure. Separation columns for high-performance liquid chromatography (HPLC) have been fabricated using the PMSQ monoliths, and acceptable separation performances in both the reversed-phase and normal-phase modes have been demonstrated due to the presence of both hydrophilic silanol groups and hydrophobic methyl groups. (C) 2015 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.123.770

Novel soft touch silicone beads from methyltrimethoxysilane and dimethyldimethoxysilane using easy aqueous solution reaction Reviewed

Reiichiro Tsuchiya, Takumi Tanaka, Gen Hayase, Kazuyoshi Kanamori, Kazuki Nakanishi

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN Vol. 123 ( 1441 ) page： 714 - 718 2015.9

Language：English Publishing type：Research paper (scientific journal) Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

Conventionally, commercialized spherical silicone powders, such as silicone resin powder [INCI: POLYMETHYLSILSESQUIOXANE (PMSQ beads)] 1) and silicone rubber powder [INCI: DIMETHICONE/VINYL DIMETHICONE CROSSPOLYMER (DVDC beads)], 2) have been formulated into cosmetics for soft and smooth feeling. Due to the low crosslink density, silicone rubber powder shows soft touch and high oil absorption. However, it is too agglomerative to be formulated into powder foundation. In this work, we have developed the novel soft touch spherical silicone beads made from methyltrimethoxysilane (MTMS) and dimethyldimethoxysilane (DMDMS), using a surfactant, cetyltrimethylammonium chloride (CTAC). The preparation procedure of the novel silicone beads requires only homogeneous mixing and includes no other complicated operations. The Si-29 NMR and TG measurements indicate that DMDMS is randomly incorporated into the methylsiloxane network. The particle size of the beads can be controlled by the concentration of urea as well as by the stirring speed in the sol-gel reaction. By carefully adjusting these parameters, the size of the beads has been optimized for the use in make-up cosmetics. It was revealed by various evaluation measurements that the novel silicone beads exhibit unique characteristics, such as softness, low oil absorption, high transparency and light diffusion effects. (C) 2015 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.123.714

High-performance liquid chromatography separation of unsaturated organic compounds by a monolithic silica column embedded with silver nanoparticles Reviewed

Yang Zhu, Kei Morisato, George Hasegawa, Nirmalya Moitra, Tsutomu Kiyomura, Hiroki Kurata, Kazuyoshi Kanamori, Kazuki Nakanishi

JOURNAL OF SEPARATION SCIENCE Vol. 38 ( 16 ) page： 2841 - 2847 2015.8

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

The optimization of a porous structure to ensure good separation performances is always a significant issue in high-performance liquid chromatography column design. Recently we reported the homogeneous embedment of Ag nanoparticles in periodic mesoporous silica monolith and the application of such Ag nanoparticles embedded silica monolith for the high-performance liquid chromatography separation of polyaromatic hydrocarbons. However, the separation performance remains to be improved and the retention mechanism as compared with the Ag ion high-performance liquid chromatography technique still needs to be clarified. In this research, Ag nanoparticles were introduced into a macro/mesoporous silica monolith with optimized pore parameters for high-performance liquid chromatography separations. Baseline separation of benzene, naphthalene, anthracene, and pyrene was achieved with the theoretical plate number for analyte naphthalene as 36 000 m(-1). Its separation function was further extended to cis/trans isomers of aromatic compounds where cis/trans stilbenes were chosen as a benchmark. Good separation of cis/trans-stilbene with separation factor as 7 and theoretical plate number as 76 000 m(-1) for cis-stilbene was obtained. The trans isomer, however, is retained more strongly, which contradicts the long-established retention rule of Ag ion chromatography. Such behavior of Ag nanoparticles embedded in a silica column can be attributed to the differences in the molecular geometric configuration of cis/trans stilbenes.

DOI： 10.1002/jssc.201500444

High-Level Doping of Nitrogen, Phosphorus, and Sulfur into Activated Carbon Monoliths and Their Electrochemical Capacitances Reviewed

George Hasegawa, Takeru Deguchi, Kazuyoshi Kanamori, Yoji Kobayashi, Hiroshi Kageyama, Takeshi Abe, Kazuki Nakanishi

CHEMISTRY OF MATERIALS Vol. 27 ( 13 ) page： 4703 - 4712 2015.7

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

The present report demonstrates a new technique for doping heteroatoms (nitrogen, phosphorus, and sulfur) into carbon materials via a versatile post-treatment. The heat-treatment of carbon materials with a reagent, which is stable at ambient temperatures and evolves reactive gases on heating, in a vacuum-closed tube allows the introduction of various heteroatom-containing functional groups into a carbon matrix. In addition, the sequential doping reactions give rise to dual- and triple-heteroatom-doped carbons. The pore properties of the precursor carbon materials are preserved through each heteroatom doping process, which indicates that independent tuning of heteroatom doping and nanostructural morphology can be achieved in various carbon materials. The electrochemical investigation on the undoped and doped carbon monolithic electrodes applied to supercapacitors provides insights into the effects of heteroatom doping on electrochemical capacitance.

DOI： 10.1021/acs.chemmater.5b01349

Effect of Calcination Conditions on Porous Reduced Titanium Oxides and Oxynitrides via a Preceramic Polymer Route (vol 54, pg 2802, 2015) Reviewed

Hasegawa George, Sato Tatsuya, Kanamori Kazuyoshi, Sun Cheng-Jun, Ren Yang, Kobayashi Yoji, Kageyama Hiroshi, Abe Takeshi, Nakanishi Kazuki

INORGANIC CHEMISTRY Vol. 54 ( 11 ) page： 5614 - 5614 2015.6

Preparation of macroporous zirconia monoliths from ionic precursors via an epoxide-mediated sol-gel process accompanied by phase separation Reviewed

Xingzhong Guo, Jie Song, Yixiu Lvlin, Kazuki Nakanishi, Kazuyoshi Kanamori, Hui Yang

SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS Vol. 16 ( 2 ) page： 025003 2015.4

Language：English Publishing type：Research paper (scientific journal) Publisher：IOP PUBLISHING LTD

Monolithic macroporous zirconia (ZrO2) derived from ionic precursors has been successfully fabricated via the epoxide-mediated sol-gel route accompanied by phase separation in the presence of propylene oxide (PO) and poly(ethylene oxide) (PEO). The addition of PO used as an acid scavenger mediates the gelation, whereas PEO enhances the polymerization-induced phase separation. The appropriate choice of the starting compositions allows the production of a macroporous zirconia monolith with a porosity of 52.9% and a Brunauer-Emmett-Teller (BET) surface area of 171.9 m(2) . g(-1). The resultant dried gel is amorphous, whereas tetragonal ZrO2 and monoclinic ZrO2 are precipitated at 400 and 600 degrees C, respectively, without spoiling the macroporous morphology. After solvothermal treatment with an ethanol solution of ammonia, tetragonal ZrO2 monoliths with smooth skeletons and well-defined mesopores can be obtained, and the BET surface area is enhanced to 583.8 m(2) . g(-1).

DOI： 10.1088/1468-6996/16/2/025003

Effect of Calcination Conditions on Porous Reduced Titanium Oxides and Oxynitrides via a Preceramic Polymer Route Reviewed

George Hasegawa, Tatsuya Sato, Kazuyoshi Kanamori, Cheng-Jun Sun, Yang Ren, Yoji Kobayashi, Hiroshi Kageyama, Takeshi Abe, Kazuki Nakanishi

INORGANIC CHEMISTRY Vol. 54 ( 6 ) page： 2802 - 2808 2015.3

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

A preceramic polymer route from Ti-based inorganicorganic hybrid networks provides electroconductive N-doped reduced titanium oxides (Ti(n)O2(n-1)) and titanium oxynitrides (TiOxNy) with a monolithic shape as well as well-defined porous structures. This methodology demonstrates an advantageously lower temperature of the crystal phase transition compared to the reduction of TiO2 by carbon or hydrogen. In this study, the effect of calcination conditions on various features of the products has been explored by adopting three different atmospheric conditions and varying the calcination temperature. The detailed crystallographic and elemental analyses disclose the distinguished difference in the phase transition behavior with respect to the calcination atmosphere. The correlation between the crystallization and nitridation behaviors, porous properties, and electric conductivities in the final products is discussed.

DOI： 10.1021/ic502972v

Efficiency of short, small-diameter columns for reversed-phase liquid chromatography under practical operating conditions Reviewed

Yan Ma, Alexander W. Chassy, Shota Miyazaki, Masanori Motokawa, Kei Morisato, Hideyuki Uzu, Masayoshi Ohira, Masahiro Furuno, Kazuki Nakanishi, Hiroyoshi Minakuchi, Khaled Mriziq, Tivadar Farkas, Oliver Fiehn, Nobuo Tanaka

JOURNAL OF CHROMATOGRAPHY A Vol. 1383 page： 47 - 57 2015.2

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Prototype small-size (1.0 mm I.D., 5 cm long) columns for reversed-phase HPLC were evaluated in relation to instrument requirements. The performance of three types of columns, monolithic silica and particulate silica (2 mu m, totally porous and 2.6 mu m, core-shell particles) was studied in the presence of considerable or minimal extra-column effects, while the detector contribution to band broadening was minimized by employing a small size UV-detector cell (6- or 90 nL). A micro-LC instrument having small system volume (<1 mu L) provided extra-column band variance of only 0.01-0.02 mu L-2. The three columns generated about 8500 theoretical plates for solutes with retention factor, k> 1-3 (depending on the column), in acetonitrile/water mobile phase (65/35 = vol/vol) at 0.05 mL/min, with the instrument specified above. The column efficiency was lower by up to 30% than that observed with a 2.1 mm 1.12 commercial column. The small-size columns also provided 8000-8500 theoretical plates for well retained solutes with a commercial ultrahigh-pressure liquid chromatography (UHPLC) instrument when extra-column contributions were minimized. While a significant extra-column effect was observed for early eluting solutes (k<2-4, depending on column) with methanol/water (20/80 = vol/vol) as weak-wash solvent, the use of methanol/water = 50/50 as wash solvent affected the column efficiency for most analytes. The results suggest that the band compression effect by the weak-wash solvent associated with partial-loop injection may provide a practical means to reducing the extra-column effect for small-size columns, while the use of an instrument with minimum extra-column effect is highly desirable. (C) 2015 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.chroma.2015.01.014

Other Link： http://orcid.org/0000-0002-8069-4780

Ultralow-Density, Transparent, Superamphiphobic Boehmite Nanofiber Aerogels and Their Alumina Derivatives Reviewed

Gen Hayase, Kazuya Nonomura, George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi

CHEMISTRY OF MATERIALS Vol. 27 ( 1 ) page： 3 - 5 2015.1

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Ultralow-density aerogels that have high visible-light transparency were obtained via a simple process. To achieve such materials, aqueous dispersion of boehmite nanofibers (BNF) was used. Hexamethylenetetramine (HMT) was used, which homogeneously raises pH by hydrolysis into ammonia in a mild condition. All the results suggest that the BNF aerogels are formed not by chemical bonds in-between nanofibers or assembling with a morphological change through, for instance, dissolution-reprecipitation of nanofibers, but by physical attractive interactions, which can be strong enough to support the ultralow-density structure. Due to the needle-like structure on the surface, the FAS-treated BNF aerogels exhibit superamphiphobicity, which is essential for antifouling applications.

DOI： 10.1021/cm503993n

Other Link： http://orcid.org/0000-0002-8069-4780

Hierarchically Porous Li4Ti5O12 Anode Materials for Li- and Na-Ion Batteries: Effects of Nanoarchitectural Design and Temperature Dependence of the Rate Capability Reviewed

George Hasegawa, Kazuyoshi Kanamori, Tsutomu Kiyomura, Hiroki Kurata, Kazuki Nakanishi, Takeshi Abe

ADVANCED ENERGY MATERIALS Vol. 5 ( 1 ) 2015.1

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Integrated design of both porous structure and crystalline morphology is expected to open up the way to a new class of materials. This report dem- onstrates new nanostructured Li4Ti5O12 materials with hierarchically porous structures and ?ower-like morphologies. Electrochemical studies of the electrodes of Li-ion and Na-ion batteries clearly reveal the advantage of nano- architectural design of active materials. In addition, the temperature depend- ence of Na + -insertion/extraction capacity in relation to Li4Ti5O12 electrodes is for the ?rst time evaluated and it is found that elevation of the cell operating temperature effectively improves the rate capability of the Na-ion batteries. Based on the new ?ndings, it is suggested that specially designed Li4Ti5O12 materials allow for high-performance Na-ion batteries that are available as large-scale storage devices for applications such as automotive and stationary energy storage.

DOI： 10.1002/aenm.201400730

Direct preparation and conversion of copper hydroxide-based monolithic xerogels with hierarchical pores Reviewed

Shotaro Fukumoto, Kazuki Nakanishi, Kazuyoshi Kanamori

NEW JOURNAL OF CHEMISTRY Vol. 39 ( 9 ) page： 6771 - 6777 2015

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Copper hydroxide-based monolithic xerogels with controlled hierarchical pores have been prepared directly by a sol-gel process from an ionic precursor, CuCl2 center dot 2H(2)O. Propylene oxide acts as a gelation inducer by increasing pH homogeneously in a reaction solution. Poly(acrylamide) is utilized not only to control macroscopic phase separation but also to support the network physically. Glycerol contributes to the formation of monolithic gels by suppressing the growth of copper hydroxide crystals. An appropriate starting composition leads to co-continuous gel skeletons and macropores. Although the as-dried gels were amorphous, post-treatments (calcination and solvothermal treatment) formed metallic copper and copper oxides (CuO and Cu2O) without the collapse of the monolithic form and macrostructure.

DOI： 10.1039/c5nj00479a

Mechanically stable, hierarchically porous Cu-3(btc)(2) (HKUST-1) monoliths via direct conversion of copper(II) hydroxide-based monoliths Reviewed

Nirmalya Moitra, Shotaro Fukumoto, Julien Reboul, Kenji Sumida, Yang Zhu, Kazuki Nakanishi, Shuhei Furukawa, Susumu Kitagawa, Kazuyoshi Kanamori

CHEMICAL COMMUNICATIONS Vol. 51 ( 17 ) page： 3511 - 3514 2015

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

The synthesis of highly crystalline macro-meso-microporous monolithic Cu-3(btc)(2) (HKUST-1; btc(3-) = benzene-1,3,5-tricarboxylate) is demonstrated by direct conversion of Cu(OH)(2)-based monoliths while preserving the characteristic macroporous structure. The high mechanical strength of the monoliths is promising for possible applications to continuous flow reactors.

DOI： 10.1039/c4cc09694k

Mesoscopic superstructures of flexible porous coordination polymers synthesized via coordination replication Reviewed

Kenji Sumida, Nirmalya Moitra, Julien Reboul, Shotaro Fukumoto, Kazuki Nakanishi, Kazuyoshi Kanamori, Shuhei Furukawa, Susumu Kitagawa

CHEMICAL SCIENCE Vol. 6 ( 10 ) page： 5938 - 5946 2015

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

The coordination replication technique is employed for the direct conversion of a macro- and mesoporous Cu(OH)(2)-polyacrylamide composite to three-dimensional superstructures consisting of the flexible porous coordination polymers, Cu-2(bdc)(2)(MeOH)(2) and Cu-2(bdc)(2)(bpy) (bdc(2-) = 1,4-benzenedicarboxylate, bpy = 4,4'-bipyridine). Detailed characterization of the replicated systems reveals that the structuralization plays an important role in determining the adsorptive properties of the replicated systems, and that the immobilization of the crystals within a higher-order architecture also affects its structural and dynamic properties. The polyacrylamide polymer is also found to be crucial for maintaining the structuralization of the monolithic systems, and in providing the mechanical robustness required for manual handling. In all, the results discussed here demonstrate a significant expansion in the scope of the coordination replication strategy, and further confirms its utility as a highly versatile platform for the preparation of functional three-dimensional superstructures of porous coordination polymers.

DOI： 10.1039/c5sc02034d

Preparation of silver nanoparticles embedded hierarchically porous AlPO4 monoliths Reviewed

Xiaobo Cai, Wenjun Zhu, Hui Yang, Chenyang Xu, Kazuki Nakanishi, Kazuyoshi Kanamori, Xingzhong Guo

NEW JOURNAL OF CHEMISTRY Vol. 39 ( 8 ) page： 6238 - 6243 2015

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Hierarchically porous AlPO4 monoliths with well-defined macropores are prepared via a sol-gel process accompanied by phase separation. Appropriate amounts of the precursors, poly(ethylene oxide) and propylene oxide, allow the formation of a mesoporous structure with uniform macropore size distribution in the gel. A crystalline phase of tridymite forms after heat-treatment at 1000 degrees C in air, while the meso-and macro-porous structure is preserved, maintaining a BET surface area of 120.8 m(2) g(-1). The resultant crystalline AlPO4 monolith is used as the host to immobilize silver nanoparticles (Ag NPs) by immersing it in silver colloid under an ambient condition. The result shows that Ag NPs were homogeneously embedded on the surface of skeletons without spoiling the appearance and macroporous structure of the initial AlPO4 monolith. Ag NPs embedded in monolithic AlPO4 show promise in a wide range of applications, including catalysis and separation.

DOI： 10.1039/c5nj00490j

Spontaneous preparation of hierarchically porous silica monoliths with uniform spherical mesopores confined in a well-defined macroporous framework Reviewed

Xingzhong Guo, Rui Wang, Huan Yu, Yang Zhu, Kazuki Nakanishi, Kazuyoshi Kanamori, Hui Yang

DALTON TRANSACTIONS Vol. 44 ( 30 ) page： 13592 - 13601 2015

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Hierarchically porous silica monoliths with well-defined interconnected macropores and uniform spherical mesopores were spontaneously prepared by combining polymerization-induced phase separation with an epoxide-mediated sol-gel route without any complicated aging and drying and high-temperature heat treatment. The precise control of pore structures can be realized by using propylene oxide (PO) as the gelation mediation agent, poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (P123) as the phase-separation inducer as well as the structure-directing agent and 1,3,5-trimethyl-benzene (TMB) as the micelle-swelling agent. The as-prepared silica monolith possesses an interesting hierarchically porous structure constructed by 10 nm uniform spherical mesopores confined in a macroporous framework of well-defined 1 mu m macropores, and exhibits a BET surface area as high as 848 m(2) g(-1). Heat treatment at 400-800 degrees C gradually decreases the BET surface area to 195 m(2) g(-1), while most of the uniform mesoporous structure remains intact.

DOI： 10.1039/c5dt01672j

Sol-gel synthesis of nanocrystal-constructed hierarchically porous TiO2 based composites for lithium ion batteries Reviewed

Wenjun Zhu, Hui Yang, Kazuki Nakanishi, Kazuyoshi Kanamori, Xingzhong Guo

RSC ADVANCES Vol. 5 ( 31 ) page： 24803 - 24813 2015

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Hierarchically porous TiO2 based composites (pure TiO2 and TiO2/carbon (TiO2/C) composite) were synthesized by a facile sol-gel process followed by post- calcination. Poly(vinylpyrrolidone) (PVP) acts as a phase separation inducer as well as a carbon source. The as-prepared TiO2 based composites possess an interesting hierarchically porous structure constructed of cocontinuous macropores and mesoporous skeletons consisting of interconnected nanocrystals and in situ distributed carbon. The hierarchically porous TiO2/C composite shows excellent electrochemical performance with fast lithium ion diffusion and electronic transport, resulting from the hierarchically porous structure and conductive carbon material. The TiO2/C composite calcined at 500 degrees C exhibits the highest BET surface area of 170 m(2) g(-1), superior cycling stability (delivers a remarkable discharge capacity of 132 mA h g(-1) at 1 C after 100 cycles) and excellent rate capability (over 96 mA h g(-1) at 30 C rate). The results indicate that these hierarchically porous TiO2 based composites could be promising anode materials for high performance lithium ion batteries.

DOI： 10.1039/c5ra03491d

Other Link： http://orcid.org/0000-0002-8069-4780

Impact of Electrolyte on Pseudocapacitance and Stability of Porous Titanium Nitride (TiN) Monolithic Electrode Reviewed

George Hasegawa, Atsushi Kitada, Shota Kawasaki, Kazuyoshi Kanamori, Kazuki Nakanishi, Yoji Kobayashi, Hiroshi Kageyama, Takeshi Abe

JOURNAL OF THE ELECTROCHEMICAL SOCIETY Vol. 162 ( 1 ) page： A77 - A85 2015

Language：English Publishing type：Research paper (scientific journal) Publisher：ELECTROCHEMICAL SOC INC

We report the fabrication of porous titanium nitride (TiN) monoliths through the ammonolysis of porous TiO2 monoliths prepared via the sol-gel process accompanied by phase separation. The obtained TiN monoliths possess good mechanical strength as well as excellent electric conductivity with a superconducting transition at T-c similar to 5.0 K. We have investigated the electrochemical properties of the porous TiN monoliths as an electrode using various electrolytes. The results reveal that the pseudocapacitance of TiN increases in the order of K+ < Na+ < Li+ contrary to the case of EDL capacitance in neutral aqueous electrolytes. It is also found that acidic and strongly basic electrolytes are not suitable due to high corrosivity, while there is no significant deterioration when neutral aqueous electrolytes and organic electrolytes are used. (C) 2014 The Electrochemical Society. All rights reserved.

DOI： 10.1149/2.0491501jes

Fabrication of hierarchically porous monolithic layered double hydroxide composites with tunable microcages for effective oxyanion adsorption Reviewed

Naoki Tarutani, Yasuaki Tokudome, Megu Fukui, Kazuki Nakanishi, Masahide Takahashi

RSC ADVANCES Vol. 5 ( 70 ) page： 57187 - 57192 2015

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Removal of toxic substances from industrial wastes is an urgent issue for realizing a sustainable society. Layered double hydroxides ( LDHs) are expected to be an effective adsorbent for toxic anions, especially oxyanions, because of their high anion adsorption capacity and reusability. Monolithic LDH materials with rational meso- and macropores are expected to show high adsorption capacity/rate towards targeted toxic substances owing to their large specific surface area and liquid transport property. Besides fabricating hierarchical pores, size control of microcages in LDH crystals is required to achieve selective removal of oxyanions. Herein, we prepared hierarchically porous monolithic LDH composites with tunable microcages by changing the combination of cationic species in the LDH crystal. Monolithic Mg-, Mn-, Fe-, Co- and Ni-Al type LDH composites with hierarchical pores were successfully prepared via an epoxide-mediated sol-gel reaction accompanied with phase separation. The monolithic Co-Al type LDH composite with hierarchical pores exhibited the highest CrO42- adsorption capacity because its microcage size easily fits the CrO42- size. Also Co-Al type LDH composites adsorbed different oxyanions, depending on their affinity with the LDH, in a SO42-, CrO42-, MoO42- and HVO42- co-existing solution. The pore size controllability in discrete length-scales of micrometers, nanometers, and picometers offers LDHs with tailored surface chemistries and physical properties desirable for effective and selective oxyanion adsorption.

DOI： 10.1039/c5ra05942a

Synthesis of robust hierarchically porous zirconium phosphate monolith for efficient ion adsorption Reviewed

Yang Zhu, Taiyo Shimizu, Takara Kitajima, Kei Morisato, Nirmalya Moitra, Nicolas Brun, Tsutomu Kiyomura, Kazuyoshi Kanamori, Kazuyuki Takeda, Hiroki Kurata, Masamoto Tafu, Kazuki Nakanishi

NEW JOURNAL OF CHEMISTRY Vol. 39 ( 4 ) page： 2444 - 2450 2015

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Hierarchically porous monolithic materials are advantageous as adsorbents, catalysts and catalyst supports due to the better accessibility of reactants to the active sites and the ease of recycle and reuse. Traditional synthetic routes, however, have limitations in designing hierarchical porosity as well as the mechanically stable monolithic shape in inorganic phosphate materials, which are useful as adsorbents and catalysts. We present a low-temperature, one-step liquid phase synthesis of hierarchically porous zirconium phosphate (ZrP) monoliths with tunable compositions (from Zr(HPO4)(2) (Zr : P = 1:2) to NaSICON (Na super ionic conductor)-type ZrP (Zr : P = 1:1.5)) as well as macropore size (from 0.5 to 5 mu m). The as-synthesized ZrP monolith with a high reactive surface area (600 m(2) g(-1)) and relatively high mechanical strength (Young's modulus 320 MPa) was applied to ion adsorption. A simple syringe device inserted tightly with the ZrP monolith as a continuous flow setup was demonstrated to remove various toxic metal ions in aqueous solutions, which shows promising results for water purification.

DOI： 10.1039/c4nj01749h

Facile synthesis of monolithic mayenite with well-defined macropores via an epoxide-mediated sol-gel process accompanied by phase separation Reviewed

Xingzhong Guo, Xiaobo Cai, Jie Song, Yang Zhu, Kazuki Nakanishi, Kazuyoshi Kanamori, Hui Yang

NEW JOURNAL OF CHEMISTRY Vol. 38 ( 12 ) page： 5832 - 5839 2014.12

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Monolithic mayenite with well-defined macropores has been successfully synthesized from ionic precursors via a sol-gel process accompanied by phase separation. The addition of propylene oxide (PO) to the starting solution leads to homogenous gelation and modifies the gel skeleton, whereas the addition of poly(ethylene oxide) (PEO) induces phase separation. Glycol acts as a chelating agent to suppress the precipitation of Ca2+ ions, and formamide works as a drying control chemical additive to enhance the drying behavior. Appropriate amounts of solvents, PEO, and PO allow the formation of calcium aluminate gets with co-continuous macroporous structure. The reaction mechanism of the sol-gel process of the Ca-Al-O system is also investigated by TG-DSC, FT-IR and NMR. The dried gels are amorphous and the crystalline phase Ca12Al14O32Cl2 forms after heat-treatment at 1000 degrees C in air, while the macroporous structure is preserved. The resultant monoliths before and after heat-treatment possess both high porosity and smooth and dense skeletons.

DOI： 10.1039/c4nj00898g

Other Link： http://orcid.org/0000-0002-8069-4780

Facile preparation of silver nanoparticles homogeneously immobilized in hierarchically monolithic silica using ethylene glycol as reductant Reviewed

Huan Yu, Yang Zhu, Hui Yang, Kazuki Nakanishi, Kazuyoshi Kanamori, Xingzhong Guo

DALTON TRANSACTIONS Vol. 43 ( 33 ) page： 12648 - 12656 2014.9

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

A facile and "green" method was proposed to introduce Ag nanoparticles (Ag NPs) into the hierarchically monolithic silica uniformly in the presence of (3-aminopropyl)-triethoxysilane (APTES) and ethylene glycol. APTES is used to modify the monolith by incorporating amino groups onto the surface of meso-macroporous skeletons, while ethylene glycol is employed as the productive reductant. Ag NPs are homogeneously immobilized in hierarchically monolithic silica after reduction and drying at 40 degrees C for different duration times, and the embedded amount of Ag NPs can reach 15.44 wt% when treated once. The embedment of Ag NPs increases with the repeat treatment and the APTES amount, without uncontrollable crystalline growth. The surface areas of Ag NPs embedded in silica monoliths after heat treatment at 300 and 400 degrees C are higher than those before heat treatment. The modification via APTES and the embedment of Ag NPs does not spoil the morphology of monolithic silica, while changing the pore structures of the monolith. A tentative formation process and a reduction mechanism are proposed for the modification, reduction and embedment. Ag NPs embedded in monolithic silica is promising for wide applications such as catalysis and separation.

DOI： 10.1039/C4DT00655K

Experimental and numerical validation of the effective medium theory for the B-term band broadening in 1st and 2nd generation monolithic silica columns Reviewed

Sander Deridder, Alison Vanmessen, Kazuki Nakanishi, Gert Desmet, Deirdre Cabooter

JOURNAL OF CHROMATOGRAPHY A Vol. 1351 page： 46 - 55 2014.7

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Effective medium theory (EMT) expressions for the B-term band broadening in monolithic silica columns are presented at the whole-column as well as at the mesoporous skeleton level. Given the bi-continuous nature of the monolithic medium, regular as well as inverse formulations of the EMT-expressions have been established. The established expressions were validated by applying them to a set of experimental effective diffusion (D-eff)-data obtained via peak parking on a number of 1st and 2nd generation monolithic silica columns, as well as to a set of numerical diffusion simulations in a simplified monolithic column representation (tetrahedral skeleton model) with different external porosities and internal diffusion coefficients. The numerically simulated diffusion data can be very closely represented over a very broad range of zone retention factors (up to k '' = 80) using the established EMT-expressions, especially when using the inverse variant. The expressions also allow representing the experimentally measured effective diffusion data very closely. The measured D-eff/D-mol-values were found to decrease significantly with increasing retention factor, in general going from about D-eff/D-mol = 0.55 to 0.65 at low k '' (k '' congruent to 1.5-3.8) to D-eff/D-mol = 0.25 at very high k '' (k '' congruent to 40-80). These values are significantly larger than observed in fully-porous and core-shell particles. The intra-skeleton diffusion coefficient (D-pz) was typically found to be of the order of D-pz/D-mol = 0.4, compared to D-pz/D-mol = 0.2-0.35 observed in most particle-based columns. These higher D-pz/D-mol values are the cause of the higher D-eff/D-mol values observed. In addition, it also appears that the higher internal diffusion is linked to the higher porosity of the mesoporous skeleton that has a relatively open structure with relatively wide pores. The observed (weak) relation between D-pz/D-mol and the zone retention factor appears to be in good agreement with that predicted when applying the regular variant of the EMT-expression directly to the mesoporous skeleton level. (C) 2014 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.chroma.2014.04.099

Other Link： http://orcid.org/0000-0002-8069-4780

Polymethylsilsesquioxane-Cellulose Nanofiber Biocomposite Aerogels with High Thermal Insulation, Bendability, and Superhydrophobicity Reviewed

Gen Hayase, Kazuyoshi Kanamori, Kentaro Abe, Hiroyuki Yano, Ayaka Maeno, Hironori Kaji, Kazuki Nakanishi

ACS APPLIED MATERIALS & INTERFACES Vol. 6 ( 12 ) page： 9466 - 9471 2014.6

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Polymethylsilsesquioxane-cellulose nanofiber (PMSQ:CNF) composite aerogels have been prepared through sol-gel in a solvent containing a small amount of CNFs as suspension. Since these composite aerogels do not show excessive aggregation of PMSQand CNF, the original PMSQnetworks are not disturbed. Composite aerogels with low density (0.020 g cm(-3) at lowest), low thermal conductivity (15 mW rn(-1) K-1), visible light translucency, bending flexibility, and superhydrophobicity thus have been successfully obtained. In particular, the lowest density and bending flexibility have been achieved with the aid of the physical supporting effect of CNFs, and the lowest thermal conductivity is comparable with the original PMSQ aerogels and standard silica aerogels. The PMSQ: CNF composite aerogels would be a candidate to practical high-performance thermal insulating materials.

