The dielectric spectra of the title systems (with moderate to high salt concentrations) have been measured between MHz frequencies and 72 GHz at 20, 40 and 60 °C (EtAc only 20 °C). Apart from the conductivity contribution, there are two evidently discernible relaxation contributions. These are ascribed to unaffected solvent (at higher frequencies) and, on the other hand, to affected solvent and to ionic species (at lower frequencies). The nature of the latter and their relaxation mechanism are discussed by comparing the respective relaxation parameters with those of other liquid systems.

The real part of conductivity was measured for a number of salt solutions in different polar (nonaqueous) solvents over a broad frequency range up to 72 GHz at 20°C. The slope of the double log representation of conductivity versus frequency decreases with increasing salt concentration and solution viscosity. An extrapolation to infinite viscosity yields slope values similar to those found with vitreous systems which are claimed to exhibit “universal” behaviour.