Polyatomic ions, infrared spectrum

Ionic interactions in ionomers are reflected in their spectra both directly and indirectly. They indirectly influence the spectral features associated with the polymeric backbone and the pendant sites as well as some of the spectral characteristics of polyatomic cations. Studies of these spectral properties are extensive. Ionic interactions are probed more directly by observing the vibrations of the cations at their anionic sites. Ion-motion vibrational bands, which occur in the far-infrared spectrum, have been studied in PFSA (Nation) (1), PEMA (2-3), PSMA (4-5), and PSSA (6) ionomers with a range of cations, ionic site concentrations, and other conditions. The force field elements that can be derived from them reflect how the interionic forces vary with the nature of the ionomer. 

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