In this study, the viscosity behavior of two mixtures of Ethaline (1 ChCl:2 ethylene glycol) with either methanol or ethanol were investigated over the temperature range of 283.15-333.15 K at atmospheric pressure. The measured viscosities of neat Ethaline, methanol, and ethanol showed reliable agreement with the corresponding reported literature values. The mixture viscosities were modeled by an Arrhenius-like model to determine the behavior of viscosity with respect to temperature. The data were also modeled by the four well-known mixture viscosity models of Grunberg-Nissan, Jouyban-Acree, McAllister, and Preferential Solvation. All of the model results were reliable, with the Jouyban-Acree and Preferential Solvation models showing the most accurate agreement with the experimental measurements. The Jones-Dole viscosity model was also investigated for the measured viscosities, and by analyzing the results of this model, strong interactions among Ethaline and the alcohol molecules were proposed for both systems. As a final analysis, viscosity deviations of the investigated systems were calculated to study the deviations of the viscosity behaviors with respect to ideal behavior. Both systems showed negative viscosity deviations at all of the investigated temperatures, with the negative values tending towards zero, and hence more ideal behavior, with increasing temperatures. Moreover, in order to correlate the calculated viscosity deviations, the Redlich-Kister model was successfully used for both systems and at each investigated temperature.
Keywords: Deep Eutectic Solvent; alcohol; alkanol; eutectic mixture; excess property; green solvent; physical property; thermodynamic modeling; viscosity deviation.