Measurement and Correlation of Phase Equilibria in Aqueous Two-Phase Systems Containing Polyoxyethylene Lauryl Ether and Three Kinds of Potassium Salts at Different Temperatures

Abstract

The binodal curves of the aqueous two-phase system (ATPS) containing the polyoxyethylene (10) lauryl ether (POELE10, C32H66O11) and three potassium salts (KOH/K2CO3/K3PO4) were determined at the temperatures (288.15, 293.15, 303.15, and 308.15) K. The three experience equations were used to fit the binodal data for the studied systems, and a satisfactory correlation effect was obtained. The effect of salts on the binodal curves for the investigated systems was discussed by the effective excluded volume (EEV), and we found that the salting-out effect is mainly influenced by valence of anion of salts. The salt containing the higher valence of anion has a stronger phase-forming ability than that with a lower charge of anion. The liquid–liquid equilibrium (LLE) data for the investigated systems were determined and correlated by the Othmer–Tobias and Bancroft equations. The effect of the change of temperature on the binodal curves and tie-lines was also studied through the analysis of the EEV values and cloud point (CP) figure. The increase in temperature leads to the strengthening hydrophobicity of POELE10 that drive more water transferring from the top phase to the bottom phase, which means the phase-forming ability of the whole systems was strengthened. Thus, the critical concentration of POELE10 and salts for forming ATPS decreases with the rising temperature.

Phase behavior at Different Temperatures of an Aqueous Two-Phase Ionic Liquid Containing ([BPy] NO3 + Ammonium Sulfate and Sodium Sulfate + Water)

“…Another set of expressions was also used to correlate the data: in which w 1 and w 2 are the mass fraction of the IL and salt, respectively. Equations and , were also used to correlate the binodal data; the values for the coefficients a 1 , a 2 , b 1 , b 2 , c and a , b , c , and d are listed in Tables and along wit the R 2 and SD. On the basis of the obtained R 2 and SD, we find that the three equations can be satisfactorily used to model the binodal curves.…”

Measurement and Correlation of Phase Equilibria in Aqueous Two-Phase Systems Containing Polyoxyethylene Cetyl Ether and Three Organic Salts at Different Temperatures

“…It was found that polyoxyethylene n -alkyl ether was an appropriate option for building polymer–salt ATPS because they were composed of two types of diametrically opposed components: polyoxyethylene (hydrophilic) and alkyl (hydrophobic). In our previous papers, − the polyoxyethylene(10) lauryl ether (POELE10, C 32 H 66 O 11 ) and polyoxyethylene(20) cetyl ether (POELE20, C 56 H 114 O 21 ) were used in the ATPS, and the ATPSs composed of POELE10 and 14 kinds of salt have been given. The phase behaviors of the ATPSs containing POELE20 and six kinds of inorganic salt (KOH, K 2 CO 3 , K 3 PO 4 , Li 2 SO 4 , MgSO 4 , and ZnSO 4 ) have been reported in our articles. , Although the phase-forming ability of organic salt is weaker than the inorganic salt with the same valence, the organic salt has the merit of easy biodegradation.…”

Liquid–Liquid Equilibria for Ternary (Methyl Propyl Ketone + Hydroquinone or Resorcinol + Water) Systems at 298.15, 318.15, and 333.15 K

“…The slope of the tie-line (STL) at different compositions and temperatures was calculated using eq as follows where represent the equilibrium mass fraction of methyl propyl ketone (1) and water (3) in the aqueous phase and organic phase, respectively.…”