Abstract

Silica aerogels are highly porous, lightweight materials renowned for their exceptional thermal insulation, low density, and high surface area, making them valuable across diverse scientific and industrial applications. Their fabrication typically involves a sol–gel process followed by controlled drying to preserve the delicate nanoporous network. The choice of precursor—commonly tetraethyl orthosilicate (TEOS) or sodium silicate—along with catalyst type and processing parameters, significantly influences the aerogel’s structural and functional properties. Drying techniques such as supercritical drying, ambient pressure drying, and freeze-drying each present distinct advantages and limitations in terms of cost, scalability, pore retention, and environmental impact. Advances in surface modification, composite reinforcement, and hybrid material synthesis have further expanded the performance and application range of silica aerogels. This review outlines the fundamental steps of silica aerogel fabrication, compares various processing methods, and highlights recent innovations aimed at achieving an optimal balance between performance, economic feasibility, and sustainability.