Amphiphilic block copolymers containing hydrophilic phosphorylcholine segments and fluorinated methacrylate segments were incorporated into perfluorosulfonic acid (PFSA) membranes via solution blending and casting to improve proton transport. The resulting PFSA/PMPCF-x composite membranes exhibit good structural stability and interfacial compatibility, accompanied by slight modification of the membrane microstructure and reduced crystallinity. The PFSA/PMPCF-6 membrane with 1 wt % additive achieves a proton conductivity of 214 mS cm–1 at 80 °C and 100% RH. Notably, significantly enhanced conductivity is observed under low-humidity conditions, reaching 28.88 mS cm–1 at 80 °C and 50% RH, corresponding to a 6.73-fold increase over pristine PFSA. The improvement is mainly attributed to the hygroscopic and water-retention capability of the phosphorylcholine groups. Membrane electrode assembly tests further demonstrate improved device performance. This work provides a practical strategy for improving the PFSA membrane performance under low-humidity conditions and offers useful insights for the design of advanced proton exchange membranes.
Zhang et al. (Fri,) studied this question.