Preparation of Antimicrobial Nanofiltration Membrane via Self-polymerization of Dopamine and Surface Grafting of PHGH

A novel antimicrobial nanofiltration membrane was fabricated by the self-polymerization of dopamine on polysulfone membrane surface and following surface grafting of polyhexamethylene guanidine hydrochloride ( PHGH) in aqueous conditions. The membrane structures, morphologies and hydrophilicity were characterized by attenuated total reflectance-Fourier transform infrared spectroscopy ( ATR-FTIR), scanning electron microscopy ( SEM) and water contact angle measurement. The concentration of PHGH on grafting degree and filtration performance were investigated. Furthermore, the antibacterial performance of composite membranes was evaluated. The results showed that an active layer with nanofiltration performance was formed on polysulfone membrane surface and the hydrophilicity of membranes was significantly improved by the introduction of dopamine and PHGH. The fluxes decreased while the rejections of inorganic salts and dyes increased with the increasing concentration of PHGH. The composite membranes after grafting exhibited excellent antibacterial performance, when mass fraction of PHGH was 3%, the antibacterial rate reached up to 98.5%.