Abstract
Isotherms are measured for nitrogen, n hexane, triethylamine, and water vapor adsorption on sil icas of different origins, the surface layers of which contain functional groups of the ≡Si(CH2)2P(O)(OH)2 composition, namely, ethylene and phenylene bridged polysilsesquioxane xerogels produced by the sol-gel method, silica microspheres synthesized from tetraethoxysilane in the presence of [CH3(CH2)17N(CH3)3]Br as a template by spray drying method, and SBA 15 mesoporous silica produced based on tetraethoxysilane using Pluronic 123 as a template. It is shown that all of the samples possess high specific surface areas, while the types of adsorption isotherms and the accessibility of active acidic sites for adsorption interactions with electron donor molecules depend on the structures of pores and surface layers, which are governed by the methods of synthesis and postsynthesis sample treatment.