Quaternized poly(2.6 dimethyl-1.4 phenylene oxide)/polysulfone blend composite membrane doped with ZnO-nanoparticles for alkaline fuel cells

A series of quaternized poly(2.6 dimethyl-1.4 phenylene oxide)/polysulfone (QPPO/PSF) blend anion exchange membrane (AEM) were successfully fabricated and characterized for alkaline fuel cell application. Zinc oxide (ZnO) nanoparticles were introduced in the polymer matrix to enhance the intrinsic properties of the AEM. To confirm successful fabrication, Fourier-transform infrared spectroscopy and nuclear magnetic resonance (¹H-NMR) were used. The membrane properties were enhanced by the addition of ZnO nanoparticles. The addition of ZnO nanoparticles resulted to a higher ion exchange capacity (IEC) of 3.72 mmol g⁻¹, increase of ion conductivity (IC) up to 52.34 mS cm⁻¹ at 80 °C, enhancement of water uptake, and reduced methanol permeability. The QPPO/PSF/2% ZnO composite retained over 80% of its initial IC at room temperature and also retained over 50% of its initial IC at 80 °C when evaluated for alkaline stability. The maximum power output reached for the membrane electrode assembly constructed with QPPO/PSF/2%ZnO was 69 mW cm⁻² at room temperature, which is about three times more than the parent QPPO membrane. The above results indicate that QPPO/PSF/ZnO is a good candidate as an AEM for fuel cell application.