Abstract
Nuclear resonant quasielastic scattering from ferrous cations in ion-exchange Nafion membranes was measured at room temperature, and the intrinsic dynamics of the cations inside the spherical regions surrounded by the sulfonic groups of Nafion was studied. For the analysis, the formula of nuclear resonant absorption for a particle diffusing in a sphere with an impermeable surface was derived. The formula indicates that the effect of the surface upon the diffusive motion is small if the radius of the sphere is larger than a critical value; in the case of 57 Fe ions, the value is about 2 A. As the radius of the spherical regions in our Nafion samples is estimated to be about 5 A, the existence of the surface can be ignored and the intrinsic dynamics of Fe cations can be extracted. The diffusion coefficient estimated from the least squares fit was (1.12±0.13)×10 -5 cm 2 /s for 15 wt% water content. This value is in good agreement with that of Fe cations in an HCl solution. As a result, Fe cations in Nafion d...
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call