High-Performance PA Nanofiltration Membrane with Coral-Reef-Like Morphology atop Polydopamine Decorated EVOH Nanofiber Scaffold

The pursuit of highly permeable thin-film nanocomposite (TFNC) nanofiltration (NF) membranes with desirable selectivity is an eternal topic for desalination and wastewater treatment. Herein, a facile route to engineer polyamide (PA) NF membranes is reported with a coral-reef-like thin PA active layer atop a polydopamine pre-decorated ethylene vinyl alcohol copolymer (EVOH) nanofiber scaffold (EVOH-PDA) via interfacial polymerization (IP). EVOH-PDA possesses a submicron pore size and super-hydrophilic surface, which provides abundant thin water layers covering nanofibers in the IP process resulting in the PA layer with a morphology of coral-reef-like highland surrounded by flat low-lying regions. The resultant NF membrane presents high permeance of 32.19 L m −2 h −1 bar −1 and high rejection of 96.52% to 1000 ppm Na 2 SO 4 feed solution with a stable performance against operation time and high salt concentration. This work provides a new approach to fabricating PA TFNC membranes with outstanding NF performance in liquid separation applications.