Process for the preparation of monolithic silica aerogels and silica aerogels so obtained

摘要

Prepn. of monolithic silica aerogel comprises hydrolysing and polycondensing a mixt., contg. organic silicon and an organic solvent in an acidic medium to obtain a transparent gel substituting the organic solvent with liq. carbon dioxide and then removing the carbon dioxide under supercritical conditions where the organic solvent is ethylacetoacetate. Also claimed is a silica aerogel prepd. by the above process.