ATRP Grafting of Hydrophilic and Antifouling PSPMK Brushes on Commercial TFC-PA RO Membrane

Abstract

Properties of TFC PA reverse osmosis membrane can be enhanced by grafting 3sulfopropyl methacrylate potassium brushes via Atom Transfer Radical Polymerization. It took place in three steps which involves functionalization of membrane to achieve desirable functional group, initiator immobilization on functionalized membrane and growth of PSPMK polymer brushes on RO membrane. Grafting of PA was done at varied concentration of PSPMK and its effect on the surface properties was studied by FTIR analysis, SEM, optical microscopy, optical profilometry and contact angle analysis which took place at every step of grafting. Properties like permeation flux, antibacterial activity, morphology and hydrophilicity were analyzed. Modified membrane shows reduction in contact angle from 81° to 36°due to grafting of hydrophilic polymer brushes which results in increase in wettability. Gram negative bacteria Escherichia coli and gram positive bacteria Staphylococcus aureus were used to test the bacterial efficacy of modified membrane. Grafting of PSPMK brushes enhances the antibacterial properties of membrane by forming significant and well defined inhibition zones as compared to pristine membrane. Flux rate has also been increased from 31.5 L/m2hr. to 43.7L/m2hr. Modified membrane showed high hydrophilicity, enhanced antibacterial properties and increased permeation flux.