Interfacial reorganization of scalable PEEK/ COF membrane via crystallization-induced shrinkage strategy for molecular sieving

Incorporating covalent organic frameworks (COF)-fillers into mixed matrix membranes (MMMs) has great potential for scalable organic solvent nanofiltration (OSN). However, the deficient interfacial compatibility poses a fatal defect and contributes to dissatisfactory molecular sieving capability. Herein, we fabricate scalable polyether ether ketone/covalent organic frameworks (PEEK/COF) mixed-matrix membranes by crystallization-induced shrinkage strategy. By virtue of crystallization-induced shrinkage of the polymer substrate, the interface between COF and PEEK reorganized to form a defect-free separation layer. The optimal PEEK/COF membrane realizes a high ethanol permeance of 61.4 L m − 2 h − 1 bar − 1 and 90.6% rejection of sunset yellow (452 Da). The resultant membranes maintain superior rejection performance after immersing in an organic solvent at high temperature or continuous operation for 36 h. The universality is proved by blending other nanomaterials. This study provides a feasible method for the preparation of OSN membranes and promotes the practical scalable OSN application of nanomaterials-based separation membranes.