DOI： 10.1021/am501822y

Other Link： http://orcid.org/0000-0002-8069-4780

Preparation of macroporous cordierite monoliths via the sol-gel process accompanied by phase separation Reviewed

Xingzhong Guo, Kazuki Nakanishi, Kazuyoshi Kanamori, Yang Zhu, Hui Yang

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY Vol. 34 ( 3 ) page： 817 - 823 2014.3

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCI LTD

Monolithic cordierite with a cocontinuous macroporous structure has been successfully prepared by the sol-gel process accompanied by phase separation in the presence of poly(acrylamide) (PAAm). Propylene oxide (PO) acts as an acid scavenger to mediate the gelation of MgO-Al2O3-SiO2 ternary system, while PAAm works as a phase-separation inducer as well as a network former. The dried gel and that heat-treated at 800 degrees C are amorphous, and the sapphirine begins to precipitate at 900 degrees C, then transforming to orthorhombic beta-cordierite at 1100 degrees C. After heat-treated at and above 1200 degrees C, the resultant beta-cordierite further transforms to stable hexagonal alpha-cordierite. Heat-treatment changes the macroporous structure of cordierite monoliths such as macropore size and its distribution. The macroporous cordierite monolith after heat-treated at 1200 degrees C is found to possess a total porosity of 54%, interconnected macropores and dense solid skeletons. (C) 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.jeurceramsoc.2013.08.016

Fabrication of nitrogen-doped TiO2 monolith with well-defined macroporous and bicrystalline framework and its photocatalytic performance under visible light Reviewed

Olim Ruzimuradov, Suvankul Nurmanov, Mirabbos Hojamberdiev, Ravi Mohan Prasad, Aleksander Gurlo, Joachim Broetz, Kazuki Nakanishi, Ralf Riedel

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY Vol. 34 ( 3 ) page： 809 - 816 2014.3

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCI LTD

In this study, hierarchically porous bicrystalline nitrogen-doped titania (N-doped TiO2) monolithic material was fabricated by a simple two-step approach: (i) preparation of TiO2 porous monolith by a sol-gel process of titanium alkoxide in a mild condition utilizing a chelating agent and mineral salt and (ii) annealing of TiO2 porous monolith obtained under a modest flow of ammonia gas at 700 degrees C for 2 h. The phase composition, crystal structure, morphology, pore structure, and porous properties of the final product were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), mercury porosimetry, and nitrogen physisorption measurement, respectively. The resultant N-doped TiO2 porous monolith possesses a bicrystalline (anatase and rutile) framework with a well-defined macroporosity. The results from X-ray photoelectron spectroscopy (XPS) confirm the formation of O-Ti-N bonds in the N-doped TiO2 porous monolith. The photocatalytic activity of N-doped TiO2 porous monolith was evaluated by the photodegradation of Rhodamine B over the samples under visible light. Nearly 50% of Rhodamine B in aqueous solution was efficiently degraded by N-doped TiO2 porous monolith with the mixed-phase of anatase and ruffle under visible light within 120 mm. (C) 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.jeurceramsoc.2013.10.009

Controlled polymerization of protic ionic liquid monomer by ARGET-ATRP and TERP Reviewed

Nakamura Y., Nakanishi K., Yamago S., Tsujii Y., Takahashi K., Morinaga T., Sato T.

Macromolecular Rapid Communications Vol. 35 ( 6 ) page： 642 - 648 2014.3

Language：English Publishing type：Research paper (scientific journal) Publisher：Macromolecular Rapid Communications

The direct synthesis of structurally well-defined protic polymeric ionic liquid (PIL) with controlled molecular weight and molecular weight distribution is examined using N,N-diethyl-N-(2-methacryloylethyl) ammonium bis(tri-fluoromethylsulfonyl)imide (DEMH-TFSI) as a monomer. Three polymerization methods, namely, atom transfer radical polymerization (ATRP), activators regenerated by electron transfer (ARGET)-ATRP, and organotellurium-mediated living radical polymerization (TERP) are employed in this study. While the polymerization by ATRP is slow and does not reach high monomer conversion that under ARGET-ATRP and TERP proceeds smoothly and affords structurally well-defined poly(DEMH-TFSI)s. TERP is especially efficient for the control and poly(DEMH-TFSI)s with low to high molecular weights (M̄n = 49 100-392 500) and narrow molecular weight distributions (M̄w/M̄n = 1.17-1.46) are obtained. These results represent the first example of synthesis of a structurally well-defined protic, ammonium PIL by direct polymerization of the protic ionic liquid monomer. The polymerization of N,N-diethyl-N-(2- methacryloylethyl)-N-methylammonium bis(trifluoromethylsulfonyl)imide (DEMM-TFSI), which possesses a quaternary ammonium salt, also proceeds in a highly controlled manner under TERP conditions. A diblock copolymer, polystyrene-block-poly(DEMH-TFSI), is also successfully synthesized by TERP. Structurally well-defined protic polymeric ionic liquid is prepared by the direct polymerization of protic ammonium-salt ionic liquid monomers, N,N-diethyl-N-(2-methacryloylethyl) ammonium bis(tri-fluoromethylsulfonyl)imide (DEMH-TFSI), under ARGET-ATRP and TERP conditions. TERP is especially suitable for the controlled polymerization and afforded poly(DEMH-TFSI) with low to high molecular weight (M̄n = 49 100-392 500) and a narrow molecular weight distribution (M̄w/M̄n = 1.17-1.46). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOI： 10.1002/marc.201300855

Preparation and characterization of macroporous TiO2-SrTiO3 heterostructured monolithic photocatalyst Reviewed

Ohm Ruzimuradov, Suvankul Nurmanov, Mirabbos Hojamberdiev, Ravi Mohan Prasad, Alexander Gurlo, Joachim Broetz, Kazuki Nakanishi, Ralf Riedel

MATERIALS LETTERS Vol. 116 page： 353 - 355 2014.2

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Macroporous TiO2 monolith was first prepared by the sol-gel method and then macroporous TiO2-SrTiO3 heterostructured monolith was obtained by the impregnation of the as-prepared macroporous TiO2 monolith in the strontium-containing aqueous solution followed by calcination at different temperatures. The formation of SrTiO3 crystals in the TiO2 network was confirmed by X-ray diffraction and electron microscopy analyses. Macroporous structure of the heterostructured monolith was analyzed by mercury porosimetry. The photocatalytic activity of macroporous TiO2-SrTiO3 heterostructured monolithic photocatalyst was evaluated for the photodegradation of Rhodamine B over the samples under visible light irradiation. The obtained results reveal that the samples show an enhanced photocatalytic activity for the degradation of organic dye molecules. (C) 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.matlet.2013.11.065

Detailed characterization of the kinetic performance of first and second generation silica monolithic columns for reversed-phase chromatography separations Reviewed

Deirdre Cabooter, Ken Broeckhoven, Roman Sterken, Alison Vanmessen, Isabelle Vandendael, Kazuki Nakanishi, Sander Deridder, Gert Desmet

JOURNAL OF CHROMATOGRAPHY A Vol. 1325 page： 72 - 82 2014.1

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

The kinetic performance of commercially available first generation and prototype second generation silica monoliths has been investigated for 2.0 mm and 3.0-3.2 mm inner diameter columns. It is demonstrated that the altered sol-gel process employed for the production of second generation monoliths results in structures with a smaller characteristic size leading to an improved peak shape and higher efficiencies. The permeability of the columns however, decreases significantly due to the smaller throughpore and skeleton sizes. Scanning electron microscopy pictures suggest the first generation monoliths have cylindrical skeleton branches, whereas the second generation monoliths rather have skeleton branches that resemble a single chain of spherical globules. Using recently established correlations for the flow resistance of cylindrical and globule chain type monolithic structures, it is demonstrated that the higher flow resistance of the second generation monoliths can be entirely attributed to their smaller skeleton sizes, which is also evident from the external porosity that is largely the same for both monolith generations (epsilon(e) similar to 0.65). The recorded van Deemter plots show a clear improvement in efficiency for the second generation monoliths (minimal plate heights of 13.6-14.1 mu m for the first and 6.5-8.2 mu m for the second generation, when assessing the plate count using the Foley-Dorsey method). The corresponding kinetic plots, however, indicate that the much reduced permeability of the second generation monoliths results in kinetic performances (time needed to achieve a given efficiency) which are only better than those of the first generation for plate counts up to N similar to 45,000. For more complex samples (N >= 50,000), the first generation monoliths can intrinsically still provide faster analysis due to their high permeability. It is also demonstrated that - despite the improved efficiency of the second generation monoliths in the practical range of separations (N = 10,000-50,000) - these columns can still not compete with state-of-the-art core-shell particle columns when all columns are evaluated at their own maximum operating pressure (200 bar for the monolithic columns, 600 bar for core-shell columns). It is suggested that monolithic columns will only become competitive with these high efficiency particle columns when further improvements to their production process are made and their pressure resistance is raised. (C) 2013 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.chroma.2013.11.047

Other Link： http://orcid.org/0000-0002-8069-4780

The thermal conductivity of polymethylsilsesquioxane aerogels and xerogels with varied pore sizes for practical application as thermal superinsulators Reviewed

G. Hayase, K. Kugimiya, M. Ogawa, Y. Kodera, K. Kanamori, K. Nakanishi

JOURNAL OF MATERIALS CHEMISTRY A Vol. 2 ( 18 ) page： 6525 - 6531 2014

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

High-performance thermal insulating materials are desired especially from the viewpoint of saving energy for a sustainable society. Aerogel is the long-awaited material for extended applications due to its excellent thermal insulating ability. These materials are, however, seriously fragile against even small mechanical stress due to their low density, and their poor mechanical properties inhibit their practical use as superinsulators. In this paper, we report relationships between the thermal conductivity, pore size and mechanical properties of organic-inorganic hybrid polymethylsilsesquioxane (PMSQ) aerogels with improved mechanical properties and controllable pore sizes from similar to 50 nm to 3 mu m. The dependency of thermal conductivity on gas pressure and pore properties can be well explained by the thermal conduction theory of porous materials. These PMSQ aerogels show improved mechanical properties due to their elastic networks, which enable easier handling compared to conventional aerogels and facile production by simple ambient pressure drying. An aerogel-like "xerogel" monolithic panel has been successfully prepared via ambient pressure drying, which shows a low thermal conductivity (0.015 W m(-1) K-1) comparable with those of the corresponding PMSQ aerogel and conventional silica aerogels. These results would open the gate for practical applications of these porous materials.

DOI： 10.1039/c3ta15094a

Layered double hydroxide composite monoliths with three-dimensional hierarchical channels: structural control and adsorption behavior Reviewed

Naoki Tarutani, Yasuaki Tokudome, Kazuki Nakanishi, Masahide Takahashi

RSC ADVANCES Vol. 4 ( 31 ) page： 16075 - 16080 2014

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Hierarchically porous layered double hydroxide (LDH) materials have potential in anion-exchange, adsorption and catalysis applications, because of their large surface areas and liquid transportation capabilities. The preparation of monolithic LDH-Al(OH)(3) composites with hierarchical mm and nm-scale channels and their adsorption behavior is reported. Monolithic gels were synthesized via sol-gel processing, from metal salt precursor solutions. mu m-scale macrochannels spontaneously formed by inducing phase separation during sol-gel transition. nm-scale mesochannels were accommodated as interstices between primary/secondary particles. In this study, these hierarchical channel sizes were controlled. The macrochannel size was controlled by tuning the degree of phase separation. The mesochannel size was controlled independently, by tuning the crystallite size of LDH under different solvothermal conditions. The relationship between pore characteristics and adsorption behavior of tailored hierarchically porous LDH-Al(OH)(3) monolithic gels were investigated by using dye molecules as adsorbates. Monolithic gels with larger macrochannels and mesochannels exhibit faster adsorption rate and higher affinity, respectively. LDH-Al(OH)(3) monolithic gels with hierarchical channels may have potential in some applications such as biosensing, water purification and catalysis.

DOI： 10.1039/c4ra00873a

Other Link： http://orcid.org/0000-0002-8069-4780

A new hierarchically porous Pd@HSQ monolithic catalyst for Mizoroki-Heck cross-coupling reactions Reviewed

Nirmalya Moitra, Ayumi Matsushima, Toshiyuki Kamei, Kazuyoshi Kanamori, Yumi H. Ikuhara, Xiang Gao, Kazuyuki Takeda, Yang Zhu, Kazuki Nakanishi, Toyoshi Shimada

NEW JOURNAL OF CHEMISTRY Vol. 38 ( 3 ) page： 1144 - 1149 2014

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Pore architecture of catalyst supports is an important factor facilitating accessibility of reactants to catalytic sites. This holds the key to improving catalytic activities. Amongst various catalytic reactions, supported Pd nanoparticles-catalyzed C-C cross-coupling reactions have been attracting a great deal of attention in the last decade. Although various supports have been examined, applications of hierarchically porous monolithic materials have never been reported, mainly because of difficulties in multistep synthesis of catalysts. We herein report a novel on-site reduction-based methodology using hierarchically porous hydrogen silsesquioxane (HSQ) monoliths for one-step synthesis of Pd nanoparticles-embedded monoliths (Pd@HSQ). Characterization of these monoliths evidences the on-site reduction, i.e. formation of Pd nanoparticles and conversion of Si-H present in the monolith to Si-OB similar to. Fast, quantitative reduction of Pd2+ to Pd(0) to form supported Pd nanoparticles is achieved with preservation of the porous structure of the original monolith, which makes this material attractive as a catalyst for C-C cross-coupling reactions. The obtained Pd@HSQ catalyst has been employed in the Mizoroki-Heck cross-coupling reaction. High accessibility of reactant molecules, undetectable leaching of Pd nanoparticles and easy separation of the monolith from liquid media provide high catalytic activity, reusability and easy handling.

DOI： 10.1039/c3nj01433a

Porous chromium-based ceramic monoliths: oxides (Cr2O3), nitrides (CrN), and carbides (Cr3C2) Reviewed

Yasuki Kido, George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi

JOURNAL OF MATERIALS CHEMISTRY A Vol. 2 ( 3 ) page： 745 - 752 2014

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

In this research, we have successfully prepared hierarchically porous chromium-based non-oxide ceramic monoliths (chromium nitride (CrN) and chromium carbide (Cr3C2)) by facile two-step methods. By utilizing an epoxide-mediated sol-gel reaction accompanied by phase separation, a well-defined macroporous structure is tailored in the chromium (oxy) hydroxide-urea composites in the presence of poly(acrylic acid). Urea works as a nitrogen and/or carbon source through the following heat-treatment, whereas poly(acrylic acid) behaves as a phase separation inducer as well as a network-supporting constituent. The macroporous morphology of xerogels is controllable by changing the starting composition. Heat-treatment for thus obtained xerogels under an air atmosphere provides chromium oxide (Cr2O3), whereas that under a nitrogen atmosphere leads to the crystallization of CrN at 700 degrees C and Cr3C2 at 900 degrees C without any deterioration of the porous morphologies. The heat-treated samples possess a high specific surface area up to 450 m(2) g(-1) as well as high porosity over 80%, preserving good mechanical strength. This facile and novel synthesis strategy has a potential extendability to other macroporous monoliths with high surface area based on various metal nitrides and carbides, which are useful in various applications such as catalysts, semiconductor devices, magnetic materials, and refractory materials.

DOI： 10.1039/c3ta13725b

Synthesis and electrochemical performance of hierarchically porous N-doped TiO2 for Li-ion batteries Reviewed

George Hasegawa, Tatsuya Sato, Kazuyoshi Kanamori, Kazuki Nakanishi, Takeshi Abe

NEW JOURNAL OF CHEMISTRY Vol. 38 ( 4 ) page： 1380 - 1384 2014

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Hierarchically porous N-doped TiO2 materials have been synthesized from macroporous inorganic-organic hybrid gels composed of titanium bridged with ethylenediamine. Homogeneously dispersed nitrogen in the precursor gel networks leads to TiO2 doped with a large amount of nitrogen, which delivers high discharge capacity and good cycle performance as a negative electrode for Li-ion batteries.

DOI： 10.1039/c3nj01332d

Other Link： http://orcid.org/0000-0002-8069-4780

Reduction on reactive pore surfaces as a versatile approach to synthesize monolith-supported metal alloy nanoparticles and their catalytic applications Reviewed

Nirmalya Moitra, Kazuyoshi Kanamori, Yumi H. Ikuhara, Xiang Gao, Yang Zhu, George Hasegawa, Kazuyuki Takeda, Toyoshi Shimada, Kazuki Nakanishi

JOURNAL OF MATERIALS CHEMISTRY A Vol. 2 ( 31 ) page： 12535 - 12544 2014

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Supported metal alloy nanoparticles demonstrate high potential in designing heterogeneous catalysts for organic syntheses, pollution control and fuel cells. However, requirements of high temperature and multistep processes remain standing problems in traditional synthetic strategies. We herein present a low-temperature, single-step, liquid-phase methodology for designing monolith-supported metal alloy nanoparticles with high physicochemical stability and accessibility. Metal ions in aqueous solutions are reduced to form their corresponding metal alloy nanoparticles within hierarchically porous hydrogen silsesquioxane (HSQ, HSiO1.5) monoliths bearing well-defined macro-and mesopores and exhibiting high surface redox activity due to the presence of abundant Si-H groups. Supported bi-, tri- and tetrametallic nanoparticles have been synthesized with controlled compositions and loadings, and characterized in detail by microscopy and spectroscopy techniques. Examination of these supported metal alloy nanoparticles in catalytic reduction of 4-nitrophenol shows high catalytic activities depending on their compositions. Their recyclability and potential application in continuous flow reactors are also demonstrated.

DOI： 10.1039/c4ta01767f

Other Link： http://orcid.org/0000-0002-8069-4780

Pore structure control of macroporous methylsilsesquioxane monoliths prepared by in situ two-step processing Reviewed

Xingzhong Guo, Huan Yu, Hui Yang, Kazuyoshi Kanamori, Yang Zhu, Kazuki Nakanishi

JOURNAL OF POROUS MATERIALS Vol. 20 ( 6 ) page： 1477 - 1483 2013.12

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Macroporous methylsilsesquioxane (MSQ) monoliths have been prepared by in situ two-step processing using an initial acid catalysis step accompanied by an epoxide-mediated condensation step in the presence of ammonium chloride (NH4Cl). We investigate the effects of duration time of acidic step, heat-treatment and hydrothermal treatment on the macroporous morphology and pore structures of MSQ monoliths. The duration time of acidic step gives an important effect on the macroporous morphology and pore structures of MSQ monoliths, resulting from the polymerization of MSQ. Heat-treatment and hydrothermal treatment basically do not spoil the macroporous morphology of MSQ monoliths, while obviously varies the mesopore/micropore structures including pore size, pore volume, and pore size distribution. The macroporous MSQ materials with thick skeleton and intrinsic hydrophobicity are promising for wide applications such as ultra performance liquid chromatography (UPLC), superhydrophobic materials and so on.

DOI： 10.1007/s10934-013-9733-z

Recyclable functionalization of silica with alcohols via dehydrogenative addition on hydrogen silsesquioxane Reviewed

Nirmalya Moitra, Toshiyuki Kamei, Kazuyoshi Kanamori, Kazuki Nakanishi, Kazuyuki Takeda, Toyoshi Shimada

Langmuir Vol. 29 ( 39 ) page： 12243 - 12253 2013.10

Language：English Publishing type：Research paper (scientific journal)

Synthesis of class II hybrid silica materials requires the formation of covalent linkage between organic moieties and inorganic frameworks. The requirement that organosilylating agents be present to provide the organic part limits the synthesis of functional inorganic oxides, however, due to the water sensitivity and challenges concerning purification of the silylating agents. Synthesis of hybrid materials with stable molecules such as simple alcohols, rather than with these difficult silylating agents, may therefore provide a path to unprecedented functionality. Herein, we report the novel functionalization of silica with organic alcohols for the first time. Instead of using hydrolyzable organosilylating agents, we used stable organic alcohols with a Zn(II) catalyst to modify the surface of a recently discovered highly reactive macro-mesoporous hydrogen silsesquioxane (HSQ, HSiO1.5) monolith, which was then treated with water with the catalyst to form surface- functionalized silica. These materials were comprehensively characterized with FT-IR, Raman, solid-state NMR, fluorescence spectroscopy, thermal analysis, elemental analysis, scanning electron microscopy, and nitrogen adsorption-desorption measurements. The results obtained from these measurements reveal facile immobilization of organic moieties by dehydrogenative addition onto surface silane (Si-H) at room temperature with high loading and good tolerance of functional groups. The organic moieties can also be retrieved from the monoliths for recycling and reuse, which enables cost-effective and ecological use of the introduced catalytic/reactive surface functionality. Preservation of the reactivity of as-immobilized organic alcohols has been confirmed, moreover, by successfully performing copper-catalyzed azide-alkyne cycloaddition (CuAAC) "click" reactions on the immobilized silica surfaces. © 2013 American Chemical Society.

DOI： 10.1021/la402205j

Hierarchically porous monoliths based on N-doped reduced titanium oxides and their electric and electrochemical properties Reviewed

George Hasegawa, Tatsuya Sato, Kazuyoshi Kanamori, Kousuke Nakano, Takeshi Yajima, Yoji Kobayashi, Hiroshi Kageyama, Takeshi Abe, Kazuki Nakanishi

Chemistry of Materials Vol. 25 ( 17 ) page： 3504 - 3512 2013.9

Language：English Publishing type：Research paper (scientific journal)

In this report, we demonstrate a novel synthesis method to obtain reduced titanium oxides with monolithic shape and with a well-defined hierarchically porous structure from the titanium-based network bridged with ethylenediamine. The hierarchically porous monoliths are fabricated by the nonhydrolytic sol-gel reaction accompanied by phase separation. This method allows a low-temperature crystallization into Ti4O7 and Ti3O5 at 800 and 900 C, respectively, with N-doped carbon. These reduced titanium oxides are well-doped with N atoms even under argon atmosphere without NH 3, which accounts for the low-temperature reduction. The resultant monolithic materials possess controllable macropores and high specific surface area together with excellent electric conductivity up to 230 S cm-1, indicating promise as a conductive substrate that can substitute carbon electrodes. © 2013 American Chemical Society.

DOI： 10.1021/cm401933a

Synthesis of Concentrated Polymer Brushes via Surface-Initiated Organotellurium-Mediated Living Radical Polymerization Reviewed

Yamago, Shigeru, Yahata, Yoshikazu, Nakanishi, Kouji, Konishi, Shota, Kayahara, Eiichi, Nomura, Akihiro, Goto, Atsushi, Tsujii, Yoshinobu

Macromolecules Vol. 46 ( 17 ) page： 6777 - 6785 2013.9

Preparation of mullite monoliths with well-defined macropores and mesostructured skeletons via the sol-gel process accompanied by phase separation Reviewed

Xingzhong Guo, Wenyan Li, Kazuki Nakanishi, Kazuyoshi Kanamori, Yang Zhu, Hui Yang

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY Vol. 33 ( 10 ) page： 1967 - 1974 2013.9

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCI LTD

Mullite monoliths with well-defined macropores and mesostructured skeletons have been prepared via the sol gel process accompanied by phase separation in the presence of poly(ethylene oxide) (PEO). Gelation of Al2O3-SiO2 binary system with chloride salts as an additional precursor has been mediated by propylene oxide (PO) as an acid scavenger, while PEO worked as a phase-separation inducer. The dried gel and that heat-treated at 800 degrees C are amorphous, and gamma-Al2O3 or Si-Al spinel phase nanocrystals are crystallind at 900-1000 degrees C. After heat-treated at and above 1100 degrees C for 5 h, the complete crystalline mullite is generated, and the macroporous monoliths in large dimensions of more than 15 mm x 15 mm x 10 mm are obtained. Heat-treatment at 200-1400 degrees C does not basically spoil the macroporous structure of monoliths, while decreases the macropore size and significantly alters the phase compositions and micro-mesoporous structure. (C) 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.jeurceramsoc.2013.02.018

Sol-gel synthesis of macroporous TiO2 from ionic precursors via phase separation route Reviewed

Wenyan Li, Xingzhong Guo, Yang Zhu, Yang Hui, Kazuyoshi Kanamori, Kazuki Nakanishi

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 67 ( 3 ) page： 639 - 645 2013.9

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Monolithic macroporous titanium dioxide (TiO2) derived from ionic precursors has been successfully prepared via the sol-gel route accompanied by phase separation in the presence of formamide (FA) and poly(vinylpyrrolidone) (PVP). The addition of FA promotes the gelation, whereas PVP enhances the polymerization-induced phase separation. Appropriate choice of the starting compositions allows the production of cocontinuous macroporous TiO2 monoliths in large dimensions, and controls the size of macropores. The resultant dried gel is amorphous, whereas anatase and rutile phases are precipitated at 500 and 900 A degrees C respectively, without spoiling the macroporous morphology. Nitrogen adsorption-desorption measurements revealed that the dried gels exhibits mesostructure with a median pore size of about 3 nm and BET surface area of 228 m(2)/g, whereas 15 nm and 73 m(2)/g for the gels calcined at 600 A degrees C.

DOI： 10.1007/s10971-013-3123-5

Other Link： http://orcid.org/0000-0002-8069-4780

Gelation behavior and phase separation of macroporous methylsilsesquioxane monoliths prepared by in situ two-step processing Reviewed

Xingzhong Guo, Wenyan Li, Hui Yang, Kazuyoshi Kanamori, Yang Zhu, Kazuki Nakanishi

Journal of Sol-Gel Science and Technology Vol. 67 ( 2 ) page： 406 - 413 2013.8

Language：English Publishing type：Research paper (scientific journal)

An in situ two-step processing using an initial acid catalysis step accompanied by an epoxide-mediated condensation step in the presence of ammonium chloride (NH4Cl) is reported, and macroporous cocontinuous methylsilsesquioxane (MSQ) monoliths have been successfully prepared by this processing. We explain the hydrolysis, gelation behavior and phase separation of MTMS(methyltrimethoxysilane)-MeOH(methanol)-HCl-PO(propylene oxide) system and the in situ effect of NH4Cl, and examine the macroporous morphology and pore structures of MSQ monoliths obtained under different conditions. Macroporous MSQ monolith under optimized conditions possesses a narrow macropore size distribution between 3 to 10 μm, surface area as high as 366 m 2·g-1 and minimal shrinkage of only 1 %. © 2013 Springer Science+Business Media New York.

DOI： 10.1007/s10971-013-3094-6

Hierarchically porous nickel/carbon composite monoliths prepared by sol-gel method from an ionic precursor Reviewed

Yasuki Kido, Kazuki Nakanishi, Nao Okumura, Kazuyoshi Kanamori

MICROPOROUS AND MESOPOROUS MATERIALS Vol. 176 page： 64 - 70 2013.8

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Utilizing a facile sol-gel reaction accompanied by phase separation, rigid monolithic nickel hydroxide-based xerogels and nickel/carbon composites with hierarchical porosity have been successfully fabricated. In the synthetic route starting from nickel chloride as a nickel precursor, trimethylene oxide acts as a gelation initiator to increase pH in a reaction solution. In addition, poly(acrylic acid) plays a double role as a phase separation inducer and as a co-constituent with nickel hydroxide to comprise continuous gel skeletons in the micrometer range. As a result, obtained xerogels possess well-defined macropores evidenced by microscopy observation and mercury porosimetry. Subsequent heat-treatment in air led to the crystallization of NiO at 300 degrees C, while calcination under argon flow brought about the formation of nickel/carbon (Ni/C) composites with hierarchical pores and large specific surface area at temperatures higher than 300 degrees C. This is the first report on the preparation of rigid monolithic xerogels and metal/carbon composite with well-defined macropores based on a metal salt precursor containing "divalent" cation. (c) 2013 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.micromeso.2013.03.042

Preparation of a hierarchically porous AlPO4 monolith via an epoxide-mediated sol-gel process accompanied by phase separation Reviewed

Wenyan Li, Yang Zhu, Xingzhong Guo, Kazuki Nakanishi, Kazuyoshi Kanamori, Hui Yang

SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS Vol. 14 ( 4 ) page： 045007 2013.8

Language：English Publishing type：Research paper (scientific journal) Publisher：TAYLOR & FRANCIS LTD

Monolithic aluminum phosphate (AlPO4) with a macro-mesoporous structure has been successfully prepared via the sol-gel process accompanied by phase separation in the presence of poly(ethylene oxide) (PEO). Gelation of the system has been mediated by propylene oxide (PO), while PEO induces a phase separation. The dried gel is amorphous, whereas the crystalline tridymite phase precipitates upon heating above 1000 degrees C. Heat treatment does not spoil the macroporous morphology of the AlPO4 monoliths. Nitrogen adsorption-desorption measurements revealed that the skeletons of the dried gels possess a mesostructure with a median pore size of about 30 nm and a surface area as high as 120 m(2) g(-1). Hydrothermal treatment before heat treatment can increase the surface area to 282 m(2) g(-1).

DOI： 10.1088/1468-6996/14/4/045007

Synthesis of Hierarchically Porous Hydrogen Silsesquioxane Monoliths and Embedding of Metal Nanoparticles by On-Site Reduction Reviewed

Nirmalya Moitra, Kazuyoshi Kanamori, Toyoshi Shimada, Kazuyuki Takeda, Yumi H. Ikuhara, Xiang Gao, Kazuki Nakanishi

ADVANCED FUNCTIONAL MATERIALS Vol. 23 ( 21 ) page： 2714 - 2722 2013.6

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

A facile synthesis of a new class of reactive porous materials is reported: hierarchically porous hydrogen silsesquioxane (HSiO1.5, HSQ) monoliths with well-defined macropores and mesopores. The HSQ monoliths are prepared via sol-gel accompanied by phase separation in a mild condition, and contain micrometer-sized co-continuous macropores and high specific surface area reaching up to 800 m2 g-1 because of the small mesopores. A total preservation of Si-H, which is always an issue of HSQ materials, is confirmed by 29Si solid-state NMR. The HSQ monolith has then been subjected to reduction of noble metal ions to their corresponding metal nanoparticles in simple aqueous solutions under an ambient condition. The nanoparticles produced in this manner are immobilized on the HSQ monolith and are characterized by X-ray diffraction (XRD) and high angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). Both the bare HSQ and nanoparticles-embedded HSQ are promising as heterogeneous catalysts, exhibiting reusability and recyclability.

DOI： 10.1002/adfm.201202558

Fabrication of large-sized silica monolith exceeding 1000 mL with high structural homogeneity Reviewed

Riichi Miyamoto, Yukiko Ando, Chie Kurusu, Hong-zhi Bai, Kazuki Nakanishi, Masamichi Ippommatsu

JOURNAL OF SEPARATION SCIENCE Vol. 36 ( 12 ) page： 1890 - 1896 2013.6

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Reproducible fabrication of the hierarchically porous monolithic silica in a large volume exceeding 1000 mL has been established. By the hydrothermal enlargement of the fully accessible small pores to exceed 50 nm in diameter, the capillary force emerged on solvent evaporation was dramatically reduced, which allowed the preparation of crack-free monoliths with evaporative solvent removal under an ambient pressure. The local temperature inhomogeneity within a reaction vessel in a large volume was precisely controlled to cancel the heat evolved by the hydrolysis reaction of tetramethoxysilane and that consumed to melt ice cubes dispersed in the solution, resulting in large monolithic silica pieces with improved structural homogeneity. Homogeneity of the pore structure was confirmed, both on macro- and mesoscales, using SEM, mercury intrusion, and nitrogen adsorption/desorption measurements. Furthermore, the deviations in chromatographic performance were examined by evaluating multiple smaller monolithic columns prepared from the monolithic silica pieces cut from different parts of a large monolith. All the daughter columns thus prepared exhibited comparable performances to each other to prove the overall homogeneity of the mother monolith. Preliminary results on high-speed separation of peptides and proteins by the octadecylsilylated silica monolith of the above production have also been demonstrated.

