Molecular dynamical studies of the mobility of benzene and water o nsilica surfaces: correlation with the influence of surface chemistry and morphology

摘要

The close inter-relationship between silica surface chemistry and surface morphology has been studied using nitrogen sorption and DRIFT spectroscopy. The influence of the nature of the silica surface o nthe molecular motion of non-polar benzene and highly polar water on that surface has been studied using NMR techniques. It was found that rougher, more convoluted and microporous silica surfaces are characterised by vicinal hydroxyl groups more resistant to condensation udner thermal treatment. Higher degrees of surface roughness facilitate the motion of molecules such as benzene which interact via dispersion forces. More corrugated, microporous silica surfaces also provide pockets of strongly interacting hydroxyls which, it is suggested, hinder the motion of diffusing water molecules.