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Jose Carlos Cobos - One of the best experts on this subject based on the ideXlab platform.
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characterization of 1 alkanol strongly Polar Compound mixtures from thermophysical data and the application of the kirkwood buff integrals and kirkwood frohlich formalisms
Fluid Phase Equilibria, 2019Co-Authors: J A Gonzalez, Isaias Garcia De La Fuente, Fernando . Hevia, L F Sanz, Jose Carlos CobosAbstract:Abstract Mixtures formed by 1-alkanol and one strongly Polar Compound, nitromethane (NM), ethanenitrile (EtN), dimethyl sulfoxide (DMSO, sulfolane (SULF), nitrobenzene (NTBz) or benzonitrile (BzCN), have been investigated on the basis of a set of thermophysical data, which includes: excess molar functions, enthalpies, H m E , Gibbs energies, G m E , entropies, T S m E , isobaric heat capacities, C p m E , volumes, V m E ; liquid-liquid equilibria (LLE), excess permittivies and deviations from the linearity of dynamic viscosities. In addition, calculations have been conducted to determine the Kirkwood-Buff integrals and the Kirkwood correlations factors, g K , of the investigated mixtures. In the former case, DISQUAC has been employed for modeling the needed vapour-liquid equilibria data. Many systems under consideration are characterized by diPolar interactions between like molecules and have positive values of H m E , C p m E and T S m E . On the other hand, alkanol-solvent interactions, for mixtures with a fixed 1-alkanol, become weakened in the sequence: DMSO ≈ SULF > EtN > NM > BzCN > NTBz. In systems with a given solvent, such interactions become also weaker when the chain length of the 1-alkanol is increased. Interestingly, the considered mixtures also show strong structural effects. Results on Kirkwood-Buff integrals reveal that nitriles are more preferred than nitroalkanes around a central alcohol molecule. Calculations on g K show that, in terms of the mixture Polarization, the systems are rather unstructured, and that this trend becomes more important when the 1-alkanol size increases in solutions with a given solvent.
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thermodynamics of aromatic Polar Compound alkanone alkanal or alkanoate hydrocarbon mixtures
Fluid Phase Equilibria, 2016Co-Authors: J A Gonzalez, Isaias Garcia De La Fuente, Cristina Alonsotristan, Jose Carlos CobosAbstract:Abstract Liquid-liquid equilibrium (LLE) temperatures have been determined for the mixtures: phenyl acetone + CH3(CH2)uCH3 (u = 8,10,12,14), or + 2,2,4-trimethylpentane, benzyl acetone + decane and benzyl acetate + dodecane by means of the critical opalescence method using a laser scattering technique. All the systems are characterized by an upper critical solution temperature (UCST). The coexistence curves have a rather flat maximum, and become shifted to higher concentrations of phenyl acetone when the alkane size increases. Aromatic alkanone, or alkanal or alkanoate + alkane, or + benzene mixtures have been investigated using DISQUAC. The interaction parameters for the X/aliphatic and X/aromatic contacts (X = CO, CHO, COO) are reported. The model correctly describes experimental data on LLE, vapour-liquid equilibria (VLE) and excess molar enthalpies ( H m E ) . UNIFAC (Dortmund version) results are poorer. This shows that new UNIFAC groups for the mentioned aromatic systems should be defined. Proximity effects depend on the number of CH2 groups (n) between the phenyl ring and the Polar group of the aromatic Compound considered. Proximity effects lead to enhanced diPolar interactions, which change in the order n = 1 > n = 2 > n = 0. Comparison of thermodynamic properties for systems with isomeric molecules (benzyl ethanoate and phenyl acetone) shows that dispersive interactions are more relevant in the benzyl ethanoate system.
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thermodynamics of mixtures containing a very strongly Polar Compound 10 liquid liquid equilibria for n n dimethylacetamide selected alkanes
Journal of Chemical & Engineering Data, 2013Co-Authors: Cristina Alonso Tristan, J A Gonzalez, Isaias Garcia De La Fuente, Jose Carlos CobosAbstract:Liquid–liquid equilibrium (LLE) temperatures versus composition for N,N-dimethylacetamide (DMA) + decane, + dodecane, + tetradecane, + 2,2,4-trimethylpentane, + methylcyclohexane, or + cyclooctane mixtures have been measured by means of the critical opalescence method using a laser scattering technique. All the systems show an upper critical solution temperature (UCST). In the case of n-alkane mixtures, UCST increases almost linearly with the chain length of the n-alkane. Moreover, these solutions show higher UCST values than those with isomeric cyclic alkanes. Branching leads to a strong decrease of UCST. The symmetry of the LLE curves depends on the size and shape of the alkane. DISQUAC correctly represents the coordinates of the critical points using interaction parameters available in the literature.
