On the Synthesis and Characterization of Silica Doped/Sulfonated Poly (2,6 Dimethyl 1,4 Phenylene Oxide) Composite Membranes for Fuel Cells

Abstract

The objective of this investigation is to study silicadoped/sulfonated poly(2,6dimethyl1,4phenylene oxide) (PPO) composite membranes for operation in hydrogen/oxygen protonexchange membrane fuel cells ranging from room temperature (RT) up to 120 آ°C. The sulfonated PPO composite membranes were prepared using a sol–gel process employing reaction with tetraethoxysilane (TEOS) followed by heat treatment at 60, 90, and 120 آ°C, respectively. The presence of silicon oxide in the composite membranes was evaluated using FTIR spectroscopy, while thermal properties were studied using thermal gravimetric analysisdifferential scanning calorimetric (TGADSC) measurements. Additionally, ion exchange capacity, water uptake, and proton conductivity characterizations were also carried out. It was observed that water uptake for 75% PPO sulfonated composite membrane treated at 120 آ°C is higher than that of NafionTM membrane and the proton conductivity value measured at 120  آ°C is 0.35آ·10−1 S/cm. Therefore, the composite membranes are potentially suitable for high temperature fuel cell applications.