Dielectric constant of polyhydric alcohol-DMSO mixture solution at the microwave frequency.

Dielectric spectrum of polyhydric alcohol (1,2,3)-DMSO (dimethyl sulfoxide) mixtures, at full concentration, have been determined by the dielectric relaxation spectroscopy (DRS) method at frequencies from 20 MHz to 20 GHz at room temperature. The mixture behavior is described according to four Davidson-Cole terms whose evolution with composition is analyzed. The binding energies and hydrogen bond (HB) numbers between solute-solute and solvent-solute pairs are obtained from the permittivity using the Luzar model. The average HBs number associated with DMSO decreases with increasing mole fraction of DMSO. The binding energy of solute-solute (E11) and solvent-solute (E12) interaction decreases with the increased numbers of carbon atoms in the alcohols.