研究者詳細 - 中西　和樹

論文 - 中西　和樹

分割表示 412 件中 41 - 60 件目／全件表示 >>

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

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

Materials Research Society Symposium Proceedings 888 巻頁： 251 - 256 2006年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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 査読有り

Kanamori K., Nakanishi K., Hanada T.

Materials Research Society Symposium Proceedings 947 巻頁： 66 - 71 2006年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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 査読有り

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

Materials Research Society Symposium Proceedings 847 巻頁： 147 - 157 2005年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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 査読有り

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

Materials Research Society Symposium Proceedings 847 巻頁： 121 - 126 2005年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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 査読有り

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

Materials Research Society Symposium Proceedings 847 巻頁： 203 - 208 2005年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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 査読有り

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

Polymer Preprints, Japan 54 巻 ( 2 ) 2005年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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 査読有り

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

Polymer Preprints, Japan 54 巻 ( 1 ) 2005年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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 査読有り

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

Polymer Preprints, Japan 54 巻 ( 2 ) 頁： 3512 - 3513 2005年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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 査読有り

Vervoort, N; Saito, H; Nakanishi, K; Desmet, G

ANALYTICAL CHEMISTRY 77 巻 ( 13 ) 頁： 3986 - 3992 2005年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Analytical Chemistry

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 μm < d s < 8 μm) and porosities (0.47 < ε < 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. © 2005 American Chemical Society.

DOI： 10.1021/ac0502798

Three dimensional structure and liquid transport behavior of siloxane gels with co-continuous macropores 査読有り

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

ORGANIC/INORGANIC HYBRID MATERIALS-2004 847 巻頁： 203 - 208 2005年

Morphological Control and Mechanical Properties of Porous Phenolic Resins Derived from Poly(4-Vinylphenol): Effects of Molecular Weight and Polydispersity of Prepolymer 査読有り

Hasegawa, G; Takano, A; Hiei, C; Kusano, K; Nakanishi, K

ADVANCED ENGINEERING MATERIALS 26 巻 ( 21 ) 2024年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Advanced Engineering Materials

Improvement of mechanical stability for porous polymer monoliths is one of the prime concerns as represented by the long-standing research efforts on resorcinol-formaldehyde (RF) aerogels. To this end, it is imperative not only to tailor mechanically robust porous morphology but also to design macromolecular structure of polymer scaffolds. Previously, we have developed porous RF gels showing a unique mechanical feature combining high mechanical strength and outstanding flexibility against uniaxial compression. Comparison of mechanical properties between the porous gels with varied morphologies has elucidated the influence of porous structure, whereas effects of macromolecular structure still remain elusive. Herein, we have fabricated a series of macroporous phenolic resins from three types of linear prepolymers with phenol pendant groups, poly(4-vinylphenol) or poly(4-hydroxystyrene), which differ in molecular-weight properties, by the sol–gel process in conjunction with spinodal decomposition. The difference in gelation and phase separation behaviors observed for the discrete systems indicates the dissimilar cross-linked networks developed in the respective gels, which consequently influence the mechanical strength and flexibility against uniaxial compression. This study also demonstrates the improvement of mechanical features by thermal treatment for the porous monoliths derived from the high-molecular-weight prepolymer with a view to the application in mechanical energy absorption.

DOI： 10.1002/adem.202401038

Crystalline organic monoliths with bicontinuous porosity 査読有り

Matsumoto, N; Nakagawa, S; Morisato, K; Kanamori, K; Nakanishi, K; Yanai, N

CHEMICAL SCIENCE 15 巻 ( 29 ) 頁： 11500 - 11506 2024年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemical Science

Organic crystals are a promising class of materials for various optical applications. However, it has been challenging to make macroscopic organic crystals with bicontinuous porosity that are applicable to flow chemistry. In this study, a new class of porous materials, cm-scale crystalline organic monoliths (COMs) with bicontinuous porosity, are synthesized by replicating the porous structure of silica monolith templates. The COMs composed of p-terphenyl can take up more than 30 wt% of an aqueous solution, and the photophysical properties of the p-terphenyl crystals are well maintained in the COMs. The relatively high surface area of the COMs can be exploited for efficient Dexter energy transfer from triplet sensitizers on the pore surface. The resulting triplet excitons in the COMs encounter and annihilate, generating upconverted UV emission. The COMs would open a new avenue toward applications of organic crystals in flow photoreaction systems.

