Engineering Perspective, sa.3, ss.100-107, 2024 (Hakemli Dergi)
Membranes play a critical role in the performance of proton exchange membrane fuel cells. Membrane thicknesses have positive and negative effects on the characteristics of proton exchange membranes. In this study, sulfonated polysulfone (SPSf) polymer-based membranes with thicknesses of 50 µm, 100 µm, and 150 µm were fabricated, and their characteristic properties were
investigated. Water uptake capacity, swelling ratio, proton conductivity, contact angle, chemical stability, and mechanical strength
tests were carried out on the membranes. Maximum water uptake capacity and swelling ratio were 45.81% and 13.1% for 100
µm SPSf membrane, respectively. The results of contact angle analysis proved that all synthesized membranes were hydrophilic.
Proton conductivity values were measured at different temperatures and solution environments. Significant decreases in resistance
values and increases in proton conductivity were observed with decreasing membrane thickness. The increase in temperature and
acid in the measurement conditions caused an increase in the proton conductivity value. The highest proton conductivity value
was obtained as 0.1971 S/cm in 65 °C and 1 mM hydrochloric acid (HCl) aqueous solution environment in 50 µm SPSf membrane. It was determined that the chemical stability and mechanical strength decreased with the decrease in membrane thickness
but remained within the appropriate limits.