Dielectric relaxation study of dimethylene chloride with ethanol using time domain reflectometry

Dielectric relaxation study of chlorobenzene with formamide at microwave frequency using time domain reflectometry

Dielectric study of methanol–ethanol mixtures using TDR method

High-frequency dielectric study on the hydrogen bonding interaction on aqueous Cyanoacetamide

FTIR and Dielectric relaxation studies on ethylene glycol monomethyl ether with methanol binary mixtures have been carried out at eleven concentrations at 303K. Complex dielectric spectra were obtained in the frequency range of 10 MHz to 20 GHz using TDR. The least squares fit method has been used to obtain the static dielectric constant (ε0) and relaxation time (τ). By using these dielectric parameters, the excess permittivity (εE), excess inverse relaxation time (1/τ)E, and Kirkwood correlation factor (geff) are also obtained for investigating the intermolecular interaction. The dielectric parameters show systematic change with concentration and alkyl chain length of alcohols.

The values of complex permittivity of molecules containing chlorine with propan-1-ol binary mixtures have been determined over the frequency range of (0.1 to 20) GHz, at temperatures of (288, 298, 308, and 318) K, using the time-domain reflectometry (TDR) method for 11 molalities of each molecule containing chlorine with propan-1-ol system. The dielectric relaxation in these systems can be described by a single relaxation time using the Havriliak and Negami model. The static dielectric constant (ε0) and relaxation time (τ) have been obtained by fitting experimental data with the Havriliak−Negami equation.

The complex dielectric spectra of 2-butoxyethanol with aniline and substituted anilines like aniline, o-chloroaniline, m-chloroaniline, o-anisidine and m-anisidine binary mixtures in the composition of different volumes of percent (0%, 25%, 50%, 75%, and 100%) have been measured as a function of frequency between 10 MHz and 30 GHz at 298.15 K. The dielectric parameters like static dielectric constant ε0 and relaxation time τ have been obtained by using least square fit method. By using these parameters ε0,τ, effective Kirkwood correlation factor geff, corrective Kirkwood correlation factor gf, Bruggeman factor fB, excess dielectric constant εE, and excess inverse relaxation time 1/τE values are calculated and discussed to yield information on the dipolar alignment and molecular rotation of the binary liquid mixtures. From all the derived dielectric parameters, molecular interactions are interpreted through hydrogen bonding.

Dielectric relaxation study of aqueous diethylamine using a time domain reflectometry

The Complex permittivity spectra of glycol ether (GE) compounds such as ethylene glycol mono-methyl ether (EGME) with water mixture over entire concentration range and in temperature range of 10–25∘C have been determined using Time Domain Reflectometry (TDR) technique in the frequency range 10[Formula: see text]MHz to 50[Formula: see text]GHz. The complex permittivity spectra for EGME-water were fitted in the Cole–Davidson model. The Static dielectric constant ([Formula: see text], Relaxation time ([Formula: see text], effective Kirkwood correlation factor ([Formula: see text], excess permittivity ([Formula: see text], thermodynamic parameters (activation enthalpy and activation entropy) and Bruggeman factor ([Formula: see text] have been calculated by the nonlinear least square fit method. The intermolecular interactions between EGME-water binary mixtures suggest the nonlinear behavior of dielectric parameters. The contribution of hydrogen bonding interactions among the solute–solvent mixtures is confirmed by Excess properties and Bruggeman factor.

Dielectric relaxation study of dipropylsulfoxide/water mixtures

Dielectric behavior of indole in the GHz region using TDR

Dielectric studies on binary mixtures of ester with alcohol using time domain reflectometry

ABSTRACTUsing time-domain reflectometry (TDR) technique, we have measured the complex permittivity of tertiary butyl alcohol (TBA)–water mixtures in the frequency range of 10 MHz–30GHz, at temperatures 15°C, 20°C and 25°C. The complex permittivity of TBA–water mixture shows Debye-type behaviour. The dielectric parameters such as dielectric constant and relaxation time were obtained from the complex permittivity spectra. The Kirkwood correlation factor and Bruggeman factor have also been determined to investigate inter- and intramolecular interaction among associating liquids.

A dielectric relaxation study on alcohol–acrylic ester binary mixtures has been carried out at different concentrations using time domain reflectometry (TDR). The least‐squares fit method has been used to obtain the dielectric parameters (the static dielectric constant ϵ0 and the relaxation time τ). By using these parameters, the Bruggeman factor, the Kirkwood correlation factor, and excess inverse relaxation time were determined and discussed to yield information on the molecular structure and dynamics of the mixture. The ϵ0 and τ values decreased with an increase in the percent of acrylic ester in alcohol for all the systems. The value of t increased with an increase in chain length of both the alcohol and acrylic ester, whereas the reverse trend is observed for ϵ0. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

The complex permittivity for chlorobenzene–alcohol binary mixtures have been determined over the frequency range of 10 MHz to 20 GHz, at 15, 25, 35, and 45°C, using the time-domain reflectometry (TDR) method for 11 concentrations of each chlorobenzene–alcohol system. The alcohols used were methanol, ethanol, and 1-propanol. The values of static dielectric constant, relaxation time, the corresponding excess properties, the Redlich–Kister coefficients up to the third order, the Kirkwood correlation factor, and thermodynamic parameters of the mixtures have been determined. The excess permittivity is found to be negative for chlorobenzene–methanol and chlorobenzene–ethanol, whereas it is positive in the 1-propanol rich region. The excess inverse relaxation time is negative for all the systems studied here. The Kirkwood effective correlation factor increases with an increasing in the molecular size of the alcohol, but decreases with increasing temperature.

The Complex permittivity spectra of glycol ether (GE) compounds such as ethylene glycol mono-methyl ether (EGME), ethylene glycol ethyl ether (EGEE) and ethylene glycol butyl ether (EGBE) with water mixture over entire concentration range and at 25 °C has been determined using Time Domain Reflectometry technique in the frequency range 10 MHz to 50 GHz. The complex permittivity spectra for GE–water were fitted in Cole–Davidson model. The Static dielectric constant (ε0), Relaxation time (τ), effective Kirkwood correlation factor (g eff), excess permittivity () and Bruggeman factor (fB ) have been calculated by non-linear least square fit method. The intermolecular interactions between GE-water binary mixtures suggest the non-linear behavior of dielectric parameters. The contribution of hydrogen bonding interactions among the solute-solvent mixtures is confirmed by Excess properties and Bruggeman factor.