DEVELOPMENT OF HIGH-SELECTIVITY, HIGH-PERMEABILITY, FLEXIBLE PLASMA-POLYMER MEMBRANES

THE POTENTIAL ADVANTAGES OF MEMBRANE-BASED PROCESSES FOR SEPARATIONS ARE WELL KNOWN, BUT CURRENT MEMBRANE SYSTEMS HAVE CAPTURED ONLY A SMALL FRACTION OF THE TOTAL SEPARATIONS MARKET-PRIMARILY BECAUSE CURRENT MEMBRANES DO NOT OFFER THE COMBINATION OF HIGH SELECTIVITY AND HIGH FLUX REQUIRED FOR MANY APPLICATIONS. PLASMA POLYMERIZATION IS, IN PRINCIPLE, AN ATTRACTIVE PROCESS FOR MAKING EXCEEDINGLY THIN, DEFECT-FREE POLYMER FILMS THAT HAVE HIGH SELECTIVITY. UNFORTUNATELY, MOST OF THE CONVENTIONAL PLASMA-POLYMER MEMBRANES INVESTIGATED THUS FAR SUFFER FROM LOW PERMEABILITY, WHICH MEANS THAT TO ATTAIN PRACTICAL FLUXES, THEY MUST BE MADE SO THIN THAT CONVENTIONAL MEMBRANE STRUCTURES CANNOT SUPPORT THEM. FURTHERMORE, CONVENTIONAL PLASMA POLYMERS ARE BRITTLE AND PRONE TO CRACKING. THE GOAL OF THIS PROJECT IS PRODUCTION OF PLASMA-POLYMER MEMBRANES THAT OVERCOME THE DUAL PROBLEMS OF LOW FLUX AND BRITTLENESS THROUGH A NOVEL, MULTILAYER MEMBRANE STRUCTURE. THE NEW PLASMA-POLYMER MEMBRANES SHOULD HAVE THE HIGH SELECTIVITIES ASSOCIATED WITH THE CONVENTIONAL SINGLE-LAYER PLASMA POLYMERS INVESTIGATED THUS FAR, BUT THEY SHOULD HAVE FLUXES COMPARABLE TO OR BETTER THAN THOSE OF ANY MEMBRANES THAT ARE CURRENTLY AVAILABLE. IN ADDITION, THESE NEW PLASMA-POLYMER MEMBRANES SHOULD BE MORE FLEXIBLE, ALLOWING THEIR USE IN PRACTICAL APPLICATIONS. PHASE I IS STUDYING THE FEASIBILITY OF THIS APPROACH BY PREPARING MULTILAYER MEMBRANES WITH THE CHARACTERISTICS DESCRIBED ABOVE. PHASE II WOULD OPTIMIZE THE MULTILAYER PLASMA-POLYMER MEMBRANES FOR APPLICATIONS THAT MIGHT BE OF INTEREST TO PHASE III SPONSORS, AND WOULD ALSO PRODUCE AND TEST A PROTOTYPE MEMBRANE MODULE.