Organically modified silica aerogel with different functional silylating agents and effect on their physico-chemical properties

In this paper, we have successfully focused on a hydrophobic silica aerogels synthesis by the ambient drying of silica gels and the silylation with mono-, di-, and tri-functional agents was studied to improve physico-chemical properties of the aerogels. Silylated silica aerogels with water contact angles 161 ± 2°, 152 ± 3°, 147 ± 3° were obtained using trimethylchlorosilane, dimethyldichlorosilane, and methyltrimethoxysilane as a mono-, di- and tri-functional silylation reagents, respectively. The prepared mono-functional silylated silica aerogels exhibited relatively high thermal stability, low thermal conductivity, transparency, high porosity, and enhanced superhydrophobicity with low surface free energy making them suitable as multifunctional for many domestic and industrial applications. Our mono-functional silylated silica aerogels showed superior physico-chemical properties compared with di- and tri-functional silylated silica aerogels.