Vapor-liquid and liquid-liquid equilibrium for aqueous solutions containing of choline-based deep eutectic solvent and PPG400 at 298.15 K

Phase behavior including vapor-liquid and liquid-liquid equilibria of aqueous solutions of deep eutectic solvents (DES), prepared by mixing of choline chloride as HBA, and froctose as HBD at a molar ratio of 2:1 were investigated in the presence of water soluble polymer polypropylene glycol400 (PPG400) at 298.15 K. This work shows that the system containing of DES/PPG400/water can form the aqueous biphasic system (ABS). Evidently, the ABS formation appeared to be controlled by the competition between the preferential hydration and hydrogen bonding interaction depending on the polymer and DES structure. The results revealed that choline chloride as HBA and froctose as HBD could solute-out PPG400 and undergo phase separation in the aqueous solutions. The equal water activity lines obtained from the isopiestic measurements for DES/Polymer/water system indicated a relationship between the vapor- liquid equiliria and liquid-liquid equiliria behavior of this system. Finally, the binodal curve of the system was also investigated and the results were discussed on the basis of the hydrogen bond interactions in this system.

کلیدواژه ها:

Deep eutectic solvents ، Aqueous biphasic systems ، Isopiestic ، Polymer ، Liquid-liquid ، equilibria ، Water activity