Reduced Fouling Ultrafiltration Membranes via In-Situ Polymerisation Using Polydopamine Functionalised Titanium Oxide

The trade-off phenomenon between selectivity and permeation flux is a major challenge in pressure-driven membranes, and specifically for ultrafiltration membranes. Currently, many research studies have been performed to try to increase permeability while maintaining the rejection at a high level. However, in most of these studies, the improvement of permeability was accompanied by a decrease in rejection or vice versa. To tackle this problem, TiO2 nanoparticles were attached on the surface of PES membranes using polydopamine as adhesive agent. In general, it is quite challenging to attach/bind TiO2 on the surface of membranes due to agglomeration of nanoparticles. Therefore, we developed a practical, simple and a scalable method to attach TiO2 nanoparticles (NPs) on the top surface of membrane using one-step dip coating. Experimental results revealed that the modified layer enhanced the hydrophilicity of the PES UF membranes as confirmed by the decrease of contact angle from. As a result, the modified membranes exhibited a significant improvement in anti-fouling properties, with 12 times higher water permeation flux (962 LMH for pDA-f-TiO2-PES30) as compared to the pristine PES membranes (79.9 LMH). The static adsorption of BSA on the surface of membranes was reduced from (60 µg/cm2 for pristine PES to 21 µg/cm2 for pDA-f-TiO2- PES120). Furthermore, the modified PES membranes displayed a higher flux recovery ratio (97%) and fouling reversibility (98.62%) than pristine PES membrane (37.63%). Also, the coated PES membranes bestowed a good antibacterial property relative to the pristine one. Besides, the membranes showed better physical and chemical stability as compared with unmodified PES membranes. Thus, this study provided a facile approach for enhancing the anti-fouling performance of PES ultrafiltration membranes.