Binodal data for the ethanol/1-propanol/2-propanol + ammonium sulfate + water systems were determined at 29815 K On the basis of an empirical equation and lever rule, the liquid−liquid equilibrium compositions of the ethanol + ammonium sulfate + water system were directly calculated by Matlab The Othmer−Tobias equation and Bancroft equation proved the reliability of the calculation method and the corresponding tie-line data The phase-separation abilities of hydrophilic alcohols were compared by the effective excluded volume (EEV) of salt and the binodal curves plotted in molality The phase-separation abilities of the investigated alcohols are in the order of 1-propanol > 2-propanol > ethanol > methanol The mechanism of phase separation and the effects of alcohols, salts, and pH values are also discussed The results show that the increase in the amount of phase-forming substance and the decrease in pH values (from 903 to 358) are both advantageous to the formation of the aqueous two-phase system (

Phase Diagrams of Ammonium Sulfate + Ethanol/1-Propanol/2-Propanol + Water Aqueous Two-Phase Systems at 298.15 K and Correlation

Binodal data for the ethanol + (NH4)3C6H5O7 + water system and the 2-propanol + (NH4)3C6H5O7/Na3C6H5O7/K3C6H5O7 + water systems were experimentally determined at 298.15 K. Three empirical equations were used to correlate binodal data. On the basis of the equation with the highest accuracy and lever rule, the liquid−liquid equilibrium data were calculated by MATLAB. The reliability of the calculation method and the corresponding tie-line data was proved by the Othmer−Tobias equation and Bancroft equation. The determined binodal data were also correlated by two theoretical equations on the basis of excluded volume theory. The calculated effective excluded volume (EEV) of salt and the binodal curves plotted in molality both indicate that the salting-out abilities of the investigated salts are in the order Na3C6H5O7 ≈ K3C6H5O7 > (NH4)3C6H5O7, and the phase-separation abilities of the investigated alcohols are in the order 2-propanol > ethanol.

Measurement and Correlation of Phase Diagram Data for Several Hydrophilic Alcohol + Citrate Aqueous Two-Phase Systems at 298.15 K

Binodal data for the ethanol + K3PO4/K3C6H5O7/Na3C6H5O7 + water systems were experimentally determined at (298.15 and 313.13) K. On the basis of the binodal data fitting equation with the highest accuracy and the Lever rule, the liquid−liquid equilibrium data for the investigated systems at 298.15 K were directly calculated by MATLAB. The Othmer−Tobias equation and Bancroft equation were used to correlate tie-line data and evaluate the reliability of the calculation method and the corresponding tie-line data. The salting-out strength of salt ions was compared by the parameter of effective excluded volume and the binodal curves plotted in molality, while the salting-out strength of salts was compared by the parameter of salting-out coefficient and the binodal curves plotted in mass fraction. The salting-out strength of the investigated salts is in the order K3PO4 > Na3C6H5O7 > K3C6H5O7. As for salt ions, the salting-out strength of anions is in the order PO43− < C6H5O73−, while the salting-out strength of ...

Liquid−Liquid Equilibrium of Potassium Phosphate/Potassium Citrate/Sodium Citrate + Ethanol Aqueous Two-Phase Systems at (298.15 and 313.15) K and Correlation

Impact of pH and temperature on phase diagrams of different aqueous biphasic systems.

Phase diagrams of aqueous two-phase systems formed by polyethylene glycol + ammonium sulfate + water: equilibrium data and thermodynamic modeling

Liquid−liquid equilibrium for an aqueous two-phase system containing poly(ethylene glycol) 6000 + triammonium citrate + water was studied at five different temperatures, (25, 30, 35, 40, and 45) °C. The binodal curve was fitted to an empirical equation relating the concentrations of PEG 6000 and triammonium citrate, and the coefficients were estimated for the respective temperatures. The effective excluded volume values were obtained from the binodal data. Tie line compositions were estimated and correlated using Othmer−Tobias and Bancroft equations, and the parameters are reported.

Murugesan Thanapalan

Papers

Liquid−Liquid Equilibrium of Poly(ethylene glycol) 6000 + Triammonium Citrate + Water Systems at Different Temperatures