DOI： 10.1039/d4sc01650e

Hydrogarnet-Derived Porous Polyhedral Particles of SrFeO<inf>3-δ</inf> Perovskite 査読有り

Otaguro H., Takeno T., Sugimoto R., Hosokawa S., Akamatsu H., Yamamoto T., Nakanishi K., Hayashi K., Hasegawa G.

Chemistry of Materials 35 巻 ( 16 ) 頁： 6423 - 6436 2023年8月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemistry of Materials

Introduction of open mesoporosity into microparticles with a robust morphology provides a high active surface area together with good thermal stability and shows benefit in various applications at high temperatures. Recently, nonstoichiometric Sr-Fe perovskites with an oxygen release/absorption capability have attracted interests as an oxidation catalyst operated at elevated temperatures. Here, we demonstrate the topotactic synthesis approach to fabricate mesoporous microparticles of SrFeO3−δ with monodispersibility as well as rhombic dodecahedral morphology from the correspondent hydrogarnet precursor (Sr3Fe2(OH)12) prepared by the hydrothermal reaction. Relationship between synthetic conditions and the formed crystal morphology has been systematically explored, which discloses that the crystallization of hydrogarnet can take place at as low as 40 °C. On heating, the dehydration of Sr3Fe2(OH)12 gives rise to phase separation into Sr(OH)2 and SrFeO3−δ via a transient phase of “oxyhydrogarnet”. Selective removal of the Sr(OH)2-derived phase leaves three-dimensionally interconnected mesopores in individual polyhedral microparticles. Meanwhile, further increase of the heat-treatment temperature sets off the reaction between the two separated phases, ending up in nonporous polyhedral particles composed of Ruddlesden-Popper-type layered perovskite (Sr3Fe2O7−δ) at 1200 °C. The mesoporous SrFeO3−δ polyhedral microparticles exhibit an enhanced catalytic performance of CO oxidation superior to the nonporous counterparts, which is associated with the stimulated oxygen release capability owing to mesoporosity rather than the oxygen uptake rate.

DOI： 10.1021/acs.chemmater.3c01150

Preparation of Hierarchically Porous Niobium(V) Oxide and Alkaline Niobate Monoliths via Sol-Gel Accompanied by Phase Separation 査読有り

Sato, Y; Kanamori, K; Nakanishi, K

CHEMISTRY OF MATERIALS 35 巻 ( 13 ) 頁： 5177 - 5184 2023年6月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Chemistry of Materials

Hierarchically porous niobium(V) oxide monoliths were prepared through the sol-gel process accompanied by phase separation and subsequent heat treatment. Macroporous and mesoporous characteristics as well as crystal structures were investigated in detail. Macroporous structures were controlled by the starting composition to manipulate phase separation, whereas mesoporous structures were modified by heat treatment in air to crystallize niobium(V) oxide. The results showed that by heat treating the as-dried gel at 550 °C in air, a hierarchically ordered macro/mesoporous material with BET surface area of 54 m2 g-1 was obtained. With an increase of the heat treatment temperature, an increase in the mesopore size accompanied by a decrease in the specific surface area was observed as a result of crystallite growth. Heat treatment under a N2 atmosphere resulted in the formation of phases with lower-valence niobium such as NbO2 and Nb12O29, which were derived from the reduction by the carbothermal reaction due to the presence of carbonized organic compounds. The conversion of niobium(V) oxide into niobium-containing complex oxides was also examined. Alkaline metals, namely, Li, Na, and K, were incorporated by postgelation treatments. Niobium-rich alkaline niobate phases were obtained when alkaline chloride was incorporated, whereas the majority of lithium niobate (LiNbO3) phases were obtained when samples were treated with lithium hydroxide.

