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Idesaki, Akira; Sugimoto, Masaki; Yoshikawa, Masahito
Advances in Polymer Derived Ceramics and Composites; Ceramic Transactions, Vol.213, p.7 - 12, 2010/07
Recently, catalyst-loaded ceramic materials have been developed to apply for gas separators in the engineering field of hydrogen generation. Oxide ceramics of alumina and silica are used for the matrix in that field. However, the oxide ceramics are inferior to non-oxide ceramics in the point of resistance for high temperature, strong acid or alkali, hot steam, and so on. Si-based polymers are used as precursors for Si-based non-oxide ceramics. They have a good point of high formability and ability to form polymer blends with various materials. So far, we have established a fabrication technique of SiC products such as a fine fiber with average diameter of 6
m and a membrane for hydrogen separation. In this work, we fabricate a catalyst-loaded SiC material from a blend of Si-based polymer and transition metal compound. The catalyst-loaded SiC material showed a catalytic performance of evolution of CO
gas oxidizing CO gas.
Kita, Kenichiro; Narisawa, Masaki*; Nakahira, Atsushi*; Mabuchi, Hiroshi*; Ito, Masayoshi*; Sugimoto, Masaki; Yoshikawa, Masahito
Advances in Polymer Derived Ceramics and Composites; Ceramic Transactions, Vol.213, p.45 - 50, 2010/06
Sugimoto, Masaki; Idesaki, Akira; Yoshikawa, Masahito; Watanabe, Shogo*; Seki, Shu*
Advances in Polymer Derived Ceramics and Composites; Ceramic Transactions, Vol.213, p.105 - 110, 2010/06
We have succeeded in synthesizing ceramic nano fibers from precursor polymers using Single Particle Nanofabrication Technique (SPNT). A thin film of the precursor polymer was cross-linked by MeV-order heavy-ion beam irradiation along ion tracks of nano-size in radius through the whole thickness of the thin film. Nano fibers were developed on the surface of the substrate by dissolution and washing away of un-crosslinked polymer. Subsequent pyrolysis converted polymeric into ceramic nano fibers. The radius, length and number density of nano fibers are controlled by liner energy transfer (LET) of ion beam, thickness of polymeric target and number of projected ions, respectively.
Suzuya, Kentaro; Okamura, Kiyohito*; Suzuki, Kenji*; Ichikawa, Hiroshi*; Kohara, Shinji*
no journal, ,
The local atomic structure and intermediate-range order of Si-C-O fibers produced from the pyrolysis of a polycarbosilane precursor have been investigated by high-energy (61.6 keV) X-ray diffraction (HEXRD) at SPring-8 and reverse Monte Carlo (RMC) modelling technique. In previous study (Okamura et. al., Key Eng. 352 (2007) 65), we suggest that the Si-C-O fibers basically have a network structure that consists of two tetrahedral units: SiC
and SiO from the pair distribution function analysis of HEXRD data. In the network model, 3-membered ring of SiC as that in SiC crystal and 6-membered ring of SiO as that in silica glass are assumed as intermediate-range order. Thus, we carried out RMC modelling analysis with the HEXRD data to study more detailed short- and intermediate-range ordering structure. The relationship between the intermediate-range ordering and these behaviors has also been discussed.