Hydrophobic Effect of Modifying Molecules on the Surface of Ultrafine Silica Particles

Abstract

The surface of ultrafine silica powder was modified with three kinds of normal alcohol having different chain length. A conformation of substituted alkyl group on the surface of powder was argued through the adsorbed density of alkyl groups and the molecular occupational area on the silica surface. The obstruction effect against adsorption of water molecules on the modified silica surface was explained on the basis of conformation difference of the substituted alkyl groups.