Crosslinking improved ion transport in polymer inclusion membrane‐electrodialysis process and the underlying mechanism

Abstract Electric field intensification has been demonstrated as an effective strategy for facilitating ion transfer and separation in polymer inclusion membrane (PIM) involved processes. However, it is still a challenge to develop compatible PIMs with high performance and to reveal the underlying mechanisms. Herein, crosslinked PIMs with different base polymers have been employed in PIM‐electrodialysis processes. Cross‐linked cellulose triacetate (CTA) based PIMs exhibited significant improvement in Cr(VI) transport, which permeability coefficient was 5.9 times larger than the non‐cross‐linked counterpart. The characterizations of cross‐linked PIMs showed higher hydrophilicity and lower membrane area resistance. Furthermore, cross‐linked polymeric network inside CTA based PIMs structure increased their crystallinity, thus supporting the fixed‐site jumping mechanism, thereby enabling ions to be transported directly in a manner of continuous pathway at low current density. This study shed light on further improvement of efficient ion transport and gave insights into the mechanism understanding in PIM‐ED systems.