Abstract
The permeability of sodium chloride, potassium chloride, and tetra-ethyl-ammonium chloride salt solution through anionically charged poly(vinyl alcohol) membrane was determined at 25${\pm}$0.1 $^{\circ}C$. The membranes used were poly(vinyl alcohol-co-itaconic acid) copolymer membranes. Plots of the salt concentration in the membrane versus the outer solution concentration indicated partition type isotherm in this experiment. The membrane permeability as a function of the salt concentration was analysed by means of the T.M.S theory. In the case of potassium chloride, sodium chloride, and tetraethylammonium chloride, the permeability coefficients of the cation in water-swollen membranes decreased with increasing stokes radius of the cation, i.e., KCl>NaCl>$(CH_{3}CH_{2})_{4}NCI$. The sequence was explained by considering the partition and hydration of the ions in these hydrophilic membranes. Ionic mobility ratio in these membranes decreased with increasing stokes radius of the cations as in bulk aqueous solution. The effectiveness of the fixed charged density was found on the ionic species and was explained by considering the counter ions bound by the anionically charged membrane.
