Functionalized TiO2 mediated organic-inorganic composite membranes based on quaternized poly(arylene ether ketone) with enhanced ionic conductivity and alkaline stability for alkaline fuel cells.

In this work, quaternized poly(arylene ether ketone) (QPAEK)/functionalized TiO 2 (f -TiO 2) composite membranes were fabricated with different f -TiO 2 contents (1, 3, 5, 7, and 9 wt%), and the structure of the materials was characterized by 1H NMR, ATR-FT-IR, XRD, XPS, and FE-SEM. The addition of f -TiO 2 enlarges the ion cluster in the membrane due to enhancing the interaction between the functional groups, and SAXS analysis revealed an extension of the ion domain size with an increase in the filler content (up to 5 wt%). In particular, the composite membrane with 5 wt% f -TiO 2 displayed the highest ion conductivity (74.6 mS cm−1); such a result was attributed to the formation of water traps by the deliquescence of TiO 2 and enhanced interfacial interactions between the pure organic polymers and inorganic nanomaterials. This work proves that a composite membrane with an appropriate f -TiO 2 concentration is a promising candidate for application to anion exchange membranes. [Display omitted] • Anionic organic-inorganic composite membranes are prepared by introducing various amount of f -TiO 2. • The properties of composite membranes are optimized by changing the contents of f -TiO 2. • The prepared membranes show improved mechanical and dimensional stabilities. • The QPAEK/ f -TiO 2 composite membranes demonstrate superior oxidative/alkaline stabilities. [ABSTRACT FROM AUTHOR]