Organic–inorganic hybrid aerogels with high mechanical properties via organotrialkoxysilane-derived sol–gel process

A brief overview of siloxane-based low-density aerogels and aerogels-like xerogels is presented. Aerogels are highly porous solids composed of inorganic oxides, metals, cross-linked polymers and carbons, and are known to possess a number of excellent physical properties such as high visible-light transparency with low refractive index, low dielectric properties, and extremely-low thermal conductivity. Aerogels are therefore regarded as a promising candidate for applications such as superinsulators; however, a mass production and applications of aerogels have been significantly discouraged due to the lack of mechanical properties since the first invention in 1931. This review introduces the substantial effort to improve the mechanical properties of aerogels with particularly highlighting our recent findings on elastic organic­inorganic hybrid aerogel monoliths obtained from methyltrimethoxysilane (MTMS) using the controlled sol­gel chemistry.