Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

Phase behavior of aqueous two-phase systems composed of 1-ethyl-3-methylimidazolium tetrafluoroborate and phosphate-based salts at different temperatures

Lv, H.[Hekun], Guo, D.[Dan], Jiang, Z.[Zhenxi], Li, Y.[Yanhong], Ren, B.[Baozeng]
Fluid Phase Equilib. 2013, 341, 23-29
ABSTRACT
Liquid liquid phase diagram of ionic liquid based 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim][BF4]) + sodium dihydrogen phosphate/disodium hydrogen phosphate aqueous two-phase systems have been determined at 298.15 K, 303.15 K and 308.15 K. The phase diagrams and the liquid liquid equilibrium (LLE) data of the [Emim][BF4] + sodium phosphate buffer aqueous two-phase systems were determined experimentally at different pH values at 298.15 K. The results show the stronger salt-out ability of Na2HPO4 than that of NaH2PO4, which could be related to the Gibbs free energy of hydration of the ions. The nonlinear equation developed by Merchuk was used to correlate the experimental binodal data. The tie-line data were correlated by Othmer-Tobias and Bancroft equation and a two-parameter equation. The results show a good agreement with the experimental data. The temperature dependence on the binodal curves and tie lines has been discussed. The effect of pH value of the sodium phosphate buffer on the phase diagram has also been studied.
Compounds
# Formula Name
1 HNa2O4P disodium hydrogen phosphate
2 H2O water
3 C6H11BF4N2 1-ethyl-3-methylimidazolium tetrafluoroborate
4 H2NaO4P sodium dihydrogen phosphate
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • 2
  • 3
  • Mass fraction - 1 ; Liquid mixture 2
  • Mass fraction - 1 ; Liquid mixture 1
  • Mass fraction - 3 ; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Mass fraction - 3; Liquid mixture 2
  • Pressure, kPa; Liquid mixture 2
  • Liquid mixture 2
  • Liquid mixture 1
  • OTHER
  • OTHER
  • OTHER
  • 15
  • POMD
  • 1
  • 2
  • 3
  • Mass fraction - 1 ; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Mass fraction - 3; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • UV spectroscopy
  • 48
  • POMD
  • 4
  • 2
  • 3
  • Mass fraction - 3 ; Liquid mixture 2
  • Mass fraction - 4 ; Liquid mixture 1
  • Mass fraction - 3 ; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Mass fraction - 4; Liquid mixture 2
  • Pressure, kPa; Liquid mixture 2
  • Liquid mixture 2
  • Liquid mixture 1
  • OTHER
  • OTHER
  • OTHER
  • 15
  • POMD
  • 4
  • 2
  • 3
  • Mass fraction - 4 ; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Mass fraction - 3; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • UV spectroscopy
  • 64