2.2 DES formation
ChCl and DHBA were first mixed at molar ratios of 3:2, 2:1, 1:1, 1:2,
and 2:3 at 110 °C to determine the optimal composition of binary DES
prior to the formation of two types of ternary DESs (Figure
S1 ). Among the five tested molar ratios, 3:2 and 2:1 resulted in a
clear and homogeneous liquid. Two solvents, distilled water and ethylene
glycol, were added as the third constituent in the DES system with a
3:2:5 molar ratio of ChCl, DHBA, and the solvent component. The molar
ratio of the third constituent was chosen based on the previous
study.28 The DES solvent formation temperature and
time were 90–120 °C for 0.5 – 3 h in a 150 ml Pyrex bottle.