ABSTRACT

Three pyridinium-based ionic liquids of [Cnpy][DCA] (n = 3,4,5) (N-alkyl-pyridinium dicyanamide) were prepared and characterized by 1H NMR (1H nuclear magnetic resonance) spectroscopy, 13C NMR (13C nuclear magnetic resonance) spectroscopy. Their densities, surface tensions and refractive indices were measured at different temperatures. The molar surface Gibbs energy, gs, critical temperature, Tc and E.tv.s empirical parameter related to polarity, kE, were also calculated. In terms of the concept of molar surface Gibbs energy, gs, a new E.tv.s equation was obtained. It is found that the slope of the new E.tv.s equation is the molar surface entropy of the ILs and the intercept is the molar surface enthalpy which is a temperature-independent constant. By using the refractive index and the molar surface Gibbs energy, an equation to predict surface tension of the ILs was derived and the predicted values of the surface tension of [Cnpy][DCA] (n = 3,4,5) are all most the same with the corresponding experimental values.

Compounds

#	Formula	Name
1	C10H12N4	1-propylpyridinium dicyanamide
2	C11H14N4	1-butylpyridinium dicyanamide
3	C12H16N4	1-pentylpyridinium dicyanamide
4	H2O	water

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	8
POMD	1	Surface tension liquid-gas, N/m ; Liquid	Temperature, K; Liquid		Liquid Air at 1 atmosphere	Maximal bubble pressure	8
POMD	1	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Standard Abbe refractometry	8
POMD	2	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	8
POMD	2	Surface tension liquid-gas, N/m ; Liquid	Temperature, K; Liquid		Liquid Air at 1 atmosphere	Maximal bubble pressure	8
POMD	2	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Standard Abbe refractometry	8
POMD	3	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	8
POMD	3	Surface tension liquid-gas, N/m ; Liquid	Temperature, K; Liquid		Liquid Air at 1 atmosphere	Maximal bubble pressure	8
POMD	3	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Standard Abbe refractometry	8
POMD	4 1	Mass density, kg/m3 ; Liquid	Mass fraction - 4; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	40
POMD	4 1	Surface tension liquid-gas, N/m ; Liquid	Mass fraction - 4; Liquid Temperature, K; Liquid		Liquid Air at 1 atmosphere	Maximal bubble pressure	40
POMD	4 1	Refractive index (Na D-line) ; Liquid	Mass fraction - 4; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Standard Abbe refractometry	40
POMD	4 2	Mass density, kg/m3 ; Liquid	Mass fraction - 4; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	40
POMD	4 2	Surface tension liquid-gas, N/m ; Liquid	Mass fraction - 4; Liquid Temperature, K; Liquid		Liquid Air at 1 atmosphere	Maximal bubble pressure	40
POMD	4 2	Refractive index (Na D-line) ; Liquid	Mass fraction - 4; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Standard Abbe refractometry	40
POMD	4 3	Mass density, kg/m3 ; Liquid	Mass fraction - 4; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vibrating tube method	40
POMD	4 3	Surface tension liquid-gas, N/m ; Liquid	Mass fraction - 4; Liquid Temperature, K; Liquid		Liquid Air at 1 atmosphere	Maximal bubble pressure	40
POMD	4 3	Refractive index (Na D-line) ; Liquid	Mass fraction - 4; Liquid Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Standard Abbe refractometry	40

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

The molar surface Gibbs energy and prediction of surface tension of [Cnpy][DCA] (n = 3,4,5)

Xing, N.[Nannan], Dai, B.[Bing], Ma, X.[Xiaoxue], Wei, J.[Jie], Pan, Y.[Yi], Guan, W.[Wei]

ABSTRACT