DOI： 10.1002/jssc.201300123

Synthesis of Silver Nanoparticles Confined in Hierarchically Porous Monolithic Silica: A New Function in Aromatic Hydrocarbon Separations Reviewed

Yang Zhu, Kei Morisato, Wenyan Li, Kazuyoshi Kanamori, Kazuki Nakanishi

ACS APPLIED MATERIALS & INTERFACES Vol. 5 ( 6 ) page： 2118 - 2125 2013.3

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Silver nanoparticles (Ag NPs) have been homogeneously introduced into hierarchically porous monolithic silica columns with well-defined macropores and SBA-15-type hexagonally ordered mesopores by using ethanol as the mild reductant. Within the cylindrical silica mesopores treated with aminopropyl groups as the host, monocrystalline Ag NPs and nanorods are obtained after being treated in silver nitrate/ethanol solution at room temperature for different durations of reducing time. The loading of Ag NPs in the monolith can be increased to 33 wt % by the repetitive treatment, which also led to the formation of polycrystalline Ag nanorods in the mesopores. Although the bare silica column cannot separate aromatic hydrocarbons, good separation of those molecules by noncharged Ag NPs confined in the porous structure of the monolith has been for the first time demonstrated with the Ag NP-embedded silica column. The NP-embedded monolithic silica would be a powerful separation tool for hydrocarbons with different number, position, and configuration of unsaturated bonds.

DOI： 10.1021/am303163s

Macroporous SiO2 monoliths prepared via sol-gel process accompanied by phase separation Reviewed

Xing-Zhong Guo, Wen-Yan Li, Yang Zhu, Kazuki Nakanishi, Kazuyoshi Kanamori, Hui Yang

Wuli Huaxue Xuebao/ Acta Physico - Chimica Sinica Vol. 29 ( 3 ) page： 646 - 652 2013.3

Language：English Publishing type：Research paper (scientific journal)

Macroporous SiO2 monoliths were prepared via a sol-gel process accompanied by phase separation using a tetramethoxysilane (TMOS) precursor, 0.01 mol·L-1 HCl catalyst, propylene oxide (PO) gelation agent, and poly(ethylene oxide) (PEO, viscosity-averaged molecular weight (Mv): 10000) phase separation inducer. Monoliths were characterized by differential thermal analysis/thermogravimetry (DTA/ TG), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), mercury porosimetry, and nitrogen adsorption/desorption analysis (BET). The mechanism of the epoxide-mediated sol-gel reaction and PEO induced phase separation was discussed. The addition of PEO induced phase separation, and monolithic SiO2 with a cocontinuous macroporous skeletal structure was obtained at PEO/TMOS molar ratio of 0.0018. Monoliths had a narrow pore size distribution of 1-3 μm, surface area as high as 719 m2·g-1 and pore volume of 0.48 m3·g-1. This sol-gel transition is mediated by PO because of its strong nucleophilic properties and irreversible ring-opening reaction. Simultaneous phase separation is induced by PEO adsorbed on the SiO2 oligomers. © Editorial office of Acta Physico-Chimica Sinica.

DOI： 10.3866/PKU.WHXB201212252

New Li2FeSiO4-carbon monoliths with controlled macropores: effects of pore properties on electrode performance Reviewed

George Hasegawa, Mai Sannohe, Yuya Ishihara, Kazuyoshi Kanamori, Kazuki Nakanishi, Takeshi Abe

PHYSICAL CHEMISTRY CHEMICAL PHYSICS Vol. 15 ( 22 ) page： 8736 - 8743 2013

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Monolithic Li2FeSiO4-carbon composites with well-defined macropores have been prepared from the silica-based gels containing Li, Fe, and carbon sources. The macroporous precursor gels can be fabricated by the sol-gel method accompanied by phase separation. A fine control of the macropore size in the resultant composites has been achieved by controlling the macropore size of the precursor gels simply by adjusting the starting compositions. The effects of pore properties on Li insertion-extraction capabilities have been investigated by utilizing the resultant Li2FeSiO4-carbon composites as the cathode of lithium ion batteries. The electrodes prepared from the Li2FeSiO4-carbon composites with different macropore sizes exhibit significant differences in the charge-discharge properties. The results strongly suggest that the smaller macropore size (equal to the thinner macropore skeletons) and the presence of micro-and mesopores in the macropore skeletons (hierarchically porous structure) are desirable for a better electrode in the case of Li2FeSiO4, which has extremely low ionic and electrical conductivities.

DOI： 10.1039/c3cp50352f

Sol-gel synthesis of zinc ferrite-based xerogel monoliths with well-defined macropores Reviewed

Yasuki Kido, Kazuki Nakanishi, Kazuyoshi Kanamori

RSC ADVANCES Vol. 3 ( 11 ) page： 3661 - 3666 2013

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Starting from an aqueous solution, porous zinc ferrite-based xerogel monoliths have been prepared via a sol-gel route accompanied by phase separation mediated by propylene oxide in the presence of poly(acrylamide). The xerogels possess well-defined macropores, and the macroporous morphologies could be easily controlled (macropore size ranges from 0.55 to 1.29 mu m) by simply changing the starting composition. As-dried xerogel samples were amorphous under X-ray diffraction, while heat-treatment in air brought about the formation of spinel type ferrite phase, ZnFe2O4. Calcination under Ar atmosphere allowed the crystallization of various iron-based phases/carbon composites (Fe3O4, Fe1-delta O, Fe3N, Fe4N, Fe3C, and Fe). Samples heated under Ar flow exhibited hierarchical pore structures, including continuous macropores, in addition to mesopores and micropores embedded in the carbon-containing composite matrices.

DOI： 10.1039/c3ra22481c

Erratum: Hierarchically porous monoliths of oxygen-deficient anatase TiO<sub>2-x</sub> with electronic conductivity (RSC Advances (2013) DOI:10.1039/C3RA40545A) Reviewed

A. Kitada, G. Hasegawa, Y. Kobayashi, K. Miyazaki, T. Abe, K. Kanamori, K. Nakanishi, H. Kageyama

RSC Advances Vol. 3 ( 48 ) page： 26475- 2013

Hierarchically Porous Monoliths of Oxygen-deficient Anatase TiO2-x with Electronic Conductivity (vol 3, pg 7205, 2013) Reviewed

Atsushi Kitada, George Hasegawa, Yoji Kobayashi, Kohei Miyazaki, Takeshi Abe, Kazuyoshi Kanamori, Kazuki Nakanishi, Hiroshi Kageyama

RSC ADVANCES Vol. 3 ( 48 ) page： 26475 - 26475 2013

Layered double hydroxide (LDH)-based monolith with interconnected hierarchical channels: enhanced sorption affinity for anionic species Reviewed

Yasuaki Tokudome, Naoki Tarutani, Kazuki Nakanishi, Masahide Takahashi

JOURNAL OF MATERIALS CHEMISTRY A Vol. 1 ( 26 ) page： 7702 - 7708 2013

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Monolithic layered double hydroxides (LDHs) with interconnected channels have been expected to enhance sorption rate as well as increase accumulation of anions. Although powder molding can form easily-handled LDH compacts, interconnected channel formation therein has not been achieved. Herein, we demonstrate cm-scale monolithic LDH-based composites with interconnected hierarchical channels via a spontaneous sol-gel reaction. The synthesis was performed on Mg-Al hydrotalcite-type LDHs starting from metal chlorides aqueous/ethanolic solution with poly(ethylene oxide) incorporated. Addition of propylene oxide triggers a sol-gel reaction to form monolithic xerogels with a formula of [ Mg0.66Al0.33(OH)(2)Cl-0.33 center dot 2.92H(2)O]center dot 3.1Al(OH)(3). LDH crystals together with aluminum hydroxide crystals homogeneously build up gel skeletons with well-defined hierarchical channels. The interconnected channel in mm range (macrochannel) are formed as a phase-separated structure, whereas the channel in nm range (nanochannel) are as interstices of primary particles. The channel architectures are preserved in the course of rehydration process, affording enhanced sorption affinity for anion species in the process. Both of macro and mesochannels as well as high charge density of the obtained LDHs (Mg/Al = 2.0) contribute to enhanced anion sorption in the monolithic xerogels. The materials obtained here opens up applications of high performance adsorbents and ion-storage free from diffusion limitation.

DOI： 10.1039/c3ta11110e

Hierarchically porous monoliths of oxygen-deficient anatase TiO2-x with electronic conductivity Reviewed

Atsushi Kitada, George Hasegawa, Yoji Kobayashi, Kohei Miyazaki, Takeshi Abe, Kazuyoshi Kanamori, Kazuki Nakanishi, Hiroshi Kageyama

RSC ADVANCES Vol. 3 ( 20 ) page： 7205 - 7208 2013

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

We report an electrically conducting oxygen-deficient anatase TiO2-x monolith with macro/meso/micro trimodal pores, prepared by reducing insulating porous TiO2 monoliths at low temperature. Without adding any conductive materials, the TiO2-x monolith itself was electrically conducting enough for lithium insertion, potentially opening a new avenue for carbon-free electrode materials.

DOI： 10.1039/c3ra40545a

New Insights into the Relationship between Micropore Properties, Ionic Sizes, and Electric Double-Layer Capacitance in Monolithic Carbon Electrodes Reviewed

George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi, Takeshi Abe

JOURNAL OF PHYSICAL CHEMISTRY C Vol. 116 ( 50 ) page： 26197 - 26203 2012.12

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

The effects of the pore properties and the ionic sizes on the electric double-layer capacitances have been investigated by using the monolithic carbon electrodes with different pore properties. The carbon monoliths with high surface areas which possess homogeneous pore properties in the whole monoliths were prepared from the bridged-polysilsesquioxane gels via the nanophase extraction technique. The detailed investigations of the pore properties of the carbon monoliths were conducted by the nitrogen physisorption measurement as well as the mercury porosimetry. The electrochemical property of each monolithic carbon electrode was examined by the cyclic voltammetry in the different aqueous electrolytes in order to investigate the effects of the ionic sizes. These fundamental analyses have provided new insights into the efficient micropore sizes in each electrolyte for the superior electric double-layer capacitors.

DOI： 10.1021/jp309010p

Structure and properties of polymethylsilsesquioxane aerogels synthesized with surfactant n-hexadecyltrimethylammonium chloride Reviewed

Gen Hayase, Kazuyoshi Kanamori, Kazuki Nakanishi

MICROPOROUS AND MESOPOROUS MATERIALS Vol. 158 page： 247 - 252 2012.8

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Structure and physical properties of monolithic polymethylsilsesquioxane (PMSQ CH3SiO1.5) aerogels have been systematically examined with varied starting compositions using a sol-gel system containing surfactant n-hexadecyltrimethylammonium chloride (CTAC). The precursor methyltrimethoxysilane (MTMS) undergoes hydrolysis and polycondensation under an acid-base two-step reaction to obtain uniform gels as a one-pot reaction. To compare the samples, each factor of starting composition, such as amount of CTAC, concentration of aqueous acetic acid solution, volume of solvent and amount of urea, is independently varied. With appropriate concentrations of surfactant CTAC, the aerogels with high light transmittance (at 550 nm) are obtained, owing to the effective suppression of macroscopic phase separation. Acid-base catalysts, acetic acid and urea also impose significant effects on the properties of obtained aerogels including their molecular-level structures. The aerogel with 91% of light transmittance was obtained under an optimized condition. The lowest density of the PMSQ aerogel in this system reaches 0.045 g cm(-3). (C) 2012 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.micromeso.2012.03.049

Synthesis of Monolithic Hierarchically Porous Iron-Based Xerogels from Iron(III) Salts via an Epoxide-Mediated Sol-Gel Process Reviewed

Yasuki Kido, Kazuki Nakanishi, Akira Miyasaka, Kazuyoshi Kanamori

CHEMISTRY OF MATERIALS Vol. 24 ( 11 ) page： 2071 - 2077 2012.6

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Various iron-based polycrystalline monoliths, Fe3O4, iron, and Fe3C, with hierarchically distributed pores have been synthesized from ionic precursors using a sol-gel process accompanied by phase separation. Propylene oxide acts as a proton scavenger to increase pH moderately and uniformly in a reaction solution, which leads to homogeneous gelation. On the other hand, poly(acrylamide) works as a phase separation inducer as well as a precipitation inhibitor. Appropriate choice of iron precursor, solvent, polymer, and epoxide allowed the formation of iron(III)-based xerogels with cocontinuous macroporous structures. The dried gels were amorphous, whereas heating in air above 300 degrees C led to the formation of alpha-Fe2O3. Calcination under an inert condition above 400 degrees C formed Fe3O4, iron, and Fe3C without collapse of macrostructures. Examination has been carried out using SEM, TG-DTA, FT-IR, Hg diffraction, and N-2 adsorption-desorption.

DOI： 10.1021/cm300495j

Facile preparation of macroporous graphitized carbon monoliths from iron-containing resorcinol-formaldehyde gels Reviewed

George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi

MATERIALS LETTERS Vol. 76 page： 1 - 4 2012.6

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

In this report, we demonstrate the facile preparation of macroporous monolithic materials based on graphitized carbon by utilizing catalytic graphitization at relatively low temperature (1000 degrees C). The precursor polymer, macroporous resorcinol-formaldehyde (RF) xerogel, can be obtained without any surfactants or polymeric additives in water/ethanol mixed solvent via the sol-gel reaction accompanied by phase separation. The use of iron chloride as an acid catalyst for polymerization provides the RF monoliths incorporated with Fe, which catalyzes the graphitization. The effects of the starting composition on the morphologies of the resultant RF gels and the characteristics of the graphitized carbon monoliths have been discussed. (C) 2012 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.matlet.2012.02.069

Pore properties of hierarchically porous carbon monoliths with high surface area obtained from bridged polysilsesquioxanes Reviewed

George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi

MICROPOROUS AND MESOPOROUS MATERIALS Vol. 155 page： 265 - 273 2012.6

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Hierarchically porous carbon monoliths with high specific surface area have been prepared via a nano-phase extraction technique from carbon/silica composites which had been prepared from arylene-bridged polysilsesquioxanes. The nano-sized silica phase developed in the composite has been removed to increase micropores, resulting in a similar effect to thermal activation of carbons. The resultant carbons are expected to possess homogeneously distributed micropores. Here we report the changes of the pore characteristics through the synthesis process by the nitrogen adsorption-desorption method and mercury porosimetry. In particular, the growth of silica phase in carbon/silica composites at different temperatures has been characterized by the micropore analysis using the Horvath-Kawazoe method. (C) 2012 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.micromeso.2012.02.001

Development of flexible porous materials from organotrialkoxysilanes Reviewed

Kazuyoshi Kanamori, Gen Hayase, Kazuki Nakanishi

Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy Vol. 59 ( 6 ) page： 320 - 325 2012.6

Language：Japanese Publishing type：Research paper (scientific journal)

Organosiloxane (RnSiO(4-n)/2) gels can be prepared from organoalkoxysilanes using the sol-gel process. In general,however, formation of uniform networks from these precursors is strongly inhibited due to cyclization reactions. In addition, phase separation of hydrophobic condensates from polar solvent leads to inhomogeneous gels in these systems. A careful control of the hydrolysis and polycondensation reactions is therefore required to obtain a monolithic gel with desired properties. We have been trying to control the sol-gel reactions as well as phase separation in these systems to obtain unique porous materials particularly from methyltrimethoxysilane(MTMS) and dimethyldimethoxysilane (DMDMS). Flexible aerogels and xerogels based on the methylsiloxane networks are discussed.

DOI： 10.2497/jjspm.59.320

Flower-like surface modification of titania materials by lithium hydroxide solution Reviewed

George Hasegawa, Kazuyoshi Kanamori, Yoshihiro Sugawara, Yuichi Ikuhara, Kazuki Nakanishi

JOURNAL OF COLLOID AND INTERFACE SCIENCE Vol. 374 ( 1 ) page： 291 - 296 2012.5

Language：English Publishing type：Research paper (scientific journal) Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE

Surface modification of titania materials to give flower-like structures has been achieved simply by the treatment in lithium hydroxide aqueous solution under mild conditions. The flower-like structured materials were characterized by X-ray diffraction, thermogravimetric analysis, and Raman scattering. The analyses indicate that the flower-like materials are composed of layered hydrous lithium titanate. It is suggested that the unique intercalation behavior of lithium ions into titania allows dissolution and re-precipitation of titania to form the flower-like structure. The obtained flower-like structure can be retained up to 700 degrees C, while the crystal phase transforms into Li4Ti5O12. (C) 2012 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.jcis.2012.02.002

New Monolithic Capillary Columns with Well-Defined Macropores Based on Poly(styrene-co-divinylbenzene) Reviewed

George Hasegawa, Kazuyoshi Kanamori, Norio Ishizuka, Kazuki Nakanishi

ACS APPLIED MATERIALS & INTERFACES Vol. 4 ( 5 ) page： 2343 - 2347 2012.5

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Macroporous polymer monoliths based on poly(styrene-co-divinylbenzene) with varied styrene/divinylbenzene ratios have been prepared by organotellurium-mediated living radical polymerization. The well-defined cocontinuous macroporous structure can be obtained by polymerization-induced spinodal decomposition, and the pore structures are controlled by adjusting the starting composition. The separation efficiency of small molecules (alkylbenzenes) in the obtained monoliths has been evaluated in the capillary format by high-performance liquid chromatography (HPLC) under the isocratic reversed-phase mode. Baseline separations of these molecules with a low pressure drop (similar to 2 MPa) have been achieved because of the well-defined macropores and to the less-heterogeneous cross-linked networks.

DOI： 10.1021/am300552q

New flexible aerogels and xerogels derived from di- and trifunctional organosilanes co-precursors

Hayase Gen, Kanamori Kazuyoshi, Nakanishi Kazuki

Preprints of Annual Meeting of The Ceramic Society of Japan<br>Preprints of Fall Meeting of The Ceramic Society of Japan Vol. 2012 ( 0 ) page： 280-280 2012

Language：English Publishing type：Research paper (scientific journal)

We report new flexible “marshmallow-like” aerogels and xerogels with a bendable feature from the di- and trifunctional organosilane co-precursor systems. A 2-step acid/base sol–gel process and surfactant are employed to control the phase separation of the hydrophobic networks, which give porous monolithic gels. The obtained gels from methyltrimethoxysilane (MTMS) and dimethyldimethoxysilane (DMDMS) become softer and more flexible with increasing DMDMS fractions.

DOI： 10.14853/pcersj.2012S.0.280.0

612 Synthesis of Macroporous Layered Double Hydroxide with a Bulk Form for High Performance Ion Exchange Reaction

TOKUDOME Yasuaki, TARUTANI Naoki, TAKAHASHI Masahide, NAKANISHI Kazuki

Vol. 61 page： 159-160 2012

Evolution of Mesopores in Monolithic Macroporous Ethylene-Bridged Polysilsesquioxane Gels Incorporated with Nonionic Surfactant Reviewed

Atsushi Mushiake, Kazuyoshi Kanamori, Kazuki Nakanishi

INTERNATIONAL JOURNAL OF POLYMER SCIENCE Vol. 2012 2012

Language：English Publishing type：Research paper (scientific journal) Publisher：HINDAWI PUBLISHING CORPORATION

By combining the micellar templating in nanometer scale with the polymerization-induced phase separation in micrometer scale, ethylene-bridged polysilsesquioxane gels with hierarchical macropores and mesopores are prepared. The difference of mesopore structures depending on the method of the solvent removal has been observed by the X-ray diffraction and the nitrogen adsorption-desorption measurements. During the hydrothermal treatment under the basic condition, the reorganization of the polysilsesquioxane gel network occurred differently depending on the alkoxy group contained in the precursors. From Si-29 CP/MAS NMR measurements, it was revealed that the crosslinking density of the hydrothermally treated gels was increased so that the highly ordered mesostructure of the wet gel could be preserved even after the evaporative drying of solvent.

DOI： 10.1155/2012/460835

2011 Donald R. Ulrich Awards Reviewed

K. Nakanishi

Journal of Sol-Gel Science and Technology page： 1 - 2 2012

Selective Preparation of Macroporous Conductive Oxide Ti<SUB><I>n</I></SUB>O<SUB>2<I>n</I>-1</SUB> (<I>n</I> = 2, 3, 4, 6) Monoliths Reviewed

Kitada Atsushi, Hasegawa George, Kobayashi Yoji, Kanamori Kazuyoshi, Nakanishi Kazuki, Kageyama Hiroshi

Preprints of Annual Meeting of The Ceramic Society of Japan<br>Preprints of Fall Meeting of The Ceramic Society of Japan Vol. 2012 ( 0 ) page： 526 - 526 2012

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：The Ceramic Society of Japan

We report selective preparation of macroporous monoliths of conductive titanium oxides Ti<SUB><I>n</I></SUB>O<SUB>2<I>n</I>-1</SUB> (<I>n</I> = 2, 3, 4, 6) as a single phase, by reducing a macroporous TiO<SUB>2</SUB> monolith using zirconium getter. All the reduced monoliths have uniform pore size distribution, retaining that of the precursor TiO<SUB>2</SUB> monoliths. Furthermore, their bulk densities of 1.8 g cm<SUP>-3</SUP> are about half smaller and their porosities of 60% are about three times larger than that of commercial porous Ebonex (shaped conductive Ti<SUB><I>n</I></SUB>O<SUB>2<I>n</I>-1</SUB>). The obtained Ti<SUB><I>n</I></SUB>O<SUB>2<I>n</I>-1</SUB> (<I>n</I> = 2, 3, 4, 6) macroporous monoliths could find their applications as electrodes for many electrochemical reactions.

DOI： 10.14853/pcersj.2012S.0.526.0

Role of block copolymer surfactant on the pore formation in methylsilsesquioxane aerogel systems Reviewed

Masayuki Kurahashi, Kazuyoshi Kanamori, Kazuyuki Takeda, Hironori Kaji, Kazuki Nakanishi

RSC ADVANCES Vol. 2 ( 18 ) page： 7166 - 7173 2012

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Transparent and low-density methylsilsesquioxane (MSQ, CH3SiO1.5) aerogels can be obtained solely from methyltrimethoxysilane (MTMS) by a one-pot two-step process under the co-presence of surfactant. In the present study, we have systematically investigated the effects of the molecular structure of triblock copolymer-type nonionic surfactants PEO-b-PPO-b-PEO (PEO and PPO denote poly(ethylene oxide) and poly(propylene oxide) units, respectively) on the properties of the resultant MSQ aerogels. Macroscopic phase separation of hydrophobic MSQ networks from polar solvent occurs when no surfactant is employed, which results in macroporous opaque aerogels. In contrast, a co-presence of appropriate surfactant effectively suppresses the phase separation and yields transparent aerogels after supercritical drying. By employing various surfactants having different molecular weight and PO/EO ratio, the mechanism of suppression of phase separation or pore formation is discussed in detail. In situ H-1 NMR suggests that the PO units of surfactant interact with the hydrophobic MSQ network enriched with methyl groups and make the MSQ network hydrophilic by extending EO chains toward the aqueous solvent in the late phase of gelation, until which hydrogen bonding dominates between the Si-OH groups of polymerizing MSQ and the ether oxygens of the EO unit. Through the comprehensive understanding of the role of surfactant, the strategy for rational design of MSQ aerogels materials has become developable.

DOI： 10.1039/c2ra20799k

Facile Preparation of Monolithic LiFePO4/Carbon Composites with Well-Defined Macropores for a Lithium-Ion Battery Reviewed

George Hasegawa, Yuya Ishihara, Kazuyoshi Kanamori, Kohei Miyazaki, Yuki Yamada, Kazuki Nakanishi, Takeshi Abe

CHEMISTRY OF MATERIALS Vol. 23 ( 23 ) page： 5208 - 5216 2011.12

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

A novel and facile method for the preparation of monolithic LiFePO4/carbon composites with well-defined macropores has been developed. The precursor macroporous gels consisting of inorganic networks as well as organic polymers were fabricated by the epoxide-mediated sol-gel method accompanied by phase separation. The inorganic-organic hybrid gels were calcined under an inert atmosphere, resulting in LiFePO4/carbon monoliths. The influence of the starting compositions on the gel morphologies has been investigated, and the constituents of the gel network were discussed. The reaction mechanism of the crystallization of LiFePO4 from green bodies during calcination has also been investigated by thermal analysis, X-ray diffraction, and Raman scattering. In addition, the electrochemical properties of the resultant LiFePO4/carbon composites were examined by the charge-discharge test.

DOI： 10.1021/cm2021438

Macroporous carbon monoliths with large surface area for electric double-layer capacitor

George Hasegawa, Mami Aoki, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada, Kiyoharu Tadanaga

Materials Research Society Symposium Proceedings Vol. 1304 page： 38 - 43 2011.12

Language：English Publishing type：Research paper (international conference proceedings)

Macro/meso/microporous carbon monoliths doped with sulfur have been prepared from sulfonated polydivinylbenzene networks followed by the activation with CO 2 resulted in the activated carbon monoliths with high surface area of 2400 m 2 g -1. The monolithic electrode of the activated carbon shows remarkably high specific capacitance (175 F g -1 at 5 mV s -1 and 206 F g -1 at 0.5 A g -1). © 2011 Materials Research Society.

DOI： 10.1557/opl.2011.604

Synthesis of new flexible aerogels from di- and trifunctional organosilanes

Gen Hayase, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada

Materials Research Society Symposium Proceedings Vol. 1306 page： 68 - 73 2011.12

Language：English Publishing type：Research paper (international conference proceedings)

Recent years, although silica aerogels are expected to be the promising material for energy savings, the lack of mechanical strength prevents from commercial applications such as to low-density thermal insulators. To improve mechanical properties, methyltrimethoxysilane (MTMS) and dimethyldimethoxysilane (DMDMS) are used in this study as the co-precursor of aerogels because the network becomes flexible due to the relatively low cross-linking density and to the unreacted methyl groups. Because of the strong hydrophobicity of MTMS/DMDMS-derived condensates, phase separation occurs in aqueous sol and must be suppressed to obtain uniform and monolithic gel. We employed surfactant n-hexadecyltrimethylammonium chloride (CTAC) in starting compositions to control phase separation during a 2-step acid/base sol-gel reaction. By changing the starting composition, various microstructures of pores are obtained. In the uniaxial compression test, the aerogel showed high flexibility and spring-back to the original shape after removing the stress. © 2011 Materials Research Society.

DOI： 10.1557/opl.2011.216

Organosiloxane transparent aerogels and hierarchically porous monoliths

Yasunori Kodera, Gen Hayase, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada

Materials Research Society Symposium Proceedings Vol. 1306 page： 54 - 59 2011.12

Language：English Publishing type：Research paper (international conference proceedings)

A transition of porous structures in monolithic poly(methylsilsesquioxane) (PMSQ, CH 3SiO 1.5) gels from uniform mesopores to hierarchical pore structures consisting of macro- and mesopores, has been investigated using a sol-gel system containing surfactant Pluronic F127. A broad variation of porous morphology is controlled by changing the concentration of F127. Sufficient concentrations of F127 inhibit the occurrence of macroscopic phase separation of hydrophobic PMSQ condensates and lead to well-defined mesoporous transparent aerogels with high specific pore volume. Mesopores are developed through microscopic phase separation of PMSQ colloid-surfactant complexes in the solvent. Macroscopic phase separation regulates well-defined macropores in the micrometer range on decreasing concentrations of F127, in which microscopic phase separation concurrently takes place in the PMSQ-rich gelling phase after the onset of macroscopic phase separation. Monolithic PMSQ gels with hierarchical macro- and mesopore structures are consequently obtained. © 2011 Materials Research Society.

DOI： 10.1557/opl.2011.96

Hierarchically Porous Materials by Phase Separation: Monoliths

Kazuki Nakanishi

Hierarchically Structured Porous Materials: From Nanoscience to Catalysis, Separation, Optics, Energy, and Life Science page： 241 - 267 2011.11

Hierarchically Structured Porous Materials: Application to Separation Sciences

Kazuki Nakanishi

Hierarchically Structured Porous Materials: From Nanoscience to Catalysis, Separation, Optics, Energy, and Life Science page： 517 - 529 2011.11

New hierarchically porous titania monoliths for chromatographic separation media Reviewed

George Hasegawa, Kei Morisato, Kazuyoshi Kanamori, Kazuki Nakanishi

JOURNAL OF SEPARATION SCIENCE Vol. 34 ( 21 ) page： 3004 - 3010 2011.11

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-BLACKWELL

Separation media based on hierarchically porous titania (TiO(2)) monoliths for high-performance liquid chromatography (HPLC) have been successfully fabricated by the sol-gel process of titanium alkoxide in a mild condition utilizing a chelating agent and mineral salt. The as-gelled TiO(2) monoliths were subjected to a simple solvent exchange process from ethanol (EtOH) to H(2)O followed by drying and calcination. The resultant monolithic TiO(2) columns consist of anatase crystallites with the typical specific surface area of more than 200 m(2)/g. The resultant monolithic TiO(2) column calcined at 200 and 400 degrees C exhibited a good separation performance for organophosphates as well as for polar benzene derivatives in the normal-phase mode.

DOI： 10.1002/jssc.201100538

Other Link： http://orcid.org/0000-0002-8069-4780

Preparation of Hierarchically Porous Nanocrystalline CaTiO3, SrTiO3 and BaTiO3 Perovskite Monoliths Reviewed

Olim Ruzimuradov, George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi

JOURNAL OF THE AMERICAN CERAMIC SOCIETY Vol. 94 ( 10 ) page： 3335 - 3339 2011.10

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-BLACKWELL

Hierarchically porous nanocrystalline CaTiO3, SrTiO3, and BaTiO3 ceramics have been produced by impregnating corresponding alkaline-earth metal ions into preformed macroporous TiO2 monoliths in a solution containing urea, followed by calcination. The macroporous TiO2 had been obtained via the sol-gel process accompanied by phase separation utilizing a chelating agent, ethyl acetylacetonate (EtAcAc), together with mineral salt and ammonium chloride, to decrease the reactivity of titanium alkoxide. Formations of CaCO3, SrCO3, and BaCO3 on the surface of TiO2 monoliths are promoted by CO2 generated by the concurrent two processes during impregnation; hydrolysis, and decarbonation of the chelating agent EtAcAc, and hydrolysis of urea at 60 degrees C. The latter also raises pH of the impregnating solution which further promotes the mineralization of the carbonate salts. Calcination of the resultant monolithic composite of metal carbonate/TiO2 allows the crystallization of metal titanate. The addition of urea to the impregnating solution is found to be an effective strategy for the formation of perovskite monoliths by the impregnation process. This study provides a versatile approach to the preparation of hierarchically porous titania-based perovskites.

