研究者詳細 - 中西　和樹

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

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

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

JOURNAL OF THE EUROPEAN CERAMIC SOCIETY 33 巻 ( 10 ) 頁： 1967 - 1974 2013年9月

Sol-gel synthesis of macroporous TiO2 from ionic precursors via phase separation route 査読有り

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

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY 67 巻 ( 3 ) 頁： 639 - 645 2013年9月

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

JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY 67 巻 ( 2 ) 頁： 406 - 413 2013年8月

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

Kido Yasuki, Nakanishi Kazuki, Okumura Nao, Kanamori Kazuyoshi

MICROPOROUS AND MESOPOROUS MATERIALS 176 巻頁： 64 - 70 2013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：Microporous and Mesoporous Materials

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 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 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. © 2013 Elsevier B.V.All rights reserved.

DOI： 10.1016/j.micromeso.2013.03.042

Preparation of a hierarchically porous AlPO<sub>4</sub> monolith via an epoxide-mediated sol-gel process accompanied by phase separation. 査読有り

Li W, Zhu Y, Guo X, Nakanishi K, Kanamori K, Yang H

Science and technology of advanced materials 14 巻 ( 4 ) 頁： 045007 2013年8月

Fabrication of large-sized silica monolith exceeding 1000 mL with high structural homogeneity 査読有り

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

JOURNAL OF SEPARATION SCIENCE 36 巻 ( 12 ) 頁： 1890 - 1896 2013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：Journal of Separation Science

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. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOI： 10.1002/jssc.201300123

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

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

ACS APPLIED MATERIALS & INTERFACES 5 巻 ( 6 ) 頁： 2118 - 2125 2013年3月

Macroporous SiO2 Monoliths Prepared via Sol-Gel Process Accompanied by Phase Separation 査読有り

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

ACTA PHYSICO-CHIMICA SINICA 29 巻 ( 3 ) 頁： 646 - 652 2013年3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：Wuli Huaxue Xuebao/ Acta Physico - Chimica Sinica

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

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

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

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 52 巻 ( 7 ) 頁： 1986 - 1989 2013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：Angewandte Chemie - International Edition

Soaking up s'more: Marshmallow-like flexible gels synthesized from organoalkoxysilanes by a facile process show superior oil/water separation properties. The gels are superhydrophobic and can be used to remove organic compounds from water through absorption; they can then be recovered by squeezing them out of the gel, as if it were a sponge. The gel retains flexibility over a wide temperature range, even in liquid nitrogen (see photo). Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOI： 10.1002/anie.201207969

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

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

PHYSICAL CHEMISTRY CHEMICAL PHYSICS 15 巻 ( 22 ) 頁： 8736 - 8743 2013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：Physical Chemistry Chemical Physics

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 Li 2FeSiO4-carbon composites as the cathode of lithium ion batteries. The electrodes prepared from the Li2FeSiO 4-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. © 2013 The Owner Societies.

DOI： 10.1039/c3cp50352f

Sol-gel synthesis of zinc ferrite-based xerogel monoliths with well-defined macropores 査読有り

Kido Yasuki, Nakanishi Kazuki, Kanamori Kazuyoshi

RSC ADVANCES 3 巻 ( 11 ) 頁： 3661 - 3666 2013年

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

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

RSC Advances 3 巻 ( 48 ) 頁： 26475- 2013年

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

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

RSC ADVANCES 3 巻 ( 48 ) 頁： 26475 - 26475 2013年

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

Tokudome Yasuaki, Tarutani Naoki, Nakanishi Kazuki, Takahashi Masahide

JOURNAL OF MATERIALS CHEMISTRY A 1 巻 ( 26 ) 頁： 7702 - 7708 2013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：Journal of Materials Chemistry A

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)2Cl 0.33·2.92H2O]·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 μm 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. © 2013 The Royal Society of Chemistry.

DOI： 10.1039/c3ta11110e

Hierarchically porous monoliths of oxygen-deficient anatase TiO2-x with electronic conductivity 査読有り

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

RSC ADVANCES 3 巻 ( 20 ) 頁： 7205 - 7208 2013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：RSC Advances

We report an electrically conducting oxygen-deficient anatase TiO 2-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. © The Royal Society of Chemistry 2013.

DOI： 10.1039/c3ra40545a

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

Hasegawa George, Kanamori Kazuyoshi, Nakanishi Kazuki, Abe Takeshi

JOURNAL OF PHYSICAL CHEMISTRY C 116 巻 ( 50 ) 頁： 26197 - 26203 2012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 Physical Chemistry C

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. © 2012 American Chemical Society.

DOI： 10.1021/jp309010p