DIELECTRIC BEHAVIOR OF THE N,N-DIMETHYLFORMAMIDE-2-METHOXYETHANOL-1,2-DIMETHOXYETHANE TERNARY SOLVENT SYSTEM FROM -10-DEGREES-C TO +20-DEGREES-C

The static relative permittivities, epsilon, and excess properties, epsilon(E), of the ternary mixtures N,N-dimethylformamide (DMF)-2-methoxyethanol (ME)-1,2-dimethoxyethane (DME) have been measured at several temperatures in the range -10 to +20-degrees-C. This ternary system shows interesting properties for use as a mixed solvent and for electroanalytical applications. The study of these mixtures should help to increase our understanding of the co-solvation of ionizable and inert solutes. The behaviour of epsilon(E) is quite interesting because this quantity assumes partly positive and partly negative values in the composition domain. As a consequence, there are mixtures which have epsilon(E) = 0, indicating ideal dielectric mixing behaviour. The excess property is discussed in terms of the influence of specific interactions between components, the order and degree of packing in the mixtures and any other effects which produce long-range structure in these mixed liquids.