Permeation in filled membranes: role of solute-filter interactions

Abstract

An experimental study of permeation in membranes containing adsorptive fillers is reported. The aim of the study was to investigate the effect of solute adsorption on the permeation flux. Pervaporation of pure components in the homologous series of lower (C1-C3) alcohols and lower carboxylic acids was used for the experimental studies which involved measurement of sorption and permeation data. The results indicate that the permeation flux decreases with increasing equilibrium sorption capacity of the filler for iso-propanol and the carboxylic acids which are strongly adsorbed by the fillers. Using the theoretical model proposed by Cussler et al. [1] as the basis, a correlation for the permeation flux of these solutes is obtained. This correlation incorporates the effect of solute adsorption on the permeation flux. For ethanol and methanol which are weakly adsorbed implying that desorption is easy, the permeation flux increases with the incorporation of the fillers.