Excess Inverse Relaxation Research Articles

Structural and molecular dynamics of methyl acetate-xylene solutions using dielectric relaxation spectroscopy

Frequency, temperature and composition dependent complex permittivity spectra (CPS) of Methyl Acetate (MA)-Xylene solutions were measured using Time Domain Reflectometry (TDR) technique from 10 MHz to 50 GHz. The Debye relaxation model has been used to obtain dielectric relaxation parameters of methyl acetate-xylene solution for all concentrations and temperatures. Dielectric constant and relaxation time increases with increase in concentration of MA in Xylene. Objective of this manuscript is to investigate and offer more pertinent data concerning static dielectric parameters, excess permittivity, excess inverse relaxation and Bruggeman factor at higher frequency which has been obtained to understand dielectric behavior of MA-Xylene binary solutions such that calculation of these parameters is an attempt to reveal ideal or non-ideal nature of solutions at different compositions in relation to specific or non-specific intermolecular interactions.

Bubble Point Pressure and Some Dielectric Properties of Propane+Ethanol Liquid Mixture at 303.2 K

Bubble point pressure and dielectric spectra of propane+ethanol liquid mixtures were measured at 303.2 K. The bubble point pressure was measured by use of a static type apparatus. The experimental pressure increased with increase in the mole fraction of propane, and the tendencies were well correlated with NRTL equations. The dielectric constants decreased with the mole fraction of propane. Otherwise the dielectric relaxation times showed convex shapes for the mole fraction of propane. The excess dielectric constants and the excess inverse dielectric relaxation times showed negative values over the whole range of the propane concentration. These phenomena suggested that hydrophobic interactions and dipole-dipole interactions play important roles in determining the dielectric properties of propane+ethanol liquid mixtures at the experimental temperature and pressure.

Temperature dependent dielectric relaxation study of ethyl acetate — Alcohol mixtures using time domain technique

The dielectric relaxation studies of Ethyl Acetate in Methanol, Ethanol and Propan-1-ol have been carried out using a Time domain Reflectometry (TDR) technique in the frequency range 10 MHz to 20 GHz, at different concentrations and temperature range from 15 to 45°C. The dielectric parameters, the Kirkwood correlation factor, the excess dielectric properties have also been determined. The excess permittivity is found to be negative for all the systems. The excess inverse relaxation is negative except near methanol rich region. The Bruggeman model for the nonlinear case has been fitted to the dielectric data for mixtures.