Dynamics of PFSA polymer hydration measured by SAXS in situ

FUEL 146

Andrew M. Herring, aherring@mines.edu1, Michael A. Yandrasits2, Niccolo Aieta, naieta@mines.edu1, Ronald J. Stanis, rstanis@mines.edu1, Steven J. Hamrock, sjhamrock@mmm.com3, and David J. Cookson, Cookson@cars.uchicago.edu4. (1) Department of Chemical Engineering, Colorado School of Mines, Golden, CO 80401, (2) 3M Fuel Cell Components Program, 3M Corporation, St. Paul, MN, St. Paul, MN 55144, (3) Fuel Cell Components Program, 3M Company, 3M Center, St. Paul, MN 55144, (4) ChemMat CARS at APS, Argonne National Laboratory, 9700 South Cass Ave, Argonne, IL 60439-4859
The proton exchange membrane in low temperature fuel cells is currently a perfluoro sulfonic acid polymer (PFSA) that must be fully hydrated to achieve practical proton conductivity. A great deal of information is available about the morphology of well known PFSA polymer NafionŽ. Very little information is publicly available about the morphology of the intermediate side chain 3M ionomer and few studies have actually followed the dynamics of hydration of PFSA ionomers in real time. As such information is critical to the development of PEM fuel cells and is especially useful for the many start stop cycles that will occur in automobile applications of fuel cells we measured the hydration dynamics of these membranes using syncotron X-rays. Small angle X-ray scattering (SAXS) was chosen as these membranes show a strong peaks due both the hydrophobic region, the matrix knee, and the hydrophilic domains, the so called ionomer peak.
 

Fuel Cell Chemistry and Operation
9:00 AM-12:05 PM, Tuesday, 12 September 2006 Palace -- Gold Ballroom, Oral

Sci-Mix
8:00 PM-10:00 PM, Monday, 11 September 2006 Moscone Center -- Hall D, Sci-Mix

Division of Fuel Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006