Silica aerogels are advanced materials with outstanding properties, including high specific surface area and porosity, low thermal conductivity, density, dielectric constant, and refractive index. However, the excellent properties of silica aerogels have shown limited utility in industrial applications, primarily as thermal insulation materials, where they hold only a small (1.1–2.6%) market share. The emergence of clean energy technologies stimulated renewed interest in silica and other aerogels. Here the recent advances in the production and applications of silica aerogels are summarized, and the current challenges and future development opportunities are discussed. The conventional and emerging syntheses and characterization methods of silica aerogels are introduced, followed by a discussion on thermophysical properties and potential applications. The fabrication processes of silica aerogels are analysed at different industry development stages. Recent advances in aerogels research are considered, highlighting the obstacles and possible solutions for the successful translation and industry uptake and focusing on the emerging applications in electric vehicles and building insulation.

Synthesis of methylsilsesquioxane aerogels by ambient pressure drying instead of supercritical drying has recently emerged as a major trend, but the issues of low mechanical strength and unstable performance still need to be resolved. This work reveals the microscopic formation mechanisms of gel skeleton based on the kinetic characteristics of methyltrimethoxysilane (MTMS) precursor hydrolysis and the associated sol-gel reactions. The effects of oxalic acid concentration (c_OA) and hydrolysis time of MTMS solution (t_h) on the gelation time, morphologies, microstructures, chemical structure, and compression properties of the as-synthesized methylsilsesquioxane aerogels are investigated. The optimal c_OA and t_h are 38.4 mmol/L and 120 min, respectively, endowing the methylsilsesquioxane aerogels with a compression strength of 0.170 MPa and a maximum compression strain of 61.2%. Precise control of the hydrolysis conditions ensures the formation of branched particle-to-particle networks, which is crucial for maximizing the compression properties of methylsilsesquioxane aerogels synthesized under industry-relevant conditions.