High-Performance Thin-Film nanocomposite forward osmosis membranes modified with Poly(dopamine) coated UiO66-(COOH)2

Abstract

• Surface functionalization of UiO-66 with polydopamine (UiO-PDA). • Thin film nanocomposite (TFN) forward osmosis (FO) membranes were fabricated by incorporating UiO-PDA. • UiO-PDA as a hydrophilic nanomaterial enhanced the separation performance of TFN-FO membranes. • The UiO-PDA modified TFN membrane exhibited better anti-fouling performance and Cu +2 ions rejection in comparison with bare TFC one. In this study, a new family of thin-film nanocomposite forward osmosis (TFN-FO) membranes was synthesized by embedding polydopamine (PDA) coated UiO-66-(COOH) 2 (UiO-PDA) nanofiller in polyamide (PA) rejection layer via interfacial polymerization (IP). The PDA coating assisted the UiO dispersion in MPD/water media, resulting in better chemical miscibility between the UiO-PDA and PA matrix. The impact of the UiO-PDA incorporation on the physicochemical properties (surface chemical composition, hydrophilicity, morphology, and roughness) of the TFN membranes are systematically examined via different characterization techniques. Besides, the effect of UiO-PDA concentration on the overall performances (FO water flux, reverse salt flux, antifouling tendency) of the obtained UiO-PDA modified TFN-FO membranes were investigated in a cross-flow FO system. Compared with the pristine thin film composite (TFC) membrane, the modified TFN membranes presented higher selectivity, water flux, and anti-fouling tendency. Finally, the TFN-UC.2 (modified with 0.03 wt% UiO-PDA) membrane exhibited greater Cu 2+ ions removal in FO mode (feed solution in contact with PA active layer) than the control TFC membrane, arising from their improved PA rejection layer characteristics.