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thermodynamics of mixtures containing a strongly Polar Compound 9 liquid liquid equilibria for e caprolactam selected alkanes
Journal of Chemical & Engineering Data, 2010Co-Authors: Victor Alonso, J A Gonzalez, Isaias Garcia De La Fuente, Ivan Alonso, Ismael Mozo, Jose Carlos CobosAbstract:The coexistence curves of the liquid−liquid equilibria (LLE) for (e-caprolactam + heptane), (e-caprolactam + octane), (e-caprolactam + nonane), (e-caprolactam + decane), and (e-caprolactam + 2,2,4-trimethylpentane) have been determined by critical opalescence with a laser scattering technique. All the curves show an upper critical solution temperature (UCST) and have a rather horizontal top, and their symmetry depends on the size of the alkane. The UCST increases almost linearly with the chain length of the alkane. For the octane mixture, the UCST is lower than for the solution including 2,2,4-trimethylpentane.
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thermodynamics of mixtures containing a strongly Polar Compound 8 liquid liquid equilibria for n n dialkylamide selected n alkanes
Journal of Chemical & Engineering Data, 2006Co-Authors: Juan Lobos, J A Gonzalez, Ismael Mozo, Marta Fernandez Regulez, And Isaias Garcia De La Fuente, Jose Carlos CobosAbstract:The coexistence curves of the liquid−liquid equilibria (LLE) for systems of dimethylformamide (DMF) with hexane, heptane, octane, or nonane and of dimethylacetamide (DMA) with heptane have been determined visually. All the curves show an upper critical solution temperature (UCST) and have a rather horizontal top. The measured LLE curves for DMF mixtures show that their symmetry depends on the size of the alkane. For a given alkane, the UCST is higher for systems with DMF. This reveals that dipole−dipole interactions between amide molecules are stronger in such solutions. The DISQUAC model represents fairly well the LLE curves.
J A Gonzalez - One of the best experts on this subject based on the ideXlab platform.
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characterization of 1 alkanol strongly Polar Compound mixtures from thermophysical data and the application of the kirkwood buff integrals and kirkwood frohlich formalisms
Fluid Phase Equilibria, 2019Co-Authors: J A Gonzalez, Isaias Garcia De La Fuente, Fernando . Hevia, L F Sanz, Jose Carlos CobosAbstract:Abstract Mixtures formed by 1-alkanol and one strongly Polar Compound, nitromethane (NM), ethanenitrile (EtN), dimethyl sulfoxide (DMSO, sulfolane (SULF), nitrobenzene (NTBz) or benzonitrile (BzCN), have been investigated on the basis of a set of thermophysical data, which includes: excess molar functions, enthalpies, H m E , Gibbs energies, G m E , entropies, T S m E , isobaric heat capacities, C p m E , volumes, V m E ; liquid-liquid equilibria (LLE), excess permittivies and deviations from the linearity of dynamic viscosities. In addition, calculations have been conducted to determine the Kirkwood-Buff integrals and the Kirkwood correlations factors, g K , of the investigated mixtures. In the former case, DISQUAC has been employed for modeling the needed vapour-liquid equilibria data. Many systems under consideration are characterized by diPolar interactions between like molecules and have positive values of H m E , C p m E and T S m E . On the other hand, alkanol-solvent interactions, for mixtures with a fixed 1-alkanol, become weakened in the sequence: DMSO ≈ SULF > EtN > NM > BzCN > NTBz. In systems with a given solvent, such interactions become also weaker when the chain length of the 1-alkanol is increased. Interestingly, the considered mixtures also show strong structural effects. Results on Kirkwood-Buff integrals reveal that nitriles are more preferred than nitroalkanes around a central alcohol molecule. Calculations on g K show that, in terms of the mixture Polarization, the systems are rather unstructured, and that this trend becomes more important when the 1-alkanol size increases in solutions with a given solvent.
