In fuel cell applications, the proton exchange membrane (PEM) is the major component where the balance among dimensional stability, proton conductivity, and durability is a long-term trail. In this research, a series of blended SPEEK/SPPO membranes were designed by varying the amounts of sulfonated poly(ether ether ketone) (SPEEK) into sulfonated poly(phenylene) oxide (SPPO) for fuel cell application. Fourier transform infrared spectroscopy (FTIR) was used to confirm the successful synthesis of the blended membranes. Morphological features of the fabricated membranes were characterized by using scanning electron microscopy (SEM). Results showed that these membranes exhibited homogeneous structures. The fabricated blended membranes SPEEK/SPPO showed ion exchange capacity (IEC) of 1.23 to 2.0 mmol/g, water uptake (WR) of 22.92 to 64.57% and membrane swelling (MS) of 7.53 to 25.49%. The proton conductivity of these blended membranes was measured at different temperature. The proton conductivity and chemical stability of the prepared membranes were compared with commercial membrane Nafion 117 (Sigma-Aldrich, St. Louis, Missouri, United States) under same experimental conditions. The proton conductivity of the fabricated membranes increased by enhancing the amount of SPPO into the membrane matrix. Moreover, the proton conductivity of the fabricated membranes was investigated as a function of temperature. Results demonstrated that these membranes are good for applications in proton exchange membrane fuel cell (PEMFC).
Keywords: SPEEK; SPPO; blended membranes; fuel cell; ion exchange membrane; proton conductivity; redox flow battery; stability.