• Title/Summary/Keyword: Mesoporous polycarbosilane

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Fabrication and Characterization of Macro/Mesoporous SiC Ceramics from SiO2 Templates (실리카 주형을 이용한 메크로/메조다공성 탄화규소 세라믹의 제조와 비교특성)

  • ;Hao Wang
    • Journal of the Korean Ceramic Society
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    • v.41 no.7
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    • pp.528-533
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    • 2004
  • Macroporous SiC with pore size 84∼658 nm and mesoporous SiC with pore size 15∼65 nm were respectively prepared by infiltrating low viscosity preceramic polymer solutions into the various sacrificial templates obtained by natural sedimentation or centrifuge of 20∼700 nm silica sol, which were subsequently etched off with HF after pyrolysis at 1000∼140$0^{\circ}C$ in an argon atmosphere. Three-dimensionally long range ordered macroporous SiC ceramics derived from polymethylsilane (PMS) showed surface area 584.64$m^2$g$^{-1}$ when prepared with 112nm silica sol and at 140$0^{\circ}C$, whereas mesoporous SiC from polycarbosilane (PCS) exhibited the highest surface area 619.4 $m^2$g$^{-1}$ with random pore array when prepared with 20-30 nm silica sol and at 100$0^{\circ}C$. Finally, tile pore characteristics of porous SiC on the types of silica sol, polymers and pyrolytic conditions were interpreted with the analytical results of SEM, TEM, and BET instruments.