Porous structure and adsorption properties of SiO2 aerogels prepared from different silicon sources
SiO2 aerogels were prepared using sodium silicate,tetraethyl orthosilicate(TEOS),and methyl triethoxy silane(MTES)/dimethyl diethoxy silane(DMDES)as silicon sources,respectively,through sol-gel process and supercritical drying process.The microscopic morphology and pore structure characteristics of the SiO2 aerogels prepared from different silicon sources were investigated by SEM and BET.The adsorption properties of SiO2 aerogels prepared from different silicon sources were analyzed and compared organic solvents such as methylene chloride and toluene.The results show that the SiO2 aerogel prepared from sodium silicate as silicon source has the best adsorption characteristics of organic solvents and high transparency,while the SiO2 aerogel prepared from MTES/DMDES as silicon source has micron-sized pores and shows good flexibility.The adsorption data were fitted and analyzed with different adsorption models,and the results indicate that the adsorption curves of SiO2 aerogels for different organic solvents such as dichloromethane and toluene are more in line with the pseudo-first order adsorption kinetic model.
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