| 摘要 |
PURPOSE:To produce a porous glass having a thickness of several cm and containing pores having diameter of several tens Angstrom , by mixing a sol produced by the complete hydrolysis of a metal alkoxide with a gel produced by the partial hydrolysis, stirring the mixture and gelling, drying and calcining the mixture. CONSTITUTION:A metal alkoxide such as silicon ethoxide is added with a prescribed amount of hydrochloric acid and completely hydrolyzed e.g. by vigorous agitation. The obtained solution is converted to a sol 1. Separately, silicon ethoxide is added with a small amount of hydrochloric acid to effect partial hydrolysis and the obtained solution is converted to a sol 2. The sol 1 is mixed to the sol 2, stirred and the pH of the mixture is controlled e.g. by the addition of ammonia water. The obtained sol solution is charged in a vessel, closed and left standing to obtain a gel. The vessel is bored with holes accounting for several % - ten odd % of the surface area of the vessel and the content is dried e.g. for 10 days to obtain a dry gel. The dry gel is put into an electric furnace and calcined e.g. at 600-800 deg.C. A porous glass having a thickness of as thick as several cm and containing pores with several tens Angstrom in diameter can be produced by this process. |
