Interaction of Ethanol with Modified Aerosil Samples

Abstract

The interaction of ethanol with heat treated aerosil samples; silylated with various silanes at various temperatures has been investigated by ethanol adsorption at 293 K. Type II adsorption isotherms were retained in all cases except for dimethyldichlorosilane modified sample which changed to type I. The values of the BET constants and specific surface areas were found to depend on the concentration and type of modifier silane as well as the concentration and accessibility of residual silanols. The initial ethanol molecules adsorbed are believed to react with silanols, the next lot to hydrogen bond with the less accessible silanols to form and develop clusters. The final molecules physisorb laterally through hydrophobic interactions, as well as on top of the organic layer by dispersion forces.