Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Evaluation of the impact of phosphate salts on the formation of ionic-liquid-based aqueous biphasic systems

Mourao, T.[Teresa], Claudio, A. F. M.[Ana Filipa M.], Boal-Palheiros, I.[Isabel], Freire, M. G.[Mara G.], Coutinho, J. A. P.[Joao A. P.]
J. Chem. Thermodyn. 2012, 54, 398-405
ABSTRACT
The present study aims at evaluating the capability of phosphate-based salts, whose anions can coexist in water depending on the media pH, to promote aqueous biphasic systems (ABS) formation with 1-butyl-3- methylimidazolium based ionic liquids, as well as to infer on the influence of the ionic liquid anion in the overall process of liquid liquid demixing. In this context, novel phase diagrams of ABS composed of several imidazolium based ionic liquids and three phosphate salts and a mixture of salts (K3PO4, K2HPO4, K2HPO4 + KH2PO4, and KH2PO4) were determined by the cloud point titration method at 298 K and atmospheric pressure. The corresponding tie-line compositions, tie-line lengths, and pH values of the coexisting phases were also determined. The ionic liquids ability to promote ABS is related with the hydrogenbond basicity of the composing anion - the lower it is the higher the ability of the ionic fluid to undergo liquid-liquid demixing. Moreover, similar patterns on the ionic liquids sequence were observed with the different phosphate salts. The phosphate anion charge plays a determinant role in the formation of ABS. The two-phase formation aptitude (with a similar ionic liquid) decreases in the rank: K3PO4 greater than K2HPO4 greater than K2HPO4 + KH2PO4 greater than KH2PO4. Yet, besides the charge of the phosphate anion, the pH and ionic strength of the aqueous media also influence the phase separation ability.
Compounds
# Formula Name
1 H2O water
2 K3O4P tripotassium phosphate
3 C15H22N2O3S 1-butyl-3-methylimidazolium tosylate
4 C9H18N2O4S 1-butyl-3-methylimidazolium methyl sulfate
5 C10H20N2O4S 1-butyl-3-methyl-1H-imidazolium ethyl sulfate
6 C10H21N2O4P 1-butyl-3-methyl-1H-imidazolium dimethylphosphate
7 HK2O4P dipotassium hydrogen phosphate
8 C9H15F3N2O3S 1-butyl-3-methylimidazolium trifluoromethanesulfonate
9 C10H15N5 1-butyl-3-methylimidazolium dicyanamide
10 C8H15ClN2 1-butyl-3-methylimidazolium chloride
11 C8H15BrN2 1-butyl-3-methylimidazolium bromide
12 C10H18N2O2 1-butyl-3-methylimidazolium acetate
13 C9H18N2O3S 1-butyl-3-methylimidazolium methanesulfonate
14 H2KO4P monopotassium 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 - 3 ; Liquid mixture 1
  • Mass fraction - 2; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 54
  • POMD
  • 1
  • 2
  • 3
  • Mass fraction - 2 ; Liquid mixture 1
  • Mass fraction - 3 ; Liquid mixture 2
  • Mass fraction - 2 ; Liquid mixture 2
  • Mass fraction - 3; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 2
  • Temperature, K; Liquid mixture 2
  • Liquid mixture 1
  • Liquid mixture 2
  • gravimetric
  • gravimetric
  • gravimetric
  • 2
  • POMD
  • 1
  • 2
  • 4
  • Mass fraction - 4 ; Liquid mixture 1
  • Mass fraction - 2; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 17
  • POMD
  • 1
  • 2
  • 4
  • Mass fraction - 2 ; Liquid mixture 2
  • Mass fraction - 2 ; Liquid mixture 1
  • Mass fraction - 4 ; Liquid mixture 1
  • Mass fraction - 4; Liquid mixture 2
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 2
  • Liquid mixture 1
  • gravimetric
  • gravimetric
  • gravimetric
  • 2
  • POMD
  • 1
  • 2
  • 5
  • Mass fraction - 5 ; Liquid mixture 1
  • Mass fraction - 2; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 21
  • POMD
  • 1
  • 2
  • 5
  • Mass fraction - 2 ; Liquid mixture 2
  • Mass fraction - 2 ; Liquid mixture 1
  • Mass fraction - 5 ; Liquid mixture 1
  • Mass fraction - 5; Liquid mixture 2
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 2
  • Liquid mixture 1
  • gravimetric
  • gravimetric
  • gravimetric
  • 2
  • POMD
  • 1
  • 2
  • 6
  • Mass fraction - 6 ; Liquid mixture 1
  • Mass fraction - 2; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 15
  • POMD
  • 1
  • 2
  • 6
  • Mass fraction - 6 ; Liquid mixture 2
  • Mass fraction - 2 ; Liquid mixture 1
  • Mass fraction - 6 ; Liquid mixture 1
  • Mass fraction - 2; Liquid mixture 2
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 2
  • Liquid mixture 1
  • gravimetric
  • gravimetric
  • gravimetric
  • 2
  • POMD
  • 1
  • 7
  • 8
  • Mass fraction - 8 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 35
  • POMD
  • 1
  • 7
  • 8
  • Mass fraction - 8 ; Liquid mixture 2
  • Mass fraction - 7 ; Liquid mixture 1
