TEMPERATURE-DEPENDENT DIELECTRIC-RELAXATION STUDY OF ETHYLENE GLYCOL-WATER MIXTURES

Using the picosecond time domain reflectometry method, dielectric relaxation measurements for 13 ethylene glycol (EG)-water mixtures have been studied from 0 to 40-degrees-C. The dielectric relaxations in the mixtures show a Debye-type behavior, whereas the relaxation in pure EG can be described by the Cole-Cole model. The static dielectric constant epsilon(o), the relaxation time tau and the dielectric constant at high frequency epsilon(infinity) have also been determined at various temperatures. The dielectric relaxation data suggests that there is no tendency to form hydrogen bonds with the addition of water to EG unlike other alcoholic systems but this tendency becomes increasingly important with decreasing temperature. The activation energy decreases with increased water content in the mixture as expected.