DOI： 10.1111/j.1551-2916.2011.04613.x

Fabrication of highly crosslinked methacrylate-based polymer monoliths with well-defined macropores via living radical polymerization Reviewed

George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi, Shigeru Yamago

POLYMER Vol. 52 ( 21 ) page： 4644 - 4647 2011.9

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCI LTD

Rigid methacrylate-based polymer monoliths with well-defined macropores have been synthesized from glycerol 1,3-dimethacrylate (GDMA) and trimethylolpropane trimethacrylate (Trim) by organotellurium-mediated living radical polymerization. In each system, poly(ethylene oxide) induced spinodal decomposition with the progress of polymerization of COMA or Trim. Well-defined macroporous structure can be tailored by fixing the bicontinuous structure by the sol gel transition. Both polymer monoliths possessed macropores with narrow size distributions and the macropore size can be controlled simply by varying the amount of poly(ethylene oxide). Starting from GDMA, polymer monoliths with unimodal macropores can be obtained due to the collapse of micro- and mesopores, which were originally embedded in macropore skeletons, by large shrinkage during drying. In contrast, starting from Trim, the obtained polymer monoliths include not only macropores but also micro- and mesopores, which lead to high specific surface area (470 m(2) g(-1)), owing to the higher crosslinking density. (C) 2011 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.polymer.2011.08.028

Facile preparation of monolithic magnesium titanates with hierarchical porosity Reviewed

Olim N. Ruzimuradov, George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN Vol. 119 ( 1390 ) page： 440 - 444 2011.6

Language：English Publishing type：Research paper (scientific journal) Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

In this study, we for the first time came up with a facile approach to fabricate hierarchically porous nano-crystalline monolithic magnesium titanates (MgTi2O5/MgTiO3) by impregnating magnesium chloride into hierarchically porous TiO2 monolith in a solution containing urea followed by appropriate heat-treatment. The formation of porous MgTi2O5/MgTiO3 monolithic materials took place by the solid-state reaction between original TiO2 networks and precipitated MgCO3. The MgCO3 is precipitated within the TiO2 wet gel by the reaction between impregnated Mg2+ and CO2, which is produced by hydrolysis and decarbonation of chelating agent in the TiO2 wet gels and by the hydrolysis of urea at 60 degrees C. The resultant porous magnesium titanates retained narrow macropore size distribution centered at the diameter similar to 1 mu m. These porous monoliths produced by impregnation, a facile and the low-cost method, are expected to open various engineering applications owing to the low thermal expansion coefficients and high chemical and physical stabilities. (C)2011 The Ceramic Society of Japan. All rights reserved

DOI： 10.2109/jcersj2.119.440

Performance evaluation of long monolithic silica capillary columns in gradient liquid chromatography using peptide mixtures Reviewed

Hamed Eghbali, Koen Sandra, Frederik Detobel, Frederic Lynen, Kazuki Nakanishi, Pat Sandra, Gert Desmet

JOURNAL OF CHROMATOGRAPHY A Vol. 1218 ( 21 ) page： 3360 - 3366 2011.5

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

A systematic study is reported on the performance of long monolithic capillary columns in gradient mode. Using a commercial nano-LC system, reversed-phase peptide separations obtained through UV-detection were conducted. The chromatographic performance, in terms of conditional peak capacity and peak productivity, was investigated for different gradient times (varying between 90 and 1320 min) and different column lengths (0.25, 1, 2 and 4m) all originating from a single 4m long column. Peak capacities reaching values up to n = 10(3) were measured in case of the 4 m long column demonstrating the high potential of these long monoliths for the analysis of complex biological mixtures, amongst others. In addition, it was found that the different column fragments displayed similar flow resistance as well as consistent chromatographic performance in accordance with chromatographic theory indicating that the chromatographic bed of the original 4 m long column possessed a structural homogeneity over its entire length. (C) 2010 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.chroma.2010.10.045

Transition from transparent aerogels to hierarchically porous monoliths in polymethylsilsesquioxane sol-gel system Reviewed

Kazuyoshi Kanamori, Yasunori Kodera, Gen Hayase, Kazuki Nakanishi, Teiichi Hanada

JOURNAL OF COLLOID AND INTERFACE SCIENCE Vol. 357 ( 2 ) page： 336 - 344 2011.5

Language：English Publishing type：Research paper (scientific journal) Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE

A transition from hierarchical pore structures (macro- and meso-pores) to uniform mesopores in monolithic polymethylsilsesquioxane (PMSQ CH(3)SiO(1.5)) gels has been investigated using a sol-gel system containing surfactant Pluronic F127. The precursor methyltrimethoxysilane (MTMS) undergoes an acid/base two-step reaction, in which hydrolysis and polycondensation proceed in acidic and basic aqueous media, respectively, as a one-pot reaction. Porous morphology is controlled by changing the concentration of F127. Sufficient concentrations of F127 inhibit the occurrence of micrometer-scale phase separation (spinodal decomposition) of hydrophobic PMSQ condensates and lead to well-defined mesoporous transparent aerogels with high specific pore volume as a result of the colloidal network formation in a large amount of solvent. Phase separation regulates well-defined macropores in the micrometer range on decreasing concentrations of F127. In the PMSQ-rich gelling domain formed by phase separation, the PMSQ colloidal network formation forms mesopores, leading to monolithic PMSQ gels with hierarchical macro- and meso-pore structures. Mesopores in these gels do not collapse on evaporative drying owing to the flexible networks and repulsive interactions of methyl groups in PMSQ. (C) 2011 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.jcis.2011.02.027

Monolithic silica rod columns for high-efficiency reversed-phase liquid chromatography Reviewed

Shota Miyazaki, Masakazu Takahashi, Masayoshi Ohira, Hiroyuki Terashima, Kei Morisato, Kazuki Nakanishi, Tohru Ikegami, Kanji Miyabe, Nobuo Tanaka

JOURNAL OF CHROMATOGRAPHY A Vol. 1218 ( 15 ) page： 1988 - 1994 2011.4

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Chromatographic properties of a new type of monolithic silica rod columns were examined. Silica rod columns employed for the study were prepared from tetramethoxysilane, modified with octadecylsilyl moieties, and encased in a stainless-steel protective column with two polymer layers between the silica and the stainless-steel tubing. A 25 cm column provided up to 45,000 theoretical plates for aromatic hydrocarbons, or a minimum plate height of about 5.5 mu m, at optimum linear velocity of ca. 2.3 mm/s and back pressure of 7.5 MPa in an acetonitrile-water (80/20, v/v) mobile phase at 40 degrees C. The permeability of the column was similar to that of a column packed with 5 mu m particles, with K-F about 2.4 x 10(-14) m(2) (based on the superficial linear velocity of the mobile phase), while the plate height value equivalent to that of a column packed with 2.5 mu m particles. Generation of 80,000-120,000 theoretical plates was feasible with back pressure below 30 MPa by employing two or three 25 cm columns connected in series. The use of the long columns enabled facile generation of large numbers of theoretical plates in comparison with conventional monolithic silica columns or particulate columns. Kinetic plot analysis indicates that the monolithic columns operated at 30 MPa can provide faster separations than a column packed with totally porous 3-mu m particles operated at 40 MPa in a range where the number of theoretical plates (N) is greater than 50,000. (C) 2010 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.chroma.2010.11.032

Synthesis of hierarchical macro/mesoporous dicalcium phosphate monolith via epoxide-mediated sol-gel reaction from ionic precursors Reviewed

Yasuaki Tokudome, Akira Miyasaka, Kazuki Nakanishi, Teiichi Hanada

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 57 ( 3 ) page： 269 - 278 2011.3

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Starting from calcium chloride dihydrate (CaCl(2)center dot 2H(2)O), phosphoric acid (H(3)PO(4)), and poly(acrylic acid) (PAA) dissolved in a mixture of water and methanol (MeOH), dicalcium phosphate anhydrous (DCPA, CaHPO(4)) monoliths with co-continuous macropores and mesopores have been synthesized by the addition of propylene oxide. Macropores are formed as a result of phase separation, while mesopores as interstices between primary particles with the size of ca. 30 nm. Propylene oxide acts as a proton scavenger and leads to moderate pH increase in a reaction solution, which brings about gelation in several minutes. On the other hand, PAA acts as a crystal growth inhibitor as well as a phase separation inducer. The extensive crystal growth of DCPA is hindered by the addition of PAA which allows morphological control of the structure in micrometer range. Fourier transform infrared spectroscopy indicates that PAA and DCPA form composite via interaction between the carboxyl groups and the surface of crystals, and together form gel phase. The solvent phase, which is converted to macropores after evaporative drying, is mainly comprised of solvent. The degree of supersaturation in a reaction solution considerably influence on the crystallization process, and thereby, influences on the porous structure in nano- and micrometer ranges.

DOI： 10.1007/s10971-010-2184-y

Microscopic Characterizations Reviewed

Haruko Saito, Kazuyoshi Kanamori, Kazuki Nakanishi

Monolithic Silicas in Separation Science: Concepts, Syntheses, Characterization, Modeling and Applications, First Edition page： 81 - 102 2011.1

Synthesis Concepts and Preparation of Silica Monoliths Reviewed

Kazuki Nakanishi

Monolithic Silicas in Separation Science: Concepts, Syntheses, Characterization, Modeling and Applications, First Edition page： 11 - 33 2011.1

(3-Mercaptopropyl)trimethoxysilane-derived Porous Gel Monolith via Thioacetal Reaction-Assisted Sol-Gel Route Reviewed

S. Ito, M. Nishi, K. Kanamori, K. Nakanishi, T. Kurahashi, S. Matsubara, Y. Shimotsuma, K. Miura, K. Hirao

3RD INTERNATIONAL CONGRESS ON CERAMICS (ICC): NOVEL CHEMICAL PROCESSING SOL-GEL AND SOLUTION-BASED PROCESSING Vol. 18 ( SYMPOSIUM 2A ) 2011

Language：English Publishing type：Research paper (international conference proceedings) Publisher：IOP PUBLISHING LTD

Porous gel monolith was synthesized by reacting (3mercaptopropyl)trimethoxysilane (MPTMS) with acetone on acidic conditions. It is known that MPTMS itself is difficult to turn into gel on acidic conditions and instead oligomers are obtained owing to the large mercaptopropyl group. In our system, the gels were obtained since acetone worked as a cross-linker via thioacetal reaction. Additionally, Au ions were selectively adsorbed on the obtained gel. When an obtained white gel was soaked in a chloroauric acid solution, the gel turned brown and was getting dark depending on the soaked time; on the other hand, the color of the solution turned from yellow to colorless.

DOI： 10.1088/1757-899X/18/3/032003

Other Link： http://orcid.org/0000-0002-8069-4780

Pore Structure and Mechanical Properties of Poly(methylsilsesquioxane) Aerogels Reviewed

Kanamori K., Hayase G., Nakanishi K., Hanada T.

3RD INTERNATIONAL CONGRESS ON CERAMICS (ICC): NOVEL CHEMICAL PROCESSING SOL-GEL AND SOLUTION-BASED PROCESSING Vol. 18 2011

Hierarchically Porous Carbon Monoliths with High Surface Area from Bridged Poly(silsesquioxane) without Thermal Activation Process Reviewed

G. Hasegawa, K. Kanamori, K. Nakanishi, T. Hanada

3RD INTERNATIONAL CONGRESS ON CERAMICS (ICC): NOVEL CHEMICAL PROCESSING SOL-GEL AND SOLUTION-BASED PROCESSING Vol. 18 ( SYMPOSIUM 2A ) 2011

Language：English Publishing type：Research paper (international conference proceedings) Publisher：IOP PUBLISHING LTD

Hierarchically porous carbon monoliths with high specific surface areas have been fabricated by removing nano-sized silica phase from carbon/silica composites pyrolyzed from bridged poly(silsesquioxane). This activation method improves the homogeneity between inner and outer parts of the monoliths compared to the conventional thermal activation methods.

DOI： 10.1088/1757-899X/18/3/032005

Other Link： http://orcid.org/0000-0002-8069-4780

Synthesis of new flexible aerogels from MTMS/DMDMS via ambient pressure drying Reviewed

Gen Hayase, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada

IOP Conference Series: Materials Science and Engineering Vol. 18 page： 032013 2011

Language：English Publishing type：Research paper (international conference proceedings)

Although silica aerogel is expected to be the material for energy savings, the lack of the strength prevents from commercial applications such as to low-density thermal insulators and acoustic absorbents. To improve mechanical properties, methyltrimethoxysilane (MTMS) and dimethyldimethoxysilane (DMDMS) are used as the co-precursor of aerogels in this study because the network becomes flexible due to the relatively low cross-linking density and to the unreacted methyl groups. Because of the strong hydrophobicity of MTMS/DMDMS-derived condensates, phase separation occurs, which must be suppressed in aqueous sol to obtain uniform and monolithic gel networks. We also employed surfactant n-hexadecyltrimethylammonium chloride (CTAC) in starting compositions to control phase separation during a 2-step acid/base sol-gel reaction. By changing the starting composition, various microstructures of pores are obtained. In the uniaxial compression test, the aerogel showed high flexibility and spring-back to the original shape after removing the stress.

DOI： 10.1088/1757-899X/18/3/032013

Monolithic electrode for electric double-layer capacitors based on macro/meso/microporous S-Containing activated carbon with high surface area Reviewed

George Hasegawa, Mami Aoki, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada, Kiyoharu Tadanaga

JOURNAL OF MATERIALS CHEMISTRY Vol. 21 ( 7 ) page： 2060 - 2063 2011

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Macro/meso/microporous carbon monoliths doped with sulfur have been prepared from sulfonated poly(divinylbenzene) networks followed by the activation with CO2 resulted in the activated carbon monoliths with high surface area of 2400 m(2) g(-1). The monolithic electrode of the activated carbon shows remarkably high specific capacitance (175 F g(-1) at 5 mV s(-1) and 206 F g(-1) at 0.5 A g(-1)).

DOI： 10.1039/c0jm03793a

New flexible aerogels and xerogels derived from methyltrimethoxysilane/dimethyldimethoxysilane co-precursors Reviewed

Gen Hayase, Kazuyoshi Kanamori, Kazuki Nakanishi

JOURNAL OF MATERIALS CHEMISTRY Vol. 21 ( 43 ) page： 17077 - 17079 2011

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

We report new flexible "marshmallow-like'' aerogels and xerogels with a bendable feature from the methyltrimethoxysilane (MTMS) and dimethyldimethoxysilane (DMDMS) co-precursor systems. A 2-step acid/base sol-gel process and surfactant are employed to control the phase separation of the hydrophobic networks, which give porous monolithic gels. The obtained gels become softer and more flexible with increasing DMDMS fractions.

DOI： 10.1039/c1jm13664j

In situ SAXS observation on metal-salt-derived alumina sol-gel system accompanied by phase separation Reviewed

Yasuaki Tokudome, Kazuki Nakanishi, Kazuyoshi Kanamori, Teiichi Hanada

JOURNAL OF COLLOID AND INTERFACE SCIENCE Vol. 352 ( 2 ) page： 303 - 308 2010.12

Language：English Publishing type：Research paper (scientific journal) Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE

The structure formation process of hierarchically porous alumina gels has been investigated by in situ small angle X ray scattering (SAXS) The measurement was performed on the sol-gel solution containing aluminum chloride hexahydrate (AlCl(3) 6H(2)O) poly(ethylene oxide) (PEO) and propylene oxide (PO) The temporal divergence of scattering intensity in the low q regime was observed in the early stage of reaction indicating that the occurrence of spinodal-decomposition-type phase separation Detailed analysis of the SAXS profiles revealed that phase separation occurs between weakly branched polymenzing aluminum hydroxide (AH) and PEO Further progress of the condensation reaction forms phase-separated two phases that is AH rich phase and PEO rich phase with the micrometer range heterogeneity The growth and aggregation of primary particles occurs in the phase-separated AH-rich domain and there fore the addition of PEO influences on the structure in nanometer regime as well as micrometer regime The moderate stability of oligomeric species allows homogeneous condensation reaction parallel to phase separation and successful formation of hierarchically porous alumina gel (C) 2010 Elsevier Inc All rights reserved

DOI： 10.1016/j.jcis.2010.08.041

Synthesis of high-silica and low-silica zeolite monoliths with trimodal pores Reviewed

Yasuaki Tokudome, Kazuki Nakanishi, Sho Kosaka, Ayuta Kariya, Hironori Kaji, Teiichi Hanada

MICROPOROUS AND MESOPOROUS MATERIALS Vol. 132 ( 3 ) page： 538 - 542 2010.8

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Using macroporous alumina as an aluminum source as well as structural support, high- and low-silica zeolites with trimodal pores have been fabricated in a monolithic form. Trimodally porous zeolites are obtained by the hydrothermal treatment of a monolithic alumina support impregnated with a mixture of AEROSIL 200, H(2)O, and sodium hydroxide or tetrapropylammonium hydroxide. The results of XRD measurement and (27)Al NMR analysis reveal the formation of zeolites and the incorporation of Al into zeolite frameworks in tetrahedrally-coordinated environment. Low-silica zeolites, such as PHI- and ANA-type zeolites are formed when sodium hydroxide is utilized as a base and a structure directing agent (SDA). On the other hand, MFI-type zeolites are crystallized from highly supersaturated solutions with the use of tetrapropylammonium hydroxide. High alkaline resistance of alumina support enables the choice of wide range of OH(-)/SiO(2) ratio, and moreover, the choice of desirable degree of supersaturation. As a result, the homogeneous crystallization of zeolites onto the alumina support has been successfully achieved. (C) 2010 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.micromeso.2010.04.005

Sol-gel preparation of Ni/TiO2 catalysts with bimodal pore structures Reviewed

Masayuki Numata, Ryoji Takahashi, Ikuya Yamada, Kazuki Nakanishi, Satoshi Sato

APPLIED CATALYSIS A-GENERAL Vol. 383 ( 1-2 ) page： 66 - 72 2010.7

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Ni/TiO2 with bimodal pore structure was prepared from nickel nitrate and titanium alkoxide by a sol-gel process under acidic conditions in the presence of formamide. The Ni/TiO2 has continuous macropores which are formed by fixing the transitional structure of phase separation. Although the addition of nickel nitrate in the sol-gel reaction of titanium alkoxide steeply decreases the phase separation tendency, the macropore size can be controlled by changing the composition of preparation. The Ni/TiO2 prepared by sol-gel has higher dispersion of Ni compared with that prepared by impregnation, and shows catalytic activity for the selective hydrogenation of crotonaldehyde: selectivity in the hydrogenation of C=C bond is much higher than that of C=O bond over sol-gel-derived Ni/TiO2. (C) 2010 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.apcata.2010.05.025

Fabrication of activated carbons with well-defined macropores derived from sulfonated poly(divinylbenzene) networks Reviewed

George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada

CARBON Vol. 48 ( 6 ) page： 1757 - 1766 2010.5

Language：English Publishing type：Research paper (scientific journal) Publisher：PERGAMON-ELSEVIER SCIENCE LTD

Poly(divinylbenzene) (PDVB) monoliths with well-defined macropores that have been sulfonated and carbonized to obtain macroporous carbon monoliths. The original macroporous PDVB networks have been synthesized by living radical polymerization accompanied by spinodal decomposition. Sulfonation prevents polymer networks from large shrinkage and weight loss during carbonization by heat-treatment in an inert atmosphere. In the case of PDVB gels sulfonated at 120 degrees C using conc. H(2)SO(4), mesopores in the original skeletons as well as macropores are retained after carbonization. The obtained carbon monoliths are subsequently activated by CO(2), which resulted in activated carbons. The specific surface area of the obtained activated carbons reaches up to 2360 m(2) g(-1). (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.carbon.2010.01.019

Other Link： http://orcid.org/0000-0002-8069-4780

A New Route to Monolithic Macroporous SiC/C Composites from Biphenylene-bridged Polysilsesquioxane Gels Reviewed

George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakamshi, Teiichi Hanada

CHEMISTRY OF MATERIALS Vol. 22 ( 8 ) page： 2541 - 2547 2010.4

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Macroporous polysilsesquioxane monoliths have been synthesized from biphenylene-bridged alkoxysilane via the sol-gel transition and concurrent phase separation both induced by the polycondensation reaction The obtained polysilsesquioxane gels have been subsequently converted to macroporous SiC/C composites by the carbothermal reduction The SiC/C monoliths thus obtained involve no visible cracks and their porosity reaches as high as >90%. In addition, according to the nitrogen adsorption-desorption measurement results, the micro- and mesopore characteristics of the samples did not undergo a significant change during the carbothermal reduction and the SiC/C composites have large specific surface areas owing to the microporous carbons in the skeletons These composites therefore are more suitable for the applications to gas storage and catalyst supports compared to pure SiC.

DOI： 10.1021/cm9034616

Macro- and microporous carbon monoliths with high surface areas pyrolyzed from poly(divinylbenzene) networks Reviewed

Joji Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada

COMPTES RENDUS CHIMIE Vol. 13 ( 1-2 ) page： 207 - 211 2010.1

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER

Carbon monoliths with well-defined macropores and high surface areas were prepared by carbonization of macroporous poly(divinylbenzene) (PDVB) monoliths The carbonization reactions of PDVB networks are studied by thermal analysis and FT-IR measurements. According to the measurement results. the PDVB networks are mostly pyrolyzed at 430 degrees C and their structures dynamically change to graphite-like structure between 600 and 700 degrees C The macropore structure retained while the mesopores disappeared after carbonization In addition, the surface area of the obtained carbons dramatically increased over 900 degrees C The typical carbon monolith carbonized at 1000 degrees C for 2 h had a surface area of 1500 m(2) g(-1) and uniform macropores with a diameter of jam To cite this article: J. Hasegawa et al., C. R. Chunk 13 (2010). (C) 2009 Academic des sciences. Published by Elsevier Masson SAS All rights reserved

DOI： 10.1016/j.crci.2009.04.003

Facile preparation of transparent monolithic titania gels utilizing a chelating ligand and mineral salts Reviewed

George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 53 ( 1 ) page： 59 - 66 2010.1

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Highly homogeneous transparent titania gels have been successfully prepared from titanium alkoxide by a sol-gel method utilizing chelating agent, ethyl acetylacetate (EtAcAc), in the presence of strong acid anions. Only catalytic amount of a strong acid anion suppress the rapid hydrolysis of titanium alkoxide by blocking the nucleophilic attack of HO(-) and H(2)O, and the resultant moderate sol-gel reactions thus afford homogeneous gelation, leading to transparent monolithic titania gels. Gelation time can be widely controlled by changing amounts of water, chelating agent and salt. The ability of salts to suppress the too abrupt sol-gel reactions is strongly dependent on the electronegativity of anions and valence of cations. With employing NH(4)NO(3) as a suppressing electrolyte, the obtained titania gels can be converted to pure TiO(2) by simple washing and heat-treatment, and transformations to anatase and rutile structures were found to start at 400 and 600 A degrees C, respectively.

DOI： 10.1007/s10971-009-2056-5

Hierarchically porous carbon monoliths with high surface area from bridged polysilsesquioxanes without thermal activation process Reviewed

George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada

CHEMICAL COMMUNICATIONS Vol. 46 ( 42 ) page： 8037 - 8039 2010

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Hierarchically porous carbon monoliths with high specific surface areas have been fabricated by removing nano-sized silica phase from carbon/silica composites pyrolyzed from bridged polysilsesquioxane. This activation method improves the homogeneity between inner and outer parts of the monoliths compared to the conventional thermal activation methods.

DOI： 10.1039/c0cc02974b

Effects of Starting Compositions on the Properties of Methylsilsesquioxane Aerogels Reviewed

Gen Hayase, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada

MRS Online Proceedings Library Archive Vol. 1247 page： 1247-C08-17 2010

Sol-gel synthesis, porous structure, and mechanical property of polymethylsilsesquioxane aerogels Reviewed

Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN Vol. 117 ( 1372 ) page： 1333 - 1338 2009.12

Language：English Publishing type：Research paper (scientific journal) Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

Organic-inorganic hybrid aerogels with polymethylsilsesquioxane (PMSQ, CH3SiO15) composition have been synthesized by A modified two-step sol-gel process. The precursor alkoxysilane is hydrolyzed in weakly acidic condition, and subsequently allowed to undergo polycondensation in a weakly basic condition which is brought up fly the hydrolysis of urea. Two kinds of surfactant (nonionic and cationic) have been utilized to suppress macroscopic phase separation. The resultant porous morphology could be modified by the kind of surfactant used small angle X-ray scattering (SAXS) and nitrogen adsorption have been employed to assess the porous morphology and it is found that the obtained PMSQ aerogels consist of aggregated particles and each particle contains micropores. Compressive mechanical properties have also been discussed based oil tie obtained information oil porous morphology. (C) 2009 The Ceramic Society at Japan All rights reserved

DOI： 10.2109/jcersj2.117.1333

ワイドポアモノリスシリカカラムによるネイティブタンパク質の分離性能評価 Reviewed

森坂裕信, 桐野彩, 水口博義, 中西和樹, 植田充美

Chromatography Vol. 30 ( Supplement 2 ) page： 42 - 43 2009.10

Semi-micro-monolithic columns using macroporous silica rods with improved performance Reviewed

Kei Morisato, Shota Miyazaki, Masayoshi Ohira, Masahiro Furuno, Masahiko Nyudo, Hiroyuki Terashima, Kazuki Nakanishi

JOURNAL OF CHROMATOGRAPHY A Vol. 1216 ( 44 ) page： 7384 - 7387 2009.10

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Monolithic silica columns in semi-micro-format have been synthesized using poly(acrylic acid) as a phase-separation inducer Via a Sol-gel route. The absence of a thick skin layer accompanied by deformation of the micrometer-sized gelling skeletons on the outermost part of the macroporous silica rod contributed to improve the efficiency of monolithic silica columns as thick as 2.4 mm in diameter The kinetic plot analysis revealed that monolithic silica columns with macropore diameter of 1 mu m and skeleton thickness of 1 mu m with decreased macroporosity behave similarly to columns packed with 3 mu m particles with slightly lower back pressure. (C) 2009 Elsevier B V. All rights reserved.

DOI： 10.1016/j.chroma.2009.05.028

Sol-gel synthesis of macro-mesoporous titania monoliths and their applications to chromatographic separation media for organophosphate compounds Reviewed

Junko Konishi, Koji Fujita, Kazuki Nakanishi, Kazuyuki Hirao, Kei Morisato, Shota Miyazaki, Masayoshi Ohira

JOURNAL OF CHROMATOGRAPHY A Vol. 1216 ( 44 ) page： 7375 - 7383 2009.10

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

We have developed a method of independently tailoring the macro- and mesoporous structres in titania (TiO(2)) monoliths in order to achieve liquid chromatographic separations of phosphorous-containing compounds Anatase TiO(2) monolithic gels with well-defined bicontinuous macropores and microstructured skeletons are obtained via the sol-gel process in strongly acidic conditions using poly(ethylene oxide) as a phase separator and N-methylformamide as a proton scavenger Aging treatment of (lie wet gels in the mother liquor at temperatures of 100-200 degrees C and subsequent heat treatment at 400 degrees C allow the formation and control of mesoporous structures with uniform pore size distributions in the gel skeletons, without disturbing the preformed macroporous morphology The monolithic TiO(2) rod columns with bimodal macro-mesoporous structures possess the phospho-sensitivity and exhibit excellent chromatographic separations of phosphorus-containing compounds (C) 2009 Elsevier B V. All rights reserved.

DOI： 10.1016/j.chroma.2009.06.016

Structural characterization of hierarchically porous alumina aerogel and xerogel monoliths Reviewed

Yasuaki Tokudome, Kazuki Nakanishi, Kazuyoshi Kanamori, Koji Fujita, Hirofumi Akamatsu, Teiichi Hanada

JOURNAL OF COLLOID AND INTERFACE SCIENCE Vol. 338 ( 2 ) page： 506 - 513 2009.10

Language：English Publishing type：Research paper (scientific journal) Publisher：ACADEMIC PRESS INC ELSEVIER SCIENCE

Detailed nanostructures have been investigated for hierarchically porous alumina aerogels and xerogels prepared from ionic precursors via sol-gel reaction. Starting from AlCl(3)center dot 6H(2)O and poly(ethylene oxide) (PEO) dissolved in a H(2)O/EtOH mixed solvent, monolithic wet gels were synthesized using propylene oxide (PO) as a gelation initiator. Hierarchically porous alumina xerogels and aerogels were obtained after evaporative drying and supercritical drying, respectively. Macroporous structures are formed as a result of phase separation, while interstices between the secondary particles in the micrometer-sized gel skeletons work as mesoporous structures. Alumina xerogels exhibit considerable shrinkage during the evaporative drying process, resulting in relatively small mesopores (from 5.4 to 6.2 nm) regardless of the starting composition. For shrinkage-free alumina aerogels, on the other hand, the median mesopore size changes from 13.9 to 33.1 nm depending on the starting composition; the increases in PEO content and H(2)O/EtOH volume ratio both contribute to producing smaller mesopores. Small-angle X-ray scattering (SAXS) analysis reveals that variation of median mesopore size can be ascribed to the change in agglomeration state of primary particles. As PEO content and H(2)O/EtOH ratio increase, secondary particles become small, which results in relatively small mesopores. The results indicate that the agglomeration state of alumina primary particles is influenced by the presence of weakly interacting phase separation inducers such as PEO. (C) 2009 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.jcis.2009.06.042

Performance of wide-pore monolithic silica column in protein separation Reviewed

Hironobu Morisaka, Kengo Kobayashi, Aya Kirino, Masahiro Furuno, Hiroyoshi Minakuchi, Kazuki Nakanishi, Mitsuyoshi Ueda

JOURNAL OF SEPARATION SCIENCE Vol. 32 ( 15-16 ) page： 2747 - 2751 2009.8

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

A monolithic wide-pore silica column was newly prepared for protein separation. The wide distribution of the pore sizes of monolithic columns was evaluated by mercury porosimetry. This column, as well as the conventional monolithic column, shows high permeability in the chromatographic separation of low-molecular-sized substances. In higher-molecular-sized protein separation, the wide-pore monolithic silica column shows better performance than that of the conventional monolithic column. Under optimized conditions, five different proteins - ribonuclease A, albumin, aldolase, catalase, and ferritin - were baseline-separated within 3 min, which is faster than that using the particle-packed columns. In addition, the monolithic wide-pore silica column could also be prepared in fused silica capillary (600 min long, 0.2 mm i.d.) for highly efficient protein separation. The peak capacity of the wide-pore monolithic silica capillary column is estimated to be approximately 300 in the case of protein separation, which is a characteristic performance.

DOI： 10.1002/jssc.200800653

Rigid Crosslinked Polyacrylamide Monoliths with Well-Defined Macropores Synthesized by Living Polymerization Reviewed

Joji Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada, Shigeru Yamago

MACROMOLECULAR RAPID COMMUNICATIONS Vol. 30 ( 12 ) page： 986 - 990 2009.6

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Rigid crosslinked polyacrylamide monoliths with well-defined macropores have been successfully fabricated by organotellurium-mediated living radical polymerization (TERP) accompanied by spinodal decomposition. The TERP forms homogeneous networks derived from N,N-methylenebis(acrylamide) (BIS), in which spinodal decomposition is induced to form macropores. Macropore diameter can be controlled from submicrons to a few microns, and also the obtained networks contain mesopores in the macroporous skeletons, which are collapsed by evaporative drying. They are promising materials with hydrophilic polyacrylamide surfaces and have enough strength to preserve the macropores from the surface tension arising in the repetitive swelling and drying that may occur in many applications.

DOI： 10.1002/marc.200900066

Effect of La addition on thermal microstructural evolution of macroporous alumina monolith prepared from ionic precursors Reviewed

Yasuaki Tokudome, Kazuki Nakanishi, Teiichi Hanada

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN Vol. 117 ( 1363 ) page： 351 - 355 2009.3

Language：English Publishing type：Research paper (scientific journal) Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

Porous alumina monoliths with high thermal stability have been prepared using sol-gel processing from ionic precursors. Samples were synthesized from AlCl3 center dot 6H(2)O and LaCl3 center dot 7H(2)O dissolved in a H2O/etanol solution containing poly(ethylene oxide) (PEO) via propylene oxide (PO) involved sol-gel reaction accompanied by phase separation. The heat-treated gels consist of controllable size of macropores and La-doped alumina skeletons. Doped lanthanum ions are homogeneously embedded in the gel matrix, which retards the phase transition from gamma-alumina to alpha-alumina during the sintering. The 3 mol% La-doped aluminate exhibits the BET surface area of 55.3 m(2)/g, after the heat treatment at 1100 degrees C for 24 It. Drying condition are also related to the thermal stability of obtained gels. Aluminate aerogels show higher thermal stability than corresponding xerogels due to relatively large mesopore size and high porosity. As a result, the 3 mol% lanthanum doped aluminate aerogel shows BET surface area as high as 82.5 m(2)/g even after heat treatment at 1100 degrees C for 24 h. (C) 2009 The Ceramic Society of Japan. All rights reserved.

