IR Studies of adhesion promoters. Part 1.—Methoxytrimethylsilane on silica at the solid/liquid interface

Abstract

The adsorption of methoxytrimethylsilane on silica immersed in heptane or carbon tetrachloride primarily involves hydrogen-bonding interactions between surface silanol groups and the O atoms of MeOSiMe₃ molecules. A 1 : 1 interaction is dominant for isolated SiOH groups but adjacent interacting pairs of silanol groups adsorb a single silane molecule at low adsorbate concentrations, changing to pairs of silane molecules with increasing concentration. Hydrogen-bonded silane is removed from the surface by evacuation at 293 K but removal of solvent initially promotes a low level of chemisorption resulting in —SiOMe and —SiOSiMe₃ on the silica.