Abstract:
Sol-gel derived hybrid aerogel monoliths and coatings of methyltrimethoxysilane (MTMS) and glycidoxypropyltrimethoxysilane (GPTMS) are prepared sucessfully. MTMS/GPTMS is hydrolyzed under acidic conditions and further condensed under basic conditions to generate a gel network followed by a sequential solvent exchange process and ambient drying to obtain aerogel monoliths. The as-synthesized alcogel is homogenized in methanol and coatings are fabricated on glass substrates by dip coating method followed by controlled thermal treatment at 400 8C to get organically modified silica (ORMOSIL) based aerogel coatings. The transparent ORMOSIL aerogel coating made from the composition of MTMS/GPTMS ratio 1: 0.5 is found to be highly porous with an average pore size of ~100 nm and hydrophobic coatings with water contact angle of ~100 8 are obtained. The hybrid aerogel has ~334 m2g 1 surface area (BET) with an average pore diameter
of ~2.7 nm, and the coating retains its hydrophobicity even after thermal treatment at 400 8C. Hybrid aerogel coatings were also made on cotton canvas fabrics which demonstrate oil adsorption-desorption properties and is a viable remedy for oilspill cleanup.
