Dielectric Relaxation Studies of Binary Mixture of α‐Picoline and Methanol Using Time Domain Reflectometry at Different Temperatures

Abstract

AbstractComplex permittivity spectra of binary mixtures of varying concentrations of α‐picoline and methanol (MeOH) were obtained using time domain reflectometry (TDR) technique over frequency range 10 MHz to 25 GHz at 283.15 K, 288.15 K, 293.15 K and 298.15 K temperatures. The dielectric relaxation parame‐ ters namely static permittivity (σ0), high frequency limit permittivity (σoo1) and the relaxation time (ρ) were determined by fitting complex permittivity data to the single Debye/Cole‐Davidson model. Complex non linear least square (CNLS) fitting procedure was carried out using LEVMW software. The excess static permittivity (σ0E) and the excess inverse relaxation time (1/ρ)E which contains information regarding mo‐ lecular structure and interaction between polar — polar liquids, were also determined. From the experimental data, effective Kirkwood correlation factor (geff) and Bruggeman factor (fB) were calculated. Excess parameters were fitted to the Redlich‐Kister polynomial equation. The values of static permittivity and relaxation time increase non‐linearly with increase in the mol fraction of MeOH at all temperatures. The values of excess static permittivity (σ0E) and the excess inverse relaxation time (1/ρ)E are negative for the studied α‐picoline — MeOH system at all temperatures.