A Comprehensive Study of Density, Viscosity, and Electrical Conductivity of (Choline Chloride + Glycerol) Deep Eutectic Solvent and Its Mixtures with Dimethyl Sulfoxide

Abstract

The data for density (ρ) and the transport properties viscosity (η) and electrical conductivity (κ) of a deep eutectic solvent (DES), glyceline, composed of choline chloride (ChCl) and glycerol at a 1:2 molar ratio are presented. Density was determined in the temperature range from T = (278.15 to 363.15) K, while measurements for η and κ were performed at T = (278.15 to 368.15) K and T = (278.15 to 338.15) K, respectively. The results were compared to the corresponding data provided in the literature, and their possible discrepancies are discussed. Additionally, ρ(T), η(T), and κ(T) were determined for mixtures of glyceline with dimethyl sulfoxide (DMSO) covering an entire miscibility range. For both neat DES and its mixtures, density data vary linearly with temperature, whereas η(T) and κ(T) were best fit by the empirical Vogel-Fulcher-Tammann equation. For the {glyceline+DMSO} system, the analysis of excess molar properties revealed that observed deviations from ideal density are mainly caused by packing effects. Nevertheless, the presence of strong H-bonding is supported by the sign and temperature dependence of excess viscosity. Similar to concentrated solutions of conventional electrolytes, the conductivity of {glyceline+DMSO} mixtures shows a pronounced maximum. Expectedly, its position depends significantly on temperature but is also sensitive to the type of a hydrogen bond donor used to prepare the DES.