Hydrophobic transition of soluble polymer aerogel composites

Abstract In order to overcome the hydrophilic problem of aerogels based on soluble polymer, the transition of aerogel composites from hydrophilic to hydrophobic was achieved by grafting 1H, 1H, 2H, 2H‐Perfluorodecyltrimethoxysilane (FAS). Simply immersing in FAS ethanol solution and then ambient drying, this method is universal and efficient, we successfully achieved the soluble polymer aerogels hydrophobic transition. Taking polyvinyl alcohol (PVOH)/SiO 2 as an example, the changes of structure and properties of aerogels before and after modification were characterized in detail. It was proved that FAS was successfully grafted and ethanol evaporation had little effect on the microstructure of aerogel. The resulting aerogels possess very good hydrophobicity, with water contact angle of up to 147.5° (3 wt.% FAS). The aerogel exhibits good stability in maintaining hydrophobicity in a harsh environment, such as in extreme pH and temperature. We introduced a universal method for hydrophobic modification, which is of great significance for the practical application of aerogels.