A NOVEL APPROACH TO MAKE LOW-FOULING POLYMERIC MEMBRANES

THE PHENOMENON OF FOULING PLAYS A MAJOR ROLE IN THE PERFORMANCE OF A WIDE RANGE OF SYSTEMS INCLUDING HEAT EXCHANGERS, ORGAN IMPLANTS, CARDIOVASCULAR DEVICES, TEETH, AND MEMBRANES. IN AREAS OTHER THAN THE MEMBRANES, IT APPEARS THAT THE MOST NON-ADHESIVE, NON-FOULING SURFACES ARE QUITE HYDROPHOBIC, WITH CRITICAL SURFACE TENSIONS OF LESS THAN 30 DYNKM. IN THE MEMBRANE INDUSTRY, HOWEVER, THE OPPOSITE APPROACH HAS BEEN ADOPTED IN THE MAKING OF LOW-FOULING MEMBRANES. HYDROPHILIC, HIGH ENERGY SURFACE MEMBRANES ARE PRODUCED HAVING CRITICAL SURFACE TENSIONS OF GREATER THAN 40 DYNKM. BY INCORPORATING POLAR AND EVEN CHARGED FUNCTIONAL GROUPS IN THE MEMBRANE. ONE INCENTIVE FOR DOING THIS IS THAT MEMBRANES OF LOW SURFACE ENERGY ARE DIFFICULT TO WET. BEYOND THIS AND FOR A FEW OTHER POSSIBLE REASONS, THERE REMAINS THE QUESTION OF WHY THE APPROACH IS DIFFERENT. IN THE PROPOSED WORK, BOTH LOW AND HIGH SURFACE ENERGY MEMBRANES WILL BE PRODUCED USING A NOVEL GRAFTING TECHNIQUE. THESE MEMBRANES WILL UNDERGO FOULING TESTS AND PERFORMANCE TESTS WITH A VARIETY OF FOULANTS TO DEFINE THE EFFECT OF THE MEMBRANE SURFACES AND OTHER FACTORS ON FOULINTPHENOMENA. SUCCESSFUL RESEARCH CAN LEAD TO NEW MEMBRANE MATERIALS, OTHER APPROACHES AT MINIMIZING FOULING IN MEMBRANE SYSTEMS, AND TO A COST-EFFECTIVE MEANS OF PRODUCING LOW-FOULING MEMBRANES.