ABSTRACT

Pure component pressure-volume-temperature (pVT) data for five imidazolium-based ionic liquids, 1-ethyl- 3-methylimidazolium hexafluorophosphate [emim][PF6], 1-hexyl-3-methylimidazolium hexafluorophosphate [hmim][PF6], 1-octyl-3-methylimidazolium hexafluorophosphate [omim][PF6], 1-ethyl-3-methylimidazolium tetrafluoroborate [emim][BF4], and 1-hexyl-3-methylimidazolium tetrafluoroborate [hmim][BF4], were measured with a bellows type apparatus. High-pressure densities of ionic liquids showed smooth trends with temperature and pressure variations except for [emim][PF6] which exhibited a solid phase transition at temperatures below 352.7 K and which solidified at 100 MPa at 352.7 K. Solid densities were measured and were about 6.3 % higher than those of the liquid. Isothermal compressibilities and thermal expansion coefficients were calculated from the Tait equation that was fit to the pVT data. Isothermal compressibilities increased with alkyl chain length which is probably related to the ionic liquid free volume.

Compounds

#	Formula	Name
1	C6H11F6N2P	1-ethyl-3-methylimidazolium hexafluorophosphate
2	C10H19F6N2P	1-hexyl-3-methylimidazolium hexafluorophosphate
3	C6H11BF4N2	1-ethyl-3-methylimidazolium tetrafluoroborate
4	C10H19BF4N2	1-hexyl-3-methylimidazolium tetrafluoroborate
5	C12H23F6N2P	1-octyl-3-methylimidazolium hexafluorophosphate

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	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	2
POMD	1	Mass density, kg/m3 ; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid		Liquid	Bellows volumetry	129
POMD	1	Mass density, kg/m3 ; Crystal	Temperature, K; Crystal Pressure, kPa; Crystal		Crystal	Bellows volumetry	51
POMD	2	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	4
POMD	2	Mass density, kg/m3 ; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid		Liquid	Bellows volumetry	180
POMD	3	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	4
POMD	3	Mass density, kg/m3 ; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid		Liquid	Bellows volumetry	180
POMD	4	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	4
POMD	4	Mass density, kg/m3 ; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid		Liquid	Bellows volumetry	180
POMD	5	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	4
POMD	5	Mass density, kg/m3 ; Liquid	Pressure, kPa; Liquid Temperature, K; Liquid		Liquid	Bellows volumetry	180

Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

High-Pressure Densities of 1-Alkyl-3-methylimidazolium Hexafluorophosphates and 1-Alkyl-3-methylimidazolium Tetrafluoroborates at Temperatures from (313 to 473) K and at Pressures up to 200 MPa

Taguchi, R.[Ryosuke], Machida, H.[Hiroshi], Sato, Y.[Yoshiyuki], Smith, R. L.[Richard L.]

ABSTRACT