DOI： 10.2109/jcersj2.117.351

Pore Formation in Poly(divinylbenzene) Networks Derived from Organotellurium-Mediated Living Radical Polymerization Reviewed

Joji Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada, Shigeru Yamago

MACROMOLECULES Vol. 42 ( 4 ) page： 1270 - 1277 2009.2

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Macroporous cross-linked polymeric dried gets have been obtained by inducing phase separation in a homogeneous poly (divinylbenzene) (PDVB) network formed by organotellurium-mediated living radical polymerization (TERP). The living polymerization reaction of DVB with the coexistence of a nonreactive polymeric agent, poly(dimethylsiloxane) (PDMS), in solvent 1,3,5-trimethylbenzene (TMB) resulted in polymerization-induced phase separation (spinodal decomposition), and the transient structure of spinodal decomposition has been frozen by gelation. Well-defined macroporous monolithic dried gels with bicontinuous structure in the micrometer scale are obtained after removing PDMS and TMB by simple washing and drying. Inside the skeletons that comprise the macroporous structure, "skeletal pores" with various sizes in nanometer scale have also been found by gas sorption measurements. The skeletal pores are deduced to be formed by secondary phase separation in the skeletons due to the thermodynamic instability that arises in the separated phases during the polymerization. The properties of the macropores and the skeletal pores have been controlled by changing starting composition, molecular weight of PDMS, and reaction temperature.

DOI： 10.1021/ma802343a

Spinodal decomposition in siloxane sol-gel systems in macroporous media Reviewed

Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada

SOFT MATTER Vol. 5 ( 16 ) page： 3106 - 3113 2009

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Spinodal decomposition in siloxane sol-gel systems has been investigated in a macroporous silica mould (pore diameter D 2.74 mu m) with a bicontinuous structure. Methyltrimethoxysilane (MTMS) and tetramethoxysilane ( TMOS) have been employed as siloxane gel sources and as-sintered hydrophilic and octadecylsilylated hydrophobic macroporous silica were used as the confining moulds. In an MTMS-formamide system with a longer phase separation time and higher viscosity, the phase-separated gels in both moulds exhibited a similar morphology when the bulk correlation length Lambda, i.e. spinodal wavelength in a free volume, was enough shorter than D. As Lambda was made longer by altering the starting composition, a wetting transition occurred in both the hydrophilic and hydrophobic moulds. In an MTMS-methanol system with a shorter phase separation time and lower viscosity, the wetting transition unexpectedly occurred when Lambda was much shorter than D in the hydrophobic mould. In TMOS-formamide system, fine and disordered structure has formed in the hydrophilic mould and never exhibited the wetting transition. A hydrodynamic wetting transition in each system was considered to occur when the ratio D/Lambda becomes smaller than unity, whereas a diffusive wetting transition takes place in the early stage of spinodal decomposition in the case where the chemical affinity between siloxane gel and the mould is high. Additionally, when the initial wavelength of spinodal decomposition is shorter than D, spinodal decomposition is highly suppressed due to the presence of the random surfaces of macropores. These effects may interplay depending on the physical and chemical nature of the sol-gel systems and the moulds.

DOI： 10.1039/b903444g

Elastic Aerogels and Xerogels Synthesized From Methyltrimethoxysilane (MTMS) Reviewed

Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada

POLYMER-BASED SMART MATERIALS - PROCESSES, PROPERTIES AND APPLICATION Vol. 1134 page： 173 - + 2009

Language：English Publishing type：Research paper (international conference proceedings) Publisher：MATERIALS RESEARCH SOC

Transparent organic-inorganic hybrid aerogels and aerogel-like xerogels have been prepared from methyltrimethoxysilane (MTMS) respectively by supercritical drying (SCD) and ambient pressure drying (APD). The new aerogels and xerogels significantly deform without collapsing on uniaxial compression and almost fully relax when unloaded. This elastic behavior., termed as "spring-back", allows APD without noticeable shrinkage and cracking. The flexible network composed of lower cross-linking density (up to three bonds per every silicon atom) compared to silica gels (up to four bonds) and repulsion between hydrophobic methyl groups bonded to every silicon atom largely contributes to the pronounced deformability and relaxing, respectively. Lower surface silanol group density also plays a crucial role for the "spring-back" behavior.

Preparation of Macroporous Poly(divinylbenzene) Gels Via Living Radical Polymerization Reviewed

Joji Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada, Shigeru Yamago

POLYMER-BASED SMART MATERIALS - PROCESSES, PROPERTIES AND APPLICATION Vol. 1134 page： 139 - + 2009

Language：English Publishing type：Research paper (international conference proceedings) Publisher：MATERIALS RESEARCH SOC

Macroporous cross-linked polymeric dried gels have been obtained by inducing phase separation in a homogeneous poly(divinylbenzene) (PDVB) network formed by organotellurium-mediated living radical polymerization (TERP). The living polymerization reaction of DVB with the coexistence of a non-reactive polymeric agent, poly(dimethylsiloxane) (PDMS), in solvent 1,3,5-trimethylbenzene (TMB) resulted in polymerization-induced phase separation (spinodal decomposition), and the transient structure of spinodal decomposition has been frozen by gelation. Well-defined macroporous monolithic dried gels with bicontinuous structure in the micrometer scale are obtained after removing PDMS and TMB by simple washing and drying. The properties of the macropores have been controlled by changing starting composition.

Fabrication of macroporous silicon carbide ceramics by intramolecular carbothermal reduction of phenyl-bridged polysilsesquioxane Reviewed

George Hasegawa, Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada

JOURNAL OF MATERIALS CHEMISTRY Vol. 19 ( 41 ) page： 7716 - 7720 2009

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Macroporous SiC ceramics were obtained from porous phenyl-bridged polysilsesquioxane prepared by a sol-gel method accompanied by spinodal decomposition subsequently subjected to intramolecular carbothermal reduction. By this method, we can obtain macroporous SiC ceramics with improved atomic-level homogeneity and controlled pore size more easily than by intermolecular carbothermal reduction using a mixture of SiO(2) and carbon powder. Therefore, the resultant SiC ceramics have sufficiently high purity without washing with hydrofluoric acid to remove residual SiO(2).

DOI： 10.1039/b913992c

Examination of mesopore structure of hierarchically macro/mesoporous silica by thermoporometry

E. Fukui, K. Shinohara, K. Nakanishi, K. Kanamori, T. Hanada

Materials Research Society Symposium Proceedings Vol. 1056 page： 28 - 33 2008.12

Language：English Publishing type：Research paper (scientific journal)

Thermoporometry was employed to monitor the mesopore evolution in wet, drying and heat-treatment stages of monolithic macro/mesoporous silica with SBA-15 like structure. Direct comparison of mesopores in wet state was only possible with the samples extracted with sulfuric acid. In good agreement with the preceding study, the sulfuric acid not only removed the surfactant but also modified the silica gel network into that with reduced amount of micropores and increased stability against the drying stress. Thermoporometry revealed that the structural evolution takes place completely in the wet condition, which accompanies a decrease in the thickness of non-freezable water. © 2008 Materials Research Society.

Phase separation in silica sol-gel system containing anionic surfactant

Taisuke Matsui, Kazuki Nakanishi, Kazuyoshi Kanamori, Teiichi Hanada

Materials Research Society Symposium Proceedings Vol. 1056 page： 418 - 423 2008.12

Language：English Publishing type：Research paper (scientific journal)

By inducing phase separation parallel to the sol-gel transition of alkoxy-derived silica systems, silica monoliths with well-defined co-continuous macropores were obtained from the systems containing anionic surfactants.We adopted three kinds of anionic surfactants which differ from each other in the length of alkyl chain (CH3(CH2)i7SO3Na, CH 3(CH2)i5SO3Na, CH3(CH 2)i3SO3Na).Mesopores were also found in the silica skeletons presumably by the supramolecular templating.Characterization of the dried or heat-treated samples was carried out by a scanning electron microscope (SEM) and nitrogen adsorption measurements.Experimental results showed that due to the moderate interaction between silica oligomers and surfactants, most of the surfactants are distributed to the solvent phase which determines the macropore volume.The median size and volume of the macropores could be controlled independently by the starting composition.In the absence of any additive to enhance templating by the surfactant, the samples exhibited only amorphous mesopores. © 2008 Materials Research Society.

Elastic organic-inorganic hybrid aerogels and xerogels Reviewed

Kazuyoshi Kanamori, Mamoru Aizawa, Kazuki Nakanishi, Teiichi Hanada

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 48 ( 1-2 ) page： 172 - 181 2008.11

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Novel aerogels and xerogels with methylsilsesquioxane (MSQ, CH(3)SiO(1.5)) networks have been prepared by a modified sol-gel process using surfactant and urea as a phase-separation inhibitor and as an accelerator for the condensation reaction, respectively. Optimized aerogels dried under a supercritical condition not only showed the similar properties as conventional pure silica aerogels such as high transparency and porosity etc, but also demonstrated outstanding mechanical strength against compression; the aerogel drastically shrank upon loading and then recovered when unloaded, which is called a "spring-back" behavior. On ambient pressure drying, the wet gel also exhibited the similar response against compression stress originated from the capillary pressure, and thus xerogels with the comparative structure and properties to those of corresponding aerogels have also been obtained. This unusual mechanical behavior is attributed to the trifunctional flexible networks of MSQ, low silanol concentration which prevents the irreversible shrinkage, and high concentration of a hydrophobic methyl group directly attached to every silicon atom which helps re-expansion after the temporal shrinkage.

DOI： 10.1007/s10971-008-1756-6

Facile Synthesis of Macroporous Cross-Linked Methacrylate Gels by Atom Transfer Radical Polymerization Reviewed

Kazuyoshi Kanamori, Joji Hasegawa, Kazuki Nakanishi, Tefichi Hanada

MACROMOLECULES Vol. 41 ( 19 ) page： 7186 - 7193 2008.10

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Macroporous cross-linked organic polymer monoliths with well-defined bicontinuous structure have been synthesized from 1,3-glycerol dimethacrylate (GDMA) in a solvent utilizing atom transfer radical polymerization (ATRP). With the addition of an adequate polymeric agent, poly(ethylene oxide) (PEO), spinodal decomposition was induced in the course of polymerization of GDMA. A homogeneous gelation by ATRP solidified the temporal biphasic morphology of spinodal decomposition, resulting in well-defined macroporous gels after drying. Macroporous dried gels obtained in this way comprise interconnected skeletons and macropores, which is characteristic for spinodal decomposition. Macropore size and volume were controlled simply by altering the starting composition. The mechanism of spinodal decomposition is deduced that the separation takes place between polymerizing GDMA and PEO, but FTIR and thermal analyses suggested the amount of PEO that is distributed in GDMA-rich phase cannot be neglected. Free radical polymerization, which is generally utilized for synthesis of porous polymeric gels, usually leads to heterogeneous cross-linking forming local microgels and hinders the occurrence of spinodal decomposition in a cross-linking system over extended length scales. On the other hand, living polymerization allowed homogeneous cross-linking; hence, isotropic spinodal decomposition was induced in the copresence of PEO. The facile synthesis method presented here will lead to more precise control of pore properties of cross-linked organic polymer gels.

DOI： 10.1021/ma800563p

Scattering-based hole burning through volume speckles in a random medium with tunable diffusion constant Reviewed

Murai Shunsuke, Fujita Koji, Hirao Takayuki, Nakanishi Kazuki, Hirao Kazuyuki, Tanaka Katsuhisa

APPLIED PHYSICS LETTERS Vol. 93 ( 15 ) 2008.10

Preparation and properties of radiofrequency sputtered X-ray amorphous films in the system SiO2-ZrO2 Reviewed

Akira Sawa, Kazuki Nakanishi, Teiichi Hanada

THIN SOLID FILMS Vol. 516 ( 15 ) page： 4665 - 4672 2008.6

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE SA

Amorphous films in the system SiO2-ZrO2 were prepared by radiofrequency sputtering method and their density, refractive index, elastic constants, and thermal expansion coefficient were measured. All of the physical properties had a similar compositional dependence; that is, they increased, but not proportionally, with increasing ZrO2 content. The coordination states of cations in these amorphous films were estimated by the compositional dependence of volume and molar refractivity. The coordination state of silicon ions in the amorphous films did not change, but the coordination number of zirconium ions changed from 8 to 6, depending on ZrO2 content. These results indicate that, in amorphous films in the system SiO2-ZrO2, the change of the coordination state of zirconium ions in the amorphous films has an important effect on the properties. (C) 2007 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.tsf.2007.08.012

Preparation of monolithic silica columns for high-performance liquid chromatography Reviewed

Oscar Nunez, Kazuki Nakanishi, Nobuo Tanaka

JOURNAL OF CHROMATOGRAPHY A Vol. 1191 ( 1-2 ) page： 231 - 252 2008.5

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Preparation methods of monolithic silica columns for HPLC including the surface modification were reviewed. Chemical modification methods recently reported to obtain stationary phases for reversed-phase (RP), chiral, ion-exchange, and hydrophilic interaction chromatography (HILIC) separations were discussed. Recent results related to preparation methods of monolithic silica were also covered. The characteristics and properties of silica monoliths and some applications of monolithic silica columns for different analytical and bioanalytical fields will be commented. (c) 2008 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.chroma.2008.02.029

Alkoxy-derived multiscale porous TiO2 gels probed by ultra-small-angle X-ray scattering and small-angle X-ray scattering Reviewed

Junko Konishi, Koji Fujita, Kazuki Nakanishi, Shotaro Nishitsuji, Mikihito Takenaka, Kiyotaka Miura, Kazuyuki Hirao

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 46 ( 1 ) page： 63 - 69 2008.4

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Titania (TiO2) monoliths with well-defined bicontinuous macropores and gel skeletons were prepared through the alkoxy-derived sol-gel process accompanied by spinodal decomposition, and the structural evolution during evaporation drying and heat treatment was probed by a combination of ultra-small-angle X-ray scattering and small-angle X-ray scattering. X-ray scattering profiles of wet and dried gels revealed that microporous structures related to the existence of primary particles are present in the gel skeletons at the wet stage and are preserved during drying. Additionally, it is found that the primary particles swollen in the wet condition are dried to compact aggregates to produce the smooth surface of gel skeletons. Upon heating at 400 degrees C, the particle-particle correlation associated with regularity of mesostructures is enhanced. From nitrogen adsorption-desorption measurements, the average pore size is less than 1 nm in the dried gel and increases to 3.1 nm by the heat treatment. Homogeneous growth of primary particles due to interparticle-polycondensation reaction is responsible for the increased size and uniform distribution of mesopores in the heat-treated gel.

DOI： 10.1007/s10971-008-1694-3

Crystalline ZrO2 monoliths with well-defined macropores and mesostructured skeletons prepared by combining the alkoxy-derived sol-gel process accompanied by phase separation and the solvothermal process Reviewed

Junko Konishi, Koji Fujita, Satoshi Oiwa, Kazuki Nakanishi, Kazuyuki Hirao

CHEMISTRY OF MATERIALS Vol. 20 ( 6 ) page： 2165 - 2173 2008.3

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

We have successfully prepared multiscale porous crystalline zirconia (ZrO2) monoliths by combining alkoxy-derived sol-gel process accompanied by phase-separation and the solvothermal process. The gelation can be controlled by the addition of N-methylformamide to the starting solution, while the phase separation is induced by the incorporation of poly(ethylene oxide). Amorphous ZrO2 monolithic gels with well-defined bicontinuous macropores and microstructured skeletons are obtained when the transient. structure of polymerization-induced phase separation is fixed by the gelation. The size of the macropores is controlled in the range of 300 nm to 2 mu m by adjusting the amount of poly(ethylene oxide). The solvent exchange of the mother liquor in the as-gelled wet specimens with absolute ethanol, followed by the solvothermal treatment at temperatures above 210 degrees C, brings about the formation of mesopores and stabilizes tetragonal ZrO2 nanocrystals without disturbing the macroporous morphology. The resultant macro-mesoporous crystalline ZrO2 gels possess the surface area over 200 m(2) g(-1).

DOI： 10.1021/cm703351d

Cr3+-doped macroporous Al2O3 monoliths prepared by the metal-salt-derived sol-gel method Reviewed

Fujita Koji, Tokudome Yasuaki, Nakanishi Kazuki, Miura Kiyotaka, Hirao Kazuyuki

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 354 ( 2-9 ) page： 659 - 664 2008.1

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Non-Crystalline Solids

Cr3+-doped alumina (Al2O3) monoliths with well-defined macropores have been synthesized from the aqueous and ethanolic solution of aluminum and chromium salts in the presence of propylene oxide (PO) and poly(ethylene oxide) (PEO) using the sol-gel method accompanied by phase separation. The addition of PEO to the starting solution induces the phase separation, whereas the introduction of PO controls the gelation. The bicontinuous macroporous structures are obtained by inducing the phase separation parallel to the gelation, and the pore size can be controlled by adjusting the composition of starting solutions. The dried gel and that heat-treated at 700 °C are amorphous. As the heat-treatment temperature is increased over 700 °C, nanocrystalline γ-Al2O3 is precipitated at 800 °C, a mixture of θ- and α-Al2O3 phases appears at 1100 °C, and a single of α-Al2O3 is obtained at 1200 °C, while keeping the bicontinuous macroporous structure. Cr3+-doped α-Al2O3 monoliths with well-defined macropores exhibit photoluminescence as observed for ruby, indicating that Cr3+ ions are homogenously dispersed into the skeletons of bicontinuous network and substitute uniformly for the Al3+ sites. © 2007 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jnoncrysol.2007.06.091

Cr3+-doped macroporous Al2O3 monoliths prepared by the metal-salt-derived sol-gel method Reviewed

Koji Fujita, Yasuaki Tokudome, Kazuki Nakanishi, Kiyotaka Miura, Kazuyuki Hirao

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 354 ( 2-9 ) page： 659 - 664 2008.1

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Cr3+-doped alumina (Al2O3) monoliths with well-defined macropores have been synthesized from the aqueous and ethanolic solution of aluminum and chromium salts in the presence of propylene oxide (PO) and poly(ethylene oxide) (PEO) using the sol-gel method accompanied by phase separation. The addition of PEO to the starting solution induces the phase separation, whereas the introduction of PO controls the gelation. The bicontinuous macroporous structures are obtained by inducing the phase separation parallel to the gelation, and the pore size can be controlled by adjusting the composition of starting solutions. The dried gel and that heat-treated at 700 degrees C are amorphous. As the heat-treatment temperature is increased over 700 degrees C, nanocrystalline gamma-Al2O3 is precipitated at 800 degrees C, a mixture of theta- and (alpha-Al2O3 phases appears at 1100 degrees C, and a single of alpha-Al2O3 is obtained at 1200 degrees C, while keeping the bicontinuous macroporous structure. Cr3+-doped alpha-Al2O3 monoliths with well-defined macropores exhibit photoluminescence as observed for ruby, indicating that Cr3+ ions are homogenously dispersed into the skeletons of bicontinuous network and substitute uniformly for the Al3+ sites. (c) 2007 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jnonerysol.2007.06.091

22aYE-7 Effect of the gel structure on the acoustic property of liquid ^4He in silica gel

Ohmori K., Tanaka T., Abe S., Tsujii H., Suzuki H., Matsumoto K., Nakanishi K., Kanamori K.

Meeting Abstracts of the Physical Society of Japan Vol. 63 ( 0 ) 2008

Hierarchically porous oxides, hybrids and polymers via sol-gel accompanied by phase separation Reviewed

Kazuki Nakanishi

ORGANIC/INORGANIC HYBRID MATERIALS - 2007 Vol. 1007 page： 51 - 62 2008

Language：English Publishing type：Research paper (international conference proceedings) Publisher：MATERIALS RESEARCH SOCIETY

In various crosslinking systems containing metal oxides, organo-siloxane polymers and pure hydrocarbons, monolithic materials with hierarchical well-defined macropores and controlled mesopores have been synthesized. Synthetic progress in alkoxy-derived macroporous silica lead to the preparation of long-range ordered mesoporous skeletons in well-defined. macroporous framework. Alkylene-bridged silicon alkoxides can also be prepared into similarly hierarchical porous structures with broadened variations in framework morphology. Macro-mesoporous alkoxy-derived pure titania and zirconia have been prepared using hydrochloric acid - mediated processes. Compared with those prepared from colloidal dispersions, alkoxy-derived macroporous titania exhibited much higher mechanical strength. Titania monolith is a promising candidate as a separation medium to discriminate phosphorylated compounds in a liquid chromatography mode. Pure alumina macroporous monolith has been first synthesized from aluminum salt using propylene glycol as a proton scavenger to thrust the solution pH from acidic into neutral conditions. Alumina-based complex oxides such as garnets and spinels can also be prepared in pure phases. Polymerization and phase separation in organic crosslinker system was also controlled to obtain well-defined co-continuous macro-frameworks instead of those composed of aggregated particles. These examples demonstrate the versatility of using phase-separation in gelling systems to obtain well-defined macroporous structures.

Phase separation in alkoxy-derived silica system containing polyacrylamide Reviewed

Kousuke Kawamoto, Kazuki Nakanishi, Teiichi Hanada

ORGANIC/INORGANIC HYBRID MATERIALS - 2007 Vol. 1007 page： 63 - 68 2008

Language：English Publishing type：Research paper (international conference proceedings) Publisher：MATERIALS RESEARCH SOCIETY

By inducing phase separation parallel to the sol-gel transition of alkoxy-derived silica systems, gels having both macroporous and mesoporous structures can be obtained. Using poly(acrylamide) (PAAm) as a phase-separation inducer, macro/mesoporous silica gels were synthesized. After solvent exchange by water, the size distribution of mesopores of wet gels was evaluated by thermoporometry using a differential scanning calorimetry (DSC). Alternatively, gels were evaporation-dried after solvent exchange by ethanol or water/ethanol, followed by heat-treatment to completely remove volatile and organic components. Characterization of the dried or heat-treated samples was carried out using a scanning electron microscope (SEM) and by nitrogen adsorption measurements. Experimental results showed that the interaction between PAAm and silica is not so strong as the case of polymers having poly(oxyethylene) chains. The contribution of the secondary phase separation within the crosslinking silica-rich phase was suggested to be responsible for the mesopore formation in the PAAm-silica system.

Phase separation in Al<sub>2</sub>O<sub>3</sub> sol-gel system incorporated with high molecular weight poly(ethylene oxide) Reviewed

Y. Tokudome, K. Nakanishi, K. Fujita, K. Miura, K. Hirao

Materials Research Society Symposium Proceedings Vol. 1007 page： 69 - 74 2008

Phase separation in Al2O3 sol-gel system incorporated with high molecular weight poly(ethylene oxide) Reviewed

Yasuaki Tokudome, Kazuki Nakanishi, Koji Fujita, Kiyotaka Miura, Kazuyuki Hirao

ORGANIC/INORGANIC HYBRID MATERIALS - 2007 Vol. 1007 page： 69 - 74 2008

Language：English Publishing type：Research paper (international conference proceedings) Publisher：MATERIALS RESEARCH SOCIETY

Pure alumina monoliths with well-defined macropores and mesostructured skeleton have been synthesized via a spontaneous route from the aqueous and ethanolic solution of aluminum salts in the presence of propylene oxide and high molecular weight poly(ethylene oxide)(PEO). The addition of propylene oxide to the starting solution controls the gelation, while the addition of PEO induces the phase separation. Appropriate choice of the starting composition, with which the phase separation and gelation concur, produces large-dimension (10mmx10mmx10mm), bicontinuous macroporous Al2O3 monoliths. The mean size of the continuously connected pores is controlled in the micrometer range, depending on the PEO concentration and polarity of the solution. On the other hand, micropores and mesopores, originated from the interstices among primary particles, exhibit median pore size of about 2.6 mn and the BET surface area as high as 396 m(2)/g after dried temperature at 40 degrees C.

Sol-gel synthesis of macroporous YAG from ionic precursors via phase separation route Reviewed

Yasuaki Tokudome, Koji Fujita, Kazuki Nakanishi, Kazuyoshi Kanamori, Kiyotaka Miura, Kazuyuki Hirao, Teiichi Hanada

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN Vol. 115 ( 1348 ) page： 925 - 928 2007.12

Language：English Publishing type：Research paper (scientific journal) Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

Yttrium aluminum garnet, Y3Al5O12, (YAG) monoliths with well-defined macropores have been prepared from ionic precursors using the sol-gel method accompanied by phase separation. The addition of propylene oxide to the starting solution controls the gelation, while the addition of poly(ethylene oxide) induces the phase separation. Polymerization-induced phase separation and gelation concur by an appropriate selection of the starting composition, which allows the production of bicontinuous macroporous nanocomposite gels in large dimensions (similar to 10 x 10 x 10 mm(3)). During heat treatment at 800 degrees C, the monolithic nanocomposite gels crystallize into YAG without the formation of any intermediate phases or the precipitation of impurity phases, indicating higher homogeneity of cation distribution in the dried gels. The macroporous YAG network was maintained even after heat treatment at 1000 degrees C for 10 h.

DOI： 10.2109/jcersj2.115.925

Sur-face interaction of well-defined, concentrated poly,(2-hydroxyethyl methacrylate) brushes with proteins Reviewed

Chiaki Yoshikawa, Atsushi Goto, Yoshinobu Tsujii, Norio Ishizuka, Kazuki Nakanishi, Takeshi Fukuda

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY Vol. 45 ( 21 ) page： 4795 - 4803 2007.11

Language：English Publishing type：Research paper (scientific journal) Publisher：JOHN WILEY & SONS INC

The interaction of concentrated polymer brushes with proteins was chromatographically investigated. By the use of surface-initiated atom transfer radical polymerization, a low-polydispersity poly(2-hydroxyethyl methacrylate) (PHEMA) was densely grafted onto the inner surfaces of silica monoliths with mesopores of about 50 and 80 run in mean size. The graft density reached 0.4-0.5 chains/nm(2). The 80 nm-mesopore monolithic column with the concentrated PHEMA brush was characterized through the elution of low-polydispersity pullulans with different molecular weights, clearly showing two modes of size exclusion, that is, one by the mesopores and the other by the brush phase. The latter mode gave a sharp separation with a critical molecular weight (size-exclusion limit) of about 1000. This molecular size of pullulan was comparable to the distance between the nearest-neighbor graft points. The elution behaviors of five proteins of different sizes (bovine serum thyroglobulin, bovine serum immunoglobulin G, bovine serum albumin, horse heart myoglobin, and bovine serum aprotinin) were studied with this PHEMA-grafted column. The smallest protein, aprotinin, with a pullulan-reduced molecular weight slightly larger than the critical value of 1000, was eluted much behind the corresponding pullulan, and this indicated that it barely got into the brush layer, suffering from a strong affinity interaction within the brush. On the other hand, the other four larger proteins were eluted at the same elution volumes as the equivalent pullulans, and this meant that they were perfectly excluded from the brush layer and separated only in the sizeexclusion mode by the mesopores without an affinity interaction with the brush surface. This excellent inertness of the concentrated brush in the interaction with the large proteins should afford the system long-term stability against biofouling. (c) 2007 Wiley Periodicals, Inc.

DOI： 10.1002/pola.22224

Real space observation of silica monoliths in the formation process Reviewed

Haruko Saito, Kazuyoshi Kanamori, Kazuki Nakanish, Kazuyuki Hirao

JOURNAL OF SEPARATION SCIENCE Vol. 30 ( 17 ) page： 2881 - 2887 2007.11

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

The macropore structure evolution of a silica monolith during the formation process was observed by laser scanning confocal microscopy (LSCM) for two kinds of systems. The obtained LSCM images were further subjected to image analysis, and the geometrical parameters were calculated. On the basis of the parameters obtained, improved compositions for high efficiency preparation of macroporous monoliths are discussed.

DOI： 10.1002/jssc.200700360

Synthesis of monolithic Al2O3 with well-defined macropores and mesostructured skeletons via the sol-gel process accompanied by phase separation Reviewed

Yasuaki Tokudome, Koji Fujita, Kazuki Nakanishi, Kiyotaka Miura, Kazuyuki Hirao

CHEMISTRY OF MATERIALS Vol. 19 ( 14 ) page： 3393 - 3398 2007.7

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Alumina (Al2O3) monoliths with well-defined macropores and mesostructured skeletons have been synthesized via a spontaneous route from the aqueous and ethanolic solution of aluminum salts in the presence of propylene oxide and poly(ethylene oxide) (PEO). The addition of propylene oxide to the starting solution controls the gelation, whereas the addition of PEO induces the phase separation. Appropriate choice of the starting composition, by which the phase separation and gelation concur, allows the production of bicontinuous macroporous Al2O3 monoliths in large dimensions (10 x 10 x 10 mm(3)). The size of macropores is controlled in the range of 400 nm to 1.8 mu m, depending on the PEO content in starting solutions. The dried gel is amorphous, whereas heating at temperatures above 800 degrees C leads to the formation of crystalline phases without spoiling the macroporous morphology; nanocrystalline gamma-Al2O3 is precipitated at 800 degrees C, alpha-Al2O3 starts to form at 1000 degrees C, and complete transformation into alpha-Alpha l(2)O(3) is achieved at 1100 degrees C for 5 h. Nitrogen adsorption-desorption measurements revealed that the skeletons of dried gels possess the mesostructure with a median pore size of about 2.6 nm and a surface area as high as 396 m(2)/g. Heat treatment at 300 degrees C increases the pore size and surface area to 3.5 nm and 512 m(2)/g, respectively. Even after heat treatment at 800 degrees C, which results in the formation of nanocrystalline gamma-Al2O3, the surface area is 182 m(2)/g, with the pore size being 4.5 nm.

DOI： 10.1021/cm063051p

Three-dimensional observation of macroporous silica gels and the study on structural formation mechanism Reviewed

Haruko Saito, Kazuyoshi Kanamori, Kazuki Nakanishi, Kazuyuki Hirao, Yukihiro Nishikawa, Hiroshi Jinnai

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS Vol. 300 ( 1-2 ) page： 245 - 252 2007.6

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Three-dimensional (3D) observation of co-continuous macropore structure was performed using laser scanning confocal microscopy (LSCM). The obtained LSCM images were reconstructed into 3D images, and further subjected to image analysis. The LSCM observation and the following image analysis provided geometrical parameters of the macropore surfaces, which cannot be obtained by classical techniques for macropore characterization, such as scanning electron microscopy (SEM) observation or mercury intrusion method. Based on the obtained structural parameters, influences of viscoelastic properties on the liquid-phase structural formation mechanism were examined. (c) 2007 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.colsurfa.2006.12.075

Simple liquid chromatography using monolithic silica rod and capillary Reviewed

Naobumi Oi, Kei Morisato, Hiroyoshi Minakuchi, Kazuki Nakanishi

BUNSEKI KAGAKU Vol. 56 ( 4 ) page： 227 - 229 2007.4

Language：Japanese Publishing type：Research paper (scientific journal) Publisher：JAPAN SOC ANALYTICAL CHEMISTRY

Simple liquid chromatography by capillary action using a monolithic silica rod and a capillary as the separation media instead of a thin-layer plate in conventional thin-layer chromatography (TLC) was examined. Possibilities of this chromatography were demonstrated by the separation of some organic compounds. Monolithic silica rod and capillary are very handy and useful as separation media for simple open liquid chromatography.

