Low temperature dielectric relaxation study of aqueous solutions of diethylsulfoxide

TL;DR

This study investigates the dielectric relaxation behavior of diethylsulfoxide-water mixtures across various concentrations, temperatures, and frequencies, revealing glassy dynamics and a single relaxation process described by Havriliak-Negami functions.

Contribution

It provides new insights into the glass-forming properties and dielectric relaxation characteristics of DESO/water mixtures over a wide temperature and frequency range.

Findings

Mixtures exhibit strong glass-forming abilities.

A single relaxation process is observed in permittivity spectra.

Relaxation times follow Vogel-Fulcher-Tammann law.

Abstract

In the present work, dielectric spectra of mixtures of diethylsulfoxide (DESO) and water are presented, covering a concentration range of 0.2 - 0.3 molar fraction of DESO. The measurements were performed at frequencies between 1 Hz and 10 MHz and for temperatures between 150 and 300 K. It is shown that DESO/water mixtures have strong glass-forming abilities. The permittivity spectra in these mixtures reveal a single relaxation process. It can be described by the Havriliak-Negami relaxation function and its relaxation times follow the Vogel-Fulcher-Tammann law, thus showing the typical signatures of glassy dynamics. The concentration dependence of the relaxation parameters, like fragility, broadening, and glass temperature, are discussed in detail.