Dielectric relaxation in isobutyl alcohol-NMP and isobutyl alcohol-DMSO mixtures studied by microwave dielectric relaxation spectroscopy

摘要

The dielectric constant for isobutyl alcohol-NMP and isobutyl alcohol-DMSO mixtures with entire concentration have been determined in the frequency range 20 MHz to 20 GHz at 298 K using the dielectric relaxation spectroscopy (DRS) method. The mixture behavior is described according to Davidson-Cole, Cole-Cole, and two Debye-type relaxation model functions whose evolution with composition is analyzed. A distinct antiparallel arrangement of dipoles is obtained for neat NMP (DMSO) in the isobutyl alcohol liquid state according to the Kirkwood correlation factor, calculated from the static permittivity.