POROUS GLASS AS AN IONIC MEMBRANE

Porous glass has been shown to behave as an ionic membrane in electrolyte solutions. For solutions in which cation and anion mobilities are approximately equal, the membrane behavior closely approximates that predicted by Teorell and Meyer and Sievers, except with very dilute solutions and in instances involving solutions of low pH. Use of this model enables estimates of the fixed ion concentration to be made. Some deviations from the model are discussed, and it is shown that the measured membrane performance is dependent upon the way in which the porous glass is prepared.