Synthesis and characterization of sulfonated poly(vinylidene fluoride-co-hexafluoropropylene)/sAl2O3 composites as a novel-alternative electrolyte membranes of Nafion

Abstract

Fuel cell membrane of Nafion is commonly used as the electrolyte material of fuel cell which has good mechanical properties, but the hydrophobicity reduce its proton conductivity. Thus, the other polymer is used for the electrolyte membrane. A polymer modification of sulfonated poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP) by attaching sulfonate group and oxide compounds such as sAl₂O₃ would enhance the proton conductivity. The research is aimed to modify PVDF-co-HFP via the addition of sAl₂O₃ or pristine Al₂O₃ and studying the effect of sulfonated Al₂O₃ on the conductivity. The research includes Al₂O₃ particles synthesis, the sulfonation of Al₂O₃, the membrane preparation, the sulfonation of membrane, and the characterisation of membrane using FTIR, SEM-EDX, and Four-point Probe Electrical Device Analysis. SEM-EDX analysis explained that the 6% addition of Al₂O₃ showed denser cross-sectioned membrane rather than the 9% addition of Al₂O₃. The highest conductivity achieved can be revealed at the 6% sAl₂O₃ addition on PVDF-co-HFP membrane as 2.27 × 10^-3 S cm^-1 which is higher than a previous study.

Keywords: Electrochemistry; Inorganic chemistry; Materials chemistry; PVDF-co-HFP; Proton conductivity; Sulfonated Al2O3 (sAl2O3).