DOI： 10.1021/acs.chemmater.3c00916

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

Yoshii, T; Sakama, A; Kanamori, K; Nakanishi, K; Imai, H; Citterio, D; Hiruta, Y

JOURNAL OF CHROMATOGRAPHY A 1688 巻頁： 463722 2023年1月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Chromatography A

Purification of basic drugs in reversed-phase mode is often difficult, mainly due to adsorption of positively charged compounds to the silica gel-based stationary phase. Since this adsorption can be suppressed under alkaline condition, columns with alkali-resistance are required. In addition, compounds with acid-sensitive structures are sometimes degraded during separation on silica gel-based columns which exhibit acidity due to their surface structure. We prepared an alkali-resistant reversed-phase packing material, Eggshell-PMAcO based on eggshells modified with an amphiphilic copolymer, poly(maleic acid-alt-1-octadecene) (PMAcO). The height equivalent to a theoretical plate (HETP) of the Eggshell-PMAcO column was improved by surface treatment with ammonium acetate buffer (900 mM, pH = 3.7), which is an inexpensive reagent, and the retention behavior for hydrophobic compounds was compared to a typical ODS column based on silica gel, resulting in sufficient selectivity of the eggshell-based column for hydrophobic compounds, as indicated by the ratio of retention factors of pentylbenzene and butylbenzene (Eggshell-PMAcO column: 1.55, ODS column: 1.65). Column temperature-dependent retention behavior of naphthalene was investigated in the temperature range from 25 °C to 45 °C, followed by the calculation of thermodynamic parameters. There was little difference in the standard molar enthalpy (Eggshell-PMAcO: −19.6 kJ/mol, ODS: −21.7 kJ/mol). The absolute value of the standard free Gibbs energy for the Eggshell-PMAcO column was much smaller than that of the ODS column (Eggshell-PMAcO: −0.284 kJ/mol, ODS: −13.0 kJ/mol), indicating that the Eggshell-PMAcO column had a weaker retention strength for naphthalene than the ODS column mainly due to the large difference in the standard molar entropy (Eggshell-PMAcO: −64.9 J/mol K, ODS column: −29.2 J/mol K). The retention capacities for imipramine under neutral (water/methanol) and alkaline (0.1% triethylamine water/methanol) conditions were 0.2 mg and 5 mg, respectively, based on injection mass-dependent HETP, retention factor and symmetry factor. Finally, the prepared column was applied to the purification of a building block for nucleic acid drugs. This study demonstrated that reversed-phase columns, which can be fabricated from eggshells and an amphiphilic copolymer in an inexpensive and eco-friendly way, have the ability to purify basic compounds and acid-sensitive compounds.

DOI： 10.1016/j.chroma.2022.463722

Mechanical and thermal properties of porous polyimide monoliths crosslinked with aromatic and aliphatic triamines 査読有り

Ishida, M; Sashiyama, Y; Akamatsu, H; Hayashi, K; Nakanishi, K; Hasegawa, G

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY 104 巻 ( 3 ) 頁： 526 - 535 2022年12月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Journal of Sol-Gel Science and Technology

Thermal insulating materials are of importance for efficient and effective use of heat energy. Porous organic foams are widely employed for this purpose owing to their low thermal conductivity and mass productivity at low cost. However, the poor thermal stability of organic polymers limits their availability within a low temperature range (typically, < 150 °C). In this paper, we demonstrate the one-pot sol–gel synthesis of porous poly(amic acid) (PAA) xerogels and their conversion to porous polyimide (PI) monoliths by thermal imidization. The PAA networks crosslinked with either aromatic or aliphatic triamine and the bicontinuous porous morphology tailored via spinodal decomposition allow the evaporative drying at ambient pressure to obtain low-density PAA xerogels without significant shrinkage. The aromatic crosslinker yields the porous PI monoliths with higher porosity and flexible feature as compared with those prepared with the aliphatic triamine. On the other hand, the porous PI monolith based on the aliphatic crosslinker possesses slightly higher thermal stability owing to the stiffer mechanical property. The durability test results verify the porous PI thermal insulators are available in air at up to ~450 °C for a short period and up to ~350 °C for a long term. [Figure not available: see fulltext.]

