2D Metal-Organic Framework-Based Thin-Film Nanocomposite Membranes for Reverse Osmosis and Organic Solvent Nanofiltration.

Metal-organic frameworks (MOFs) are promising candidates for membrane-based liquid separations due to their intrinsic microporosity, but many are limited by their insufficient stability. In this work, a copper-benzoquinoid (Cu-THQ) MOF was synthesized and demonstrated structural stability in water and organic solvents. After incorporation into the polyamide layer, the hydrophilicity of the membranes was enhanced. The resultant thin-film nanocomposite (TFN) membranes broke the permeability-selectivity tradeoff by showing 242 % increase in water permeance and slightly enhanced salt rejection at MOF loading of 0.0192 mg cm-2 . The underlying mechanism was probed by different chemical and morphological characterizations. The membranes also showed improved tolerance to chlorine oxidation. With their excellent stability, the Cu-THQ MOF-based membranes further demonstrated impressive performance in organic solvent nanofiltration involving dimethylformamide.