Ambient pressure drying: a successful approach for the preparation of silica and silica based mixed oxide aerogels

Silica aerogels have received much attention in recent years as it has got a wide range of properties like high surface area, low density, high porosity, low dielectric constant, low thermal conductivity. Recently to make aerogels for commercial application ambient pressure drying has been preferred and also a cheap precursor like sodium silicate has been employed as the starting material instead of the alkoxides. In this review, attention will be given to the synthesis adopted for the preparation of silica and silica based mixed oxide/composite aerogels through ambient pressure drying. The properties of the prepared aerogels are also discussed in detail.