  • Mass fraction - 8 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 2
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 2
  • Liquid mixture 1
  • gravimetric
  • gravimetric
  • gravimetric
  • 2
  • POMD
  • 1
  • 7
  • 9
  • Mass fraction - 9 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 58
  • POMD
  • 1
  • 7
  • 9
  • Mass fraction - 9 ; Liquid mixture 2
  • Mass fraction - 7 ; Liquid mixture 1
  • Mass fraction - 9 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 2
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 2
  • Liquid mixture 1
  • gravimetric
  • gravimetric
  • gravimetric
  • 2
  • POMD
  • 1
  • 7
  • 3
  • Mass fraction - 3 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 81
  • POMD
  • 1
  • 7
  • 3
  • Mass fraction - 7 ; Liquid mixture 1
  • Mass fraction - 7 ; Liquid mixture 2
  • Mass fraction - 3 ; Liquid mixture 2
  • Mass fraction - 3; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 2
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • gravimetric
  • gravimetric
  • gravimetric
  • 3
  • POMD
  • 1
  • 7
  • 4
  • Mass fraction - 4 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 50
  • POMD
  • 1
  • 7
  • 4
  • Mass fraction - 4 ; Liquid mixture 2
  • Mass fraction - 7 ; Liquid mixture 1
  • Mass fraction - 4 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 2
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 2
  • Liquid mixture 1
  • gravimetric
  • gravimetric
  • gravimetric
  • 2
  • POMD
  • 1
  • 7
  • 5
  • Mass fraction - 5 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 16
  • POMD
  • 1
  • 7
  • 5
  • Mass fraction - 7 ; Liquid mixture 1
  • Mass fraction - 5 ; Liquid mixture 2
  • Mass fraction - 7 ; Liquid mixture 2
  • Mass fraction - 5; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 2
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • gravimetric
  • gravimetric
  • gravimetric
  • 2
  • POMD
  • 1
  • 7
  • 10
  • Mass fraction - 10 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • TITR:UFactor:2
  • 63
  • POMD
  • 1
  • 7
  • 10
  • Mass fraction - 10 ; Liquid mixture 2
  • Mass fraction - 7 ; Liquid mixture 1
  • Mass fraction - 10 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 2
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 2
  • Liquid mixture 1
  • gravimetric
  • gravimetric
  • gravimetric
  • 2
  • POMD
  • 1
  • 7
  • 11
  • Mass fraction - 11 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 40
  • POMD
  • 1
  • 7
  • 11
  • Mass fraction - 11 ; Liquid mixture 2
  • Mass fraction - 7 ; Liquid mixture 1
  • Mass fraction - 11 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 2
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 2
  • Liquid mixture 1
  • gravimetric
  • gravimetric
  • gravimetric
  • 2
  • POMD
  • 1
  • 7
  • 6
  • Mass fraction - 6 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • TITR:UFactor:2
  • 48
  • POMD
  • 1
  • 7
  • 6
  • Mass fraction - 6 ; Liquid mixture 2
  • Mass fraction - 7 ; Liquid mixture 1
  • Mass fraction - 6 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 2
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 2
  • Liquid mixture 1
  • gravimetric
  • gravimetric
  • gravimetric
  • 2
  • POMD
  • 1
  • 7
  • 12
  • Mass fraction - 12 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 27
  • POMD
  • 1
  • 7
  • 12
  • Mass fraction - 12 ; Liquid mixture 2
  • Mass fraction - 7 ; Liquid mixture 1
  • Mass fraction - 12 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 2
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 2
  • Liquid mixture 1
  • gravimetric
  • gravimetric
  • gravimetric
  • 2
  • POMD
  • 1
  • 7
  • 13
  • Mass fraction - 13 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 58
  • POMD
  • 1
  • 7
  • 13
  • Mass fraction - 13 ; Liquid mixture 2
  • Mass fraction - 7 ; Liquid mixture 1
  • Mass fraction - 13 ; Liquid mixture 1
  • Mass fraction - 7; Liquid mixture 2
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 2
  • Liquid mixture 1
  • gravimetric
  • gravimetric
  • gravimetric
  • 2
  • POMD
  • 1
  • 14
  • 8
  • Mass fraction - 8 ; Liquid mixture 1
  • Mass fraction - 14; Liquid mixture 1
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 1
  • Liquid mixture 2
  • Titration method
  • 23
  • POMD
  • 1
  • 14
  • 8
  • Mass fraction - 8 ; Liquid mixture 2
  • Mass fraction - 14 ; Liquid mixture 1
  • Mass fraction - 8 ; Liquid mixture 1
  • Mass fraction - 14; Liquid mixture 2
  • Pressure, kPa; Liquid mixture 1
  • Temperature, K; Liquid mixture 1
  • Liquid mixture 2
  • Liquid mixture 1
  • gravimetric
  • gravimetric
  • gravimetric
  • 2