DOI： 10.1007/s10971-022-05843-8

その他リンク： https://link.springer.com/article/10.1007/s10971-022-05843-8/fulltext.html

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

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

ACS Applied Polymer Materials 4 巻 ( 10 ) 頁： 6949 - 6957 2022年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：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 査読有り

Hara, Y; Shigetake, R; Nakanishi, K; Kanamori, K; Sakaushi, K

ACS APPLIED MATERIALS & INTERFACES 14 巻 ( 31 ) 頁： 35883 - 35893 2022年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ACS Applied Materials and Interfaces

Internal spacing of electrodes is a key point for controlling electron-transfer (ET)-related phenomena. However, their disordered porous structures often prevent the observation of microscopic effects. It hampers the development of modern electrochemical theories. The development of model porous electrodes therefore provides an ideal platform to discover intriguing fundamental principles of electrode processes. We developed a new synthetic strategy for all-oxide monolithic ruthenium dioxide (RuO2)/antimony-doped tin oxide (ATO) electrodes with a controlled hierarchically porous structure and oxide-oxide heterojunction. The use of the obtained RuO2/ATO electrodes as model electrodes suppressed influences related to different mass diffusion efficiencies between electrodes with heterojunctions of different types. Then, we showed unconventional oxide-oxide heterojunction effects, improving reversible Li+-coupled electron-transfer properties using model electrodes constituted of various nanostructured (nano-) RuO2 on porous ATO. In addition to the superior electrochemical properties of the nano-RuO2/ATO heterojunction, the quasi-two-dimensional (2D) RuO2/ATO heterojunction led to improved specific capacity at a high rate and longer cycle life. We anticipate that this oxide-oxide heterojunction effect and developed all-oxide model porous electrodes can provide a path to develop advanced reversible energy storage devices.

DOI： 10.1021/acsami.2c06297

Designing hierarchical porosity in tin oxide monoliths and their application as a solid acid catalyst 査読有り

Suzuki, Y; Hasegawa, G; Kanamori, K; Nakanishi, K

NEW JOURNAL OF CHEMISTRY 45 巻 ( 37 ) 頁： 17558 - 17565 2021年10月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：New Journal of Chemistry

Hierarchically porous tin oxide monoliths have been prepared for the first time from a low-cost tin(iv) chloride precursor through an epoxide-mediated sol-gel process in an aprotic solvent N,N-dimethylformamide. Phase separation is induced in the presence of poly(propylene glycol) in the course of polymerization triggered by an acid scavenger, propylene oxide, leading to macroporous tin-based oxyhydroxide monoliths. The resultant macropores are confirmed to be controlled in the size range of 0.9-2.9 μm. Both the post-gelation solvothermal treatment in 2-propanol and calcination in air gave rise to crystallinity and mesoporosity (2.4-103 nm in size with BET surface area up to 261 m2 g-1), and hierarchically porous tin oxide monoliths have been obtained for the first time. The monoliths are demonstrated as a catalyst for the esterification of valeric acid and methanol. This journal is

DOI： 10.1039/d1nj03307g

Sol-gel based structural designs of macropores and material shapes of metal-organic framework gels 査読有り

Hara, Y; Manabe, K; Nakanishi, K; Kanamori, K

MATERIALS ADVANCES 2 巻 ( 13 ) 頁： 4235 - 4239 2021年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：Materials Advances

We have developed a general synthetic strategy to control macroporous structures and material shapes of metal-organic framework (MOF) gels via a sol-gel based structural control process. A series of 1,3,5-benzene tricarboxylic acid (BTC) based MOF gels, Cr-BTC and Zr-BTC, have been chosen as a proof of concept.

DOI： 10.1039/d0ma01009j

　前のページ - 次のページ　

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