Dissociated ions and ion-ion interactions in poly(ethylene oxide) based NaCF3SO3 complexes

Abstract Raman scattering studies of molecular vibrations in poly(ethylene oxide) (PEO) containing NaCF 3 SO 3 salt reveal the presence of both dissociated ions and ions in pair formations. For increasing salt concentration and temperature the degree of ion-pairing is found to increase at the expense of the amount of dissociated ions. At large salt content (O:M 3 SO 3 . Increased ion-ion interaction may initiate the salt precipitation observed at elevated temperatures; the temperature dependence can be attributed to free volume dissimilarities of the host polymer and the dissociated salt.