Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
出崎 亮; Colombo, P.*
Advanced Engineering Materials, 14(12), p.1116 - 1122, 2012/12
被引用回数:13 パーセンタイル:41.68(Materials Science, Multidisciplinary)A Ni-containing porous silicon oxycarbide (SiOC) material was synthesized from a blend of polyphenylmethylsiloxane (PPMS), azodicarbonamide and nickel(II) acetylacetonate by a direct foaming technique. Homogeneous foaming of PPMS with well-controlled macropore size distribution in the range of 0.1-0.5 mm was achieved, by controlling parameters such as the composition of starting mixture, the heating rate and the sample aspect ratio. A porous SiOC material with metallic Ni was obtained by pyrolysis below 900C in Ar. However, open porosity of the obtained porous SiOC was about only 37%. Therefore, the addition of fillers or an extraction treatment process were examined in order to obtain high levels of open, interconnected porosity. It was found that the extraction treatment of foamed PPMS by ethanol is effective in producing highly open porous SiOC ceramics. The Ni-containing porous SiOC material synthesized by this treatment possessed an open porosity of about 70% and gas permeability constant of 4.1010 for Darcian permeability constant and 3.1710 for non-Darcian permeability constant. These values are sufficiently high for its application as a catalyst material. According to the results above, the synthesis of a Ni-catalyst supported on a porous SiOC ceramic by a simple one-pot process was demonstrated.
出崎 亮; Colombo, P.*
no journal, ,
Fabrication of a porous Si-O-C material with catalytic property from a blend consisted of polyphenylmethylsiloxane (PPMS) and nickel (Ni) compounds was examined. In order to fabricate a catalyst material, it is indispensable to control pore properties such as pore size distribution and open porosity because they are closely related with the catalytic performance. In this work, a Ni-containing porous Si-O-C material was synthesized from a blend of PPMS, Ni(II) acetylacetonate and azodicarbonamide (a blowing agent), and the effects of formulating ratio of blend, forming condition and pyrolysis condition on the pore properties were investigated. It was found that the pore size distribution is affected by formulating ratio of blend and forming condition. Finally, pore size in the range from 100 to 500 micro meters was obtained by the optimization of these conditions.
出崎 亮; Colombo, P.*
no journal, ,
多孔質セラミック材料は、セラミック材料が本来有する耐熱性,耐薬品性に加え、軽量,液体・気体透過性,高比表面積等の特長を兼ね備えた材料であり、断熱材やフィルター材,触媒支持材としての応用が期待されている。われわれはこれまでにポリフェニルメチルシロキサン、アゾジカルボンアミド、ニッケル(II)アセチルアセトネートからなる原料から、全気孔率約73%の多孔質シリコンオキシカーバイド(SiOC)材料を開発している。しかしながら、この材料の比表面積は約2m/gと低く、改善すべき課題であった。一方、不活性雰囲気下1200C以上の温度においてSiOCの分解反応(SiOC-SiC+SiO+CO)により発生するSiO, COガスが金属ケイ素化物を核として気相反応し、ナノファイバーが生成することが報告されている。そこで本研究では、SiOCの分解とナノファイバーの生成による比表面積の改善を試みた。その結果、窒素中1300C以上で熱処理することによってニッケルケイ素化物を核としてナノファイバーが生成すること、1400Cで熱処理後、多孔質SiOC材料の比表面積が127m/gまで改善されることを明らかにした。