Construction of ordered OH ⁻ migration channels in anion exchange membrane by synergizes of cationic metal‐organic framework and quaternary ammonium groups

Abstract

Summary A series of anion exchange membranes (quaternized chitosan/cation metal‐organic framework [MIL‐X‐QCS]) were prepared via purposeful inserting the cationic metal‐organic framework as the multifunctional filler into quaternized chitosan (QCS). The successful preparation of the anion exchange membrane was confirmed by X‐ray diffraction (XRD), Fourier transform infrared spectroscopy (FT‐IR), and Scanning electron microscope (SEM). In this research, we converted the charge‐balanced MOFs skeleton Cr‐MIL‐101 into the cationic metal skeleton (Cr‐MIL‐101)+Cl− by anion stripping, and cooperated with quaternary amine groups to construct a high‐speed OH− transmission channel. The introduction of a rigid MOF structure reduces the water uptake and swelling ratio of the composite membrane by 27% and 37%, respectively. At 80°C, the OH− conductivity of the MIL‐9‐QCS membrane (The composite membrane doped with 9 wt% Cr‐MIL‐101 crystals) reaches 2.30 × 10−2 S·cm−1 and the power density reached its maximum (90.2 mW·cm−2), and the tensile strength reaches 20.12 MPa, which was higher than 18.7 MPa of Nafion‐115 membrane. The spatial network structure of MOFs reduced the methanol permeability of MIL‐9‐QCS membrane by 24% compared with the original QCS membrane. Furthermore, the MIL‐9‐QCS composite membrane exhibited excellent alkali stability, where after being soaked in 2 mol L−1 NaOH solution at 60°C for 240 hours, its OH− conductivity still reached 77% of the initial value.

Tripartite Cationic Interpenetrating Polymer Network Anion Exchange Membranes for Fuel Cells

“…As for QVP x – y AEMs, the strong bonds among IPN make it possible for the low WU and SR (even under high IEC conditions). In comparison to several previously reported AEMs, ,− QVP x – y AEMs demonstrate low water absorption ability under similar IEC values, showing the indispensable importance of F-IPN in balancing stable dimension, good mechanical properties as well as high hydroxide conductivity.…”

A novel anion exchange membrane based on silicone/polyphenylene oxide with excellent ionic conductivity for AEMFC

“…The gradually increasing WU of QPPO‐Si‐x is due to the presence of a large number of QA groups on the QPPO membranes. Moreover, the addition of inorganic filler reduces the WU and swelling rate of QPPO membrane, which may be the spatial network crosslinking structure formed by the addition of inorganic filler 16,34 . These are attributed to water‐membrane interactions and up to 5 wt% of the filler on the uptake of water.…”