Preparing hydrophilic and antifouling polyethersulfone membrane with metal-polyphenol networks based on reverse thermally induced phase separation method

Abstract

In this study, metal-polyphenol networks (MPNs) coating was formed on the surface of polyethersulfone (PES) membrane prepared by reverse thermally induced phase separation (RTIPS) method through layer-by-layer assembly (LBL) method to endow membrane with excellent structure and permeability. MPNs coating was generated by coordination reaction between Fe3+ and tannic acid (TA), which was influenced by Fe3+ concentration and reaction time. The modified membrane was characterized in various aspects. SEM images showed that PES membrane possessed better microstructure with porous surface and spongy section prepared by RTIPS method. The analysis of Raman and XRD both confirmed the existence of MPNs coating on the membrane surface because of the coordination bonds. Moreover, the decrease of water contact angle and AFM indicated that MPNs coating endowed PES membrane with better hydrophilicity. Compared with bare PES membrane, the flux of the modified membrane was improved obviously with the maximum value of 878.29 L/m2 h. During membrane resistance process, the modified membrane showed better anti-fouling performance with the total resistance decreased by 53% and the FRR reached 80.95%. Thus, a hydrophilic and antifouling PES membrane with excellent structural properties and permeability was prepared by combining the modification method of MPNs coating with RTIPS method.