Fluorinated Covalent Organic Framework Membranes for High‐Flux Nonpolar Organic Solvent Nanofiltration

ABSTRACT Membrane‐based separation of nonpolar solvents is critically important for petroleum refining, chemical production, and food processing industries. Although membrane technology provides energy‐saving advantages, conventional organic nanofiltration membranes suffer from inadequate separation performance in nonpolar systems, hindering their practical deployment. Covalent organic frameworks (COFs) emerge as an ideal platform for this application due to their unique combination of chemical robustness, high porosity, and precisely adjustable pore structures. In this work, we present an innovative strategy that integrates trifluoromethyl‐functionalized COFs with surfactant‐assisted interfacial polymerization to achieve high‐flux nonpolar organic solvent nanofiltration. The resulting COF membranes demonstrate remarkable separation capabilities, achieving an ultrahigh hexane permeance of 251.4 L m −2 h −1 bar −1 and a remarkable 96.2% rejection for lecithin in hexane solutions, surpassing all previously reported OSN membranes. This innovative strategy not only addresses current limitations in nonpolar solvent separation but also establishes a new paradigm for developing high‐performance separation membranes, with significant potential for industrial applications.