Modification of silica surfaces by grafting of alkyl chains. II-Characterization of silica surfaces by inverse gas-solid chromatography at finite concentration

Abstract

Model compounds, resulting from the surface esterification of fumed and precipitated silicas with methanol or hexadecanol, have been characterized by inverse gassolid chromatography at finite concentration. Surface treatments are shown to result in a decrease of adsorbate-adsorbent interactions (hexadecylated silicas are indeed virtually unable to exchange any specific interaction with a solute) and with an improvement of the energetic homogeneity of the materials. Results obtained suggest moreover that the distribution of surface silanol groups on precipitated silicas is not the same as on fumed silicas of identical surface area.