Dielectric properties of benzylamine in 1,2,6-hexanetriol mixture using time domain reflectometry technique

The dielectric properties of binary mixtures of benzylamine-1,2,6-hexantriol mixtures at different volume fractions of 1,2,6-hexanetriol have been measured using Time Domain Reflectometry (TDR) technique in the frequency range of 10 MHz to 30 GHz. Complex permittivity spectra were fitted using Havriliak–Negami equation. By using least square fit method the dielectric parameters such as static dielectric constant (ε0), dielectric constant at high frequency (ε∞), relaxation time τ (ps) and relaxation distribution parameter (β) were extracted from complex permittivity spectra at 25∘C. The intramolecular interaction of different molecules has been discussed using the Kirkwood correlation factor, Bruggeman factor. The Kirkwood correlation factor (gf) and effective Kirkwood correlation factor (geff) indicate the dipole ordering of the binary mixtures

Dielectric relaxation studies of binary mixture of β-picoline and methanol using time domain reflectometry at different temperatures

Complex permittivity spectra of binary mixtures of varying concentrations of β-picoline and Methanol (MeOH) have been obtained using time domain reflectometry (TDR) technique over frequency range 10 MHz to 25 GHz at 283.15, 288.15, 293.15 and 298.15 K temperatures. The dielectric relaxation parameters namely static permittivity (ε0), high frequency limit permittivity (ε∞1) and the relaxation time (τ) were determined by fitting complex permittivity data to the single Debye/Cole-Davidson model. Complex nonlinear least square (CNLS) fitting procedure was carried out using LEVMW software. The excess permittivity (ε0E) and the excess inverse relaxation time (1/τ)E which contain information regarding molecular structure and interaction between polar–polar liquids were also determined. From the experimental data, parameters such as effective Kirkwood correlation factor (geff), Bruggeman factor (fB) and some thermo dynamical parameters have been calculated. Excess parameters were fitted to the Redlich–Kister polynomial equation. The values of static permittivity and relaxation time increase nonlinearly with increase in the mol–fraction of MeOH at all temperatures. The values of excess static permittivity (ε0E) and the excess inverse relaxation time (1/τ)E are negative for the studied β-picoline — MeOH system at all temperatures

Dielectric relaxation behaviour of triethylene glycol [TEG]+water mixture as a function of composition and temperature using TDR technique

269-275The complex dielectric spectra of binary mixture of triethylene glycol [TEG] + water have been carried out at different concentrations and temperatures (0 °C, 5 °C, 10 °C, 15 °C, 20 °C and 25 °C) in the frequency range of 10 MHz to 30 GHz using time domain reflectometry technique. The static dielectric constant (ε0), relaxation time (τ), Kirkwood correlation factor (geff), excess permittivity (ɛ ), thermodynamic parameters (activation enthalpy and entropy) and Bruggeman factor (fB) have been determined for binary mixtures. The Bruggeman model for the nonlinear case has been fitted to the dielectric data. These dielectric parameters confirm that the intermolecular homogeneous and heterogeneous hydrogen bonding vary significantly with the increase in concentration of the triethylene glycol in water mixtures

Dielectric dispersion and thermodynamic behavior of stearic acid binary mixtures with alcohol as co-solvent using time domain reflectometry

Dielectric permittivity and relaxation dynamics of binary and ternary mixture of stearic acid on various concentration and their thermodynamic effects are studied. The static dielectric constant (ε0), dielectric permittivity (ε′) and dielectric loss (ε′′) are found by bilinear calibration. The relaxation time (τ), dielectric strength (Δε) and the excess permittivity (εE) are found. The thermodynamic parameters such as enthalpy (ΔH), entropy (ΔS) and Gibb’s free energy (ΔG) are evolved. The significant changes in dielectric parameters are due to the intramolecular and intermolecular interactions in response to the applied frequency. The permittivity spectra of stearic acid–alcohol in the frequency range of 10MHz to 30GHz have been measured using picoseconds Time Domain Reflectometry (TDR). The dielectric parameters (ε0, ε′, ε′′) are found by bilinear calibration method. Influence of temperature in intermolecular interaction and the relaxation process are also studied. The FT-IR spectral analysis reveals that the conformation of functional groups and formation for hydrogen bonding are present in both binary and ternary mixtures of stearic acid