Preparation of Nafion® nanocomposite membrane modified by phosphoric acid-functionalized 3-APTES

We have fabricated a fuel cell nanocomposite membrane based on Nafion®/conductive inorganic materials. To introduce inorganic materials into Nafion® membrane, 3-aminopropyl triethoxysilane (3-APTES) was reacted with sulfuric acid groups of Nafion® and the obtained membrane was subject to reacting with phosphoric acid to bestow proton conductivity. Methanol permeability for the modified membranes was found to be at least 50% lower than for Nafion®. The proton conductivity of the membrane showed maximum conductivity of 0.07 S/cm at 3 wt% of APTES, which was comparable with the conductivity of Nafion®.