ABSTRACT

As a continuation of our systematic study on physicochemical characterization of aqueous solution of ionic liquids, new measurements of molar heat capacity for aqueous solutions of four ionic liquids were reported. The investigated ionic liquids were 1-butyl-3-methylimidazolium chloride, 1- butyl-3-methylimidazolium bromide, 1-butyl-2,3-dimethylimidazolium tetrafluoroborate, and 1-butyl- 2,3-dimethylimidazolium hexafluorophosphate. The molar heat capacities were measured at normal atmospheric condition and over the temperature range (303.2 to 353.2) K using a differential scanning calorimeter (DSC) of an estiated experimental uncertainty of about 2% with liquid water as reference. The measured molar heat capacities were reported as functions of temperature and composition and the excess molar heat capacities were calculated using a Redlich Kister type equation. For the studied ionic liquids, results showed variations on the dependence of the excess molar heat capacities on temperature and composition. The applied correlation satisfactory represented the molar heat capacity measurements as shown by an acceptable overall average deviation of 0.09 %.

Compounds

#	Formula	Name
1	H2O	water
2	C8H15ClN2	1-butyl-3-methylimidazolium chloride
3	C9H17BF4N2	1-butyl-2,3-dimethylimidazolium tetrafluoroborate
4	C8H15BrN2	1-butyl-3-methylimidazolium bromide
5	C9H17F6N2P	1-butyl-2,3-dimethylimidazolium 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	2	Normal melting temperature, K ; Crystal			Crystal Liquid Air at 1 atmosphere	DTA:corrimp	1
POMD	2	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Large sample (1 g) DSC	13
POMD	3	Normal melting temperature, K ; Crystal			Crystal Liquid Air at 1 atmosphere	DTA:corrimp	1
POMD	3	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Large sample (1 g) DSC	15
POMD	4	Normal melting temperature, K ; Crystal			Crystal Liquid Air at 1 atmosphere	DTA:corrimp	1
POMD	4	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Large sample (1 g) DSC	11
POMD	5	Normal melting temperature, K ; Crystal			Crystal Liquid Air at 1 atmosphere	DTA:corrimp	1
POMD	5	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Large sample (1 g) DSC	13
POMD	1 2	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid Mole fraction - 2; Liquid	Pressure, kPa; Liquid	Liquid	Large sample (1 g) DSC	57
POMD	1 4	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid Mole fraction - 4; Liquid	Pressure, kPa; Liquid	Liquid	Large sample (1 g) DSC	77
POMD	1 3	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid Mole fraction - 3; Liquid	Pressure, kPa; Liquid	Liquid	Large sample (1 g) DSC	59
POMD	1 5	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid Mole fraction - 5; Liquid	Pressure, kPa; Liquid	Liquid	Large sample (1 g) DSC	57

Thermodynamics Research Center / ThermoML | Thermochimica Acta

Molar heat capacity of four aqueous ionic liquid mixtures

Hu, H.-C.[Hui-Chun], Soriano, A. N.[Allan N.], Leron, R. B.[Rhoda B.], Li, M.-H.[Meng-Hui]

ABSTRACT