(622c) Free Volume Enhanced Anion Exchange Membranes from Triptycene Poly(Arylene Ether Sulfone) Copolymers

As an attractive energy conversion technology, fuel cells generate electric power from fuels with high energy density and slight chemical emissions. Anion exchange membrane fuel cells (AEMFCs) have been developed as a desirable alternative to Proton exchange membrane fuel cells (PEMFCs) because materials cost-effectiveness and comparable performance. As a pivotal module of AEMFCs, anion-exchange membranes (AEMs) serve as both the fuel barrier and hydroxide carrier. It is required to make membranes with properties of superb hydroxide conductivity, good dimensional and mechanical stability, and prominent alkaline resistance.

Here we present that we have achieved high performance AEMs from the functionalized triptycene copolymers. Quaternized triptycene copolymer were casted into a large scale film. Hydroxide conductivity of OH^-1 activated films were measured to be over 0.1 S/cm for working temperature ranges (60-80 °C). Advantages of using triptycene containing polymers are many folds: 1) triptycene containing moieties have high stability to heat and chemicals for long term usability, 2) triptycene containing polymers have nanoscale phase separation which would facilitate nanoscale binding and transport and 3) degree of functionalization would be readily controlled by reaction conditions. Extensive studies from X-ray scattering, TGA, DSC corroborated the above findings.