Enhanced proton conductivity of sulfonated poly(arylene ether ketone sulfone) polymers by incorporating phosphotungstic acid-ionic-liquid-functionalized metal-organic framework

Abstract

In this work, the MIL-100(Fe) was selected as blank-sample. Using one-pot method, phosphotungstic acids were encapsulated in the blank-sample to prepare HPW@MIL-100(Fe). Then, the ionic liquid ([EMIM][N(Tf)2]) was chosen to modify the HPW@MIL-100(Fe). And the phosphotungstic acid-ionic-liquid (HPW-ILs) modified MIL-100(Fe) (HPW-ILs@MIL-100(Fe)) was obtained. The final product was introduced into polymer matrixes (C-SPAEKS) to prepare hybrid membranes. The structures and morphologies of MOFs and membranes were characterized by field emission scanning electron microscope (FTSEM), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). This series of membranes exhibited increasing proton conductivities from 0.043 S cm−1 of C-SPAEKS to 0.138 S cm−1 of HPW-ILs@MOF-4 at 100 °C and 100% relative humidity. Furthermore, these hybrid membranes have enhanced mechanical properties and dimensional stabilities. Obviously, the HPW-ILs@MIL-100(Fe) had a beneficial function on improving the performance of PEMs and showed great potential in PEMs applications.