Modification de la surface d'un solide mésoporeux par l'imprégnation de liquides de polarités différentes

¹ USTHB, BP n° 9, Dar El Beida, Alger, Algérie.
² Laboratoire de Chimie Physique, Université de Nice-Sophia Antipolis, Parc Valrose, 06034 Nice, France.

Résumé

On étudie la modification des propriétés d'adsorption d'un polymère méso- poreux par le dépôt de deux liquides, l'un apolaire, l'autre très polaire. Les données chromatographiques relatives aux deux systèmes chromosorb 102-squalane et chromosorb 102-oxydipropionitrile ont permis de conclure à l'existence de deux zones d'adsorption différentes à la surface du solide et d'interpréter les mécanismes de rétention chromatographiques de 11 hydrocarbures et de 14 composés polaires.

Abstract

Gas chromatographic columns have been constructed with different loadings of a liquid phase on a mesoporous polymer adsorbat. Two liquid phases were chosen : squalane, an apolar liquid, and cvano-2 ethyl ether, a very polar liquid. Analysis of the retention data of 11 hydrocarbons and of 14 polar compounds provided information on the surface properties of chromosorb 102. Relationships between the retention columns of the adsorbates and the liquid loadings were established by considering the heterogeneous adsorptivity of the solid support surface and the possible distribution of squalane or of cyano-2 ethyl ether on chromosorb 102. Graphs of retention volumes per gram of liquid loading V_N/W_L against liquid W_S/W_L could be drawn with straight lines with different slopes. At low and intermediate liquid loadings the observed effects ore due to adsorption equilibria at the gas-solid, liquid-solid and gas-liquid interfaces and bulk solution partition in the pores. At high liquid loadings, bulk solution partition is the major contributor to the retention.