ABSTRACT

Heat capacity of three glass-forming imidazolium ionic liquids (ILs)was studied by adiabatic calorimetry in the temperature range (5-370) K. Using the experimental data obtained in this work and those available in literature it was demonstrated that for all the studied glass-forming imidazolium ILs except [C8mim]BF4 the Tg/Tfus quotient is close to 2/3. The anion symmetry and the alkyl chain length were found to be the most important factors affecting heat capacity changes at the glass transition. The values of the residual entropy for the [C4mim]An ILs can be explained by conformational disorder of the ions. However, since no statistically significant dependence of this quantity of the alkyl chain length was observed it is possible that the conformational disorder of the alkyl chains in ILs is lower than in molecular liquids or gases.

Compounds

#	Formula	Name
1	C8H16N2O4S	1-ethyl-3-methylimidazolium ethyl sulfate
2	C8H15BF4N2	1-butyl-3-methylimidazolium tetrafluoroborate
3	C12H23BF4N2	1-methyl-3-octylimidazolium tetrafluoroborate

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	Triple point temperature, K ; Glass			Glass Liquid Gas	Adiabatic calorimetry	1
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Glass	Temperature, K; Glass	Pressure, kPa; Glass	Glass	Small (less than 1 g) adiabatic calorimetry	23
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Small (less than 1 g) adiabatic calorimetry	20
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Glass	Temperature, K; Glass	Pressure, kPa; Glass	Glass	Small (less than 1 g) adiabatic calorimetry	160
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Small (less than 1 g) adiabatic calorimetry	150
POMD	1	Molar entropy, J/K/mol ; Glass	Temperature, K; Glass	Pressure, kPa; Glass	Glass	Small (less than 1 g) adiabatic calorimetry	23
POMD	1	Molar entropy, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Small (less than 1 g) adiabatic calorimetry	20
POMD	1	Molar enthalpy function {Hm(T)-Hm(0)}/T, J/K/mol ; Glass	Temperature, K; Glass	Pressure, kPa; Glass	Glass	Small (less than 1 g) adiabatic calorimetry	23
POMD	1	Molar enthalpy function {Hm(T)-Hm(0)}/T, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Small (less than 1 g) adiabatic calorimetry	20
POMD	2	Triple point temperature, K ; Glass			Glass Liquid Gas	Adiabatic calorimetry	1
POMD	2	Molar heat capacity at constant pressure, J/K/mol ; Glass	Temperature, K; Glass	Pressure, kPa; Glass	Glass	Small (less than 1 g) adiabatic calorimetry	23
POMD	2	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Small (less than 1 g) adiabatic calorimetry	20
POMD	2	Molar heat capacity at constant pressure, J/K/mol ; Glass	Temperature, K; Glass	Pressure, kPa; Glass	Glass	Small (less than 1 g) adiabatic calorimetry	158
POMD	2	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Small (less than 1 g) adiabatic calorimetry	75
POMD	2	Molar entropy, J/K/mol ; Glass	Temperature, K; Glass	Pressure, kPa; Glass	Glass	Small (less than 1 g) adiabatic calorimetry	23
POMD	2	Molar entropy, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Small (less than 1 g) adiabatic calorimetry	20
POMD	2	Molar enthalpy function {Hm(T)-Hm(0)}/T, J/K/mol ; Glass	Temperature, K; Glass	Pressure, kPa; Glass	Glass	Small (less than 1 g) adiabatic calorimetry	23
POMD	2	Molar enthalpy function {Hm(T)-Hm(0)}/T, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Small (less than 1 g) adiabatic calorimetry	20
POMD	3	Triple point temperature, K ; Glass			Glass Liquid Gas	Adiabatic calorimetry	1
POMD	3	Triple point temperature, K ; Crystal			Crystal Liquid Gas	Adiabatic calorimetry	1
POMD	3	Molar enthalpy of transition or fusion, kJ/mol ; Crystal			Crystal Liquid Gas	Adiabatic calorimetry	1
POMD	3	Molar heat capacity at constant pressure, J/K/mol ; Glass	Temperature, K; Glass	Pressure, kPa; Glass	Glass	Small (less than 1 g) adiabatic calorimetry	24
POMD	3	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Small (less than 1 g) adiabatic calorimetry	30
POMD	3	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Small (less than 1 g) adiabatic calorimetry	20
POMD	3	Molar entropy, J/K/mol ; Glass	Temperature, K; Glass	Pressure, kPa; Glass	Glass	Small (less than 1 g) adiabatic calorimetry	25
POMD	3	Molar entropy, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Small (less than 1 g) adiabatic calorimetry	30
POMD	3	Molar entropy, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Small (less than 1 g) adiabatic calorimetry	20
POMD	3	Molar enthalpy function {Hm(T)-Hm(0)}/T, J/K/mol ; Glass	Temperature, K; Glass	Pressure, kPa; Glass	Glass	Small (less than 1 g) adiabatic calorimetry	24
POMD	3	Molar enthalpy function {Hm(T)-Hm(0)}/T, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Small (less than 1 g) adiabatic calorimetry	30
POMD	3	Molar enthalpy function {Hm(T)-Hm(0)}/T, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Small (less than 1 g) adiabatic calorimetry	20
POMD	3	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Small (less than 1 g) adiabatic calorimetry	230
POMD	3	Molar heat capacity at constant pressure, J/K/mol ; Glass	Temperature, K; Glass	Pressure, kPa; Glass	Glass	Small (less than 1 g) adiabatic calorimetry	137
POMD	3	Molar heat capacity at constant pressure, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Small (less than 1 g) adiabatic calorimetry	103
POMD	3	Molar enthalpy, kJ/mol ; Glass	Temperature, K; Glass Pressure, kPa; Glass		Glass	Small (less than 1 g) adiabatic calorimetry	1

Thermodynamics Research Center / ThermoML | Thermochimica Acta

Evaluation of thermodynamic properties for non-crystallizable ionic liquids

Paulechka, Y. U.[Yauheni U.], Blokhin, A. V.[Andrey V.], Kabo, G. J.[Gennady J.]

ABSTRACT