Published online by Cambridge University Press: 21 February 2011
Water transport rates through Dow experimental polyperfluorosulfonic acid membranes were investigated by using dynamic thermogravimetry. A mathematical model was developed to describe water transport rates within the membrane. Values for the diffusion coefficient of water in membrane samples of the same equivalent weight but of three different thicknesses, 265, 4.0, and 7.0 mil, were obtained for temperatures of 60, 80, and 90° C. Results show that the diffusion coefficient of water increases with water content and temperature.