Contributions of Dipolar Relaxation Processes and Ionic Transport to the Response of Liquids to Electrical Perturbation Fields

摘要

The objective of this work was to study the influence of small variations in theudchemical structure on the molecular dynamics of liquids using as models bis(cyclohexylmethyl)ud2-methyl- and dicyclohexyl 2-methylsuccinate. The dielectric behavior of the low molecularudweight liquids was studied over a wide range of frequencies and temperatures. The results showudthat the temperature dependence of the dielectric strengths, relaxation times, and shapeudparameters of the secondary and glass liquid relaxations are very sensitive to the slightuddifferences in the structures of the liquids. Significant changes take place in the dielectricudstrength of the β relaxation in the glass liquid transition. Moreover, the temperature dependenceudof the β relaxation exhibits Arrhenius behavior in the glassy state and departs from this behaviorudin the liquid state. Special attention is paid to the temperature dependence of low-frequencyudrelaxations produced by the motion of a macrodipole arising from charges located near the liquid electrode boundaries.