The effect of incorporation of ferrous titanate nanoparticles in sulfonated poly(ether ether ketone)/poly (amide imide) acid-base polymer for cations exchange membrane fuel cells

Abstract

The sulfonated poly(ether ether ketone) (SPEEK) is one of the most promising aromatic proton exchange polymer membranes concerning fluorinated aliphatic polymer of Nafion in the hydrogen fuel cell. The solvent casting technique is manipulated to achieve the nanocomposite membrane based on the acid (SPEEK)-base poly(amide imide) (PAI)-inorganic nanoparticles (Fe2TiO5) organization. The fabricated proton exchange membrane is examined by the XRD, FTIR, FE-SEM, TGA, oxidative stability, and electrochemical property. The ionic types of acid-base interactions of SPEEK-PAI polymer chain extensively extend the stability criteria such as the thermal and mechanical and diminish the hydrophilic property that delivered the smaller proton conductivity than SPEEK membrane. The incorporation of ferrous titanate (Fe2TiO5) pseudobrookite nanoparticles in the SPEEK-PAI (acid-base) polymer matrix through the electrostatic interplay of metal-oxide nanoparticles and sulfonic acids facile the proton migrations. The presence of hydrophilic nanoparticles in the blended membrane lets more water channels to form the enriched conductivity, water uptake, stability, and constrained swelling ratio in the elevated temperature. The optimized composition of SPEEK (90 wt%)/PAI (10 wt%)/Fe2TiO5 (6 wt%) secures the highest conductivity of 2.54 mS cm−1 at 80 °C under the fully humidified condition and suits to the proton exchange membrane in the fuel cell. The polarization study shows the current density and power density at 80 °C in the RH100% for the R3 prepared nanocomposite membrane whose values are 284 mA cm−2 and 54 mW cm−2 in the OCV of 0.92 V.