Silica Aerogels Based on Sodium Silicate and Their Applications

The conventional method for preparing such materials involves the sol–gel process followed by supercritical drying or ambient pressure drying. By gaining a deeper understanding of the interdependent processing parameters—such as the pH of the silica sol, aging time and temperature, washing, solvent exchange, surface modification, and the adjustment of these factors—it is possible to produce high-quality aerogels tailored to specific applications.

In this study, the preparation of silica aerogels using sodium silicate, the mechanism of gel formation, the influence of processing parameters on pore structure and, consequently, the properties of aerogels are reviewed. Finally, the most important applications of silica aerogels in engineering sciences and examples of recent advancements in this field are presented.

Silica aerogels are nanostructured porous materials consisting of a three-dimensional network with an open-pore architecture and exceptional properties such as low density, high porosity, low thermal conductivity, large specific surface area, low refractive index, and high optical transmittance.

These unique features offer tremendous potential for a wide range of applications, including thermal insulation, catalysts, optics, adsorbents, and drug delivery systems.