Robust self cleaning polypyrrole-polysulfone blend hollow fiber membrane for biofouling mitigation

BACKGROUNDPersistent biofouling of membrane is the most commonly encountered problem during separation diminishing the throughput of the system. Many techniques have been adopted to mitigate biofouling. This paper describes the fabrication of polysulfone and polypyrrole blend hollow fiber membrane with outstanding self-cleaning potential. Blending of polypyrrole promoted excellent anti-biofouling surface against Gram positive and Gram negative bacteria. The impact of flow rate and pressure on membrane performance was also evaluated during the separation process. RESULTSLoading of polypyrrole resulted in enhanced hydrophilicity, permeability, zeta potential and tensile strength. Scanning electron microscopy confirmed the appearance of macrovoids with increase of polypyrrole concentration, indicating the porous structure of the membrane. Hollow fibers exhibited negative potential at pH7, leading to excellent anti-biofouling surface. Roughness of fibers was dramatically reduced from 120 to 3nm with polypyrrole concentration imparting superior self cleaning surface on the membrane. Fluorescence microscopy analyses revealed significant reduction in bacteria adhesion on 1wt% polypyrrole loaded fibers. Modified membrane showed striking antibacterial property due to the leakage of cytoplasmic materials through lysis, as supported by A(260) nm absorption study. Morphological analysis of the used blend membrane showed almost no deposition of bacteria even after a long run, holding the promise of biofouling mitigation. CONCLUSIONModification of membrane by polypyrrole imparted an outstanding self-cleaning property to the hollow fiber; hence, it is a simple and scalable approach to prevent biofouling during long-term performance. (c) 2018 Society of Chemical Industry