REVERSE-OSMOSIS BY COMPOSITE CHARGED MEMBRANES

The charged membranes were prepared from the sulfonation and amination of SBR resins, and their reverse osmosis performances were investigated. The sulfonated membranes show high salt rejection. This result is in accord with the result of membrane potentials. Relatively excellent membranes were obtained by amination of the sulfonated membranes. This is probably owing to the formation of a dense charged region near the membrane surface; the composite charged membranes of sandwich-type are obtained by this method. The reverse osmosis performances of these membranes from various materials were made clear. © 1979.