High frequency dielectric measurements of alcohol-dioxane mixtures using a time domain technique

The values of complex permittivity for alcohol -dioxane mixtures with various concentrations have been determined in the frequency range of 10 MHz - 20 GHz using time domain reflectometry (TDR) method. TDR method involves the generation of step pulse with rise time of 25 picosecond in a coaxial line system and monitoring the change in pulse shape after reflection from the sample placed at the end of the coaxial line. There is a great interest to study the dielectric relaxation behaviour in alcohol systems to understand the role of hydrogen bond in liquid alcohol system. The dielectric constant for the mixtures can be explained using hydrogen bonded model by assuming the formation of hydrogen bonds between alcohol-alcohol and alcohol-dioxane pairs. The orientation correlation between neighbouring molecules due to hydrogen bonding interactions are determined in terms of Kirkwood factors. The number of hydrogen bonds of alcohol-alcohol and alcohol-dioxane molecules are computed. The theoretical model to explain the experimental results has been discussed.