The role of CuO/TS-1, ZnO/TS-1, and Fe₂O₃/TS-1 on the desalination performance and antifouling properties of thin-film nanocomposite reverse osmosis membranes

The thin-film nanocomposite reverse osmosis (TFN-RO) membranes were prepared by the introduction of hydrophilic nanoparticles into the polyamide (PA) layer to improve desalination performance. First, the hydrothermal method was used to synthesize titanium silicate-1 (TS-1) as a base additive for the fabrication of the TFN-RO membrane. Since the particle size has a significant effect on its dispersion in the membrane matrix, changing the nucleation rate of TS-1 precursor solution with a simple method conducted to reduce the size of TS-1. Then metal oxide composites were prepared via the wet impregnation method. FESEM and AFM analyses were performed to investigate the surface alteration of the membranes due to the introduction of nanoparticles. The results showed that the surface of the TFN membranes was smoother than the unmodified one. To assess the changes in membrane properties after incorporating additives, the water contact angle, and zeta potential were measured. Compared to TFC, the 0.02TS1-Fe-TFN membrane had a ∼ 30% increase in pure water flux. Meanwhile, the rejection of NaCl increased from ∼ 95% to ∼ 99%. The probing of antifouling performance using bovine albumin serum (BSA) and humic acid (HA) contaminants also showed that due to reduced roughness, the modified membranes had higher fouling resistance than TFC. Also, the TFN membranes exhibited good long-term and pH stability.