Synthesis and Characterization of Type-VI Silica by Sol-Gel Method

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J. Korean Ceram. Soc. > Volume 35(3); 1998 > Article

Journal of the Korean Ceramic Society 1998;35(3): 264.

졸-겔법을 이용한 Tape-VI형 실리카 에어로겔의 제조 및 특성분석

김성철, 최대원, 최용수, 이종혁¹, 이해욱², 김창은

연세대학교 세라믹공학과
¹삼성전관 기초연구소
²가야대학교 공학부 세라믹공학과

Synthesis and Characterization of Type-VI Silica by Sol-Gel Method

ABSTRACT

The effect of catalytic condition on the properties of SiO2 aerogels has been investigated and then the dri-ed aerogels were partially densified to induce mechanical strength by heat treatment in order to prepare Type-VI silica by Sol-Gel method. Aerogel made by 1-step base process had the highest skeletal density lowest shrinkage and the smallest particle size. But in case of using acid catalyst in both 1st and 2nd step had the lowest skeletal density highest shrinkage and the largest particle size The aerogel synthesized by 1-step base process was most transparent because of its homogeneous microstructure. During heat treatments cracks occurred below 200$^{circ}C$ for aerogel with the skeletal density lower than 1.9 g/cm3 but the with the higher skeletal density did not cracked up to 800$^{circ}C$ shrinkage and skeletal density increased as heating temperature increased due to condensation and viscous sintering mechanism.

Key words: Aerogel, Supercritical drying, Partial densfication, Type-VI silica, Impregnation