Dual-Functional Coatings for RO Membranes: Optimizing Graphene Oxide and Polydopamine for Fouling and Scaling Control

This study reports the development of a novel thin-film nanocomposite (TFN) reverse osmosis (RO) membrane with a surface functionalized using graphene oxide (GO) and polydopamine (PDA). GO was synthesized using a modified Hummers' method and integrated into a PDA-coated commercial RO membrane. The membranes were treated with UV light for varying durations to enable crosslinking of GO nanoparticles to the membranes. The modified membranes showed improved pure water permeability (PWP) and salt rejection compared to the pristine membrane. The resulting RO membrane, which was exposed to 60 min of UV and contained 0.02 g of GO, achieved the best performance, with a PWP of 23.8 L m^-2 h^-1 bar^-1 and a salt rejection of 96%. Antiscaling and antifouling properties were notably enhanced, as indicated by stable flux under silica scaling and decreased bacterial growth. These results suggest that PDA-GO functionalization is a promising approach for improving membrane durability and efficiency in desalination processes.