Enhanced proton conductivity and relative selectivity of sulfonated poly(arylene ether ketone sulfone) proton exchange membranes by using triazole-grafted 3-Glycidyloxypropyltrimethoxysilane

Herein, we demonstrate the fabrication of cross-linked membranes based on sulfonated poly(arylene ether ketone sulfone) containing pendant amino groups (AM-SPAEKS) and triazole-grafted 3-Glycidyloxypropyltrimethoxysilane (GT) cross-linkers by a sol-gel process, then the obtained cross-linked membranes are named as AMSP/GT membranes. The GT cross-linkers are synthesized by the ring-opening reaction of the epoxy group and 3-amino-1,2,4-triazole. The AMSP/GT cross-linked membranes exhibit excellent thermal, oxidation and dimensional stability. Furthermore, the AMSP/GT membranes possess a low methanol permeability coefficient (9.95 × 10−7 cm2 s−1 at 60 °C) due to the formation of cross-linked network structures. In addition, the proton conductivity and relative selectivity of the AMSP/GT membranes are higher, at elevated temperatures (>80 °C), than AM-SPAEKS membranes. The highest proton conductivity of 0.135 S cm−1 is demonstrated, for the AMSP/GT-30 membrane, at 100 °C. The relative selectivity of AMSP/GT-30 can reach 7.54 × 104 S scm−3 which is three times higher than that of the AM-SPAEKS, at 60 °C. These results indicate that the AMSP/GT membranes can be promising candidates for practical applications such as proton exchange fuel cells etc.