THE EFFECT OF HEXANE TREATMENT ON THE PERMEATION OF SILICONE-COATED POLYETHERSULFONE MEMBRANES

The polyethersulfone membranes were cast from casting solutions including poly(vinyl pyrrolidone) additive. The membranes were further dried, silicone‐coated, and used for the permeation study with hydrogen and nitrogen gases. It has been found that solvent hexane which was included in the silicone rubber solution for surface coating increased the pore size on the membranes surface when poly(vinyl pyrrolidone) was present in the membrane. The above effect counteracted the pore size decrease by silicone coating, and, as a result, an H2/N2 permeability ratio of only 8.9 was achieved as compared with 28, which was obtained when the base polyethersulfone membrane was prepared from a casting solution without poly(vinyl pyrrolidone) additive. Copyright © 1990 John Wiley & Sons, Inc.