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thermodynamics of aromatic Polar Compound alkanone alkanal or alkanoate hydrocarbon mixtures
Fluid Phase Equilibria, 2016Co-Authors: J A Gonzalez, Isaias Garcia De La Fuente, Cristina Alonsotristan, Jose Carlos CobosAbstract:Abstract Liquid-liquid equilibrium (LLE) temperatures have been determined for the mixtures: phenyl acetone + CH3(CH2)uCH3 (u = 8,10,12,14), or + 2,2,4-trimethylpentane, benzyl acetone + decane and benzyl acetate + dodecane by means of the critical opalescence method using a laser scattering technique. All the systems are characterized by an upper critical solution temperature (UCST). The coexistence curves have a rather flat maximum, and become shifted to higher concentrations of phenyl acetone when the alkane size increases. Aromatic alkanone, or alkanal or alkanoate + alkane, or + benzene mixtures have been investigated using DISQUAC. The interaction parameters for the X/aliphatic and X/aromatic contacts (X = CO, CHO, COO) are reported. The model correctly describes experimental data on LLE, vapour-liquid equilibria (VLE) and excess molar enthalpies ( H m E ) . UNIFAC (Dortmund version) results are poorer. This shows that new UNIFAC groups for the mentioned aromatic systems should be defined. Proximity effects depend on the number of CH2 groups (n) between the phenyl ring and the Polar group of the aromatic Compound considered. Proximity effects lead to enhanced diPolar interactions, which change in the order n = 1 > n = 2 > n = 0. Comparison of thermodynamic properties for systems with isomeric molecules (benzyl ethanoate and phenyl acetone) shows that dispersive interactions are more relevant in the benzyl ethanoate system.
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thermodynamics of mixtures containing a very strongly Polar Compound 11 1 alkanol alkanenitrile systems
Thermochimica Acta, 2015Co-Authors: J A Gonzalez, Isaias Garcia De La Fuente, Fernando . Hevia, Ana Cobos, Cristina AlonsotristanAbstract:Abstract 1-Alkanol + alkanonitrile systems have been studied by means of the DISQUAC, ERAS and UNIFAC (Dortmund) models. DISQUAC and ERAS parameters for the alkanol/nitrile interactions are reported. DISQUAC describes a whole set of thermodynamic properties: phase equilibria, vapor–liquid (VLE), liquid–liquid (LLE) and solid–liquid (SLE) equilibria, molar excess functions: Gibbs energies, G m E , enthalpies, H m E , and partial excess molar enthalpies at infinite dilution, H m i E , ∞ using the same set of interaction parameters for each solution. The dependence on the molecular structure of the interaction parameters is similar to that observed in other previous applications to mixtures formed by 1-alkanols and a strongly Polar Compound, in such way that the quasichemical interchange coefficients can be kept constant from 1-propanol. However, methanol and ethanol solutions behave differently. From the analysis of experimental data for H m E , T S m E ( = H m E − G m E ) , and molar excess volumes, V m E , it is concluded that the studied systems are characterized by diPolar interactions and strong structural effects. The former are more relevant in acetonitrile solutions. Association effects are more important in butanenitrile mixtures. DISQUAC gives better results than the ERAS model. ERAS results on H m E for systems containing acetonitrile are also improved by UNIFAC. This remarks the importance of diPolar interactions in the investigated mixtures. ERAS describes the variation of V m E (x1 = 0.5) with the 1-alkanol size for mixtures with a given nitrile, but the concentration dependence of this excess function is poorly represented.
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thermodynamics of mixtures containing a very strongly Polar Compound 10 liquid liquid equilibria for n n dimethylacetamide selected alkanes
Journal of Chemical & Engineering Data, 2013Co-Authors: Cristina Alonso Tristan, J A Gonzalez, Isaias Garcia De La Fuente, Jose Carlos CobosAbstract:Liquid–liquid equilibrium (LLE) temperatures versus composition for N,N-dimethylacetamide (DMA) + decane, + dodecane, + tetradecane, + 2,2,4-trimethylpentane, + methylcyclohexane, or + cyclooctane mixtures have been measured by means of the critical opalescence method using a laser scattering technique. All the systems show an upper critical solution temperature (UCST). In the case of n-alkane mixtures, UCST increases almost linearly with the chain length of the n-alkane. Moreover, these solutions show higher UCST values than those with isomeric cyclic alkanes. Branching leads to a strong decrease of UCST. The symmetry of the LLE curves depends on the size and shape of the alkane. DISQUAC correctly represents the coordinates of the critical points using interaction parameters available in the literature.
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thermodynamics of mixtures containing a strongly Polar Compound 9 liquid liquid equilibria for e caprolactam selected alkanes
Journal of Chemical & Engineering Data, 2010Co-Authors: Victor Alonso, J A Gonzalez, Isaias Garcia De La Fuente, Ivan Alonso, Ismael Mozo, Jose Carlos CobosAbstract:The coexistence curves of the liquid−liquid equilibria (LLE) for (e-caprolactam + heptane), (e-caprolactam + octane), (e-caprolactam + nonane), (e-caprolactam + decane), and (e-caprolactam + 2,2,4-trimethylpentane) have been determined by critical opalescence with a laser scattering technique. All the curves show an upper critical solution temperature (UCST) and have a rather horizontal top, and their symmetry depends on the size of the alkane. The UCST increases almost linearly with the chain length of the alkane. For the octane mixture, the UCST is lower than for the solution including 2,2,4-trimethylpentane.
