Studying Two Series of Ternary Deep Eutectic Solvents (Choline Chloride–Urea–Glycerol) and (Choline Chloride–Malic Acid–Glycerol), Synthesis and Characterizations

Deep eutectic solvents are a recent class of solvents that started to get attention to replace the ionic liquids and, of course, the traditional organic solvents. In this work, two series mixtures of choline chloride–urea–glycerol and choline chloride–malic acid–glycerol, liquids at room temperature, were synthesized in different molar ratios and their properties were studied. Electrochemical characterization test was performed using Pt/C catalyst and the results showed an interesting electrochemical stability for choline chloride–urea–glycerol mixture within the potential range of −1 to 1 V. The viscosity was reported as a function of temperature for mixtures which behaved as Newtonian fluids and as a function of shear rate for those which behaved as non-Newtonian fluids. For instance, 1–1–1 choline chloride–urea–glycerol viscosity was decreased from 706.8 to 26.9 cP when the temperature was increased from 20 to 80 ∘\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${^{\circ }}$$\end{document}C, respectively. While for the same mixture at 10 ∘\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${^{\circ }}$$\end{document}C, it was decreased from 30,933 to 3948 cP by increasing the shear rate from 0.03 to 0.38 S-1\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$^{{-}1}$$\end{document}, respectively. Thermogravimetric analysis, differential scanning calorimeter and density measurements were all reported in detail in this paper.