Synthesis of Silica Aerogel and Thin Film Coating at Ambient

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J. Korean Ceram. Soc. > Volume 34(2); 1997 > Article

Journal of the Korean Ceramic Society 1997;34(2): 188.

상입하에서의 실리카 에어로겔의 합성 및 박막코팅(I)

양희선, 최세영

연세대학교 세라믹공학과

Synthesis of Silica Aerogel and Thin Film Coating at Ambient

ABSTRACT

Wet gel with surface modification by TMCS was redispersed in EtOH and redispersed silica sol for coat-ing was prepared. After spin coating of redispersed sol was conducted on silicon substrate, processes of drying(8$0^{circ}C$) and heat treatment(>25$0^{circ}C$) were, followed at ambient pressure. The influence of heat treat-ment of properties of film was observed, changing temperature at heat treatment. The optimum redisp-ersion condition for stable silica sol was wet gel:EtOH=1g:110$mell$ and the concentration and viscosity of redispersed silica sol with average particle size of 30nm were 0.11 M, 2.0-2.2 cP respectively. Crack-free thin film with the refractive index of 1.14 and thickness of 400 nm was obtained through drying at 8$0^{circ}C$ and subsequent heat treatment at 45$0^{circ}C$ for 2 hrs respectively after spin coating of 1500rpm, 10 times.

Key words: TMCS, Surface modification, Redispersion, Ambient pressure, Heat treatment, Silica thin film, Spin coating