Isaias Garcia De La Fuente - One of the best experts on this subject based on the ideXlab platform.
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characterization of 1 alkanol strongly Polar Compound mixtures from thermophysical data and the application of the kirkwood buff integrals and kirkwood frohlich formalisms
Fluid Phase Equilibria, 2019Co-Authors: J A Gonzalez, Isaias Garcia De La Fuente, Fernando . Hevia, L F Sanz, Jose Carlos CobosAbstract:Abstract Mixtures formed by 1-alkanol and one strongly Polar Compound, nitromethane (NM), ethanenitrile (EtN), dimethyl sulfoxide (DMSO, sulfolane (SULF), nitrobenzene (NTBz) or benzonitrile (BzCN), have been investigated on the basis of a set of thermophysical data, which includes: excess molar functions, enthalpies, H m E , Gibbs energies, G m E , entropies, T S m E , isobaric heat capacities, C p m E , volumes, V m E ; liquid-liquid equilibria (LLE), excess permittivies and deviations from the linearity of dynamic viscosities. In addition, calculations have been conducted to determine the Kirkwood-Buff integrals and the Kirkwood correlations factors, g K , of the investigated mixtures. In the former case, DISQUAC has been employed for modeling the needed vapour-liquid equilibria data. Many systems under consideration are characterized by diPolar interactions between like molecules and have positive values of H m E , C p m E and T S m E . On the other hand, alkanol-solvent interactions, for mixtures with a fixed 1-alkanol, become weakened in the sequence: DMSO ≈ SULF > EtN > NM > BzCN > NTBz. In systems with a given solvent, such interactions become also weaker when the chain length of the 1-alkanol is increased. Interestingly, the considered mixtures also show strong structural effects. Results on Kirkwood-Buff integrals reveal that nitriles are more preferred than nitroalkanes around a central alcohol molecule. Calculations on g K show that, in terms of the mixture Polarization, the systems are rather unstructured, and that this trend becomes more important when the 1-alkanol size increases in solutions with a given solvent.
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thermodynamics of mixtures containing a very strongly Polar Compound 12 systems with nitrobenzene or 1 nitroalkane and hydrocarbons or 1 alkanols
Fluid Phase Equilibria, 2018Co-Authors: Juan Antonio . González, Isaias Garcia De La Fuente, Fernando . Hevia, Luis Felipe . Sanz, Cristina AlonsotristanAbstract:Abstract Mixtures involving nitrobenzene and hydrocarbons, or 1-alkanols and 1-nitroalkane, or nitrobenzene have been investigated on the basis of a whole set of thermophysical properties available in the literature. The properties considered are: excess molar functions (enthalpies, entropies, isobaric heat capacities, and volumes), vapour-liquid and liquid-liquid equilibria, permittivities or dynamic viscosities. In addition, the mixtures have been studied by means of the application of the DISQUAC, ERAS, and UNIFAC models, and using the formalism of the concentration-concentration structure factor. The corresponding interaction parameters in the framework of the DISQUAC and ERAS models are reported. In alkane mixtures, diPolar interactions between 1-nitroalkane molecules are weakened when the size of the Polar Compound increases, accordingly with the relative variation of their effective diPolar moment. DiPolar interactions are stronger in nitrobenzene solutions than in those containing the smaller 1-nitropropane, although both nitroalkanes have very similar effective dipole moment (aromaticity effect). Systems with 1-alkanols are characterized by diPolar interactions between like molecules which sharply increases when the alkanol size increases. Simultaneously, interactions between unlike molecules become weaker, as the OH group is then more sterically hindered. Interactions between unlike molecules are stronger in systems with nitromethane than in nitrobenzene solutions. The replacement of nitromethane by nitroethane in systems with a given 1-alkanol leads to strengthen those effects related with the alcohol self-association. Permittivity data and results on Kirkwood's correlation factors show that the addition of 1-alkanol to a nitroalkane leads to cooperative effects, which increase the diPolar Polarization of the solution, in such way that the destruction of the existing structure in pure liquids is partially counterbalanced. This effect is less important when longer 1-alkanols are involved.
