Preparation of anion exchange membrane by incorporating IRMOF-3 in quaternized chitosan

In this study, we prepared a novel composite membrane (QCS-IRMOF-3) by attaching IRMOF-3 (metal–organic framework materials, formed by coordination of metallic zinc and 2-aminoterephthalic acid) with a free amino group to a quaternized chitosan (QCS) by chemical cross-linking. The successful synthesis of IRMOF-3 was verified by SEM, XRD, and FT-IR. Then, the mechanical properties, swelling properties, ion exchange capacity, hydroxide conductivity and chemical stability of the composite membrane (QCS-IRMOF-3) were also investigated. It was found that the performance of the aforementioned composite membrane was affected obviously by the amount of IRMOF-3 crystals. The composite membrane doped with 15 wt% IRMOF-3 crystals exhibits better overall performance, which included that the tensile strength is 22.4 MPa, water uptake is 78.4%, hydroxide conductivity is 29.9 mS cm −1 at 80 °C, and after immersion in 6.0 mol L −1 KOH solutions at 60 °C for about 240 h, only the conductivity decreased by less than 10%. This result implies that the composite membrane synthesized in this research is promising for application in alkaline polymer electrolyte fuel cells.