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Wach, R. A.; Sugimoto, Masaki; Yoshikawa, Masahito
JAEA-Review 2006-042, JAEA Takasaki Annual Report 2005, P. 144, 2007/02
no abstracts in English
CWach, R. A.; Sugimoto, Masaki; Yoshikawa, Masahito
Journal of the American Ceramic Society, 90(1), p.275 - 278, 2007/01
Times Cited Count：33 Percentile：81.53(Materials Science, Ceramics)Silicon carbide ceramic coating was developed from precursor polymer blend of polycarbosilane and polyvinylsilane on porous alumina substrate by radiation curing. The polymers were crosslinked with oxygen present in the atmosphere during irradiation and pyrolyzed at 850C in order to convert the polymer into SiC ceramics. Fabricated SiC film was employed as a membrane for gas separation achieving high separation ratio of 206 for H
and 241 for He over the nitrogen at 250C.
O
ceramics from precursor polymers by radiation curingWach, R.; Sugimoto, Masaki; Yoshikawa, Masahito
Key Engineering Materials, 317-318, p.573 - 576, 2006/08
no abstracts in English
O ceramics from precursor polymers by radiation curingWach, R.; Sugimoto, Masaki; Lam, N. D.; Yoshikawa, Masahito
Proceedings of 8th SPSJ International Polymer Conference (IPC 2005) (CD-ROM), 60 Pages, 2005/07
no abstracts in English
Wach, R. A.*; Mitomo, Hiroshi*; Yoshii, Fumio; Kume, Tamikazu
Macromolecular Materials and Engineering, 287(4), p.285 - 295, 2002/04
Times Cited Count：58 Percentile：85.14(Materials Science, Multidisciplinary)no abstracts in English
Wach, R. A.*; Mitomo, Hiroshi*; Yoshii, Fumio; Kume, Tamikazu
Journal of Applied Polymer Science, 81(12), p.3030 - 3037, 2001/09
Times Cited Count：115 Percentile：95.31(Polymer Science)no abstracts in English
Fei, B.*; Wach, R. A.*; Mitomo, Hiroshi*; Yoshii, Fumio; Kume, Tamikazu
Journal of Applied Polymer Science, 78(2), p.278 - 283, 2000/10
Times Cited Count：192 Percentile：98.21(Polymer Science)no abstracts in English
Wach, R. A.*; Mitomo, Hiroshi*; Yoshii, Fumio; Kume, Tamikazu
IAEA-SM-365, p.174 - 175, 2000/00
no abstracts in English
Sugimoto, Masaki; Wach, R. A.; Yoshikawa, Masahito
no journal, ,
no abstracts in English
Sugimoto, Masaki; Wach, R. A.; Yoshikawa, Masahito
no journal, ,
no abstracts in English
Sugimoto, Masaki; Takano, Katsuyoshi; Wach, R. A.; Yoshikawa, Masahito
no journal, ,
Silicon carbide (SiC) ceramic coating coating can be utilized for gas separation in process for hydrogen production. We developed the SiC coating by precursor polymer method. Spinning method was applied to coat the Al
O
ceramic plates with preceramic polymers of polycarbosilane and polyvinylsilane and their blends. The coated plates were cured by electron beam (EB) to the total dose of 2 MGy. The polymer on the surface was crosslinked with oxygen present in the atmosphere during irradiation. Samples were pyrolized at 850 C in argon atmosphere in order to convert into SiC ceramics. Examination by SEM was applied to elucidate the coated surface and the gas of hydrogen, and nitrogen permeation was measured. Rutherford backscattering spectroscopy (RBS) using 2.0 MeV He
ions was employed to determine the composition and the thickness of the films.
Wach, R. A.; Sugimoto, Masaki; Yoshikawa, Masahito
no journal, ,
no abstracts in English
Sugimoto, Masaki; Piroonpan, T.; Wach, R. A.; Yoshikawa, Masahito
no journal, ,
no abstracts in English
Wach, R. A.; Sugimoto, Masaki; Takano, Katsuyoshi; Yamamoto, Shunya; Yoshikawa, Masahito
no journal, ,
no abstracts in English
Idesaki, Akira; Wach, R. A.; Sugimoto, Masaki; Yoshikawa, Masahito
no journal, ,
We have developed silicon carbide (SiC) products such as SiC fiber with average diameter of 5
m and SiC coating for gas separation membrane from a polymer blend of polycarbosilane (PCS) and polyvinylsilane (PVS). One process for fabrication of SiC product is as follows: forming of polymer, curing of polymer with radiation oxidation, and pyrolysis of cured polymer. In this process, we have found that the PCS-PVS polymer blend can be cured by radiation oxidation with the half dose of that of the PCS. In this work, a behavior of radicals in the PCS-PVS polymer blend was investigated in order to elucidate the mechanism of radiation oxidation of the PCS-PVS polymer blend. It was found that the PVS does not affect on production of the radicals in the polymer blend, and that the radicals are decayed easily by blending PVS in case of the irradiation in air at room temperature.
Idesaki, Akira; Wach, R. A.; Sugimoto, Masaki; Yoshikawa, Masahito
no journal, ,
Effects of 
-ray irradiation on a polymer blend of polycarbosilane and polyvinylsilane (a PCS-PVS blend) in the presence of oxygen were investigated. The PCS-PVS blends were oxidized during the irradiation of -rays to form crosslinking structures such as Si-O-Si and/or Si-O-C bonds. In case of a PCS-PVS blend containing 30wt% of polyvinylsilane, the absorbed dose enough for gellation decreased to less than 1/10 comparing with that for the pure polycarbosilane.
