Enhancing proton conductivity of proton exchange membranes via anchoring imidazole‐loaded MIL‐101‐NH ₂ onto sulfonated poly (arylene ether ketone sulfone) by chemical bonding

Abstract

Summary Organic‐inorganic modification by incorporating metal‐organic frameworks to copolymers is one strategy to advance the properties of membranes. Here, the imidazole‐loaded MIL‐101‐NH2 (Im@MIL‐101‐NH2) was prepared and chemically anchored onto sulfonated poly (arylene ether ketone sulfone) containing carboxyl groups (C‐SPAEKS). The chemical stabilities, mechanical properties, and dimensional stabilities of compound membranes were increased. The highest tensile strength of C‐SPAEKS‐IM6 reach to 105.36 MPa. The weight retention rate of hybrid membranes was still higher than 90% after the oxidation stability test at 80°C. Furthermore, the introducing Im@MIL‐101‐NH2 could construct new proton transport paths, and the amphiphilic imidazole molecules embedded inside Im@MIL‐101‐NH2 could act as proton carriers. The C‐SPAEKS‐IM6 showed a maximum proton conductivity of 0.082 S cm−1 at 90°C. Additionally, the peak power density of C‐SPAEKS‐IM6 was 171.52 mW cm−2. To sum up, this series of membranes have latent capacity in the application of fuel cells. Im@MIL‐101‐NH2 was anchored on polymer backbones via the Hinsberg reaction. Chemical bonds between MOFs and polymer chains improved compatibility of two phases. Cross‐linking structure enhanced the mechanical property and oxidative stability. The sulfonamide groups could devote protons and transport it to MOFs.

High H2O-Assisted Proton Conduction in One Highly Stable Sr(II)-Organic Framework Constructed by Tetrazole-Based Imidazole Dicarboxylic Acid

“…We have obtained some exciting findings, such as the optimal proton conductivity of up to 10 −3 S/cm [ 35 , 36 , 37 , 38 , 39 ]. At the same time, free N -heterolytic small molecules can be employed as a proton source or carrier in a MOF’s framework, resulting in high-efficiency proton transmission [ 40 , 41 , 42 , 43 ]. However, these post-modified molecules are not anchored firmly enough in the MOF framework, resulting in leakage defects during use.…”