Infrared study of the surface of silica immersed in liquid mixtures of hydrocarbons

Abstract

A simple infrared cell is described which enables studies to be made of the perturbation of surface hydroxyl groups caused by the immersion of powdered oxides in hydrocarbon solvents. Results are presented for silica in n-heptane + benzene and in n-heptane + toluene mixtures over the complete liquid composition ranges. Absorbance values taken from the spectra give the proportion of surface hydroxyl groups which are perturbed by contact with each component of a liquid mixture. Hence spectroscopic isotherms were deduced for the adsorption of each component onto specific (hydroxyl group) sites in the oxide surface.