Long-term durable anion exchange membranes based on imidazole-functionalized poly(ether ether ketone) incorporating cationic metal−organic framework

Abstract

In this work, poly(ether ether ketone) (PEEK) was synthesized by direct polycondensation reaction. Subsequently, PEEK was functionalized by 1-vinylimidazole to prepare the polymer matrix (Im-PEEK). Cationic UiO-66-NH2 metal-organic frameworks (C-MOF) were synthesized as fillers. The structure of the C-MOF and the morphology of the membranes were verified by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The prepared hybrid membranes exhibited excellent alkali stability, among which Im-PEEK/C-MOF-1% could retain 89.2% of the conductivity compared to the original membrane after immersing in 1 ​mol ​L−1 NaOH solution for 320 ​h at 60 ​°C. In addition, the ionic conductivity of Im-PEEK/C-MOF-1% was 73 ​mS ​cm−1 at 80 ​°C, which was higher than that of pure Im-PEEK under the same condition (44.3 ​mS ​cm−1 at 80 ​°C). The results showed that the hybrid membranes have great potential for application in the field of anion exchange membranes.