Microscopic insight into anion conduction in covalent−organic framework membranes: A molecular simulation study

Recently there has been considerable interest in the utilization of covalent-organic frameworks (COFs) as ion-exchange membranes. While rapid ion conduction is experimentally observed COF membranes, underlying mechanism remains elusive. Herein, we report a molecular simulation study on chloride (Cl−) four membranes functionalized with quaternary ammonium groups (QA-2, QA-4, QA-6 and QA-EO) different side chains (ethyl, butyl, hexyl diethyl ether). It revealed that membrane flexibility crucial to be incorporated for reliable predictions. The Cl− conductivities are predicted decrease COF-QA-2 > COF-QA-4 ≈ COF-QA-EO COF-QA-6, which good agreement experimental data. pore size, rather than membrane-Cl− interaction, unravelled key factor governing trend conductivity. microscopic insight provided by useful elucidate fundamental conduction, might facilitate design new optimal conduction.