DOI： 10.2116/bunsekikagaku.56.227

Temperature-tunable scattering strength based on the phase transition of liquid crystal infiltrated in well-defined macroporous random media Reviewed

Shunsuke Murai, Koji Fujita, Takayuki Hirao, Kazuki Nakanishi, Kazuyuki Hirao

OPTICAL MATERIALS Vol. 29 ( 8 ) page： 949 - 954 2007.4

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Temperature dependence of scattering strength for the visible light (488 nm) has been investigated for a siloxane-based macroporous monolith infiltrated with liquid crystal molecules. A macroporous gel with interconnected pores and organosiloxane skeletons is prepared via a sol-gel route by inducing the phase separation parallel to the hydrolysis and condensation of silicon alkoxide. The interconnected macropores of the dried gel are infiltrated with liquid crystal 4-cyano-4'-n-pentylbiphenyl (5CB) which undergoes the phase transition between nematic and isotropic at 35 degrees C. Temperature variation of the scattering strength for 5CB-filled gel is measured by means of coherent backscattering and total transmission, both of which exhibit a significant change in transport mean free path at around the phase transition temperature of 5CB. The results indicate that the scattering strength of 5CB-filled monolith gel can be tuned externally via temperature. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.optmat.2005.11.032

Functional porous materials via sol-gel with phase separation Reviewed

Kazuki Nakanishi

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN Vol. 115 ( 1339 ) page： 169 - 175 2007.3

Language：English Publishing type：Research paper (scientific journal) Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

Variety of functional porous materials in metal oxide, metalloxane polymer and even pure organic polymer compositions obtained by a sol-gel process are reviewed. Specifically, processes including polymerization-induced phase separation have been extensively introduced from theories to practices. The basic concept of hierarchical pore architecture in monolithic materials is explained, together with several examples of successful applications. Depending on the hierarchy, single, double and triple, unique family of materials can be fabricated. Existing and prospective applications and future challenges of the materials are also shown.

DOI： 10.2109/jcersj.115.169

High-throughput protein digestion by trypsin-immobilized monolithic silica with pipette-tip formula Reviewed

Shigenori Ota, Shota Miyazaki, Hideo Matsuoka, Kei Morisato, Yukihiro Shintani, Kazuki Nakanishi

JOURNAL OF BIOCHEMICAL AND BIOPHYSICAL METHODS Vol. 70 ( 1 ) page： 57 - 62 2007.2

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Based on the monolithic silica gel materials with hierarchical pore structure and on the SPE devices (MonoTip (R)) developed thereof, a trypsin-immobilized monolithic silica in a pipette tip (MonoTip (R) Trypsin) suitable for digesting proteins has been newly developed. The surface of monolithic silica fixed into the tip was chemically modified with trypsin via an aminopropyl group. Trypsin-immobilized monolith successfully performed a rapid digestion of reduced and alkylated proteins with only a few times pipetting operation for the pre-treatment procedure of chromatographic analysis. The novel solid-phase digestion tool using monolithic silica allows a high-throughput trypsin proteolysis of bio-substances in proteomics. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jbbm.2006.10.005

Size-exclusion effect and protein repellency of concentrated polymer brushes prepared by surface-initiated living radical polymerization Reviewed

Chiaki Yoshikawa, Atsushi Goto, Norio Ishizuka, Kazuki Nakanishi, Akio Kishida, Yoshinobit Tsujii, Takeshi Fukuda

MACROMOLECULAR SYMPOSIA Vol. 248 page： 189 - 198 2007

Language：English Publishing type：Research paper (international conference proceedings) Publisher：WILEY-V C H VERLAG GMBH

The adsorption of proteins on poly(2-hydroxyethyl methacrylate) (PHEMA) brushes was systematically investigated from the viewpoint of the size-exclusion effect of the concentrated brushes. By use of surface-initiated atom transfer radical polymerization, well-defined, concentrated PHEMA brushes were successfully grafted on the inner surface of the silica monolithic column with meso pores of ca. 80 nm as well as a silicon wafer and a quartz crystal microbalance (QCM) chip. By eluting low-polydispersity pullulans with different molecular weight through the modified monolithic column, the concentrated PHEMA brush was characterized and demonstrated to sharply exclude solute molecules with the critical molecular size (size-exclusion limit) comparable to the distance between the nearest-neigh boring graft points d. The elution behaviors of proteins with different sizes were studied with this PHEMA-grafted column: the protein sufficiently larger than the critical size was perfectly excluded from the brush layer and separated only in the size-exclusion mode by the meso pores without affinity interaction with the brush surface. Then, the irreversible adsorption of proteins on PHEMA brushes was investigated using QCM by varying graft densities (or = 0.007, o.M, and 0.7 chains/nm(2)) and protein sizes (effective diameter = 2-13 nm). A good correlation between the protein size and the graft density was observed: proteins larger than d caused no significant irreversible adsorption on the PHEMA brushes. Thus, we experimentally substantiated the postulated size-exclusion effect of the concentrated brushes and confirmed that this effect plays an important role for suppressing protein adsorption.

DOI： 10.1002/masy.200750220

Monolithic TiO2 with controlled multiscale porosity via a template-free sol-gel process accompanied by phase separation Reviewed

Junko Konishi, Koji Fujita, Kazuki Nakanishi, Kazuyuki Hirao

CHEMISTRY OF MATERIALS Vol. 18 ( 25 ) page： 6069 - 6074 2006.12

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

This article describes the fabrication of multiscale porous nanocrystalline TiO2 monoliths through a one-step method that combines a sol-gel process and phase separation in template-free conditions. A large-dimension monolith with well-defined macropores and a mesostructured anatase-type TiO2 gel skeleton is spontaneously obtained by controlling the solution pH during the hydrolysis and polycondensation reactions of titanium alkoxides. The size of the macropores is adjusted by the starting composition, and a crystallized anatase TiO2 skeleton is formed without heat treatment. The use of titanium alkoxide strengthens the gel network by the formation of chemical bonding in the condensation reaction, which yields porous monoliths with higher mechanical strength than for the case of porous monoliths derived from colloidal TiO2 using freeze drying to maintain the porous morphology. The average crystallite size of anatase TiO2 nanocrystals was found to be about 3.6 nm for the dried gel and about 5.0 nm for the gel calcined at 300 degrees C. As a result of the growth of the anatase TiO2 nanoparticles, the mesopores with a median size of 5.0 nm are obtained. The high surface area (similar to 150 m(2)/g) is maintained even after the heat treatment at 300 degrees C.

DOI： 10.1021/cm0617485

New macroporous crosslinked polymer gels prepared via living radical polymerization

K. Kanamori, K. Nakanishi, T. Hanada

Materials Research Society Symposium Proceedings Vol. 947 page： 66 - 71 2006.12

Language：English Publishing type：Research paper (scientific journal)

Macroporous crosslinked polymer gels have been prepared via TEMPO-mediated living radical polymerization of divinylbenzene (DVB) in a solvent with a counter polymer. Incorporating a counter polymer, poly(dimethylsiloxane) (PDMS), induced macroscopic spinodal-type phase separation during the course of polymerization of DVB while suppressing the segregation of DVB-derived particles from the solution by living polymerization. Well-defined macroporous morphologies comprising continuous DVB-derived skeletons have thus obtained. Macropore volume and diameter were independently controlled by altering the concentrations of PDMS and the solvent. Since the present polymer gels are prepared using only the multifunctional "crosslinker", mechanical durability against bending and compression was found to be as high as inorganic ceramics with similar morphologies and porosities. © 2007 Materials Research Society.

Performance of octadecylsilylated monolithic silica capillary columns of 530 mu m inner diameter in HPLC Reviewed

Masanori Motokawa, Masayoshi Ohira, Hiroyoshi Minakuchi, Kazuk Nakanishi, Nobuo Tanaka

JOURNAL OF SEPARATION SCIENCE Vol. 29 ( 16 ) page： 2471 - 2477 2006.11

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Monolithic silica capillary columns were successfully prepared in a fused silica capillary of 530 mu m inner diameter and evaluated in HPLC after octadecylsilylation (ODS). Their efficiency and permeability were compared with those of columns pakked with 5-mu m and 3-mu m ODS-silica particles. The monolithic silica columns having different domain sizes (combined size of through-pore and skeleton) showed 2.5-4.0-times higher permeability (K = 5.2-8.4 x 10(-14) m(2)) than capillary columns packed with 3-mm particles, while giving similar column efficiency. The monolithic silica capillary columns gave a plate height of about 11-13 mu m, or 11200-13400 theoretical plates/150 mm column length, in 80% methanol at a linear mobile phase velocity of 1.0 mm/s. The monolithic column having a smaller domain size showed higher column efficiency and higher pressure drop, although the monolithic column with a larger domain size showed better overall column performance, or smaller separation impedance (E value). The larger-diameter (530 gm id) monolithic silica capillary column afforded a good peak shape in gradient elution of proteins at a flow rate of up to 100 mu L/min and an injection volume of up to 10 mu L.

DOI： 10.1002/jssc.200600335

Thick silica gel coatings on methylsilsesquioxane monoliths using anisotropic phase separation Reviewed

Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada

JOURNAL OF SEPARATION SCIENCE Vol. 29 ( 16 ) page： 2463 - 2470 2006.11

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Silica gel coatings on methyltrimethoxysilane (MTMS)-derived monoliths have been studied using wetting transition. Wetting transition is observed in a small confined space, where a coating solution phase-separates into a well-coarsened dimension, making all the phase-separating polymerizing silica phase dynamically flow onto the existing surface of a mold. Bulk coating experiments have shown reductions of both macropore volume and diameter due to the coated layer. Comparing HPLC efficiencies of the coated monolith with those of the non-coated MTMS monolith revealed that the retention factors drastically increased in both normal- and reversed-phase modes. This is attributed to the existence of considerable amounts of accessible micropores left inside the coated layer, where analyte molecules travel and adsorb for a considerable period of time.

DOI： 10.1002/jssc.200600163

Living radical polymerization in size-exclusion silica gel column reactors

Masao Katsube, Makoto Ouchi, Tsuyoshi Ando, Mitsuo Sawamoto, Kazuki Nakanishi, Norio Ishizuka

Polymer Preprints, Japan Vol. 55 page： 150 2006.10

Language：English Publishing type：Research paper (scientific journal)

This work was aimed to development of continuous-flow living radical polymerization in a silica-gel column, "Chromolith", focusing its separation function by combination of surface chemical absorption and size-exclusion via uniquely shaped mesopores, Thus, living radical copolymerization of two monomers with different polarities, methyl methacrylate (MMA) and 2(dimethylamino)ethyl methacrylate (DMAEMA) was performed with a catalyst [2; Ru(Ind)Cl(PPh3)2] coupled with an initiator (1). Copolymers were continuously produced, and molecular weight distributions were narrower than that in the corresponding batch process.

Morphological control and strong light scattering in macroporous TiO2 monoliths prepared via a colloid-derived sol-gel route Reviewed

Koji Fujita, Junko Konishi, Kazuki Nakanishi, Kazuyuki Hirao

SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS Vol. 7 ( 6 ) page： 511 - 518 2006.9

Language：English Publishing type：Research paper (scientific journal) Publisher：NATL INST MATERIALS SCIENCE

Macroporous titania (TiO2) monoliths have been prepared via the sol-gel route started from aqueous anatase-type titania colloid in the presence of poly(ethylene oxide) (PEO), and the light-scattering properties have been investigated by means of coherent backscattering. Well-defined macroporous bicontinuous structures are formed when the transient structure of phase separation is fixed as the permanent morphology by the sol-gel transition. The macroporous morphology, i.e., the size and volume fraction of continuous macropores, can be tailored by adjusting the amount and/or molecular weight of PEO and the TiO2 concentration in the starting solution. During the heat treatment at temperatures above 1000 degrees C, the skeleton is sintered into fully dense body, and the crystalline structure is transformed from anatase to rutile phases, while keeping the macroporous morphology. We show that the rutile-type TiO2-based macroporous monoliths are strongly scattering media for visible light and that the scattering strength can be controlled by the macroporous morphology. (c) 2006 NIMS and Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.stam.2006.04.014

Monolithic silica capillary column extraction of methamphetamine and amphetamine in urine coupled with thin-layer chromatographic detection Reviewed

Akihiro Nakamoto, Akira Namera, Manami Nishida, Mikio Yashiki, Takako Kuramoto, Yoshiyuki Takei, Masahiro Furuno, Hiroyoshi Minakuchi, Kazuki Nakanishi, Kojiro Kimura

Forensic Toxicology Vol. 24 ( 2 ) page： 75 - 79 2006.9

Language：English Publishing type：Research paper (scientific journal)

A monolithic silica capillary column was first developed in Japan in 2001 as a new tool for better liquid chromatographic separation. The column is made of C18-bonded monolithic silica packed into a capillary glass tube (0.20 mm i.d.). In this study, we used this column for solid-phase extraction of methamphetamine (MA) and amphetamine (AP) in urine. Chromatographic separation was achieved by thin-layer chromatography (TLC) with double-spray detection of each spot. For extraction of amphetamines in urine, samples were mixed with phosphate buffer (pH 3.0, containing 20mM sodium octanesulfate), and the analytes were adsorbed to the column by passing the mixture through it. They were then eluted with a 10-μl volume of ethyl acetate and directly spotted onto a TLC plate. After development, the detection of MA was performed with Simon's reagent. The plate was air-dried, and then over-sprayed with fluorescamine reagent for detection of AP. A fluorescent spot of AP was observed at 365 nm using an ultraviolet viewing system. The detection limits of MA and AP in urine were about 1.0 and 2.0μg/ml, respectively. To confirm the usefulness of this method, the eluent from the column was also analyzed by gas chromatography-mass spectrometry (GC-MS) after derivatization with heptafluorobutyric anhydride. In analysis of 30 actual urine samples, the results obtained by the monolith-TLC system were generally well in accordance with those obtained by GC-MS. © 2006 Japanese Association of Forensic Toxicology and Springer-Verlag Tokyo.

DOI： 10.1007/s11419-006-0009-z

Other Link： http://orcid.org/0000-0002-8069-4780

High-performance liquid chromatographic enantioseparations on capillary columns containing crosslinked polysaccharide phenylcarbamate derivatives attached to monolithic silica Reviewed

Bezhan Chankvetadze, Takateru Kubota, Tomoyuki Ikai, Chiyo Yamamoto, Masami Kamigaito, Nobuo Tanaka, Kazuki Nakanishi, Yoshio Okamoto

JOURNAL OF SEPARATION SCIENCE Vol. 29 ( 13 ) page： 1988 - 1995 2006.8

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Monolithic capillary columns containing native silica gel were covalently modified with 3,5-disubstituted phenylcarbamate derivatives of cellulose and amylose and applied for enantioseparations in capillary LC. The method previously used for covalent immobilization of polysaccharide phenylcarbamate derivatives onto the surface of microparticulate silica gel was successfully adapted for in situ modification of monolithic fused-silica capillary columns. The effects of the nature of polysaccharide and the substituents, as well as of multiple covalent immobilization of polysaccharide derivative on chromatographic performance of capillary columns were studied. The capillary columns obtained using this technique are stable in all solvents commonly used in LC and exhibit promising enantiomer resolving ability.

DOI： 10.1002/jssc.200500388

Fabrication of Sm2+-doped macroporous aluminosilicate glasses with high alumina content Reviewed

Takayuki Hirao, Koji Fujita, Shunsuke Murai, Kazuki Nakanishi, Kazuyuki Hirao

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 352 ( 23-25 ) page： 2553 - 2557 2006.7

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Macroporous Al2O3-SiO2 glasses doped with Sm2+ have been prepared from a sol-gel system containing aluminum sec-butoxide, tetramethoxysilane, samarium chloride hexahydrate, poly(ethylene oxide), nitric acid, and water. Monolithic gels having interconnected macropores and skeletons are formed by inducing the phase separation parallel to the gelation. The use of aluminum sec-butoxide preheated at 80 degrees C as the starting material enables the incorporation of Al3+ into the gel skeleton up to 20 mol% in cation ratio. The maximum amount of Al3+, i.e., 20 mol%, is twice as large as that reported in our previous study, where aluminum sec-butoxide was diluted with sec-butanol prior to the hydrolysis. Heat-treatment of Sm3+-doped 20AlO(3/2)center dot 80SiO(2) macroporous glass under the reducing atmosphere converts Sm3+ to Sm2+, which is confirmed by the appearance of intense emission peaks attributed to 4f-4f transitions of Sm2+. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jnoncrysol.2006.02.101

Formation of photonic structures in Sm2+-doped aluminosilicate glasses through phase separation Reviewed

Koji Fujita, Shunsuke Murai, Kazuki Nakanishi, Kazuyuki Hirao

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 352 ( 23-25 ) page： 2496 - 2500 2006.7

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Sm2+-doped Al2O3-SiO2 glasses with three-dimensionally interconnected macroporous morphology have been prepared via the alkoxide-derived sol-gel process containing poly(ethylene oxide) and SmCl3 center dot 6H(2)O. The macroporous morphology is obtained by concurrently inducing the phase separation and sol-gel transition. When the macroporous aluminosilicate glasses doped with Sm2+ are irradiated with a visible light laser at the wavelength of 488 nm, a hole or a dip appears in the plot of fluorescence intensity versus the incident angle of laser beam, indicating that the valence state of Sm2+ is spatially modulated through the interference of multiply scattered light. The hole profile can be controlled by adjusting the macroporous morphology. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jnoncrysol.2006.03.024

Anisotropic siloxane-based monolith prepared in confined spaces Reviewed

Y Suzumura, K Kanamori, K Nakanishi, K Hirao, J Yamamichi

JOURNAL OF CHROMATOGRAPHY A Vol. 1119 ( 1-2 ) page： 88 - 94 2006.6

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

When bicontinuous gels are prepared via sol-gel method in a 2-dimensionally (21)) confined space, the gel skeletons in the vicinity of interface of a mold are elongated perpendicular to the interface. This phenomenon was attributed to the dynamic wetting of polymerizing siloxane phase onto the interface of the mold under gravity. In this paper, we report the successful preparation of monolithic columns with an oriented pillar structure in a variety of 2D confined spaces. Starting from a solution, which consists of methyltrimethoxysilane (MTMS), the macroporous structure is prepared in situ by a completely spontaneous process. In the oriented pillar structure, bicontinuous siloxane skeletons deformed or disappeared and most pillars are oriented along the direction of gravity. Gel morphologies with the pillar structure were examined by scanning electron microscopy (SEM) and laser scanning confocal microscopy (LSCM). Geometrical information on gel morphologies was numerically derived from the obtained 3D LSCM images. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.chroma.2006.02.059

Mutual consistency between simulated and measured pressure drops in silica monoliths based on geometrical parameters obtained by three-dimensional laser scanning confocal microscope observations Reviewed

Haruko Saito, Kazuki Nakanishi, Kazuyuki Hirao, Hiroshi Jinnai

JOURNAL OF CHROMATOGRAPHY A Vol. 1119 ( 1-2 ) page： 95 - 104 2006.6

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

The geometrical properties of co-continuous macroporous silica monoliths have been studied by laser scanning confocal microscopy (LSCM) and a comparison has been made with those obtained by conventional mercury intrusion method. Tetrahedral skeleton model (TMS), which mimics the gel skeleton shape of monoliths, was compared with real monoliths in terms of macropore and porosity using the geometrical parameters extracted from the LSCM observations. Liquid flow behavior through the macroporous silica monoliths was examined in comparison with those simulated using TSM, based on the geometrical properties obtained from LSCM observations. Heterogeneity in macropore topology and connectivity in pores and skeletons are suggested to contribute to the improvement of the model structure for macroporous monoliths. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.chroma.2006.03.087

Sol-gel process of oxides accompanied by phase separation Reviewed

Kazuki Nakanishi

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN Vol. 79 ( 5 ) page： 673 - 691 2006.5

Language：English Publishing type：Research paper (scientific journal) Publisher：CHEMICAL SOC JAPAN

A versatile sol-gel method for fabricating porous oxide materials with well-defined co-continuous macropores has been reviewed. The chemical instability, in many cases induced by polymerization of the network-forming components, triggers the formation of biphasic morphologies, followed by an irreversible freezing of the transient morphology by the sol-gel transition of the gelling phase. Upon removal of the non-gelling phase, an oxide framework comprising of controlled macropores can be obtained. The mesopore system of such macroporous materials can be further modified either by a physico-chemical treatment or a supramolecular templating technique. Pure silica and siloxane-based organic-inorganic hybrids with a hierarchical pore system in monolithic form have been successfully applied to the novel type of separation medium for high performance liquid chromatography, HPLC. Additional topics are also described including recent advances in the 3D-analysis of the interfacial properties of macroporous systems, extended compositional variations in the network-forming phase, and emerging applications in areas of biochemistry.

DOI： 10.1246/bcsj.79.673

High-performance liquid chromatographic enantioseparations on capillary columns containing monolithic silica modified with amylose tris(3,5-dimethylphenylcarbamate) Reviewed

B Chankvetadze, C Yamamoto, M Kamigaito, N Tanaka, K Nakanishi, Y Okamoto

JOURNAL OF CHROMATOGRAPHY A Vol. 1110 ( 1-2 ) page： 46 - 52 2006.3

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Monolithic capillary columns containing native silica were modified by in situ coating with amylose tris(3,5-dimethylphenylcarbamate) and applied for enantioseparations in capillary liquid chromatography. Capillary columns were examined for 10 standard racemic compounds in order to compare the performance of monolithic silica columns with the common, 4.6 mm I.D. high-performance liquid chromatographic columns packed with particulate silica. The effects of polysaccharide coating and of the linear velocity of the mobile phase on peak performance were studied. Enantioseparations with an analysis time below 1 min were achieved for some chiral analytes. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.chroma.2006.01.076

Phase-separation-induced Titania monoliths with well-derined macropores and mesostructured framework from colloid-derived sol-gel systems Reviewed

J Konishi, K Fujita, K Nakanishi, K Hirao

CHEMISTRY OF MATERIALS Vol. 18 ( 4 ) page： 864 - 866 2006.2

Direct observation of the spatial distribution of samarium ions in alumina-silica macroporous monoliths by laser scanning confocal microscopy Reviewed

S Murai, K Fujita, K Nakanishi, K Hirao

JOURNAL OF ALLOYS AND COMPOUNDS Vol. 408 page： 831 - 834 2006.2

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE SA

We have investigated the spatial distribution of Sm2+ inside macroporous alumina-silica (Al2O3-SiO2) glasses having three-dimensionally interconnected skeletons. The Sm2+-doped Al2O3-SiO2 glasses are prepared via an alkoxy-derived sol-gel route in the presence of poly (ethylene oxide) and SmCl3.6H(2)O. The well-defined macroporous morphology is obtained by the concurrence of the phase separation and the sol-gel transition. The reduction of Sm3+ to Sm2+ is accomplished by heat treatment under a reducing atmosphere. Two-dimensional images of the fluorescence due to the 4f-4f transition of Sm2+ with the aid of a laser scanning confocal microscope reveal the spatially uniform dispersion Of Sm2+ inside the Al2O3-SiO2 skeleton. (c) 2005 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jallcom.2005.01.085

Basic study of the gelation of dimethacrylate-type crosslinking agents Reviewed

H Aoki, K Hosoya, T Norisuye, N Tanaka, D Tokuda, N Ishizuka, K Nakanishi

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY Vol. 44 ( 2 ) page： 949 - 958 2006.1

Language：English Publishing type：Research paper (scientific journal) Publisher：JOHN WILEY & SONS INC

An investigation was made of the gelation of dimethacrylate-type crosslinking agents in view of an application for separation media. The study mainly centered on a crosslinking agent, glycerol dimethaerylate (GDMA), which is relatively hydrophilic because of a hydroxyl group in the middle of its structure. The gelation of GDMA was compared with that of other hydrophobic crosslinking agents such as ethylene glycol dimethacrylate and 1,6-hexanediol dimethacrylate. The diluents used in the study were toluene, toluene with methanol, and cyclohexanol. The gelation was observed in real time with a charge coupled device camera and dynamic light scattering (DLS). Also, the separated dry gels were extensively characterized with scanning electron microscopy, BET (N-2 absorption and desorption isotherm), and Fourier transform infrared. DLS analysis showed a stronger molecular interaction of GDMA gelation in toluene, whereas this interaction was much weaker in an alcoholic solvent such as toluene with methanol or cyclohexanol. This indicated that GDMA gelation might proceed through hydrogen bonding as well as a crosslinking reaction of vinyl groups. (c) 2005 Wiley Periodicals, Inc.

DOI： 10.1002/pola.21205

Size exclusion chromatography of standard polystyrenes with a wide range of molecular weight up to 7.45 x 10(6) on monolithic silica capillary columns Reviewed

Koichi Ute, Saori Yoshida, Tatsuki Kitayama, Takeshi Bamba, Kazuo Harada, Eiichiro Fukusaki, Akio Kobayashi, Norio Ishizuka, Hiroyoshi Minakuchi, Kazuki Nakanishi

POLYMER JOURNAL Vol. 38 ( 11 ) page： 1194 - 1197 2006

Porous methylsiloxane gel thick film for millimeter-wave antenna substrate prepared by gap filling method Reviewed

Takeharu Tanaka, Nobuyuki Kawakami, Takayuki Hirano, Yoshito Fukumoto, Tetsuo Suzuki, Kazuyoshi Kanamori, Kazuki Nakanishi

MATERIAL AND DEVICES FOR SMART SYSTEMS II Vol. 888 page： 251 - + 2006

Language：English Publishing type：Research paper (international conference proceedings) Publisher：MATERIALS RESEARCH SOC

A novel process to fabricate a thick silica gel film on an aluminum substrate, named the gap filling method", has been developed. The process is based on a sol-gel method accompanied by phase separation in a submillimeter thick space defined by two facing substrates. Dielectric thick film integrated on a metal ground plate is successfully formed by using a SiO2 coated aluminum substrate and a cap plate covered with an amorphous carbon thin film, which control the hydrophilicity and the hydrophobicity of the plates, respectively. A thin continuous layer of less than 0. fn thick is formed at the interface between the porous film and the cap plate, which gives the film a smooth surface preferable for patterning metal circuits of an antenna. The observed dielectric constants (epsilon r) at 60 GHz measured by the Fabry-Perot resonator method are in the range between 1.4 and 1.6. Methyl groups homogeneously distributed in the siloxane network give a hydrophobic siloxane gel film, thus the obtained films have enough environmental stability. These results show that the gap filling method is applicable to the preparation of the porous thick film that is needed for antenna applications.

Preparation of novel macroporous polymer monoliths using polymerization-induced phase separation Reviewed

K. Kanamori, K. Nakanishi

Polymer Preprints, Japan Vol. 55 ( 1 ) page： 929- 2006

Control of light scattering in organic-inorganic hybrid macroporous monoliths

Takayuki Hirao, Shunsuke Murai, Koji Fujita, Kazuki Nakanishi, Kazuyuki Hirao

Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy Vol. 52 ( 10 ) page： 781 - 785 2005.10

Language：Japanese Publishing type：Research paper (scientific journal)

The tuning of light scattering strength has been demonstrated for organic-inorganic hybrid monoliths with well-defined through-pores in micrometer range. Macroporous gels having interconnected pores and skeletons are obtained in a system containing methyltrimethoxysilane, water, nitric acid, and methanol using an alkoxy-derived sol-gel method combined with the phase separation. The sizes of pores and skeletons can be controlled by varying molar ratios of water and methanol in the starting compositions which mostly affect the onset of polymerization-induced phase separation in the system. The mercury porosimetry shows that the resultant gels have a sharp pore size distribution, and the average pore diameter increases with increasing the amount of water and methanol. The coherent backscattering measured for the gels formed in between two slide glasses reveals that the transport mean free path of light decreases with decreasing the sizes of pores and skeletons. Pore size dependence of the scattering strength can be qualitatively explained by a Mie scattering calculation using a model in which spherical pores are randomly distributed in methylsiloxane matrix. The results indicate that the scattering strength can be tuned by controlling the sizes of the pores.

DOI： 10.2497/jjspm.52.781

Tailoring spontaneous pillar structure using phase-separating organosiloxane sol-gel systems in micro-fabricated grooves Reviewed

K Kanamori, K Nakanishi, K Hirao, H Jinnai

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 35 ( 3 ) page： 183 - 191 2005.9

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

A sharp transition to pillar structure has been observed in simple sol-gel systems accompanying phase separation inside rectangular-sectioned open grooves which were fabricated on a silica glass chip. The structural variation was investigated using two contrastive systems; one with a rapid sol-gel reaction and the other with a sluggish reaction. In the slower system, transition from web-like bicontinuous structure to pillar structure, we call it as "web-to-pillar transition", occurred when the bulk characteristic length Lambda(m) m exceeded the width of the groove D. On the other hand, the transition did not occur in the same condition in the faster system; it occurred when Lambda(m) became much longer than D. A consistent formation mechanism model was also proposed using a relation between interfacial curvatures and pressure.A sharp transition to pillar structure has been observed in simple sol-gel systems accompanying phase separation inside rectangular-sectioned open grooves which were fabricated on a silica glass chip. The structural variation was investigated using two contrastive systems; one with a rapid sol-gel reaction and the other with a sluggish reaction. In the slower system, transition from web-like bicontinuous structure to pillar structure, we call it as "web-to-pillar transition", occurred when the bulk characteristic length Lambda(m) exceeded the width of the groove D. On the other hand, the transition did not occur in the same condition in the faster system; it occurred when Lambda(m) became much longer than D. A consistent formation mechanism model was also proposed using a relation between interfacial curvatures and pressure.

DOI： 10.1007/s10971-005-4166-z

An application of silica-based monolithic membrane emulsification technique for easy and efficient preparation of uniformly sized polymer particles Reviewed

K Hosoya, M Bendo, N Tanaka, Y Watabe, T Ikegami, H Minakuchi, K Nakanishi

MACROMOLECULAR MATERIALS AND ENGINEERING Vol. 290 ( 8 ) page： 753 - 758 2005.8

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

Uniformly sized polymer particles were prepared by an emulsification and polymerization technique utilizing a silica monolithic membrane, namely the "silica monolithic membrane emulsification technique". In this paper, we utilized silica monolithic membrane as a device for the preparation of uniformly sized polymer particles. A mixture of monomers, diluents and oil-soluble initiator was emulsified into a continuous medium through the silica monolithic membrane and polymerized. The particles obtained had a higher size uniformity than that of particles prepared by previously reported membrane emulsification techniques, such as the Shirasu Porous Glass (SPG) emulsification technique. Through the silica monolithic membrane emulsification technique, we could prepare particles having availability as a possible packing material for solid-phase extraction (SPE) and high performance liquid chromatography (HPLC).

DOI： 10.1002/mame.200500006

Silica monolithic membrane as separation medium - Summable property of different membranes for high-performance liquid chromatographic separation Reviewed

K Hosoya, T Ogata, Y Watabe, T Kubo, T Ikegami, N Tanaka, H Minakuchi, K Nakanishi

JOURNAL OF CHROMATOGRAPHY A Vol. 1073 ( 1-2 ) page： 123 - 126 2005.5

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

We studied an applicability of a silica monolithic membrane as separation medium for high-performance liquid chromatography (HPLC). We prepared porous monolithic silica membranes having a three-dimensional network structure to cut and shape into a membrane separation medium. We evaluated chromatographic properties of a variety of solutes using a column containing the membranes with HPLC to elucidate summable property of the membrane separation media. In addition, we made brief study on separation of HbA1c in whole blood with the "stacked" membranes having different surface characteristics in one column, which is a membrane column. We confirmed that the membrane column was able to separate HbA1c from other matrix in whole blood to some extent, and it also had an excellent ability for hydrophobic and ion exchange adsorption. &COPY; 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.chroma.2004.09.042

Monolithic periodic mesoporous silica with well-defined macropores Reviewed

T Amatani, K Nakanishi, K Hirao, T Kodaira

CHEMISTRY OF MATERIALS Vol. 17 ( 8 ) page： 2114 - 2119 2005.4

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CHEMICAL SOC

Monolithic pure silica gels with hierarchical macro-mesoporous structure have been synthesized via a spontaneous sol-gel process from silicon alkoxide using a structure-directing agent and a micelle-swelling agent. A monolithic body with well-defined co-continuous macropores is a result of concurrent phase separation and sol-gel transition induced by the polymerization reaction, whereas the mesopores are templated by the cooperative self-assembly of inorganic species, a structure-directing agent, and a micelle-swelling agent. These bimodal pore systems are formed spontaneously in a closed condition at a constant temperature. The following removal of surfactants by heat-treatment gives silica gels with hierarchical and fully accessible pores in discrete size ranges of micrometers and nanometers. The highly ordered 2D-hexagonal arrays of mesopores have been confirmed by X-ray diffraction measurements and FE-SEM observations. Furthermore, by further additions of the micelle-swelling agent, the mesostructural transition from well-ordered 2D-hexagonal arrays to mesostructured cellular foams (MCF) has been induced accompanied by minor modifications of the micrometer-range structure.

