Collect. Czech. Chem. Commun. 1994, 59, 1356-1360

Salt Separation by Charged Membranes

Jan Schauera and Takaomi Kobayashib

a Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, 162 06 Prague 6, Czech Republic
b Department of Chemistry, Nagaoka University of Technology, Kamitomioka, Nagaoka, Niigata 940-21, Japan


Two negatively charged membranes made from poly(acrylonitrile-co-sodium styrenesulfonate) having ion exchange capacity of 0.058 and 0.15 meq/g dry matter were tested in ultrafiltration of aqueous solutions of dextrans and low-molecular-weight electrolytes. The former membrane, though permeable to bulky dextrans (molecular weight cut-off approximately 500 000), fairly retained small electrolytes. The latter, extremely hydrophilic membrane showed little resistance to the feed solution and no retention of solutes was observed. The influence of the feed concentration, electrolyte type, and operating pressure on the solute retention was determined.