Dielectric relaxation and structural study of aniline–methanol mixture using picosecond time domain reflectometry

Abstract

Complex permittivity of aniline–methanol mixture for various temperatures have been measured as a function of frequency between 10 MHz and 10 GHz using time domain reflectometry technique (TDR). Dielectric parameters viz. static dielectric constant εs, relaxation time τ were obtained from complex permittivity spectra using nonlinear least-square fit method. With these parameters, excess dielectric properties, Kirkwood correlation factor and thermodynamic parameters were determined and discussed to yield the information on the molecular structure and dynamics of the mixture. At low methanol concentration, strong interaction between the solute–solvent molecules was observed through hydrogen bonding. The values of ΔH* and Kirkwood correlation factors support the same. The dielectric constant of the mixture fits well with the modified Bruggman equation.