DOI： 10.1021/cm048091c

High-performance frontal analysis of the binding of thyroxine enantiomers to human serum albumin Reviewed

Kimura T, Nakanishi K, Nakagawa T, Shibukawa A, Matsuzaki K

PHARMACEUTICAL RESEARCH Vol. 22 ( 4 ) page： 667 - 675 2005.4

Recent advances in the design of monolithic silica columns: From small to big dimensions. Reviewed

K Cabrera, A Kraus, H Minakuchi, K Nakanishi

ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY Vol. 229 page： U144 - U144 2005.3

Insight on structural change in sol-gel-derived silica gel with aging under basic conditions for mesopore control Reviewed

R Takahashi, K Nakanishi, N Soga

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 33 ( 2 ) page： 159 - 167 2005.2

Language：English Publishing type：Research paper (scientific journal) Publisher：SPRINGER

Structural rearrangement of sol-gel-derived silica gel by aging under basic conditions was investigated using small angle X-ray scattering (SAXS) and Si-29 nuclear magnetic resonance (NMR). A wet silica gel prepared under acidic conditions had a fractal nature, and many unreacted silanols remained on the surface. During aging of the gel in ammonia solution, additional Si-O-Si bonds rapidly formed, whereas the change in mesoscale structure gradually proceeded. This result was compared with that of simulation modeling the Ostwald ripening, i.e. dissolution from positive curvature and reprecipitation on negative curvature. In the simulation, structural change in a cluster from fractal nature to particle aggregates was well visualized in 2-dimmensional square lattice. Both scattering profiles calculated from the model clusters and the change in average coordination number of monomers in the cluster well agreed with the experimental SAXS and NMR results, respectively. This agreement strongly ensures us that structural change by aging under basic conditions proceeds through the Ostwald ripening. The mesopore size as well as mesopore volume in calcined silica gel is determined by the shrinkage degree during drying and calcination. The sample aged in basic solution restrains the shrinkage because of the growth of particulate structure, and retains large size and volume of pores.

DOI： 10.1007/s10971-005-5610-9

Titania-coated monolithic silica as separation medium for high performance liquid chromatography of phosphorus-containing compounds Reviewed

S Miyazaki, MY Miah, K Morisato, Y Shintani, T Kuroha, K Nakanishi

JOURNAL OF SEPARATION SCIENCE Vol. 28 ( 1 ) page： 39 - 44 2005.1

Language：English Publishing type：Research paper (scientific journal) Publisher：WILEY-V C H VERLAG GMBH

A method of preparing titania-coated monolithic silica stationary phase has been developed to achieve liquid chromatographic separation of phosphorus-containing compounds, which have recently been attracting increasing attention in biochemical research. The titania-coated silica columns exhibited efficient separation with low pressure drop, which is a typical feature of monolithic structures, and also possessed phospho-selectivity, which is a unique property of the titania surface. The material characteristics of titania-coated monolithic silica were examined, and then resin-clad columns were applied to the HPLC analysis of phosphorylated compounds. Highly efficient separation of phosphorylated substances indicated that the novel titania-coated monolithic silica column will find applications as a useful tool in the field of biochemistry, especially in post-genomic analyses.

DOI： 10.1002/jssc.200401932

Formation of photonic structures inSM(2+)-doped aluminosilicate glasses through phase separation Reviewed

K Fujita, S Murai, K Nakanishi, K Hirao

Micromachining Technology for Micro-Optics and Nano-Optics III Vol. 5720 page： 261 - 268 2005

Language：English Publishing type：Research paper (international conference proceedings) Publisher：SPIE-INT SOC OPTICAL ENGINEERING

Sm2+-doped Al2O3-SiO2 glasses with three-dimensionally interconnected macroporous morphology have been prepared via the alkoxy,-derived sol-gel process containing poly (ethylene oxide) and SmCl3 center dot 6H(2)O. The macroporous morphology . is obtained by cconcurrently inducing the phase separation and sol-gel transition. Using a visible laser with the wavelength of 488 nm, the valence State Of Sm2+ has been manipulated spatially, When the photoionization Of Sm2+ is combined with multiple light scattering in the porous glasses, holes are burned in wave-vector domain. The hole profile can be controlled by adjusting the macroporous morphology.

DOI： 10.1117/12.590712

Topical application of ionic polymers affects skin permeability barrier homeostasis Reviewed

M Denda, K Nakanishi, N Kumazawa

SKIN PHARMACOLOGY AND PHYSIOLOGY Vol. 18 ( 1 ) page： 36 - 41 2005

Language：English Publishing type：Research paper (scientific journal) Publisher：KARGER

We previously demonstrated that the external electric potential affected skin barrier homeostasis. On the other hand, topical application of an ionic polymer formed a diffusion electric double layer on the surface of the skin. Thus, we evaluated effects of topical application of ionic polymers on the damaged skin barrier. Application of a nonionic polymer did not affect barrier recovery. Application of sodium salts of anionic polymers accelerated barrier recovery, while that of cationic polymers delayed it. Topical application of a sodium-exchange resin accelerated barrier recovery, but application of a calcium-exchange resin had no effect even when the resins had the same structure. Application of a chloride-exchange resin delayed barrier recovery. Topical application of ionic polymers influenced skin barrier homeostasis.

DOI： 10.1159/000081684

Fabrication of macroporous TiO2 monoliths for photonic applications Reviewed

J Konishi, K Fujita, K Nakanishi, K Hirao

Micromachining Technology for Micro-Optics and Nano-Optics III Vol. 5720 page： 233 - 240 2005

Language：English Publishing type：Research paper (international conference proceedings) Publisher：SPIE-INT SOC OPTICAL ENGINEERING

Macroporous titania (TiO2) monoliths have been prepared by the sol-gel method including phase separation., and the light-scattering properties have been investigated by means of coherent backscattering. Macroporous TiO2 gels are obtained g a in the systems containing aqueous titania colloid and poly(ethylene oxide)(PEO). Three-dimensionally interconnected macroporous structure is formed when the transient structure of phase separation is fixed as the permanent morphology by the sol-gel transition. The domain size of macroporous TiO2 gels can be controlled reproducibly by adjusting the concentration of PEO. During the heat treatment above 1000 degrees C, the TiO2 skeleton is sintered into fully dense body and the crystalline structure is transformed from anatase to rutile, while maintaining macroporous morphology. We show that the rutile-type TiO2 -based macroporous monoliths are strongly scattering media for visible light.

DOI： 10.1117/12.591059

Hierarchical macro-mesoporous silica monolith Reviewed

T Amatani, K Nakanishi, K Hirao, T Kodaira

Organic/Inorganic Hybrid Materials-2004 Vol. 847 page： 121 - 126 2005

Language：English Publishing type：Research paper (international conference proceedings) Publisher：MATERIALS RESEARCH SOCIETY

Monolithic pure silica gels with hierarchical macro-mesoporous structure have been synthesized via spontaneous sol-gel process from silicon alkoxide using a structure-directing agent and a micelle-swelling agent. Monolithic body with well-defined co-continuous macropores is a result of concurrent phase separation and sol-gel transition induced by the polymerization reaction, whereas the mesopores are templated by the cooperative self-assembly of inorganic species, a structure-directing agent and a micelle-swelling agent. The following removal of surfactants by heat-treatment gives silica gels with hierarchical and fully accessible pores in discrete size ranges of micrometers and nanometers. The highly ordered 2D-hexagonal arrays of mesopores have been confirmed by X-ray diffraction measurements and FE-SEM observations. Furthermore, by further additions of the micelle-swelling agent, the mesostructural transition from well-ordered 2D-hexagonal arrays to mesostructured cellular foams (MCF) have been induced accompanied by minor modifications of the micrometer-range structure.

Organic-inorganic hybrid poly(silsesquioxane) monoliths with controlled macro- and mesopores Reviewed

K Nakanishi, K Kanamori

JOURNAL OF MATERIALS CHEMISTRY Vol. 15 ( 35-36 ) page： 3776 - 3786 2005

Language：English Publishing type：Research paper (scientific journal) Publisher：ROYAL SOC CHEMISTRY

Siloxane-based organic-inorganic hybrid monoliths with well-defined macropores and/or mesopores have been synthesized by a sol-gel process, accompanied by polymerization-induced phase separation. Using aklyltrialkoxysilanes and alkylene-bridged alkoxysilanes, two different categories of organosiloxane networks have been characterized in view of macroporosity (based on phase separation) and mesoporosity (supramolecularly templated by surfactants). While the alkyl-terminated poly(siloxane) networks exhibit substantial surface hydrophobicity accompanied by mechanical flexibility, the alkylene-bridged networks behave much more similarly to those prepared from tetraalkoxysilanes with regard to surface hydrophilicity, mechanical rigidness and mesopore-forming ability. The supramolecular templating of mesopores embedded in the gel skeletons (which comprise well-defined macroporous networks) has proven to give a wide variety of hierarchically-designed macro-mesoporous hybrid materials.

DOI： 10.1039/b508415f

Monolithic O/I-hybrids with hierarchically ordered meso- and macropores Reviewed

K Nakanishi, Y Kobayashi, T Amatani, K Hirao, T Kodaira

ORGANIC/INORGANIC HYBRID MATERIALS-2004 Vol. 847 page： 147 - 157 2005

Language：English Publishing type：Research paper (international conference proceedings) Publisher：MATERIALS RESEARCH SOCIETY

Organic-Inorganic hybrid gels with hierarchical well-defined macropores and supramolecularly templated mesopores with long-range orders have been synthesized in the systems of bridged poly(silsesquioxane) systems. Nonionic surfactants such as poly(ethyleneglycol)-poly(propyleneglycol)-poly(ethyleneglycol) triblock copolymers, EOPOEOs, were found to be effective both in inducing the phase separation to give macroporous morphology and in templating the mesopores with narrow size distribution. The number of methylene units in the bridge, changed from I to 6 in the present experiments, affected both the phase separation tendency and template strength. In the system containing 1,2-bis(trimethoxysilyl)ethane, 2D-hexagonal arrangement of mesopores have been prepared in the gel skeleton comprising the well-defined continuous macroporous network with an aid of micelle-stabilizing agent.

Living radical polymerization in ruthenium-bearing size-exclusion silica gel column reactors Reviewed

M. Katsube, T. Ando, M. Ouchi, M. Sawamoto, K. Nakanishi, N. Ishizuka

Polymer Preprints, Japan Vol. 54 ( 2 ) page： 2491- 2005

Real space observation of phase separating structure in a sol-gel system Reviewed

H. Saito, K. Kanamori, K. Nakanishi, K. Hirao, Y. Nishikawa, H. Jinnai

Polymer Preprints, Japan Vol. 54 ( 1 ) page： 705- 2005

Strong light scattering in macroporous TiO2 monoliths induced by phase separation Reviewed

Fujita K, Konishi J, Nakanishi K, Hirao K

APPLIED PHYSICS LETTERS Vol. 85 ( 23 ) page： 5595 - 5597 2004.12

Morphology control of phase-separation-induced alumina-silica macroporous gels for rare-earth-doped scattering media Reviewed

Murai S, Fujita K, Nakanishi K, Hirao K

JOURNAL OF PHYSICAL CHEMISTRY B Vol. 108 ( 43 ) page： 16670 - 16676 2004.10

Fabrication of dye-infiltrated macroporous silica for laser amplification Reviewed

Murai S, Fujita K, Nakanishi K, Hirao K

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 345 page： 438 - 442 2004.10

Spontaneous formation of hierarchical macro-mesoporous ethane-silica monolith Reviewed

Nakanishi K, Kobayashi Y, Amatani T, Hirao K, Kodaira T

CHEMISTRY OF MATERIALS Vol. 16 ( 19 ) page： 3652 - 3658 2004.9

Formation of interconnected macropores in Sm2+-doped silicate glasses through phase separation: Fabrication of photosensitive and dielectrically disordered materials

Fujita K, Murai S, Ohashi Y, Nakanishi K, Hirao K

CHEMISTRY LETTERS Vol. 33 ( 9 ) page： 1120-1121 2004.9

Formation of interconnected macropores in Sm<sup>2+</sup>-doped silicate glasses through phase separation: Fabrication of photosensitive and dielectrically disordered materials

Fujita K.

Chemistry Letters Vol. 33 ( 9 ) page： 1120-1121 2004.9

Tailoring photonic strength in monolithic macroporous silica for random media Reviewed

Murai S, Fujita K, Nakanishi K, Hirao K

JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS Vol. 43 ( 8A ) page： 5359 - 5364 2004.8

Development of a monolithic silica extraction tip for the analysis of proteins Reviewed

S Miyazaki, K Morisato, N Ishizuka, H Minakuchi, Y Shintani, M Furuno, K Nakanishi

JOURNAL OF CHROMATOGRAPHY A Vol. 1043 ( 1 ) page： 19 - 25 2004.7

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

In proteomics, pre-treatment of sample is the most important procedure to remove the matrix for interfacing with mass spectrometry (XIS). Additionally, for the samples with low concentration, the process of pre-concentration is required before MS analysis. We have newly developed solid-phase extraction (SPE) tool with pipette-tip shape for purification of bio-samples of various characteristics, utilizing monolithic silica gel as medium. The monolithic silica surface was modified with a C-18 phase or coated with titania phase. A C-18-bonded tip and a non-modified tip were used for sample concentration, desaltination and removal of detergents from sample. A titania-coated tip was also applied for purification and concentration of phosphorylated peptides. This novel pre-treatment method using monolithic silica extraction tip is much effective and suitable for protein analysis. (C) 2004 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.chroma.2004.03.025

High-performance liquid chromatographic enantioseparations on capillary columns containing monolithic Reviewed

Chankvetadze B, Yamamoto C, Tanaka N, Nakanishi K, Okamoto Y

JOURNAL OF SEPARATION SCIENCE Vol. 27 ( 10-11 ) page： 905 - 911 2004.7

Simple 2D-HPLC using a monolithic silica column for peptide separation Reviewed

Kimura H, Tanigawa T, Morisaka H, Ikegami T, Hosoya K, Ishizuka N, Minakuchi H, Nakanishi K, Ueda M, Cabrera K, Tanaka N

JOURNAL OF SEPARATION SCIENCE Vol. 27 ( 10-11 ) page： 897 - 904 2004.7

Structural formation of hybrid siloxane-based polymer monolith in confined spaces. Reviewed

Kanamori K, Yonezawa H, Nakanishi K, Hirao K, Jinnai H

Journal of separation science Vol. 27 ( 10-11 ) page： 874 - 86 2004.7

Simple and comprehensive two-dimensional reversed-phase HPLC using monolithic silica columns Reviewed

Tanaka N, Kimura H, Tokuda D, Hosoya K, Ikegami T, Ishizuka N, Minakuchi H, Nakanishi K, Shintani Y, Furuno M, Cabrera K

ANALYTICAL CHEMISTRY Vol. 76 ( 5 ) page： 1273 - 1281 2004.3

Controlled hierarchical pore structures in ethylene-bridged polysilsesquioxane gels Reviewed

Y Kobayashi, K Nakanishi, K Hirao

CONTINUOUS NANOPHASE AND NANOSTRUCTURED MATERIALS Vol. 788 page： 353 - 358 2004

Language：English Publishing type：Research paper (scientific journal) Publisher：MATERIALS RESEARCH SOCIETY

Formation of hierarchical macropores and mesopores in ethylene-bridged polysilsesquioxane sol-gel systems via concurrent sol-gel transition and phase separation induced by the incorporation of supramolecular templats has been investigated. A series of poly(ethyleneglycol)-poly(propyleneglycol)- poly(ethyleneglycol) triblock copolymers, EOPOEOs, have been employed as supramolecular templates, while 1,2-bis(trimethoxysilyl)ethane was used as a polysilsesquioxane source. Successful combination of templated mesopores and well-defined macropores due to phase-separation has been found in the system with EOPOEOs having 70 PO units and respective 20 EO units. Although similar macroporous morphology has been obtained for all the EOPOEOs with EO chain longer or shorter than 20 units, the optimum composition for the co-continuous macropores and that for templated mesopores deviated from each other, resulting in the failure of producing hierarchical macropores and mesopores.

Macroporous silica and alkylene-bridged polysilsesquioxane gels with templated nanopores Reviewed

Nakanishi K

CONTINUOUS NANOPHASE AND NANOSTRUCTURED MATERIALS Vol. 788 page： 337 - 346 2004

Macroporous morphology induced by phase separation in sol-gel systems derived from titania colloid Reviewed

Konishi J, Fujita K, Nakanishi K, Hirao K

CONTINUOUS NANOPHASE AND NANOSTRUCTURED MATERIALS Vol. 788 page： 391 - 396 2004

Development of a parallel HPLC system using monolithic silica capillary columns connected with chips

Daisuke Tokuda, Tohru Ikegami, Ken Hosoya, Yukihiro Shintani, Masahiro Furuno, Norio Ishizuka, Hiroyoshi Minakuchi, Kazuki Nakanishi, Nobuo Tanaka

Chromatography Vol. 25 page： 17 - 18 2004

Monolithic silica-based capillary reversed-phase liquid chromatography/electrospray mass spectrometry for plant metabolomics Reviewed

Tolstikov VV, Lommen A, Nakanishi K, Tanaka N, Fiehn O

ANALYTICAL CHEMISTRY Vol. 75 ( 23 ) page： 6737 - 6740 2003.12

Monolithic silica columns with chemically bonded beta-cyclodextrin as a stationary phase for enantiomer separations of chiral pharmaceuticals Reviewed

Lubda D, Cabrera K, Nakanishi K, Lindner W

ANALYTICAL AND BIOANALYTICAL CHEMISTRY Vol. 377 ( 5 ) page： 892 - 901 2003.11

Bonelike apatite formation on ethylene-vinyl alcohol copolymer modified with silane coupling agent and calcium silicate solutions Reviewed

A Oyane, M Kawashita, K Nakanishi, T Kokubo, M Minoda, T Miyamoto, T Nakamura

BIOMATERIALS Vol. 24 ( 10 ) page： 1729 - 1735 2003.5

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCI LTD

An ethylene-vinyl alcohol copolymer (EVOH) was treated with a silane coupling agent and calcium silicate solutions, and then soaked in a simulated body fluid (SBF) with ion concentrations approximately equal to those of human blood plasma. A smooth and uniform bonelike apatite layer was successfully formed on both the EVOH plate and the EVOH-knitted fibers in SBF within 2 days. Part of the structure of the resulting apatite-EVOH fiber composite was similar to that of natural bone. If this kind of composite can be fabricated into a three-dimensional structure similar to natural bone, the resultant composite is expected to exhibit both mechanical properties analogous to those of natural bone and bone-bonding ability. Hence, it has great potential as a bone substitute. (C) 2003 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0142-9612(02)00581-1

Monolithic silica column for in-tube solid-phase microextraction coupled to high-performance liquid chromatography Reviewed

Shintani Y, Zhou X, Furuno M, Minakuchi H, Nakanishi K

JOURNAL OF CHROMATOGRAPHY A Vol. 985 ( 1-2 ) page： 351 - 357 2003.1

Monolithic silica column for in-tube solid-phase microextraction coupled to high-performance liquid chromatography. Reviewed

Shintani Y, Zhou X, Furuno M, Minakuchi H, Nakanishi K

Journal of chromatography. A Vol. 985 ( 1-2 ) page： 351 - 7 2003.1

Phase separation in sol-gel system containing mixture of 3-and 4-functional alkoxysilanes Reviewed

Itagaki A, Nakanishi K, Hirao K

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 26 ( 1-3 ) page： 153 - 156 2003.1

Supramolecular templating of mesopores in phase-separating silica sol-gels incorporated with cationic surfactant Reviewed

Nakanishi K, Sato Y, Ruyat Y, Hirao K

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 26 ( 1-3 ) page： 567 - 570 2003.1

Controlled hierarchical pore structures in ethylene-bridged polysilsesquioxane gels Reviewed

Kobayashi Y., Nakanishi K., Hirao K.

Materials Research Society Symposium - Proceedings Vol. 788 page： 353 - 358 2003

Language：English Publishing type：Research paper (scientific journal) Publisher：Materials Research Society Symposium - Proceedings

Formation of hierarchical macropores and mesopores in ethylene-bridged polysilsesquioxane sol-gel systems via concurrent sol-gel transition and phase separation induced by the incorporation of supramolecular templats has been investigated. A series of poly(ethyleneglycol)-poly(propyleneglycol)- poly(ethyleneglycol) triblock copolymers, EOPOEOs, have been employed as supramolecular templates, while 1,2-bis(trimethoxysilyl)ethane was used as a polysilsesquioxane source. Successful combination of templated mesopores and well-defined macropores due to phase-separation has been found in the system with EOPOEOs having 70 PO units and respective 20 EO units. Although similar macroporous morphology has been obtained for all the EOPOEOs with EO chain longer or shorter than 20 units, die optimum composition for the co-continuous macropores and that for templated mesopores deviated from each other, resulting in the failure of producing hierarchical macropores and mesopores.

DOI： 10.1557/proc-788-ll3.10

Monolithic silica columns for high-efficiency chromatographic separations Reviewed

Tanaka N, Kobayashi H, Ishizuka N, Minakuchi H, Nakanishi K, Hosoya K, Ikegami T

JOURNAL OF CHROMATOGRAPHY A Vol. 965 ( 1-2 ) page： 35 - 49 2002.8

Monolithic silica columns for high-efficiency chromatographic separations. Reviewed

Tanak N, Kobayashi H, Ishizuka N, Minakuchi H, Nakanishi K, Hosoya K, Ikegami T

Journal of chromatography. A Vol. 965 ( 1-2 ) page： 35 - 49 2002.8

Monolithic silica columns with various skeleton sizes and through-pore sizes for capillary liquid chromatography Reviewed

Motokawa M, Kobayashi H, Ishizuka N, Minakuchi H, Nakanishi K, Jinnai H, Hosoya K, Ikegami T, Tanaka N

JOURNAL OF CHROMATOGRAPHY A Vol. 961 ( 1 ) page： 53 - 63 2002.6

Monolithic silica columns with various skeleton sizes and through-pore sizes for capillary liquid chromatography. Reviewed

Motokawa M, Kobayashi H, Ishizuka N, Minakuchi H, Nakanishi K, Jinnai H, Hosoya K, Ikegami T, Tanaka N

Journal of chromatography. A Vol. 961 ( 1 ) page： 53 - 63 2002.6

Monolithic silica columns for high-efficiency separations by high-performance liquid chromatography Reviewed

Ishizuka N, Kobayashi H, Minakuchi H, Nakanishi K, Hirao K, Hosoya K, Ikegami T, Tanaka N

JOURNAL OF CHROMATOGRAPHY A Vol. 960 ( 1-2 ) page： 85 - 96 2002.6

Monolithic silica columns for high-efficiency separations by high-performance liquid chromatography. Reviewed

Ishizuka N, Kobayashi H, Minakuchi H, Nakanishi K, Hirao K, Hosoya K, Ikegami T, Tanaka N

Journal of chromatography. A Vol. 960 ( 1-2 ) page： 85 - 96 2002.6

Monolithic HPLC silica columns Reviewed

Lubda D, Cabrera K, Nakanishi K, Minakuchi H

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 23 ( 2 ) page： 185 - 187 2002.2

Phase separation in alkylene-bridged polysilsesquioxane sol-gel systems Reviewed

Nakanishi K, Yamato T, Hirao K

ORGANIC/INORGANIC HYBRID MATERIALS-2002 Vol. 726 page： 291 - 296 2002

Phase separation in sol-gel process of alkoxide-derived silica-zirconia in the presence of polyethylene oxide Reviewed

Takahashi R, Sato S, Sodesawa T, Suzuki K, Tafu M, Nakanishi K, Soga N

JOURNAL OF THE AMERICAN CERAMIC SOCIETY Vol. 84 ( 9 ) page： 1968 - 1976 2001.9

Chromatographic characterization of macroporous monolithic silica prepared via sol-gel process Reviewed

N Ishizuka, H Minakuchi, K Nakanishi, K Hirao, N Tanaka

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS Vol. 187 page： 273 - 279 2001.8

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

A continuous porous silica monolith prepared by the sol-gel process including phase separation was aged in a basic solvent making use of hydrolysis of urea to prepare extended mesopore structures for chromatographic applications. The dissolution-reprecipitation kinetics at the interfaces between wet gel skeletons and an external solvent affected the size and volume of pores formed within the skeletons. At above 200 degreesC, the pore size attained the macropore dimensions ( > 50 nm). The results of chromatography indicate that the monolithic silica column with wide mesopore could reduce the separation time compared to the conventional column packed with 5 mum silica particle. (C) 2001 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0927-7757(01)00642-2

Monolithic LC columns Reviewed

Tanaka N, Kobayashi H, Nakanishi K, Minakuchi H, Ishizuka N

ANALYTICAL CHEMISTRY Vol. 73 ( 15 ) page： 420A - 429A 2001.8

About the total performance of monolithic HPLC-columns. Reviewed

K Cabrera, H Minakuchi, D Lubda, K Nakanishi

ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY Vol. 221 page： U100 - U100 2001.4

Three-dimensional structure of a sintered macroporous silica gel Reviewed

Jinnai H, Nakanishi K, Nishikawa Y, Yamanaka J, Hashimoto T

LANGMUIR Vol. 17 ( 3 ) page： 619 - 625 2001.2

Macroporous morphology of titania films prepared by sol-gel dip-coating method from a system containing poly(ethylene glycol) and poly(vinylpyrrolidone) Reviewed

Kajihara K, Nakanishi K

JOURNAL OF MATERIALS RESEARCH Vol. 16 ( 1 ) page： 58 - 66 2001.1

Apatite formation on ethylene-vinyl alcohol copolymer modified with silane coupling agent and calcium silicate Reviewed

Oyane A., Minoda M., Miyamoto T., Nakanishi K., Kawashita M., Kokubo T., Nakamura T.

Key Engineering Materials Vol. 192-195 page： 713 - 716 2001

Language：English Publishing type：Research paper (scientific journal) Publisher：Key Engineering Materials

Silanol (Si-OH) groups on materials are believed to induce the apatite nucleation in the body environment. In the present study, the apatite-forming ability of ethylene-vinyl alcohol copolymer (EVOH), whose surface was modified to be abundant in Si-OH groups, was investigated in a simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma. Surface modification of EVOH with Si-OH groups was carried out by reacting isocyanatopropyltriethoxysilane (IPTS) and subsequent hydrolysis of its Si-OC2H5 groups by 1M-HCl or saturated Ca(OH)2 aqueous solution. Apatite was, however, not formed on thus surface-modified EVOH in SBF even after 7 d. When the IPTS-treated EVOH was treated with silica or calcium silicate solution, the obtained specimen formed the apatite on its surface in SBF within 7 or 2 d, respectively. The present surface-modification of EVOH is effective for obtaining an apatite-polymer fiber composite in SBF, which could give bone substitute having bone-bonding ability as well as mechanical properties analogous to those of the natural bone.

Macroporous silicate films by dip-coating Reviewed

Kumon S, Nakanishi K, Hirao K

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 19 ( 1-3 ) page： 553 - 557 2000.12

Preparation of silicalite-1 within macroporous silica glass Reviewed

Shikata H, Nakanishi K, Hirao K

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 19 ( 1-3 ) page： 769 - 773 2000.12

Preparation and chromatographic application of macroporous silicate in a capillary Reviewed

Ishizuka N, Nakanishi K, Hirao K, Tanaka N

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 19 ( 1-3 ) page： 371 - 375 2000.12

Porous gels made by phase separation: Recent progress and future directions Reviewed

Nakanishi K

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 19 ( 1-3 ) page： 65 - 70 2000.12

Membrane emulsification using sol-gel derived macroporous silica glass Reviewed

Fuchigami T, Toki M, Nakanishi K

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 19 ( 1-3 ) page： 337 - 341 2000.12

Performance of a monolithic silica column in a capillary under pressure-driven and electrodriven conditions Reviewed

Ishizuka N, Minakuchi H, Nakanishi K, Soga N, Nagayama H, Hosoya K, Tanaka N

ANALYTICAL CHEMISTRY Vol. 72 ( 6 ) page： 1275 - 1280 2000.3

Formation of hierarchical pore structure in silica gel Reviewed

Nakanishi K, Takahashi R, Nagakane T, Kitayama K, Koheiya N, Shikata H, Soga N

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 17 ( 3 ) page： 191 - 210 2000.3

A new monolithic-type HPLC column for fast separations

Cabrera K, Lubda D, Eggenweiler HM, Minakuchi H, Nakanishi K

HRC-JOURNAL OF HIGH RESOLUTION CHROMATOGRAPHY Vol. 23 ( 1 ) page： 93-99 2000.1

Monolithic silica columns for HPLC, micro-HPLC, and CEC Reviewed

Tanaka N, Nagayama H, Kobayashi H, Ikegami T, Hosoya K, Ishizuka N, Minakuchi H, Nakanishi K, Cabrera K, Lubda D

HRC-JOURNAL OF HIGH RESOLUTION CHROMATOGRAPHY Vol. 23 ( 1 ) page： 111 - 116 2000.1

Tailoring mesopores in monolithic macroporous silica for HPLC Reviewed

Nakanishi K, Shikata H, Ishizuka N, Koheiya N, Soga N

HRC-JOURNAL OF HIGH RESOLUTION CHROMATOGRAPHY Vol. 23 ( 1 ) page： 106 - 110 2000.1

Aggregation behavior of alkoxide-derived silica in sol-gel process in presence of poly(ethylene oxide) Reviewed

R Takahashi, K Nakanishi, N Soga

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 17 ( 1 ) page： 7 - 18 2000.1

Language：English Publishing type：Research paper (scientific journal) Publisher：KLUWER ACADEMIC PUBL

Growth behavior of silica in an acid catalyzed sol-gel process from silicon alkoxide in the presence of poly(ethylene oxide), PEO, was investigated by in situ small angle X-ray scattering, SAXS, and Si-29 NMR measurements. The results of SAXS, that aggregation and gel formation behaviors of silica were affected by the presence of PEO, suggested a strong attractive interaction between silica oligomers and PEO. A possible reaction scheme of silica in the presence of PEO is as follows; (1) PEO and small silica oligomers coexist in the solution without specific interaction just after hydrolysis of the silicon alkoxide. (2) With the progress of condensation, a ramified aggregated complex between PEO and silica oligomers is formed, which is characterized by larger apparent value of radius of gyration and smaller fractal dimension than in the PEO-free system. (3) After gelation, the fractal dimension of scatterers remains to be smaller than that in the PEO-free system, because PEO associated with the silica network inhibits aggregation within the gel networks. Furthermore, PEO inhibits the condensation in the aging and in the drying process, leading to less strongly crosslinked dry gel. A temporal maximum in the time evolution of R-g was observed for the samples separated into two phases with their characteristic domain size being larger than several micrometers. This is considered to be a phenomenon related to increase and divergence of correlation length near and at the critical point.

