PREPARATION AND TESTING OF POLYVINYL-ALCOHOL COMPOSITE MEMBRANES FOR REVERSE-OSMOSIS

Thin film composite membranes were prepared by coating porous polysulf one membranes with a polyvinyl alcohol layer and further cross-linking its surface. The thin layer of cross-linked polyvinyl alcohol served as a selective membrane. The membranes were prepared under various con ditions and tested for sodium chloride separation. A high sodium chlor ide separation was achieved but the permeation rate was low compared w ith commercially available thin film composite membranes. Resistance a gainst the flow of solvent water and sodium chloride solute were deter mined for individual component barrier layers.