METHOD OF MANUFACTURING POROUS BODY COMPOSED OF DRY GEL AND POROUS BODY OBTAINED BY THE METHOD

摘要

PROBLEM TO BE SOLVED: To solve problems that it is difficult to obtain a porous body composed of high density dry gel without causing the shrinkage in the manufacture and to obtain the porous body composed of the dry gel having density distribution. SOLUTION: The porous body is manufactured by preparing wet gel from tetramethoxysilane/ethanol/water=1/1/4 (molar ratio) using ammonia as a catalyst, further adding a liquid mixture with the gel raw material of tetramethoxysilane/ethanol/water=1/3/4 to advance the gelating, repeating the same process once again to form a continuous three layer wet gel, washing with ethanol and performing drying under super critical state using carbon dioxide as a super critical fluid. As a result, the porous body composed of the dry gel having density gradient uniformly increasing in three steps is obtained. COPYRIGHT: (C)2004,JPO