writer：Jiaxue Zhang, Yingbo Chen*, Pengcheng Wang, Yanling Fang, Guangcun Liu, Liangliang Li
keywords：Nanofiltration membrane; Layer-by-layer assembly; Antifouling
source：期刊
specific source：Desalination 640 (2026) 120763
Issue time：2026年

Desalination 640 (2026) 120763

DOI: 10.1016/j.desal.2026.120763

In this study, a high-performance nanofiltration membrane was developed by integrating layer-by-layer (LbL) polyelectrolyte assembly with confined in situ growth of zeolitic imidazolate framework-8 (ZIF-8). A PEI/PSS multilayer was constructed on a polyethersulfone (PES) support through sequential electrostatic deposition, providing a nanoscale confined environment for regulating ZIF-8 nucleation and growth. Zn2+ ions and 2-methylimidazole were subsequently introduced into the multilayer structure, enabling the formation of ZIF-8 nanocrystals within the polyelectrolyte matrix rather than conventional particle incorporation. The optimized membrane achieved a Na2SO4 rejection of 98.5 ± 0.3% with a permeance of 7.1 ± 0.1 L·m?2·h?1·bar?1, representing a 65% enhancement compared with the PEI/PSS counterpart. Meanwhile, MgCl2 rejection increased from 64.6% to 93.0%, indicating improved divalent ion selectivity. These improvements were attributed to the confined ZIF-8 nanostructures, which optimized the selective layer architecture, reduced non-selective defects, and regulated ion transport behavior. Furthermore, the membrane maintained high salt rejection (>93%) under Na2SO4 concentrations of 1–5 g·L?1 and exhibited excellent antifouling performance with a flux recovery ratio of 93.8 ± 0.8%. This work provides an aqueous-phase strategy for constructing MOF-polyelectrolyte hybrid selective layers with enhanced ion selectivity, antifouling capability, and operational stability for advanced water separation applications.