COLLABORATIVE RESEARCH AND DEVELOPMENT (CR&D) Delivery Order 0067: Molecular Simulations for Hydrated Polymer Fuel Membranes

摘要

This research in support of the Air Force Research Laboratory Materials and Manufacturing Directorate was conducted at Wright-Patterson AFB, Ohio from 7 December 2006 through 1 August 2007. The effects of hydration level and temperature on solvent dynamics and nano-structural morphology for two polymers which show promise as membranes in polymer electrolyte fuel cells; sulfonated poly (thioether sulfone) (SPTES) and Nafion-117 were studied via molecular dynamics simulations. Solvent molecule behavior was characterized and examined according to proximity to polar side groups on the respective polymer chains. In addition to solvent linear diffusion and molecule vector rotation analysis, velocity autocorrelation was used to identify oscillatory molecule motions. Hydrogen bonding among solvent molecules and with polar groups was identified according to geometric criteria. It was found that these bonds are amenable to proton transfer.