研究者詳細 - 中西　和樹

Simple liquid chromatography using monolithic silica rod and capillary 査読有り

Oi Naobumi, Morisato Kei, Minakuchi Hiroyoshi, Nakanishi Kazuki

BUNSEKI KAGAKU 56 巻 ( 4 ) 頁： 227 - 229 2007年4月

Temperature-tunable scattering strength based on the phase transition of liquid crystal infiltrated in well-defined macroporous random media 査読有り

Murai Shunsuke, Fujita Koji, Hirao Takayuki, Nakanishi Kazuki, Hirao Kazuyuki

OPTICAL MATERIALS 29 巻 ( 8 ) 頁： 949 - 954 2007年4月

Functional porous materials via sol-gel with phase separation 査読有り

Nakanishi Kazuki

JOURNAL OF THE CERAMIC SOCIETY OF JAPAN 115 巻 ( 1339 ) 頁： 169 - 175 2007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：Journal of the Ceramic Society of Japan

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

Monolithic TiO2 with controlled multiscale porosity via a template-free sol-gel process accompanied by phase separation 査読有り

High-throughput protein digestion by trypsin-immobilized monolithic silica with pipette-tip formula 査読有り

Ota Shigenori, Miyazaki Shota, Matsuoka Hideo, Morisato Kei, Shintani Yukihiro, Nakanishi Kazuki

JOURNAL OF BIOCHEMICAL AND BIOPHYSICAL METHODS 70 巻 ( 1 ) 頁： 57 - 62 2007年2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 Biochemical and Biophysical Methods

Based on the monolithic silica gel materials with hierarchical pore structure and on the SPE devices (MonoTip®) developed thereof, a trypsin-immobilized monolithic silica in a pipette tip (MonoTip® 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. © 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 査読有り

Yoshikawa Chiaki, Goto Atsushi, Ishizuka Norio, Nakanishi Kazuki, Kishida Akio, Tsujii Yoshinobit, Fukuda Takeshi

MACROMOLECULAR SYMPOSIA 248 巻頁： 189 - 198 2007年

Konishi Junko, Fujita Koji, Nakanishi Kazuki, Hirao Kazuyuki

CHEMISTRY OF MATERIALS 18 巻 ( 25 ) 頁： 6069 - 6074 2006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：Chemistry of Materials

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 TiO 2 gel skeleton is spontaneously obtained by controlling the solution pH during the hydrolysis and polycon-densation 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°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 (∼150 m2/g) is maintained even after the heat treatment at 300°C. © 2006 American Chemical Society.

DOI： 10.1021/cm0617485

New macroporous crosslinked polymer gels prepared via living radical polymerization

Kazuyoshi Kanamori, Kazuki Nakanishi, Teiichi Hanada

Materials Research Society Symposium Proceedings 947 巻頁： 66 - 71 2006年12月

記述言語：英語掲載種別：研究論文（学術雑誌）

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.

Living radical polymerization in size-exclusion silica gel column reactors

Performance of monolithic silica capillary columns with increased phase ratios and small-sized domains. 査読有り

Hara T, Kobayashi H, Ikegami T, Nakanishi K, Tanaka N

Analytical chemistry 78 巻 ( 22 ) 頁： 7632 - 42 2006年11月

Performance of octadecylsilylated monolithic silica capillary columns of 530 mu m inner diameter in HPLC 査読有り

Motokawa Masanori, Ohira Masayoshi, Minakuchi Hiroyoshi, Nakanishi Kazuk, Tanaka Nobuo

JOURNAL OF SEPARATION SCIENCE 29 巻 ( 16 ) 頁： 2471 - 2477 2006年11月

Thick silica gel coatings on methylsilsesquioxane monoliths using anisotropic phase separation 査読有り

Kanamori Kazuyoshi, Nakanishi Kazuki, Hanada Teiichi

JOURNAL OF SEPARATION SCIENCE 29 巻 ( 16 ) 頁： 2463 - 2470 2006年11月

Masao Katsube, Makoto Ouchi, Tsuyoshi Ando, Mitsuo Sawamoto, Kazuki Nakanishi, Norio Ishizuka

Polymer Preprints, Japan 55 巻頁： 150 2006年10月

記述言語：英語掲載種別：研究論文（学術雑誌）

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 査読有り

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

Kanamori Kazuyoshi, Nakanishi Kazuki, Hanada Teiichi

ADVANCED MATERIALS 18 巻 ( 18 ) 頁： 2407 - + 2006年9月

Fujita Koji, Konishi Junko, Nakanishi Kazuki, Hirao Kazuyuki

SCIENCE AND TECHNOLOGY OF ADVANCED MATERIALS 7 巻 ( 6 ) 頁： 511 - 518 2006年9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：Science and Technology of Advanced Materials

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 °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. © 2006 NIMS and Elsevier Ltd.

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 査読有り

Nakamoto A., Namera A., Nishida M., Yashiki M., Kuramoto T., Takei Y., Furuno M., Minakuchi H., Nakanishi K., Kimura K.

Forensic Toxicology 24 巻 ( 2 ) 頁： 75 - 79 2006年9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：Forensic Toxicology

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

High-performance liquid chromatographic enantioseparations on capillary columns containing crosslinked polysaccharide phenylcarbamate derivatives attached to monolithic silica 査読有り

その他リンク： http://orcid.org/0000-0002-8069-4780

Chankvetadze Bezhan, Kubota Takateru, Ikai Tomoyuki, Yamamoto Chiyo, Kamigaito Masami, Tanaka Nobuo, Nakanishi Kazuki, Okamoto Yoshio

JOURNAL OF SEPARATION SCIENCE 29 巻 ( 13 ) 頁： 1988 - 1995 2006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：Journal of Separation Science

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. © 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

DOI： 10.1002/jssc.200500388

PubMed

Fabrication of Sm2+-doped macroporous aluminosilicate glasses with high alumina content 査読有り

Hirao Takayuki, Fujita Koji, Murai Shunsuke, Nakanishi Kazuki, Hirao Kazuyuki

JOURNAL OF NON-CRYSTALLINE SOLIDS 352 巻 ( 23-25 ) 頁： 2553 - 2557 2006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：Journal of Non-Crystalline Solids

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 °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 20AlO3/2 · 80SiO2 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+. © 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 査読有り

Fujita Koji, Murai Shunsuke, Nakanishi Kazuki, Hirao Kazuyuki

JOURNAL OF NON-CRYSTALLINE SOLIDS 352 巻 ( 23-25 ) 頁： 2496 - 2500 2006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：Journal of Non-Crystalline Solids

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 · 6H2O. 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. © 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jnoncrysol.2006.03.024