P.G. Hudge

Dielectric relaxation study of glycine–water mixtures using time domain reflectometry technique

The complex permittivity of glycine in water mixture for various temperatures and concentrations have been measured as a function of frequency between 10 MHz and 30 GHz using time domain reflectometry technique. Dielectric parameters, i.e. static dielectric constant and relaxation time were obtained from the complex permittivity spectra using nonlinear least square fit method. The dielectric relaxation parameter increases with an increase in molar concentration of glycine due to the formation of hydrogen bond groups by glycine molecule in an aqueous solution medium. The activation entropy, activation enthalpy and Kirkwood correlation factor have also been determined for glycine–water mixtures.

Dielectric relaxation study of aniline, N-methylaniline and N,N-dimethylaniline and alcohol in 1, 4-dioxane using picosecond time-domain reflectometry

A time-domain reflectometry technique has been used to measure complex dielectric permittivity ε*(ω) = εʹ(ω) − jε″(ω) of 1-propanol–dioxane, 2-propanol–dioxane, aniline–dioxane, N-methylaniline–dioxane and N,N-dimethylaniline–dioxane mixtures in the frequency range of 10 MHz to 30 GHz. The complex permittivity spectrum has been fitted with a single relaxation time with a small amount of Davidson–Cole behaviour. The least squares fit method has been used to obtain the static dielectric constant (ε0), relaxation time (τ), Bruggeman factor and Kirkwood correlation factor. The Luzar theoretical model is used to compute the binding energies and average number of hydrogen bond between co-solvent–co-solvent and co-solvent–dioxane molecules.

Temperature-dependent dielectric relaxation study of 1,2,6-hexanetriol using TDR method

The frequency spectra of complex permittivity for 1,2,6-hexanetriol have been determined over the frequency range of 10–30 GHz at various temperatures. The dielectric relaxation for the system can be characterised by the Davidson–Cole behaviour. The static dielectric constant (ε 0), the high-frequency dielectric constant (ε ∞), relaxation time (τ) and the Kirkwood correlation factor are also determined by using least squares fit method. The results have also been compared with results of the glycerol system.