GLASSES FROM AEROGELS .1. THE SYNTHESIS OF MONOLITHIC SILICA AEROGELS

Experiments carried out to obtain monolithic silica aerogels are reported. The different ways to synthesize silica aerogels from alkoxides are investigated. The manner by which the critical point of the solvent can be reached is discussed as a function of the nature of the solvent. Physical parameters such as the amount of additional solvent or pressure, play a very important role in the direction of the liquid-vapour interface displacement during the heating of the autoclave. Some experiments performed using hypercritical drying with CO2 liquid are also mentioned. © 1990 Chapman and Hall Ltd.