ABSTRACT

Correlations between density and refractive index of pure systems of ionic liquids were examined in this work. To this end, the density and refractive index of four 1-n-butyl-3-imidazolium-based ionic liquids were measured at atmospheric pressure and temperature up to 353.2 K. Densities and refractive indices of the ionic liquids investigated are presented as a function of temperature. A group contribution-based equation was modified to calculate the density as a function of temperature. An empirical equation was used to study the temperature-dependence of refractive index. The Lorentz Lorenz, Dale Gladstone, Eykman, Oster, Arago Biot, and Newton equations, as well as a modified Eykman were used to correlate the relation between the densities and refractive indices of the different ionic liquid systems. The correlations give satisfactory results. The results of this study can add to the newly organized database for ionic liquids and can also be used for various process design calculations.

Compounds

#	Formula	Name
1	C8H15BF4N2	1-butyl-3-methylimidazolium tetrafluoroborate
2	C8H15F6N2P	1-butyl-3-methylimidazolium hexafluorophosphate
3	C9H18N2O4S	1-butyl-3-methylimidazolium methyl sulfate
4	C9H15F3N2O3S	1-butyl-3-methylimidazolium trifluoromethanesulfonate

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	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Standard Abbe refractometry	11
POMD	1	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	17
POMD	2	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Standard Abbe refractometry	11
POMD	2	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	17
POMD	3	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Standard Abbe refractometry	11
POMD	3	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	17
POMD	4	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Standard Abbe refractometry	11
POMD	4	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	17

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Measurements of the density and refractive index for 1-n-butyl-3-methylimidazolium-based ionic liquids

Soriano, A. N.[Allan N.], Doma Jr., B. T.[Bonifacio T.], Li, M. -H.[Meng-Hui]

ABSTRACT