Preparation and Adsorption Property of Phenyltriethoxysilane Modified SiO2 Aerogel

The hydrophobic silica aerogel （SiO2 aerogel） was prepared by/n situ polymerization sol-gel method and ethanol supercritical drying, with tetraethoxysilane （TEOS） as silica source, phenyltriethoxysilane （PTES） as modifier, ethanol as solvent and ammonia as catalyst. The effects of n（PTES）/n（TOES） were investigated on gel time, structure, and hydrophobicity. The SiO2 aerogel was measured by Fourier transform infrared spectroscopy （FT-IR） and scanning electron microscopy （SEM）. The effects of n（PTES）/n（TOES） were also studied on adsorption property of pentane, hexane, heptane, octane, benzene, toluene, o-xylenc, nitromethane, nitroethane, and nitrobenzene. The adsorption intensity of SiO2 aerogel was compared with that of activated carbon. The results show, with the increasing ofn（PTES）/n（TOES）, the surface area, pore volume, and pore size of SiO2 aerogel decreased, gel time and hydrophobicity increased, and the contact angle could be 154° with n（PTES）/n（TOES）=0.7. The adsorption intensity of SiO2 aerogel with n（PTES）/n（TOES）=0.5 was bigger than that of activated carbon with an average 5.84 times of 10 organic liquid. The adsorption intensity of aerogel with n（PTES）/n（TOES） =0.1 was the best one in all samples with the average 8.33 times compared with that of activated carbon.