ABSTRACT

The alkyl chain length of 1-alkyl-3-methylimidazolium bromide ([Rmim][Br], R = propyl (C3), hexyl (C6), heptyl (C7), and octyl (C8)) was varied to prepare a series of room-temperature ionic liquids (RTILs), and experimental measurements of density and speed of sound at different temperatures ranging from (288.15 to 308.15) K for their aqueous and methanolic solutions in the dilute concentration region (0.01 to 0.30) mol * kg-1 were taken. The values of the compressibilities, expansivity and apparent molar properties for [Cnmim][Br] in aqueous and methanolic solutions were determined at the investigated temperatures. The obtained apparent molar volumes and apparent molar isentropic compressibilities were fitted to the Redlich Mayer and the Pitzer s equations from which the corresponding infinite dilution molar properties were obtained. The values of the infinite dilution molar properties were used to obtain some information about solute solvent and solute solute interactions. The thermodynamic properties of investigated ionic liquids in aqueous solutions have been compared with those in methanolic solutions. Also, the comparison between thermodynamic properties of investigated solutions and those of electrolyte solutions, polymer solutions, cationic surfactant solutions and tetraalkylammonium salt solutions have been made.

Compounds

#	Formula	Name
1	H2O	water
2	C7H13BrN2	1-methyl-3-propylimidazolium bromide
3	C11H21BrN2	1-heptyl-3-methylimidazolium bromide
4	C12H23BrN2	1-methyl-3-octylimidazolium bromide
5	C10H19BrN2	3-hexyl-1-methyl-1H-imidazolium bromide
6	CH4O	methanol

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	5	Mass density, kg/m3 ; Metastable liquid	Temperature, K; Metastable liquid	Pressure, kPa; Metastable liquid	Metastable liquid	Vibrating tube method	5
POMD	5	Speed of sound, m/s ; Metastable liquid	Temperature, K; Metastable liquid	Pressure, kPa; Metastable liquid	Metastable liquid	Sing-around technique in a fixed-path interferometer	5
POMD	6	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	5
POMD	6	Speed of sound, m/s ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	5
POMD	1 2	Mass density, kg/m3 ; Liquid	Molality, mol/kg - 2; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	85
POMD	1 2	Speed of sound, m/s ; Liquid	Molality, mol/kg - 2; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	85
POMD	1 5	Mass density, kg/m3 ; Liquid	Molality, mol/kg - 5; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	70
POMD	1 5	Speed of sound, m/s ; Liquid	Molality, mol/kg - 5; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	70
POMD	1 3	Mass density, kg/m3 ; Liquid	Molality, mol/kg - 3; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	65
POMD	1 3	Speed of sound, m/s ; Liquid	Molality, mol/kg - 3; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	65
POMD	1 4	Mass density, kg/m3 ; Liquid	Molality, mol/kg - 4; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	105
POMD	1 4	Speed of sound, m/s ; Liquid	Molality, mol/kg - 4; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	105
POMD	6 2	Mass density, kg/m3 ; Liquid	Molality, mol/kg - 2; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	70
POMD	6 2	Speed of sound, m/s ; Liquid	Molality, mol/kg - 2; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	70
POMD	6 5	Mass density, kg/m3 ; Liquid	Molality, mol/kg - 5; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	110
POMD	6 5	Speed of sound, m/s ; Liquid	Molality, mol/kg - 5; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	110
POMD	6 3	Mass density, kg/m3 ; Liquid	Molality, mol/kg - 3; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	75
POMD	6 3	Speed of sound, m/s ; Liquid	Molality, mol/kg - 3; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	75
POMD	6 4	Mass density, kg/m3 ; Liquid	Molality, mol/kg - 4; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	50
POMD	6 4	Speed of sound, m/s ; Liquid	Molality, mol/kg - 4; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Sing-around technique in a fixed-path interferometer	50

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Effect of alkyl chain length and temperature on the thermodynamic properties of ionic liquids 1-alkyl-3-methylimidazolium bromide in aqueous and non-aqueous solutions at different temperatures

Sadeghi, R.[Rahmat], Shekaari, H.[Hemayat], Hosseini, R.[Rahim]

ABSTRACT