MOLECULAR ADSORPTION ON SILICA-GEL SURFACE FROM LIQUID-MIXTURES

Adsorption isotherms from ternary liquid mixtures (polar component + binary solvent) on silica gel have been determined at 298 K. The analysis of the changes of a binary solvent composition during adsorption of a polar component enables determining if the surface phase contains the molecules of polar component only or if there exists the possibility of the formation of the mixed surface phase. Monolayer capacities have been determined for investigated systems. Taking into account appropriate cross-sectional areas of adsorbate molecules, the specific surface area of the silica gel has been calculated on the basis of liquid adsorption data. Obtained specific surface areas for different adsorbates were compared with BET values from nitrogen adsorption data.