ABSTRACT

Phase diagrams for several (salt + salt) aqueous biphasic systems containing tetrabutylammonium bromide and inorganic salts NaH2PO4, Na2HPO4, Na3PO4, Na2CO3, K3Cit and Na2SO4 were determined at T = (298.15, 308.15 and 318.15) K. The salting-out strength of the investigated kosmotropic salts on the tetrabutylammonium bromide (chaotropic salt) in aqueous solutions follows the well established Hofmeister series, as in the case of (polymer + salt) aqueous biphasic systems. In order to obtain further evidence about the salting-out effect in these systems, volumetric and compressibility behaviour of tetrabutylammonium bromide aqueous solutions were also determined in the absence and presence of the investigated inorganic salts at different temperature. It was found that there is a relation between the relative concentration of various salts to form two-phase system with tetrabutylammonium bromide and the apparent molar volume or isentropic compressibility of transfer of tetrabutylammonium bromide from water to aqueous solution of the investigated salts.

Compounds

#	Formula	Name
1	C16H36BrN	tetrabutylammonium bromide
2	H2NaO4P	sodium dihydrogen phosphate
3	H2O	water
4	Na2O4S	sodium sulfate
5	CNa2O3	sodium carbonate
6	HNa2O4P	disodium hydrogen phosphate
7	Na3O4P	trisodium phosphate
8	C6H5K3O7	potassium citrate

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	Molality, mol/kg - 2 ; Liquid mixture 1	Temperature, K; Liquid mixture 1 Molality, mol/kg - 1; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Cloud point titration method	51
POMD	1 2 3	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid	Pressure, kPa; Liquid Molality, mol/kg - 2; Liquid	Liquid	Vibrating tube method	72
POMD	1 2 3	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid	Pressure, kPa; Liquid Molality, mol/kg - 2; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	72
POMD	1 3 4	Molality, mol/kg - 4 ; Liquid mixture 1	Temperature, K; Liquid mixture 1 Molality, mol/kg - 1; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Cloud point titration method	36
POMD	1 3 4	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid	Pressure, kPa; Liquid Molality, mol/kg - 4; Liquid	Liquid	Vibrating tube method	54
POMD	1 3 4	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid	Pressure, kPa; Liquid Molality, mol/kg - 4; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	54
POMD	5 1 3	Molality, mol/kg - 5 ; Liquid mixture 1	Temperature, K; Liquid mixture 1 Molality, mol/kg - 1; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Cloud point titration method	53
POMD	5 1 3	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid	Pressure, kPa; Liquid Molality, mol/kg - 5; Liquid	Liquid	Vibrating tube method	42
POMD	5 1 3	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid	Pressure, kPa; Liquid Molality, mol/kg - 5; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	42
POMD	1 6 3	Molality, mol/kg - 6 ; Liquid mixture 1	Temperature, K; Liquid mixture 1 Molality, mol/kg - 1; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Cloud point titration method	49
POMD	1 6 3	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid	Pressure, kPa; Liquid Molality, mol/kg - 6; Liquid	Liquid	Vibrating tube method	54
POMD	1 6 3	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid	Pressure, kPa; Liquid Molality, mol/kg - 6; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	54
POMD	1 7 3	Molality, mol/kg - 7 ; Liquid mixture 1	Temperature, K; Liquid mixture 1 Molality, mol/kg - 1; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Cloud point titration method	30
POMD	1 7 3	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid	Pressure, kPa; Liquid Molality, mol/kg - 7; Liquid	Liquid	Vibrating tube method	42
POMD	1 7 3	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid	Pressure, kPa; Liquid Molality, mol/kg - 7; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	42
POMD	8 1 3	Molality, mol/kg - 8 ; Liquid mixture 1	Temperature, K; Liquid mixture 1 Molality, mol/kg - 1; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Cloud point titration method	44
POMD	1 3	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	84
POMD	1 3	Speed of sound, m/s ; Liquid	Temperature, K; Liquid Molality, mol/kg - 1; Liquid	Pressure, kPa; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	84

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Aqueous biphasic formation, volumetric and compressibility behaviour in tetrabutylammonium bromide-inorganic salts aqueous systems

Hooshyar, H.[Hosein], Sadeghi, R.[Rahmat]

ABSTRACT