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thermodynamics of aromatic Polar Compound alkanone alkanal or alkanoate hydrocarbon mixtures
Fluid Phase Equilibria, 2016Co-Authors: J A Gonzalez, Isaias Garcia De La Fuente, Cristina Alonsotristan, Jose Carlos CobosAbstract:Abstract Liquid-liquid equilibrium (LLE) temperatures have been determined for the mixtures: phenyl acetone + CH3(CH2)uCH3 (u = 8,10,12,14), or + 2,2,4-trimethylpentane, benzyl acetone + decane and benzyl acetate + dodecane by means of the critical opalescence method using a laser scattering technique. All the systems are characterized by an upper critical solution temperature (UCST). The coexistence curves have a rather flat maximum, and become shifted to higher concentrations of phenyl acetone when the alkane size increases. Aromatic alkanone, or alkanal or alkanoate + alkane, or + benzene mixtures have been investigated using DISQUAC. The interaction parameters for the X/aliphatic and X/aromatic contacts (X = CO, CHO, COO) are reported. The model correctly describes experimental data on LLE, vapour-liquid equilibria (VLE) and excess molar enthalpies ( H m E ) . UNIFAC (Dortmund version) results are poorer. This shows that new UNIFAC groups for the mentioned aromatic systems should be defined. Proximity effects depend on the number of CH2 groups (n) between the phenyl ring and the Polar group of the aromatic Compound considered. Proximity effects lead to enhanced diPolar interactions, which change in the order n = 1 > n = 2 > n = 0. Comparison of thermodynamic properties for systems with isomeric molecules (benzyl ethanoate and phenyl acetone) shows that dispersive interactions are more relevant in the benzyl ethanoate system.
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thermodynamics of mixtures containing a very strongly Polar Compound 11 1 alkanol alkanenitrile systems
Thermochimica Acta, 2015Co-Authors: J A Gonzalez, Isaias Garcia De La Fuente, Fernando . Hevia, Ana Cobos, Cristina AlonsotristanAbstract:Abstract 1-Alkanol + alkanonitrile systems have been studied by means of the DISQUAC, ERAS and UNIFAC (Dortmund) models. DISQUAC and ERAS parameters for the alkanol/nitrile interactions are reported. DISQUAC describes a whole set of thermodynamic properties: phase equilibria, vapor–liquid (VLE), liquid–liquid (LLE) and solid–liquid (SLE) equilibria, molar excess functions: Gibbs energies, G m E , enthalpies, H m E , and partial excess molar enthalpies at infinite dilution, H m i E , ∞ using the same set of interaction parameters for each solution. The dependence on the molecular structure of the interaction parameters is similar to that observed in other previous applications to mixtures formed by 1-alkanols and a strongly Polar Compound, in such way that the quasichemical interchange coefficients can be kept constant from 1-propanol. However, methanol and ethanol solutions behave differently. From the analysis of experimental data for H m E , T S m E ( = H m E − G m E ) , and molar excess volumes, V m E , it is concluded that the studied systems are characterized by diPolar interactions and strong structural effects. The former are more relevant in acetonitrile solutions. Association effects are more important in butanenitrile mixtures. DISQUAC gives better results than the ERAS model. ERAS results on H m E for systems containing acetonitrile are also improved by UNIFAC. This remarks the importance of diPolar interactions in the investigated mixtures. ERAS describes the variation of V m E (x1 = 0.5) with the 1-alkanol size for mixtures with a given nitrile, but the concentration dependence of this excess function is poorly represented.
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thermodynamics of mixtures containing a very strongly Polar Compound 10 liquid liquid equilibria for n n dimethylacetamide selected alkanes
Journal of Chemical & Engineering Data, 2013Co-Authors: Cristina Alonso Tristan, J A Gonzalez, Isaias Garcia De La Fuente, Jose Carlos CobosAbstract:Liquid–liquid equilibrium (LLE) temperatures versus composition for N,N-dimethylacetamide (DMA) + decane, + dodecane, + tetradecane, + 2,2,4-trimethylpentane, + methylcyclohexane, or + cyclooctane mixtures have been measured by means of the critical opalescence method using a laser scattering technique. All the systems show an upper critical solution temperature (UCST). In the case of n-alkane mixtures, UCST increases almost linearly with the chain length of the n-alkane. Moreover, these solutions show higher UCST values than those with isomeric cyclic alkanes. Branching leads to a strong decrease of UCST. The symmetry of the LLE curves depends on the size and shape of the alkane. DISQUAC correctly represents the coordinates of the critical points using interaction parameters available in the literature.
