Abstract

The complex dielectric permittivity spectra of Diethanolamine with 2–Alkoxyethanols like 2–Methoxyethanol, 2–Ethoxyethanol and 2–Butoxyethanol binary mixtures have been determined by using Time Domain Reflectometer (TDR) over the frequency range of 10 MHz to 20 GHz at 303.15 K. The values of the dielectric permittivity (ε'), dielectric loss (ε") and relaxation time (τ) were measured from the Time Domain Reflectometer. The static dielectric constant (εo) and dielectric constant at high frequency (ε∞) values were also determined. The molecular interaction parameters like Bruggeman factor (fB), The effective Kirkwood correlation factor (geff) and corrective Kirkwood correlation factor (gf) were also calculated. This gives useful information regarding the orientation of dipoles in polar liquids. The excess parameters like excess dielectric constant (εE) and excess inverse relaxation time (1/τ)E were also determined and discussed to yield information on the structure and dynamics of the mixtures. The long range and short range interactions between the dipoles can be studied from the thermodynamic parameter, excess Helmholtz free energy (ΔFE). Free energy of activation for relaxation time (ΔFτ) were also calculated and interpreted on the basis of nature of molecular interaction.

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