Adsorption Isotherms of Water on a Set of Fractosils and on Avicel PH 101R by Frontal Analysis Chromatography

Abstract Residual water adsorbed on the surface of solids can modify significantly e.g.: stability of solids, properties of colloidal systems, compressibility of powders, oxidation phenomena, heterogeneous nucleation in the atmosphere, and may serve as a medium, favourable for the growth of numerous micro-organisms. The aim of this work is the characterization, by physical and thermodynamic parameters, of adsorbed water on the surface of a set of Fractosils and of Avicel PH 101R. Frontal analysis chromatography is used for the determination of adsorption isotherms. The analysis of the thermodynamic parameters of adsorbed water indicates that the water adsorption is either mobile or localized depending on the nature of the solids. The adsorbed water exists under three states: strongly bonded (up to the monolayer), weakly bonded and free (condensed water).