Charge-Mosaic Membranes: Dialytic Separation of Electrolytes from Nonelectrolytes and Amino Acids

Abstract

Charge-mosaic membranes were used for dialytic separations of potassium chloride from low-molecular-weight nonelectrolytes and neutral amino acids. The permeability ratio (potassium chloride to uncharged species) ranged from about 6 in the case of methanol to about 86 in that of mannitol. A theoretical model predicts that optimum rates of dialysis should be achieved by dialyzing against salt concentrations other than zero; this prediction was confirmed by experiment. These observations suggest potential applications of mosaics in laboratory separations, industrial processing, and hemodialysis.