Impact of Alkyl Chain Length on the Properties of SiO2-Based Aerogels

Abstract

Modified silica aerogels have been obtained by co-gelation of tetramethoxysilane and acylated (3-aminopropyl)trimethoxysilane of general formula (MeO)₃Si–(CH₂)₃–NHC(O)–R) followed by supercritical drying in CO₂. Alkyl substituent elongation has been shown to increase aerogel hydrophobicity up to formation of superhydrophobic materials (contact angle is 163.7°). Specific surface area of the aerogels can vary from 40 to 1375 m²/g.