Temperature dependent dielectric relaxation studies of 2-nitrotoluene-dimethyl sulfoxide mixture using time domain reflectometry

Abstract

The dielectric relaxation measurements of 2-nitrotoluene (2-NT) with dimethyl sulfoxide (DMSO) for 11 different concentrations have been carried out in the frequency range from 10 MHz to 50 GHz using time domain reflectometry method. In this frequency range, a dielectric relaxation spectrum of 2-NT-DMSO mixtures shows Debye type relaxation behaviour. The static dielectric constant, dielectric relaxation time, Kirkwood correlation factor, excess dielectric properties have been determined from 20oC to 5oC. The excess dielectric and Kirkwood correlation factor gives the information about formation and orientation of electric dipoles in the mixture. As the concentration of 2-NT in DMSO increases, dipole changes its orientation from anti-parallel to parallel. The thermodynamic parameters (enthalpy, entropy and Gibbs free energy) have been determined from the relaxation time using least squares fit method.