Dielectric relaxation study of chlorobenzene with formamide at microwave frequency using time domain reflectometry

Abstract

The complex permittivity spectra of chlorobenzene with formamide were determined in the frequency range of 10 MHz–20 GHz using time domain reflectometry (TDR) in the temperature range 15 to 45 °C for 11 different concentrations of the system. The dielectric parameters viz. static dielectric constant ( ε 0) and relaxation time ( τ) have been obtained by the least squares fit method. Excess properties and Kirkwood correlation factor of the mixtures have been determined. For temperature range considered here, the permittivity and relaxation time increases with the percentage of formamide. The excess permittivity is found to be negative in the chlorobenzene rich region and positive in the formamide rich region. However, the excess inverse relaxation time has the reverse trend. The static dielectric constants for the mixtures have been fitted with the modified Bruggeman model.