STUDY OF REVERSE-OSMOSIS SEPARATION AND PERMEATION RATE FOR SULFONATED POLY(2,6-DIMETHYL-1,4-PHENYLENE OXIDE) MEMBRANES OF DIFFERENT ION-EXCHANGE CAPACITIES

The reverse osmosis performance of thin-film composite membranes prepa red from sulfonated polyphenylene oxide polymer with different ion-exc hange capacities was studied using various electrolyte solutes. The ef fect of the solvent used for the preparation of the polymer solution f or surface coating was also studied. It was found that the preparation of thin-film composite membranes with high selectivities and high flu xes was possible by adjusting properly the ion-exchange capacity and t he solvent. It was also found that the membrane performance was govern ed primarily by the ion-exchange reaction between the solute cation an d the proton in SO3H and the Donnan equilibrium. (C) 1995 John Wiley & Sons, Inc.