MOF@Polydopamine-incorporated membrane with high permeability and mechanical property for efficient fouling-resistant and oil/water separation

Metal organic frameworks (MOFs) have demonstrated great potential for their favorable impacts on the performance of water treatment membranes. Herein, the novel nanoparticles based on both nanoporous MOFs and organic PDA layer was exploited as a novel dopant for the fabrication of PES ultrafiltration (UF) membranes. The PDA was synthesized via oxidative self-polymerization under alkaline conditions and formed adhesive coatings on dispersed MOF. The properties of resulting membranes on the porosity, membrane morphology, hydrophilicity, permeability and anti-fouling performance were adequately investigated. The membranes incorporated with MOF@PDA exhibited exceptionally high permeability (209.02 L m-2·h-1), which is approximately 6 times higher than that of the pure PES membrane, and high BSA rejection (99.12%). Notably, the mechanical property and hydrophilicity of the PES membrane were both enhanced by MOF@PDA, and it has been demonstrated that greater hydrophilicity prevents fouling under practical conditions, which results in significant improvements in flux recovery ratio (FRR) (82%). In addition, the modified PES membranes were used to purify the oil/water emulsion, and the results indicates that the membranes have high permeability and rejection of oil/water emulsion, showing its great promise in practical oily sewage remediation.