Methyl modified SiO2 aerogel with tailored dual modal pore structure for adsorption of organic solvents

Abstract

Methyl modified silica (Me-SiO2) aerogels are prepared using tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES) as co-precursor through a two-step sol-gel reaction followed by solvent exchange and supercritical drying. They possess tailored dual modal pore structure consisting of mesopores (10–18 nm) from the stacking of TEOS-derived clusters and small mesopores (2–6 nm) from filling and stacking of small MTES-derived clusters. Moreover, the replacing Si-OH groups by Si-CH3 groups on the aerogel’s surface makes them excellent hydrophobicity with contact angle up to 148°. The dual modal pore structure and hydrophobicity endow the Me-SiO2 aerogels outstanding adsorbing capability of quality factor Q up to 23 g/g for ethanol and selective adsorption of oil from water, which makes them tremendous potential for applications of oil adsorbing and oil-water separation.