Tuesday, November 6, 2007

Modeling of Polymer Electrolyte Membrane and Proton Transport Via Atomic Scale Molecular Dynamics Simulation

Pil Seung Chung1, Parag Jain2, Haigang Chen2, Lorenz T. Biegler2, and Myung S. Jhon2. (1) Carnegie Mellon University, 5000 Forbes Ave., Pittsburgh, PA 15213, (2) Chemical Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213

Polymer electrolyte membrane (PEM), which is the critical component of the next generation fuel cell systems (e.g., PEM fuel cell and direct methanol fuel cell), has been examined via atomic scale molecular dynamics (MD). By using atomic scale model, we examined the specific PEM structure, which water molecules in the system clustered at the end of the ionic branch to make path for transferring protons (H+) with swelling the PEM system via radial distribution function between polar and polar / polar and nonpolar beads. We observed the clustered water molecules consist the porous path via the visualized density distribution of water molecules. Proton diffusion in the PEM was also investigated with the effects of water uptake and temperature.