Changes in Properties of Various Deep Eutectic Solvents According to Water Mixing Ratio and Temperature Changes

Abstract

The basic properties such as pH, electrical conductivity, and viscosity of four different deep eutectic solvents (DESs) were analyzed in this study. Additionally, the effects of temperature and mixing ratio of water on the properties of DESs were evaluated. As a result, the pH of DES was found to be affected by the pH of the two eutectic reagents includeed in DES. Organic acid based DES (lactic acid:choline chloride = 5:1) had the lowest viscosity and highest conductivity. While, alkaline inorganic salt based DES (glycerine: potassium carbonate = 5:1) had the highest viscosity and relatively low conductivity. Additionally, as the temperature increased, the conductivity value of DES increased, while the viscosity of DES decreased. The change due to the increase in water mixing ratio was also consistent with the change due to the increase in temperature.