Knowledge Bank

Dielectric relaxation measurements in the frequency range 10 MHz to 10 GHz have been carried out in Dimethylsulfoxide-water mixtures with thirteen concentrations using a time domain reflectometry $(TDR)1$. The dielectric spectra can be described by the Davidson-Cole relaxation model. The behaviour of the principal relaxation time of the mixture shows a maxima at a value corresponding to a mixture with 30% of water. The thermodynamic parameters, Kirkwood correlation factors gives structural informations. The attempt has been made to explain the dielectric behaviour of binary mixtures by the hydrogen-bonding model as suggested by $Luzar2$. The static relative permittivity of the mixtures can be explained if one assumes that the dipole moments of water and DMSO in the mixture are 14% and 10% larger than the corresponding values in the gas phase