ABSTRACT

Experimental determination of mass densities and interfacial tensions (IFT) at liquid-liquid equilibrium (LLE) for methyl ester (FAME) demixed aqueous family (from methyl formate to methyl heptanoate) are reported as a function of temperature at atmospheric pressure (101.3 kPa). Mass density determinations are carried out in a vibrating tube densimeter, whereas a spinning drop tensiometer is used for performing IFT measurements. Furthermore, the IFT data have been correlated by using a simplified version of the Square Gradient Theory (SSGT) as applied to the Non-Random Two Liquids (NRTL) activity coefficient model. Based on the experimental results, the mass densities of both aqueous and methyl ester bulk phase decrease with temperature, whereas the IFT increases with the temperature and reaches a maximum value, which is related to the maximum tie line in the LLE. For higher temperatures, IFT starts to decrease with temperature. The correlation approach of IFT (SSGT + NRTL) was found to be suitable for correlating the IFT of the mixtures as a function of temperature and also provides a route to explore other interfacial properties, such as interfacial concentration profiles, which are difficult to measure. Considering the results from the calculated interfacial profiles along the interfacial region, the components (FAMEs and water) neither exhibit surface activity nor adsorption activity and the interfacial width decreases with temperature, as it was expected.

Compounds

#	Formula	Name
1	C2H4O2	methyl methanoate
2	C3H6O2	methyl ethanoate
3	C4H8O2	methyl propanoate
4	C5H10O2	methyl butanoate
5	C6H12O2	methyl pentanoate
6	C7H14O2	methyl hexanoate
7	C8H16O2	methyl heptanoate
8	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	1
POMD	1	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	refractometer model RFM 81	1
POMD	1	Surface tension liquid-gas, N/m ; Liquid	Temperature, K; Liquid		Liquid Air at 1 atmosphere	Maximal bubble pressure	1
POMD	2	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Vibrating tube method	1
POMD	2	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	refractometer model RFM 81	1
POMD	2	Surface tension liquid-gas, N/m ; Liquid	Temperature, K; Liquid		Liquid Air at 1 atmosphere	Maximal bubble pressure	1
POMD	3	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Vibrating tube method	1
POMD	3	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	refractometer model RFM 81	1
POMD	3	Surface tension liquid-gas, N/m ; Liquid	Temperature, K; Liquid		Liquid Air at 1 atmosphere	Maximal bubble pressure	1
POMD	4	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Vibrating tube method	1
POMD	4	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	refractometer model RFM 81	1
POMD	4	Surface tension liquid-gas, N/m ; Liquid	Temperature, K; Liquid		Liquid Air at 1 atmosphere	Maximal bubble pressure	1
POMD	5	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Vibrating tube method	1
POMD	5	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	refractometer model RFM 81	1
POMD	5	Surface tension liquid-gas, N/m ; Liquid	Temperature, K; Liquid		Liquid Air at 1 atmosphere	Maximal bubble pressure	1
POMD	6	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Vibrating tube method	1
POMD	6	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	refractometer model RFM 81	1
POMD	6	Surface tension liquid-gas, N/m ; Liquid	Temperature, K; Liquid		Liquid Air at 1 atmosphere	Maximal bubble pressure	1
POMD	7	Mass density, kg/m3 ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	Vibrating tube method	1
POMD	7	Refractive index (Na D-line) ; Liquid	Temperature, K; Liquid Pressure, kPa; Liquid		Liquid	refractometer model RFM 81	1
POMD	7	Surface tension liquid-gas, N/m ; Liquid	Temperature, K; Liquid		Liquid Air at 1 atmosphere	Maximal bubble pressure	1
POMD	8 1	Mass density, kg/m3 ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Vibrating tube method	2
POMD	8 1	Mass density, kg/m3 ; Liquid mixture 2	Temperature, K; Liquid mixture 2	Pressure, kPa; Liquid mixture 2	Liquid mixture 2 Liquid mixture 1	Vibrating tube method	2
POMD	8 1	Interfacial tension, N/m ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	spinning drop method	2
POMD	8 2	Mass density, kg/m3 ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Vibrating tube method	6
POMD	8 2	Mass density, kg/m3 ; Liquid mixture 2	Temperature, K; Liquid mixture 2	Pressure, kPa; Liquid mixture 2	Liquid mixture 2 Liquid mixture 1	Vibrating tube method	6
POMD	8 2	Interfacial tension, N/m ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	spinning drop method	6
POMD	8 3	Mass density, kg/m3 ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Vibrating tube method	7
POMD	8 3	Mass density, kg/m3 ; Liquid mixture 2	Temperature, K; Liquid mixture 2	Pressure, kPa; Liquid mixture 2	Liquid mixture 2 Liquid mixture 1	Vibrating tube method	7
POMD	8 3	Interfacial tension, N/m ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	spinning drop method	7
POMD	8 4	Mass density, kg/m3 ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Vibrating tube method	8
POMD	8 4	Mass density, kg/m3 ; Liquid mixture 2	Temperature, K; Liquid mixture 2	Pressure, kPa; Liquid mixture 2	Liquid mixture 2 Liquid mixture 1	Vibrating tube method	8
POMD	8 4	Interfacial tension, N/m ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	spinning drop method	8
POMD	8 5	Mass density, kg/m3 ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Vibrating tube method	9
POMD	8 5	Mass density, kg/m3 ; Liquid mixture 2	Temperature, K; Liquid mixture 2	Pressure, kPa; Liquid mixture 2	Liquid mixture 2 Liquid mixture 1	Vibrating tube method	9
POMD	8 5	Interfacial tension, N/m ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	spinning drop method	9
POMD	8 6	Mass density, kg/m3 ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Vibrating tube method	9
POMD	8 6	Mass density, kg/m3 ; Liquid mixture 2	Temperature, K; Liquid mixture 2	Pressure, kPa; Liquid mixture 2	Liquid mixture 2 Liquid mixture 1	Vibrating tube method	9
POMD	8 6	Interfacial tension, N/m ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	spinning drop method	9
POMD	8 7	Mass density, kg/m3 ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Vibrating tube method	9
POMD	8 7	Mass density, kg/m3 ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	Vibrating tube method	9
POMD	8 7	Interfacial tension, N/m ; Liquid mixture 1	Temperature, K; Liquid mixture 1	Pressure, kPa; Liquid mixture 1	Liquid mixture 1 Liquid mixture 2	spinning drop method	8

Thermodynamics Research Center / ThermoML | Journal of Chemical Thermodynamics

Densities and interfacial tensions for fatty acid methyl esters (from methyl formate to methyl heptanoate) + water demixed mixtures at atmospheric pressure conditions

del Pozo, Irene, Cartes, Marcela, Llovell, Felix, Mejia, Andrs

ABSTRACT