Cristina Alonsotristan - One of the best experts on this subject based on the ideXlab platform.
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thermodynamics of mixtures containing a very strongly Polar Compound 12 systems with nitrobenzene or 1 nitroalkane and hydrocarbons or 1 alkanols
Fluid Phase Equilibria, 2018Co-Authors: Juan Antonio . González, Isaias Garcia De La Fuente, Fernando . Hevia, Luis Felipe . Sanz, Cristina AlonsotristanAbstract:Abstract Mixtures involving nitrobenzene and hydrocarbons, or 1-alkanols and 1-nitroalkane, or nitrobenzene have been investigated on the basis of a whole set of thermophysical properties available in the literature. The properties considered are: excess molar functions (enthalpies, entropies, isobaric heat capacities, and volumes), vapour-liquid and liquid-liquid equilibria, permittivities or dynamic viscosities. In addition, the mixtures have been studied by means of the application of the DISQUAC, ERAS, and UNIFAC models, and using the formalism of the concentration-concentration structure factor. The corresponding interaction parameters in the framework of the DISQUAC and ERAS models are reported. In alkane mixtures, diPolar interactions between 1-nitroalkane molecules are weakened when the size of the Polar Compound increases, accordingly with the relative variation of their effective diPolar moment. DiPolar interactions are stronger in nitrobenzene solutions than in those containing the smaller 1-nitropropane, although both nitroalkanes have very similar effective dipole moment (aromaticity effect). Systems with 1-alkanols are characterized by diPolar interactions between like molecules which sharply increases when the alkanol size increases. Simultaneously, interactions between unlike molecules become weaker, as the OH group is then more sterically hindered. Interactions between unlike molecules are stronger in systems with nitromethane than in nitrobenzene solutions. The replacement of nitromethane by nitroethane in systems with a given 1-alkanol leads to strengthen those effects related with the alcohol self-association. Permittivity data and results on Kirkwood's correlation factors show that the addition of 1-alkanol to a nitroalkane leads to cooperative effects, which increase the diPolar Polarization of the solution, in such way that the destruction of the existing structure in pure liquids is partially counterbalanced. This effect is less important when longer 1-alkanols are involved.
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thermodynamics of aromatic Polar Compound alkanone alkanal or alkanoate hydrocarbon mixtures
Fluid Phase Equilibria, 2016Co-Authors: J A Gonzalez, Isaias Garcia De La Fuente, Cristina Alonsotristan, Jose Carlos CobosAbstract:Abstract Liquid-liquid equilibrium (LLE) temperatures have been determined for the mixtures: phenyl acetone + CH3(CH2)uCH3 (u = 8,10,12,14), or + 2,2,4-trimethylpentane, benzyl acetone + decane and benzyl acetate + dodecane by means of the critical opalescence method using a laser scattering technique. All the systems are characterized by an upper critical solution temperature (UCST). The coexistence curves have a rather flat maximum, and become shifted to higher concentrations of phenyl acetone when the alkane size increases. Aromatic alkanone, or alkanal or alkanoate + alkane, or + benzene mixtures have been investigated using DISQUAC. The interaction parameters for the X/aliphatic and X/aromatic contacts (X = CO, CHO, COO) are reported. The model correctly describes experimental data on LLE, vapour-liquid equilibria (VLE) and excess molar enthalpies ( H m E ) . UNIFAC (Dortmund version) results are poorer. This shows that new UNIFAC groups for the mentioned aromatic systems should be defined. Proximity effects depend on the number of CH2 groups (n) between the phenyl ring and the Polar group of the aromatic Compound considered. Proximity effects lead to enhanced diPolar interactions, which change in the order n = 1 > n = 2 > n = 0. Comparison of thermodynamic properties for systems with isomeric molecules (benzyl ethanoate and phenyl acetone) shows that dispersive interactions are more relevant in the benzyl ethanoate system.
