Preparation and Adsorption Property of Phenyltriethoxysilane Modified SiO2 Aerogel

The hydrophobic silica aerogel(SiO2 aerogel) was prepared by in 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-xylene,nitromethane,nitroethane,and nitrobenzene.The adsorption intensity of SiO2 aerogel was compared with that of activated carbon.The results show,with the increasing of n(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.