Abstract
Poly(vinyl alcohol) membranes having various kinds of water content were prepared. In a dialysis system consisting of one of the membranes and solutions of KCl, CaCl2 and K2SO4 electrolytes, the membrane potential, the permeability coefficient and the partition coefficient were measured. The potential data indicate that in the membranes, the mobility of large ions decreases with decreasing water content more steeply than that of small ions. The ratio of the ionic mobility in the membranes to that in aqueous solution is in proportion to the square of membrane tortuosity as the prediction of Mackie and Meares’ theory; however, the proportion coefficient is not unity for the ions. Hence, a modified equation of the theory was proposed in order to estimate the ionic mobility in the membranes.