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thermodynamics of mixtures containing a very strongly Polar Compound 11 1 alkanol alkanenitrile systems
Thermochimica Acta, 2015Co-Authors: J A Gonzalez, Isaias Garcia De La Fuente, Fernando . Hevia, Ana Cobos, Cristina AlonsotristanAbstract:Abstract 1-Alkanol + alkanonitrile systems have been studied by means of the DISQUAC, ERAS and UNIFAC (Dortmund) models. DISQUAC and ERAS parameters for the alkanol/nitrile interactions are reported. DISQUAC describes a whole set of thermodynamic properties: phase equilibria, vapor–liquid (VLE), liquid–liquid (LLE) and solid–liquid (SLE) equilibria, molar excess functions: Gibbs energies, G m E , enthalpies, H m E , and partial excess molar enthalpies at infinite dilution, H m i E , ∞ using the same set of interaction parameters for each solution. The dependence on the molecular structure of the interaction parameters is similar to that observed in other previous applications to mixtures formed by 1-alkanols and a strongly Polar Compound, in such way that the quasichemical interchange coefficients can be kept constant from 1-propanol. However, methanol and ethanol solutions behave differently. From the analysis of experimental data for H m E , T S m E ( = H m E − G m E ) , and molar excess volumes, V m E , it is concluded that the studied systems are characterized by diPolar interactions and strong structural effects. The former are more relevant in acetonitrile solutions. Association effects are more important in butanenitrile mixtures. DISQUAC gives better results than the ERAS model. ERAS results on H m E for systems containing acetonitrile are also improved by UNIFAC. This remarks the importance of diPolar interactions in the investigated mixtures. ERAS describes the variation of V m E (x1 = 0.5) with the 1-alkanol size for mixtures with a given nitrile, but the concentration dependence of this excess function is poorly represented.
Fernando . Hevia - One of the best experts on this subject based on the ideXlab platform.
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Thermodynamics of mixtures containing a very strongly Polar Compound. 12. Systems with nitrobenzene or 1-nitroalkane and hydrocarbons or 1-alkanols
Elsevier, 2020Co-Authors: Juan Antonio . González, Fernando . Hevia, Luis Felipe . Sanz, García De La Fuente, Isaías ., Alonso Tristán CristinaAbstract:Mixtures involving nitrobenzene and hydrocarbons, or 1-alkanols and 1-nitroalkane, or nitrobenzene have been investigated on the basis of a whole set of thermophysical properties available in the literature. The properties considered are: excess molar functions (enthalpies, entropies, isobaric heat capacities, and volumes), vapour-liquid and liquid-liquid equilibria, permittivities or dynamic viscosities. In addition, the mixtures have been studied by means of the application of the DISQUAC, ERAS, and UNIFAC models, and using the formalism of the concentration-concentration structure factor. The corresponding interaction parameters in the framework of the DISQUAC and ERAS models are reported. In alkane mixtures, diPolar interactions between 1-nitroalkane molecules are weakened when the size of the Polar Compound increases, accordingly with the relative variation of their effective diPolar moment. DiPolar interactions are stronger in nitrobenzene solutions than in those containing the smaller 1-nitropropane, although both nitroalkanes have very similar effective dipole moment (aromaticity effect). Systems with 1-alkanols are characterized by diPolar interactions between like molecules which sharply increases when the alkanol size increases. Simultaneously, interactions between unlike molecules become weaker, as the OH group is then more sterically hindered. Interactions between unlike molecules are stronger in systems with nitromethane than in nitrobenzene solutions. The replacement of nitromethane by nitroethane in systems with a given 1-alkanol leads to strengthen those effects related with the alcohol self-association. Permittivity data and results on Kirkwood's correlation factors show that the addition of 1-alkanol to a nitroalkane leads to cooperative effects, which increase the diPolar Polarization of the solution, in such way that the destruction of the existing structure in pure liquids is partially counterbalanced. This effect is less important when longer 1-alkanols are involved.Consejería de Educacion y Cultura of Junta deCastilla y Leon, under Project BU034U1
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characterization of 1 alkanol strongly Polar Compound mixtures from thermophysical data and the application of the kirkwood buff integrals and kirkwood frohlich formalisms
Fluid Phase Equilibria, 2019Co-Authors: J A Gonzalez, Isaias Garcia De La Fuente, Fernando . Hevia, L F Sanz, Jose Carlos CobosAbstract:Abstract Mixtures formed by 1-alkanol and one strongly Polar Compound, nitromethane (NM), ethanenitrile (EtN), dimethyl sulfoxide (DMSO, sulfolane (SULF), nitrobenzene (NTBz) or benzonitrile (BzCN), have been investigated on the basis of a set of thermophysical data, which includes: excess molar functions, enthalpies, H m E , Gibbs energies, G m E , entropies, T S m E , isobaric heat capacities, C p m E , volumes, V m E ; liquid-liquid equilibria (LLE), excess permittivies and deviations from the linearity of dynamic viscosities. In addition, calculations have been conducted to determine the Kirkwood-Buff integrals and the Kirkwood correlations factors, g K , of the investigated mixtures. In the former case, DISQUAC has been employed for modeling the needed vapour-liquid equilibria data. Many systems under consideration are characterized by diPolar interactions between like molecules and have positive values of H m E , C p m E and T S m E . On the other hand, alkanol-solvent interactions, for mixtures with a fixed 1-alkanol, become weakened in the sequence: DMSO ≈ SULF > EtN > NM > BzCN > NTBz. In systems with a given solvent, such interactions become also weaker when the chain length of the 1-alkanol is increased. Interestingly, the considered mixtures also show strong structural effects. Results on Kirkwood-Buff integrals reveal that nitriles are more preferred than nitroalkanes around a central alcohol molecule. Calculations on g K show that, in terms of the mixture Polarization, the systems are rather unstructured, and that this trend becomes more important when the 1-alkanol size increases in solutions with a given solvent.
