Thermal relaxation of oriented ionomer films: Correlation between mechanical behavior and anisotropic absorption of visible light of an incorporated dye

By comparing the dynamic mechanical behavior of Nafion membranes to the thermal relaxation of the oriented ionic domains of an ionomer Nafion film observed by small-angle X ray scattering analysis, the relaxation of the ionic domains is shown to correspond well with the onset of viscous flow. In addition, the relaxation of an oriented dye molecule which has been incorporated into the Nafion film suggests that the strength of the ionic interactions of the ionomer matrix alters the relaxation of the incorporated dye. The strong Coulombic forces involved in the Na⁺ form Nafion matrix causes the incorporated dichroic dye to retain is orientation to higher temperatures relative to the weaker interactions involved in TBA⁺ form Nafion.