Imine‐Based Covalent Organic Frameworks With Quaternary Ammonium Groups for Enhanced Conductivity in Anion Exchange Membranes

Covalent organic frameworks (COFs) represent a novel approach for the development of anion exchange membranes (AEMs) that exhibit efficient ion transport channels due to their rigid and ordered pore structures, coupled with minimal swelling. To overcome the limitations associated with the chemical modifiability of traditional hydrazone‐bonded COFs, this study employs an imine‐based COF platform to design and synthesize a range of functionalized COF materials (COF‐Pip‐2/4/6/8), which are modified with 1‐methylpiperidinium quaternary ammonium ions via flexible alkoxy side chains. A membrane formation method utilizing trifluoroacetic acid as a solvent to induce face‐on orientation through evaporation was employed to prepare imine‐COF membranes with well‐ordered nanochannels, achieving a maximum OH – ion conductivity of 264.4 mS/cm. This study elucidates that the synergistic interaction between the vehicle and Grotthuss mechanisms, rather than an exclusive focus on vehicle‐mediated transport, is more effective in attaining high ion conductivity. These findings demonstrate the considerable potential of imine‐COFs in the fabrication of AEMs that offer both high stability and exceptional ion conductivity.