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thermodynamics of mixtures containing a very strongly Polar Compound 12 systems with nitrobenzene or 1 nitroalkane and hydrocarbons or 1 alkanols
Fluid Phase Equilibria, 2018Co-Authors: Juan Antonio . González, Isaias Garcia De La Fuente, Fernando . Hevia, Luis Felipe . Sanz, Cristina AlonsotristanAbstract:Abstract Mixtures involving nitrobenzene and hydrocarbons, or 1-alkanols and 1-nitroalkane, or nitrobenzene have been investigated on the basis of a whole set of thermophysical properties available in the literature. The properties considered are: excess molar functions (enthalpies, entropies, isobaric heat capacities, and volumes), vapour-liquid and liquid-liquid equilibria, permittivities or dynamic viscosities. In addition, the mixtures have been studied by means of the application of the DISQUAC, ERAS, and UNIFAC models, and using the formalism of the concentration-concentration structure factor. The corresponding interaction parameters in the framework of the DISQUAC and ERAS models are reported. In alkane mixtures, diPolar interactions between 1-nitroalkane molecules are weakened when the size of the Polar Compound increases, accordingly with the relative variation of their effective diPolar moment. DiPolar interactions are stronger in nitrobenzene solutions than in those containing the smaller 1-nitropropane, although both nitroalkanes have very similar effective dipole moment (aromaticity effect). Systems with 1-alkanols are characterized by diPolar interactions between like molecules which sharply increases when the alkanol size increases. Simultaneously, interactions between unlike molecules become weaker, as the OH group is then more sterically hindered. Interactions between unlike molecules are stronger in systems with nitromethane than in nitrobenzene solutions. The replacement of nitromethane by nitroethane in systems with a given 1-alkanol leads to strengthen those effects related with the alcohol self-association. Permittivity data and results on Kirkwood's correlation factors show that the addition of 1-alkanol to a nitroalkane leads to cooperative effects, which increase the diPolar Polarization of the solution, in such way that the destruction of the existing structure in pure liquids is partially counterbalanced. This effect is less important when longer 1-alkanols are involved.
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thermodynamics of mixtures containing a very strongly Polar Compound 11 1 alkanol alkanenitrile systems
Thermochimica Acta, 2015Co-Authors: J A Gonzalez, Isaias Garcia De La Fuente, Fernando . Hevia, Ana Cobos, Cristina AlonsotristanAbstract:Abstract 1-Alkanol + alkanonitrile systems have been studied by means of the DISQUAC, ERAS and UNIFAC (Dortmund) models. DISQUAC and ERAS parameters for the alkanol/nitrile interactions are reported. DISQUAC describes a whole set of thermodynamic properties: phase equilibria, vapor–liquid (VLE), liquid–liquid (LLE) and solid–liquid (SLE) equilibria, molar excess functions: Gibbs energies, G m E , enthalpies, H m E , and partial excess molar enthalpies at infinite dilution, H m i E , ∞ using the same set of interaction parameters for each solution. The dependence on the molecular structure of the interaction parameters is similar to that observed in other previous applications to mixtures formed by 1-alkanols and a strongly Polar Compound, in such way that the quasichemical interchange coefficients can be kept constant from 1-propanol. However, methanol and ethanol solutions behave differently. From the analysis of experimental data for H m E , T S m E ( = H m E − G m E ) , and molar excess volumes, V m E , it is concluded that the studied systems are characterized by diPolar interactions and strong structural effects. The former are more relevant in acetonitrile solutions. Association effects are more important in butanenitrile mixtures. DISQUAC gives better results than the ERAS model. ERAS results on H m E for systems containing acetonitrile are also improved by UNIFAC. This remarks the importance of diPolar interactions in the investigated mixtures. ERAS describes the variation of V m E (x1 = 0.5) with the 1-alkanol size for mixtures with a given nitrile, but the concentration dependence of this excess function is poorly represented.