Faculty Profiles - NAKANISHI Kazuki

Papers - NAKANISHI Kazuki

Division display 121 - 140 of about 412 ／ All the affair displays >>

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 Open Access

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 Open Access

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 Open Access

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 Open Access

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 Open Access

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 Open Access

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 Open Access

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 Open Access

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 Open Access

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

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

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

　 PREV - NEXT 　

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21