Phase Equilibria and Salt Effect on the Aqueous Two-Phase System of Polyoxyethylene Cetyl Ether and Sulfate Salt at Three Temperatures

• DOI: 10.1021/acs.jced.6b00097
• Publication Date: 2016-05-10T16:33:36Z
• Authors: Yang Lu; Miao Yu; Zhenjiang Tan; Yongsheng Yan
• Keywords: Binodal; Salting out; Aqueous two-phase system; Solvophobic

Polyoxyethylene(20) cetyl ether (C56H114O21, POELE20) and three sulfate salts (Li2SO4, ZnSO4, MgSO4) were used as phase-forming material of the aqueous two-phase system, binodal data was measured at temperatures (288.15, 298.15, 308.15 K). Three classic experienced formulas to fit data, they had better performance in association. The tie-line studied systems fitted by empirical formulas, i.e., Othmer–Tobias Bancroft equations. It has For investigated systems, influence salt type on curves Gibbs free energy ions hydration effective excluded volume, temperature tie-lines binonal also discussed. First, it is confirmed, when are same anion, with higher cation valence will have stronger abilities salting out; out strengthen increasing absolute value energies cations. Second, salting-out enhance increase system volume systems. Third, more prone formation than those lower temperature. Finally, for slope decreases falling.