Achieving High-Performance Organic Solvent Nanofiltration through Multi-Cross-Linking Sites and Twisted Spatial Configuration of Trimeric Resorcinol

Organic solvent nanofiltration (OSN) membranes have garnered significant attention for their green and efficient separation capabilities. However, conventional polymer-based OSN membranes are often constrained by the inherent trade-off between permeability and selectivity. Herein, two trimeric resorcinol isomers (i-3merH and p-3merH) were employed to fabricate cross-linked microporous polyarylate network membranes via interfacial polymerization. Owing to the multiple reactive sites and distorted spatial configurations of these isomers, the topology of the cross-linked network and the microporous channels can be effectively coregulated, thereby tuning the permeability-selectivity balance of the membranes. Specifically, the i-3merH-TMC membrane exhibits an outstanding methanol permeance (20.13 LMH bar–1) and a relatively low molecular weight cutoff (446 Da), enabling precise separation of cefixime (453 Da) and its intermediate MICA (259 Da). By elucidating how molecular spatial configuration and cross-linking site density govern membrane nanostructure, this work provides a viable strategy to balance permeability and selectivity in high-performance OSN membranes.