DEVELOPMENT OF MEMBRANES WITH LOW SURFACE-ENERGY TO REDUCE THE FOULING IN ULTRAFILTRATION APPLICATIONS

Modified ultrafiltration membranes are prepared and tested in treating oily aqueous solutions. Polyethersulfone ultrafiltration membranes ar e modified utilizing surface modifying macromolecules. Casting solutio ns are prepared containing various amounts of surface modifying macrom olecules as additives. Ultrafiltration membranes are prepared using th e phase inversion technique. The performance of the modified and contr ol membranes is subsequently evaluated in treating oil/water emulsions as well as pure water. The membrane performance is characterized in t erms of pure water permeation rates (PWP), product rate when oil/water are used as feed (PR), as well as oil separation. The resistance mode l is used to further quantify the effect of the surface modifying mole cules on the gel layer resistance of the membranes under investigation . It is found that the modified polyethersulfone membranes have a supe rior performance, reflected in their higher flux when treating oil/wat er emulsions, than the control unmodified membranes. The oil gel layer resistance of the membranes decreased with an increase in the surface modifying macromolecules.