Polyamide Membrane Tailored by Codeposition of a UiO-66 Metal–Organic Framework Nanostructure-Based Interlayer for Forward Osmosis

Adding nanomaterials such as metal–organic frameworks (MOFs) into a polyamide (PA) layer to prepare forward osmosis (FO) membranes for efficient desalination has attracted great attention. However, rational design and preparation of high-quality MOF-based PA nanocomposite forward osmosis membranes still remain a big challenge. In this study, a polyamine (PA) forward osmosis (FO) membrane was fabricated via interfacial polymerization (IP) with the assistance of a UiO-66 nanocomposite interlayer to enhance desalination and antifouling performances. Polydopamine (PDA) and polyethyleneimine (PEI) were codeposited with UiO-66 and formed a hydrophilic nanocomposite intermediate layer. The substrate with the PDA/PEI/UiO-66 interlayer had better hydrophilicity, restricting the diffusion of m-phenylenediamine (MPD) and promoting the formation of a defect-free active layer. In addition, the PDA/PEI/UiO-66 interlayer not only provided additional water channels but also enhanced the interaction of the substrate and PA layer. The water flux of the PA-PDA/PEI/UiO-66 membrane reached 40.0 L m–2 h–1 with a low reverse salt flux (3.2 g m–2 h–1). Moreover, the PA-PDA/PEI/UiO-66(0.1) membrane also possessed excellent antifouling performances with a high flux recovery of 98% and a low total fouling rate of 17%, which were 18.4% higher and 43.3% lower than those of the pristine TFC membrane, respectively. These results presented that the codeposition of the PDA/PEI/MOF interlayer greatly improved the desalination and antifouling performances of the PA FO membrane.