Abstract

TIME DOMAIN REFLECTOMETRY RESPONSE OF MONOHYDROXY ALCOHOL (ETHANOL) WITH POLAR LIQUIDS (DIMETHYL ACETAMIDE) AT HIGH FREQUENCY

Dheeraj Kadam and K. N. Shivalkar*

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Abstract

Dielectric Behavior of NN-Di-methyl Acetamide [C4H9NO] – Ethanol [C2H5OH] binary mixture at different temperatures 288,298,308 and 318 K have been determined over frequency range of 10 MHz to 20 GHz. Using the Time Domain Reflectometry Technique in reflection mode for 11 different concentrations of given binary system has been used to measure reflection coefficient. Further Fourier transform and least square fit method have been used to obtain dielectric parameters such as dielectric constant (0) and relaxation time (). The dielectric constant decreased with an increase in temperature where as it increased with increase concentration of DMA in Ethanol. Relaxation time decreased with an increase in temperature and increases with the concentration of DMA in Ethanol. By using dielectric parameters excess permittivity (E) and excess relaxation time (1/)E are determined. (E) has negative values for all concentrations and temperature indicates that total effective dipoles are decreases in the mixture. Excess inverse relaxation time (1/)E has positive values for all concentrations and temperature indicates that formation of cooperative field which rotate dipole faster. Kirkwood factor (geff) gf, and Bj coefficient gives systematic behavior of solute solvent for different concentrations and temperature at high frequency. Thermodynamic parameters enthalpy of activation (ΔH) and entropy of activation (ΔS) gives mixed nature.

Keywords: Time domain reflectometry, Dielectric parameters, Excess parameters, Kirkwood correlation Factor and Bruggeman factor.