Silicone‐Based Organic–Inorganic Hybrid Aerogels and Xerogels

Aerogels are attracting increasing attention due to their high thermal insulation ability as well as unique properties such as high porosity, surface area, and transparency. However, low mechanical strengths, originating from their unique porous structure, impede handling, formability, mass production, and extended applications. This minireview focuses on the strengthening of aerogels by several organic–inorganic hybridization strategies. In particular, successful strengthening methodologies, which employ organo‐substituted alkoxysilanes as the single precursor for the sol–gel preparations, developed by the authors are highlighted. Moreover, improvements in compressive strength and elasticity lead to monolithic aerogel‐like xerogels through ambient pressure drying. Correlations between structures in different length scales (e.g., molecular, network, and pore structure levels) and resultant mechanical properties are discussed for further understandings and better design toward mechanically improved aerogels/xerogels and their applications. Gelling together: Organic–inorganic hybrid aerogels and xerogels from organoalkoxysilane precursors are reviewed. Careful tuning of the sol–gel process yields transparent silicone‐type hybrid aerogels that show improved mechanical strength and flexibility. Further, these gels undergo “spring‐back” during ambient pressure drying, successfully leading to xerogels with comparable properties with corresponding aerogels. Focus is given to recent extensions to different silicone networks.