DOI： 10.1023/A:1008753718586

Effect of nonionic surfactant on phase separation behavior in methylsiloxane sol-gel systems Reviewed

Nakanishi K, Miyawaki S, Soga N

KOBUNSHI RONBUNSHU Vol. 57 ( 6 ) page： 396 - 401 2000

Apatite formation on ethylene-vinyl alcohol copolymer modified with silane coupling agent and calcium silicate Reviewed

A Oyane, M Minoda, T Miyamoto, K Nakanishi, M Kawashita, T Kokubo, T Nakamura

BIOCERAMICS Vol. 192-1 page： 713 - 716 2000

Language：English Publishing type：Research paper (scientific journal) Publisher：TRANS TECH PUBLICATIONS LTD

Silanol (SI-OH) groups on materials are believed to induce the apatite nucleation in the body environment. In the present study, the apatite-forming ability of ethylene-vinyl alcohol copolymer (EVOH), whose surface was modified to be abundant in Si-OH groups, was investigated in a simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma. Surface modification of EVOH with Si-OH groups was carried out by reacting isocyanatopropyltriethoxy silane (IPTS) and subsequent hydrolysis of its Si-OC2H5 groups by 1 M-HCl or saturated Ca(OH)(2) aqueous solution. Apatite was, however, not formed on thus surface-modified EVOH in SBF even after 7 d. When the IPTS-treated EVOH was treated with silica or calcium silicate solution, the obtained specimen formed the apatite on its surface in SBF within 7 or 2 d, respectively. The present surface-modification of EVOH is effective for obtaining an apatite-polymer fiber composite in SBF, which could give bone substitute having bone-bonding ability as well as mechanical properties analogous to those of the natural bone.

DOI： 10.4028/www.scientific.net/KEM.192-195.713

A new monolithic-type HPLC column for fast separations

Karin Cabrera, Dieter Lubda, Hans Michael Eggenweiler, H. Minakuchi, K. Nakanishi

Journal of Separation Science Vol. 23 ( 1 ) page： 93 - 99 2000

Language：English Publishing type：Research paper (scientific journal)

The application of a new silica-based, monolithic-type HPLC-column for fast separations is presented. The column is prepared according to a new sol-gel process, which is based on the hydrolysis and polycondensation of alkoxysilanes in the presence of water soluble polymers. The method leads to "rods" made of a single piece of porous silica with a defined pore structure, i. e. macro- and mesopores. The main feature of silica rod columns is a higher total porosity, about 15% higher than of conventional particulate HPLC columns. The resulting column pressure drop is therefore much lower, allowing operation at higher flow rates including flow gradients. Consequently, HPLC analysis can be performed much faster, as it is demonstrated by various applications. © WILEY-VCH Verlag GmbH, D-69451 Weinheim 2000.

DOI： 10.1002/(SICI)1521-4168(20000101)23:1<93::AID-JHRC93>3.0.CO;2-2

A new monolithic-type HPLC column for fast separations Reviewed

Cabrera K., Lubda D., Eggenweiler H.M., Minakuchi H., Nakanishi K.

Journal of Separation Science Vol. 23 ( 1 ) page： 93 - 99 2000

Language：English Publishing type：Research paper (scientific journal) Publisher：Journal of Separation Science

The application of a new silica-based, monolithic-type HPLC-column for fast separations is presented. The column is prepared according to a new sol-gel process, which is based on the hydrolysis and polycondensation of alkoxysilanes in the presence of water soluble polymers. The method leads to "rods" made of a single piece of porous silica with a defined pore structure, i. e. macro- and mesopores. The main feature of silica rod columns is a higher total porosity, about 15% higher than of conventional particulate HPLC columns. The resulting column pressure drop is therefore much lower, allowing operation at higher flow rates including flow gradients. Consequently, HPLC analysis can be performed much faster, as it is demonstrated by various applications. © WILEY-VCH Verlag GmbH, D-69451 Weinheim 2000.

DOI： 10.1002/(sici)1521-4168(20000101)23:1<93::aid-jhrc93>3.3.co;2-u

Apatite formation on ethylene-vinyl alcohol copolymer modified with silanol groups Reviewed

A Oyane, M Minoda, T Miyamoto, R Takahashi, K Nakanishi, HM Kim, T Kokubo, T Nakamura

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH Vol. 47 ( 3 ) page： 367 - 373 1999.12

Language：English Publishing type：Research paper (scientific journal) Publisher：JOHN WILEY & SONS INC

The surfaces of ethylene-vinyl alcohol copolymer (EVOH) substrates were modified with silanol (Si-OH) groups, and their apatite forming ability was examined in a simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma or in a solution with ion concentrations 1.5 times those of SBF (1.5SBF). The surface modification of EVOH was carried out by reacting 3-iso-cyanatopropyltriethoxysilane, followed by hydrolysis of the ethoxysilyl groups into Si-OH groups. However, no apatite formation was observed on the EVOH substrate thus modified, even after 3 weeks in SBF and 1.5SBF. The Si-OH modified EVOH substrate was further modified by hydrolysis and polycondensation of tetraethyoxysilane (TEOS). It was found that the apatite forms on the TEOS-modified substrate within 3 weeks in 1.5SBF. These results suggest that the presence of a large amount of Si-OH groups (i.e., a cluster of Si-OH groups) on the substrate is prerequisite to apatite formation in the body environment. Apatite-EVOH composites prepared by this process might be useful as hard tissues substitutes. (C) 1999 John Wiley & Sons, Inc.

DOI： 10.1002/(SICI)1097-4636(19991205)47:3<367::AID-JBM11>3.0.CO;2-A

Sol-gel modification of silicone to induce apatite-forming ability Reviewed

Oyane A, Nakanishi K, Kim HM, Miyaji F, Kokubo T, Soga N, Nakamura T

BIOMATERIALS Vol. 20 ( 1 ) page： 79 - 84 1999.1

Performance of an octadecylsilylated continuous porous silica column in polypeptide separations Reviewed

Minakuchi H, Ishizuka N, Nakanishi K, Soga N, Tanaka N

JOURNAL OF CHROMATOGRAPHY A Vol. 828 ( 1-2 ) page： 83 - 90 1998.12

Structural study of mesoporous titania and titanium stearic acid complex prepared from titanium alkoxide Reviewed

Takahashi R, Takenaka S, Sato S, Sodesawa T, Ogura K, Nakanishi K

JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS Vol. 94 ( 20 ) page： 3161 - 3168 1998.10

Preparation of macroporous titania films by a sol-gel dip-coating method from the system containing poly(ethylene glycol) Reviewed

Kajihara K, Nakanishi K, Tanaka K, Hirao K, Soga N

JOURNAL OF THE AMERICAN CERAMIC SOCIETY Vol. 81 ( 10 ) page： 2670 - 2676 1998.10

Chromatographic properties of miniaturized silica rod columns Reviewed

N Ishizuka, H Minakuchi, K Nakanishi, N Soga, K Hosoya, N Tanaka

HRC-JOURNAL OF HIGH RESOLUTION CHROMATOGRAPHY Vol. 21 ( 8 ) page： 477 - 479 1998.8

Morphology control of macroporous silica-zirconia gel based on phase separation Reviewed

Takahashi R, Nakanishi K, Soga N

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN Vol. 106 ( 8 ) page： 772 - 777 1998.8

Apatite formation on silica gel in simulated body fluid: effects of structural modification with solvent-exchange Reviewed

SB Cho, F Miyaji, T Kokubo, K Nakanishi, N Soga, T Nakamura

JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE Vol. 9 ( 5 ) page： 279 - 284 1998.5

Language：English Publishing type：Research paper (scientific journal) Publisher：KLUWER ACADEMIC PUBL

The prerequisite for glasses and glass-ceramics to bond to living bone is the formation of biologically active bone-like apatite on their surfaces. It has been shown that even a pure silica gel forms the bone-like apatite on its surface in a simulated body fluid. In the present study, pore structure of silica gels prepared by hydrolysis and polycondensation of tetraethoxysilane in an aqueous solution containing polyethylene glycol was modified by 1M HNO3, and 0.1M and 1M NH4OH solution treatments. The three kinds of resultant gels all contained large amounts of silanol groups and trisiloxane rings, but differ greatly in pore structure of nanometre pore size. Irrespective of these differences, all the gels formed the bone-like apatite on their surface in the simulated body fluid. It was speculated that a certain type of structural unit of silanol groups, which is easily formed in the presence of the polyethylene glycol, is effective for the apatite formation. (C) 1998 Chapman & Hall.

DOI： 10.1023/A:1008808828567

Designing double pore structure in alkoxy-derived silica incorporated with nonionic surfactant Reviewed

K Nakanishi, T Nagakane, N Soga

JOURNAL OF POROUS MATERIALS Vol. 5 ( 2 ) page： 103 - 110 1998.5

Language：English Publishing type：Research paper (scientific journal) Publisher：KLUWER ACADEMIC PUBL

The principle of designing double-pore structure in alkoxy-derived silica is described with the experimental system containing polyoxyethylene nonylphenylether. The formation of macropores is consistently explained in terms of the concurrence of a phase separation and a sol-gel transition in the polymerizing silica-surfactant-solvent system. The composition-morphology relationship exhibited a substantial variation depending on the length of oxyethylene units in the surfactant molecule. The mesopore volume obtained after basic solvent exchange and a heat-treatment suggested that the surfactant with shorter oxyethylene chain tends to be incorporated more in the gel phase to give higher mesopore volume. The small-angle X-ray scattering measurement of the gelling and aging system supported this hypothesis indicating micelle formation in the system containing a surfactant with shorter oxyethylene chain.

DOI： 10.1023/A:1009633102016

Designing monolithic double-pore silica for high-speed liquid chromatography Reviewed

N Ishizuka, H Minakuchi, K Nakanishi, N Soga, N Tanaka

JOURNAL OF CHROMATOGRAPHY A Vol. 797 ( 1-2 ) page： 133 - 137 1998.2

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

A novel type of silica-based chromatographic column without particle-packed structure has been recently developed. A monolithic silica gel having continuous gel skeletons and through-pores together with open mesopores is the key material of this 'rod column'. The principle and procedure of designing the built-in pore structure is explained. (C) 1998 Elsevier Science B.V.

DOI： 10.1016/S0021-9673(97)01202-8

Effect of domain size on the performance of octadecylsilylated continuous porous silica columns in reversed-phase liquid chromatography Reviewed

Minakuchi H, Nakanishi K, Soga N, Ishizuka N, Tanaka N

JOURNAL OF CHROMATOGRAPHY A Vol. 797 ( 1-2 ) page： 121 - 131 1998.2

SilicaROD (TM) - A new challenge in fast high-performance liquid chromatography separations Reviewed

Cabrera K, Wieland G, Lubda D, Nakanishi K, Soga N, Minakuchi H, Unger KK

TRAC-TRENDS IN ANALYTICAL CHEMISTRY Vol. 17 ( 1 ) page： 50 - 53 1998.1

Monolithic HPLC column via sol-gel route Reviewed

Nakanishi K, Minakuchi H, Ishizuka N, Soga N

SOL-GEL SYNTHESIS AND PROCESSING Vol. 95 page： 139 - 150 1998

Structure design of double-pore silica and its application to HPLC Reviewed

Nakanishi K, Minakuchi H, Soga N, Tanaka N

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 13 ( 1-3 ) page： 163 - 169 1998

Pore Structure Control of Silica Gels Based on Phase Separation Reviewed

Nakanishi Kazuki

JOURNAL OF POROUS MATERIALS Vol. 4 ( 2 ) page： 67 - 112 1997.6

Phase separation in silica sol-gel system containing poly(ethylene oxide) .2. Effects of molecular weight and temperature Reviewed

Nakanishi K, Soga N

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN Vol. 70 ( 3 ) page： 587 - 592 1997.3

Effect of skeleton size on the performance of octadecylsilylated continuous porous silica columns in reversed-phase liquid chromatography Reviewed

Minakuchi H, Nakanishi K, Soga N, Ishizuka N, Tanaka N

JOURNAL OF CHROMATOGRAPHY A Vol. 762 ( 1-2 ) page： 135 - 146 1997.2

Double pore silica gel monolith applied to liquid chromatography Reviewed

K Nakanishi, H Minakuchi, N Soga, N Tanaka

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 8 ( 1-3 ) page： 547 - 552 1997

Language：English Publishing type：Research paper (scientific journal) Publisher：KLUWER ACADEMIC PUBL

Silica gels retaining double pore structure in the size ranges of micrometer and nanometer have been applied to the rod-shaped monolithic column for liquid chromatography. The macropore structure was designed by controlling the phase separation process induced by the hydrolysis and polycondensation of alkoxysilane, whereas the mesopore structure was tailored by the solvent exchange treatments on wet gels. The size exclusion chromatograms on polystyrene standards exhibited almost similar features for octadecyl-modified rod and conventional packed beads columns. The dependence of plate height on the velocity of mobile phase determined for amylbenzene was by far weaker in the rod column than in the packed beads column, suggesting that additional geometrical factors should be considered in describing the separation mechanism in the rod column.

DOI： 10.1023/A:1018331101606

Phase separation process of polymer-incorporated silica-zirconia sol-gel system Reviewed

Takahashi R, Nakanishi K, Soga N

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 8 ( 1-3 ) page： 71 - 76 1997

Apatite-forming ability of silicate ion dissolved from silica gels Reviewed

SB Cho, F Miyaji, T Kokubo, K Nakanishi, N Soga, T Nakamura

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH Vol. 32 ( 3 ) page： 375 - 381 1996.11

Language：English Publishing type：Research paper (scientific journal) Publisher：JOHN WILEY & SONS INC

It is known that the prerequisite for glasses and glass-ceramics to bond to living bone is the formation of biologically active bonelike apatite on their surfaces, and a certain type of hydrated silica developed on their surfaces plays an important role in nucleating the apatite. In the present study, the apatite-forming ability of silicate ion dissolved from different silica materials into a simulated body fluid was examined as follows. Polyether sulfone substrates pretreated with O-2 plasma were placed in parallel to plates of three kinds of silica gels prepared in different media and silica glass, with a distance of 0.5 mm between them in a simulated body fluid with ion concentrations nearly equal to those of human blood plasma for 4 days, and then soaked in a solution with ion concentrations 1.5 times those of the simulated body fluid for 6 days. After the first soaking, silicon combined with oxygen was detected on the surfaces of the substrates faced to all the silica gels, whereas it was not detected on that faced to the silica glass. After the second soaking, the former formed a bonelike apatite layer on their surfaces, but the latter did not. These results indicate that silicate ion which is dissolved from the silica gels and adsorbed on the substrates has an apatite-forming ability, irrespective of the microstructure of the original silica gels. (C) 1996 John Wiley & Sons, Inc.

DOI： 10.1002/(SICI)1097-4636(199611)32:3<375::AID-JBM10>3.0.CO;2-G

Octadecylsilylated porous silica rods as separation media for reversed-phase liquid chromatography Reviewed

Minakuchi H, Nakanishi K, Soga N, Ishizuka N, Tanaka N

ANALYTICAL CHEMISTRY Vol. 68 ( 19 ) page： 3498 - 3501 1996.10

Apatite formation on various silica gels in a simulated body fluid containing excessive calcium ion Reviewed

SB Cho, F Miyaji, T Kokubo, K Nakanishi, N Soga, T Nakamura

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN Vol. 104 ( 5 ) page： 399 - 404 1996.5

Language：English Publishing type：Research paper (scientific journal) Publisher：CERAMIC SOC JAPAN-NIPPON SERAMIKKUSU KYOKAI

It was previously shown that a silica gel prepared in a solution containing polyethylene glycol (S-PEG) induces the apatite nucleation in SBF, but those prepared in pure water (S-W) and a solution containing polyacrylic acid (S-PAA) do not induce it. This indicates that a limited type of silanol groups is effective for apatite nucleation. In the present study, apatite-forming ability of these silica gels was examined in SBF containing excessive calcium ion. It was found that all these silica gels formed the apatite on their surfaces in this fluid, although the rate of apatite formation decreased in the order S-PEG > S-PAA > S-W. This indicates that any type of silanol groups has potential for inducing apatite nucleation under this condition. Such environment rich in calcium ion is produced around the surfaces of CaO, SiO2-based glasses and glass-ceramics when they are implanted into living body. The present results indicate that the CaO-SiO2 system can be a good basic composition for bioactive glasses and glass-ceramics.

DOI： 10.2109/jcersj.104.399

Apatite formation on silica gel in simulated body fluid: Its dependence on structures of silica gels prepared in different media Reviewed

Sung-Baek Cho, Kazuki Nakanishi, Tadashi Kokubo, Naohiro Soga, Chikara Ohtsuki, Takashi Nakamura

Journal of Biomedical Materials Research Vol. 33 ( 3 ) page： 145 - 151 1996

Language：English Publishing type：Research paper (scientific journal)

It has been shown that the prerequisite for glasses and glass-ceramics to bond to living bone is the formation of a layer of biologically active bonelike apatite on their surfaces. The hydrated silica formed on the surfaces of glasses and glass-ceramics plays an important role in nucleating the apatite. In the present study, the structure of the hydrated silica responsible for the apatite nucleation was investigated in an acellular simulated body fluid with ion concentrations nearly equal to those of human blood plasma. Three kinds of porous silica gels were prepared by hydrolysis and polycondensation of tetraethoxysilane in pure water or in aqueous solution containing polyethylene glycol or polyacrylic acid. The silica gels prepared in aqueous solution containing polyethylene glycol or polyacrylic acid had micron-size interconnected pores, whereas the gel prepared in pure water did not. All the gels contained a large volume of nanometer-size pores, almost the same amounts of silanol groups and D2 defect, and showed a high dissolution rate of the silica. Despite this, only the gel prepared in the solution containing polyethylene glycol formed the apatite on its surface in the simulated body fluid. This indicates that only a certain type of structural unit of the silanol group is responsible for the apatite nucleation.

DOI： 10.1002/(SICI)1097-4636(199623)33:3<145::AID-JBM4>3.0.CO;2-Q

EFFECTS OF AGING AND SOLVENT EXCHANGE ON PORE STRUCTURE OF SILICA-GELS WITH INTERCONNECTED MACROPORES Reviewed

TAKAHASHI R, NAKANISHI K, SOGA N

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 189 ( 1-2 ) page： 66 - 76 1995.8

DEPENDENCE OF APATITE FORMATION ON SILICA-GEL ON ITS STRUCTURE - EFFECT OF HEAT-TREATMENT Reviewed

SB CHO, K NAKANISHI, T KOKUBO, N SOGA, C OHTSUKI, T NAKAMURA, T KITSUGI, T YAMAMURO

JOURNAL OF THE AMERICAN CERAMIC SOCIETY Vol. 78 ( 7 ) page： 1769 - 1774 1995.7

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CERAMIC SOC 735 CERAMIC PLACE

The prerequisite for glasses and glass-ceramics to bond to living bone is the formation of biologically active bonelike apatite on their surfaces in the body. Our previous study showed that a silica gel prepared by hydrolysis and polycondensation of tetraethoxysilane in aqueous solution containing poly(ethylene glycol) induces apatite nucleation on its surface in a simulated body fluid. In the present study, the effects of heat treatment of silica gel on its catalytic effects in apatite nucleation was investigated in a simulated body fluid, It was found that apatite forms on the surfaces of silica gels heat-treated below 800 degrees C, but not on those heat-treated above 900 degrees C. The volume of nanometer-range pores in the gel remarkably decreased by heat treatment above 900 degrees C. The concentration of silanol groups in the silica gels gradually decreased with increasing heat treatment temperature. The rate of silica dissolution from the gel into the simulated body fluid decreased remarkably by heat treatment above 900 degrees C. This suggested that a special type of silanol group which is formed by soaking the gel treated below 800 degrees C into the simulated body fluid is responsible for apatite nucleation.

DOI： 10.1111/j.1151-2916.1995.tb08887.x

Formation of porous gel morphology by phase separation in gelling alkoxy-derived silica. Phenomenological study

Kaji H.

Journal of Non-Crystalline Solids Vol. 185 ( 1-2 ) page： 18-30 1995.5

FORMATION OF POROUS GEL MORPHOLOGY BY PHASE-SEPARATION IN GELLING ALKOXY-DERIVED SILICA - PHENOMENOLOGICAL STUDY

KAJI H, NAKANISHI K, SOGA N

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 185 ( 1-2 ) page： 18-30 1995.5

Formation of porous gel morphology by phase separation in gelling alkoxy-derived silica. Affinity between silica polymers and solvent.

Kaji H.

Journal of Non-Crystalline Solids Vol. 181 ( 1-2 ) page： 16-26 1995.2

FORMATION OF POROUS GEL MORPHOLOGY BY PHASE-SEPARATION IN GELLING ALKOXY-DERIVED SILICA - AFFINITY BETWEEN SILICA POLYMERS AND SOLVENT

KAJI H, NAKANISHI K, SOGA N

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 181 ( 1-2 ) page： 16-26 1995.2

Small-angle X-Ray scattering study of nanopore evolution of macroporous silica gel by solvent exchange Reviewed

Takahashi R, Nakanishi K, Soga N

FARADAY DISCUSSIONS Vol. 101 page： 249 - 263 1995

PHASE-SEPARATION IN SILICA SOL-GEL SYSTEM CONTAINING POLY(ETHYLENE OXIDE) .1. PHASE RELATION AND GEL MORPHOLOGY Reviewed

NAKANISHI K, KOMURA H, TAKAHASHI R, SOGA N

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN Vol. 67 ( 5 ) page： 1327 - 1335 1994.5

In Situ Observation of Phase Separation Processes in Gelling Alkoxy-Derived Silica System by Light Scattering Method Reviewed

Kaji Hironori, Nakanishi Kazuki, Soga Naohiro, Inoue Tadashi, Nemoto Norio

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 3 ( 3 ) page： 169 - 188 1994.1

Phase Separation Kinetics in Silica Sol-Gel System Containing Polyethylene Oxide. I. Initial Stage Reviewed

Nakanishi Kazuki, Yamasaki Yuki, Kaji Hironori, Soga Naohiro, Inoue Tadashi, Nemoto Norio

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 2 ( 1-3 ) page： 227 - 231 1994.1

THE ROLE OF HYDRATED SILICA, TITANIA, AND ALUMINA IN INDUCING APATITE ON IMPLANTS Reviewed

LI PJ, OHTSUKI C, KOKUBO T, NAKANISHI K, SOGA N, DEGROOT K

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH Vol. 28 ( 1 ) page： 7 - 15 1994.1

Dependence of bone-like apatite formation on structure of silica gel Reviewed

T Kokubo, SB Cho, K Nakanishi, N Soga, C Ohtsuki, T Kitsugi, T Yamamuro, T Nakamura

BIOCERAMICS, VOL 7 page： 49 - 54 1994

INDUCTION AND MORPHOLOGY OF HYDROXYAPATITE, PRECIPITATED FROM METASTABLE SIMULATED BODY-FLUIDS ON SOL-GEL PREPARED SILICA Reviewed

LI PJ, NAKANISHI K, KOKUBO T, DEGROOT K

BIOMATERIALS Vol. 14 ( 13 ) page： 963 - 968 1993.10

PROCESS OF FORMATION OF BONE-LIKE APATITE LAYER ON SILICA-GEL Reviewed

LI P, OHTSUKI C, KOKUBO T, NAKANISHI K, SOGA N, NAKAMURA T, YAMAMURO T

JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE Vol. 4 ( 2 ) page： 127 - 131 1993.3

Polymerization-Induced Phase Separation in Silica Sol-Gel Systems Containing Formamide Reviewed

Kaji Hironori, Nakanishi Kazuki, Soga Naohiro

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY Vol. 1 ( 1 ) page： 35 - 46 1993.1

MACROPORE STRUCTURE DESIGN OF SOL-GEL DERIVED SILICA BY SPINODAL DECOMPOSITION Reviewed

NAKANISHI K, KAJI H, SOGA N

POROUS MATERIALS Vol. 31 page： 51 - 60 1993

EFFECTS OF IONS IN AQUEOUS-MEDIA ON HYDROXYAPATITE INDUCTION BY SILICA-GEL AND ITS RELEVANCE TO BIOACTIVITY OF BIOACTIVE GLASSES AND GLASS-CERAMICS Reviewed

LI P, OHTSUKI C, KOKUBO T, NAKANISHI K, SOGA N, NAKAMURA T, YAMAMURO T

JOURNAL OF APPLIED BIOMATERIALS Vol. 4 ( 3 ) page： 221 - 229 1993

DUAL-POROSITY SILICA-GELS BY POLYMER-INCORPORATED SOL-GEL PROCESS Reviewed

K NAKANISHI, R TAKAHASHI, N SOGA

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 147 ( C ) page： 291 - 295 1992.10

Language：English Publishing type：Research paper (scientific journal) Publisher：ELSEVIER SCIENCE BV

Pore characteristics of silica gels prepared by the polymer-incorporated alkoxide-based sol-gel process have been investigated. Micrometer-range Pore sizes could be controlled by changing several reaction parameters, such as molecular weight or concentration of polymer or reaction temperature, that affect the domain formation process due to an occurrence of phase separation during a gel-forming reaction. The volume fraction and size distribution of nanometer-range pores after a heat treatment were varied by different solvent exchange treatments of a wet gel.

DOI： 10.1016/S0022-3093(05)80632-5

APATITE FORMATION INDUCED BY SILICA-GEL IN A SIMULATED BODY-FLUID Reviewed

PJ LI, C OHTSUKI, T KOKUBO, K NAKANISHI, N SOGA, T NAKAMURA, T YAMAMURO

JOURNAL OF THE AMERICAN CERAMIC SOCIETY Vol. 75 ( 8 ) page： 2094 - 2097 1992.8

Language：English Publishing type：Research paper (scientific journal) Publisher：AMER CERAMIC SOC

It has been confirmed that the essential condition for glasses and glass-ceramics to bond to living bone is,the formation of an apatite layer on their surfaces in the body. It has been proposed that a hydrated silica formed on the surfaces of these materials in the body plays an important role in forming the surface apatite layer, but this has not yet been proved. In the present study, it is shown experimentally that a pure hydrated silica gel can induce apatite formation on its surface in a simulated body fluid when its starting pH is increased from 7.2 to 7.4.

DOI： 10.1111/j.1151-2916.1992.tb04470.x

MODIFICATION OF NANOMETER RANGE PORES IN SILICA-GELS WITH INTERCONNECTED MACROPORES BY SOLVENT EXCHANGE Reviewed

KAJI H, NAKANISHI K, SOGA N, HORII F

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 145 ( 1-3 ) page： 80 - 84 1992.8

PHASE-SEPARATION IN SILICA SOL-GEL SYSTEM CONTAINING POLYACRYLIC-ACID .3. EFFECT OF CATALYTIC CONDITION Reviewed

NAKANISHI K, SOGA N

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 142 ( 1-2 ) page： 36 - 44 1992.4

PHASE-SEPARATION IN SILICA SOL-GEL SYSTEM CONTAINING POLYACRYLIC-ACID .4. EFFECT OF CHEMICAL ADDITIVES Reviewed

NAKANISHI K, SOGA N

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 142 ( 1-2 ) page： 45 - 54 1992.4

SMALL-ANGLE X-RAY-SCATTERING STUDY OF GELLING SILICA ORGANIC POLYMER-SOLUTION - SYSTEMS CONTAINING POLY(SODIUM STYRENE-SULFONATE) Reviewed

NAKANISHI K, SOGA N, MATSUOKA H, ISE N

JOURNAL OF THE AMERICAN CERAMIC SOCIETY Vol. 75 ( 4 ) page： 971 - 975 1992.4

PHASE-SEPARATION IN SILICA SOL-GEL SYSTEM CONTAINING POLYACRYLIC-ACID .1. GEL FORMATION BEHAVIOR AND EFFECT OF SOLVENT COMPOSITION Reviewed

NAKANISHI K, SOGA N

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 139 ( 1 ) page： 1 - 13 1992.1

PHASE-SEPARATION IN SILICA SOL-GEL SYSTEM CONTAINING POLYACRYLIC-ACID .2. EFFECTS OF MOLECULAR-WEIGHT AND TEMPERATURE Reviewed

NAKANISHI K, SOGA N

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 139 ( 1 ) page： 14 - 24 1992.1

MACROPORE MORPHOLOGY CONTROL OF SILICA-GEL BY SPINODAL DECOMPOSITION Reviewed

NAKANISHI K, SOGA N

CHEMICAL PROCESSING OF ADVANCED MATERIALS page： 29 - 41 1992

PHASE-SEPARATION IN GELLING SILICA ORGANIC POLYMER-SOLUTION - SYSTEMS CONTAINING POLY(SODIUM STYRENESULFONATE) Reviewed

NAKANISHI K, SOGA N

JOURNAL OF THE AMERICAN CERAMIC SOCIETY Vol. 74 ( 10 ) page： 2518 - 2530 1991.10

PORE SURFACE CHARACTERISTICS OF MACROPOROUS SILICA-GELS PREPARED FROM POLYMER-CONTAINING SOLUTION Reviewed

NAKANISHI K, SAGAWA Y, SOGA N

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 134 ( 1-2 ) page： 39 - 46 1991.9

SMALL-ANGLE X-RAY-SCATTERING STUDY ON SOL-GEL TRANSITION OF MIXTURES OF COLLOIDAL SILICA AND ORGANIC POLYMER Reviewed

MATSUOKA H, CHEN S, ISHII H, ISE N, NAKANISHI K, SOGA N

BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN Vol. 64 ( 4 ) page： 1283 - 1288 1991

EFFECT OF STRESS ON WATER CORROSION OF BORATE GLASS Reviewed

SOGA N, ZHANG ZY, NAKANISHI K, HIRAO K

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 112 ( 1-3 ) page： 377 - 380 1989.10

CRYSTALLIZATION OF SILICA-GELS CONTAINING SODIUM POLY-4-STYRENE SULFONATE Reviewed

K NAKANISHI, N SOGA

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 108 ( 2 ) page： 157 - 162 1989.3

THE EFFECT OF TWO-DIMENSIONAL COMPRESSIVE STRESS ON THE DISSOLUTION RATE OF GLASS IN WATER Reviewed

ZHANG Z, NAKANISHI K, HIRAO K, SOGA N

NIPPON SERAMIKKUSU KYOKAI GAKUJUTSU RONBUNSHI-JOURNAL OF THE CERAMIC SOCIETY OF JAPAN Vol. 97 ( 3 ) page： 365 - 369 1989

ADSORPTION OF ALCOHOL VAPORS ON ALKOXIDE-DERIVED SILICA-GELS Reviewed

K NAKANISHI, N SOGA

JOURNAL OF NON-CRYSTALLINE SOLIDS Vol. 100 ( 1-3 ) page： 399 - 403 1988.3

SORPTION OF ALCOHOL VAPORS IN A DISUBSTITUTED POLYACETYLENE Reviewed

NAKANISHI K, ODANI H, KURATA M, MASUDA T, HIGASHIMURA T

POLYMER JOURNAL Vol. 19 ( 2 ) page： 293 - 296 1987

PERMEATION OF GASES IN POLY[1-(TRIMETHYLSILYL)-1-PROPYNE] Reviewed

SHIMOMURA H, NAKANISHI K, ODANI H, KURATA M, MASUDA T, HIGASHIMURA T

KOBUNSHI RONBUNSHU Vol. 43 ( 11 ) page： 747 - 753 1986

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