Effect of “bridge” on the performance of organic-inorganic crosslinked hybrid proton exchange membranes via KH550

A series of novel organic-inorganic crosslinked hybrid proton exchange membranes were prepared using sulfonated poly(arylene ether ketone sulfone) polymers containing carboxyl groups (C-SPAEKS), (3-aminopropyl)-triethoxysilane (KH550), and tetraethoxysilane (TEOS). KH550 acted as a “bridge” after reacting with carboxyl and sulfonic groups of C-SPAEKS to form covalent and ionic crosslinked structure between the C-SPAEKS and SiO 2 phase. The crosslinked hybrid membranes (C-SPAEKS/K-SiO 2 ) were characterized by FT-IR spectroscopy, TGA , and electrochemistry , etc. The thermal stability, mechanical properties and proton conductivity of the crosslinked hybrid membranes were improved by the presence of both crosslinked structure and inorganic phase. The proton conductivity of C-SPAEKS/K-SiO 2 -8 was recorded as 0.110 S cm − 1 , higher than that of Nafion ® (0.028 S cm − 1 ) at 120 °C. Moreover, the methanol permeability of the C-SPAEKS/K-SiO 2 -8 was measured as 3.86 × 10 −7  cm 2  s − 1 , much lower than that of Nafion ® 117 membranes (29.4 × 10 −7  cm 2  s − 1 ) at 25 °C.