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Journal of the Korean Ceramic Society 1996;33(12): 1319. |
| 실리카 에어로겔의 표면 개질 |
| 현상훈, 이찬호, 김동준 |
| 연세대학교 세라믹공학과 |
| Surface Modification of Silica Aerogels |
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| ABSTRACT |
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Silica aerogels were synthesis by the sol-gel-supercritical drying process using isopropanol as a solvent. Effets of the heat-treatment and the surface modification through propoxylation on the structural reinforcement as well as the surface hydrophobic/hydrophilic characteristics of aerogels were investigated. Silica aerogels synthesized by supercritical drying were hydrophobic but aerogels heat-treated above 20$0^{circ}C$ were transformed to be hydrophilic. In particular it was found that the skeletal structure of aerogels heat-treated at 50$0^{circ}C$ was strong enough not to crack after adsorbing a large amount of water vapor. Hydrophilic aerogels modified by propoxylation at 28$0^{circ}C$ for 20 h were reversed to the hydrophobic form. Transition between hydrophobicity and hydrophilicity was reversible. The hydrophobicvity and the hydrophilicity of silica aerogels were attributed to the Si-Oh bond and the nonpolar C-H bond groups of orgainc species respectively. |
| Key words:
Silica aerogel, Supercritical drying, Hydrophobicity, ydrophilicity, Surface modification, Propoxylation |
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