High-flux and fouling-resistant reverse osmosis membrane prepared with incorporating zwitterionic amine monomers via interfacial polymerization

Zwitterionic monomers have aroused great attraction for membrane preparation due to their tremendous hydrophilicity and antifouling properties. Zwitterionic diamine monomer N-aminoethyl piperazine propane sulfonate (AEPPS) was added into m-phenylenediamine (MPD) aqueous solution to react with trimesoyl chloride (TMC) via interfacial polymerization to fabricate zwitterionic thin film composite reverse osmosis membrane (TFCMZs). The membrane preparation conditions, including AEPPS content, TMC concentration and curing temperature, were systematically evaluated. The membrane surface hydrophilicity and antifouling properties of TFCMZs were greatly enhanced via introducing AEPPS into membranes. When tested with brackish water desalination conditions (2000 ppm NaCl feed solution at 1.5 MPa and 25 °C), the water flux of TFCMZs containing 10% AEPPS was significantly increased to be 54.5 ± 3.2 L·m− 2·h− 1, which is about an 82% increase compared with the pristine membrane, while the NaCl rejection remains above 98%. Furthermore, using tannic acid (TA) and sodium alginate (NaAlg) as model foulants, the TFCMZs displayed outstanding fouling-resistant and easy-cleaning properties. TFCMZs present both admirable separation and fouling-resistance performance, which indicates that TFCMZs have wide application potential for brackish water desalination.