Dielectric study of methanol–ethanol mixtures using TDR method

Abstract

The dielectric parameters has been determined for mixtures of methanol–ethanol with various concentrations in the frequency range from 10 MHz to 20 GHz at different temperatures viz., 288 K, 298 K, 308 K and 318 K by time domain reflectometry (TDR). The bilinear calibration method has been used to obtain dielectric parameters, viz., static dielectric constant ( ε o) and relaxation time. Using these parameters the values of excess permittivity ( ε E), excess inverse relaxation time, Bruggeman factor ( f B) and thermodynamic parameters are determined. Nonlinear variations of dielectric constant and relaxation time with volume fraction of ethanol confirm structural formation due to the intermolecular interaction between methanol–ethanol. The variations of excess permittivity, excess inverse relaxation time, Bruggeman factor ( f B), and activation enthalpy (Δ Η), entropy (Δ S), Kirkwood correlation factor ( g eff) and Kirkwood correlation factor ( g f) for different mole fraction of ethanol in the binary mixtures reported in the paper.