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

Abstract 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.