실리카 주형을 이용한 메크로/메조다공성 탄화규소 세라믹의 제조와 비교특성 |
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Fabrication and Characterization of Macro/Mesoporous SiC Ceramics from SiO2 Templates |
홍난영 , Hao Wang 1, 박경훈 2, 김동표 3 |
충남대학교 신소재연구소 1Key Lab of Ceramic Fiber and Composites, National University of Defense Technology, Chin 2충남대학교 공과대학 정밀공업화학 3충남대학교 공과대학 정밀공업화학과 |
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ABSTRACT |
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. |
Key words:
Macro/Mesoporous, SiC ceramic, Precursor, $SiO_2$template |
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