The influence of temperature on the phase behavior of ionic liquid aqueous two-phase systems

Abstract

In this article, the equilibrium behavior of solutions of 1-ethyl-3-methylimidazolium dimethyl phosphate ([Emim]DMP) and ethyl acetate or acetone in aqueous two-phase system (ATPS) was discussed to understand the liquid–liquid equilibrium (LLE) behavior of these organic solvents. Thus, we determined phase diagrams and LLE data at 303.15, 308.15, 313.15, and 323.15 K for the investigated biphasic systems. Four empirical equations were used to study the tie lines. The results showed that for the [Emim]DMP + acetone + water biphasic systems within the investigated temperature range, temperature influences the phase behavior, but for the [Emim]DMP + ethyl acetate + water biphasic systems within the investigated temperature range, there are no notable changes on the phase behavior with rising temperature. The results may have important applications for the separation of antibiotics and for the recovery of ionic liquids (ILs).

Graphical Abstract

Keywords:

• Liquid–liquid equilibrium
• 1-ethyl-3-methylimidazolium dimethyl phosphate
• ethyl acetate
• acetone
• correlation

Disclosure statement

No potential conflict of interests was reported by the author(s).

Additional information

Funding

This work was sponsored by the National Natural Science Foundation of China (No. 41472220 and 21406090), the Research and Development Project of Science and Technology for Shaanxi Province (Nos. 2013JQ2019 and 2015KJXX-25), and the Fundamental Research Funds for the Central Universities (Nos. 310829153507, 310829161112 and 310829151143). The project was funded by China and Shaanxi Postdoctoral Science Foundation (Nos. 2014M552400), and the National Training Projects of the University Students’ Innovation and Entrepreneurship program (Nos. 201510710071 and 201510710077).