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Alkhatib III, Vega LF. Quantifying the effect of polar interactions on the behavior of binary mixtures: Phase, interfacial, and excess properties. J Chem Phys 2021; 154:164503. [PMID: 33940796 DOI: 10.1063/5.0046034] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
In this work, polar soft-Statistical Associating Fluid Theory (SAFT) was used in a systematic manner to quantify the influence of polar interactions on the phase equilibria, interfacial, and excess properties of binary mixtures. The theory was first validated with available molecular simulation data and then used to isolate the effect of polar interactions on the thermodynamic behavior of the mixtures by fixing the polar moment of one component while changing the polar moment of the second component from non-polar to either highly dipolar or quadrupolar, examining 15 different binary mixtures. It was determined that the type and magnitude of polar interactions have direct implications on the vapor-liquid equilibria (VLE), resulting in azeotropy for systems of either dipolar or quadrupolar fluids when mixed with non-polar or low polar strength fluids, while increasing the polar strength of one component shifts the VLE to be more ideal. Additionally, excess properties and interfacial properties such as interfacial tension, density profiles, and relative adsorption at the interface were also examined, establishing distinct enrichment in the case of mixtures with highly quadrupolar fluids. Finally, polar soft-SAFT was applied to describe the thermodynamic behavior of binary mixtures of experimental systems exhibiting various intermolecular interactions (non-polar and polar), not only demonstrating high accuracy and robustness through agreement with experimental data but also providing insights into the effect of polarity on the interfacial properties of the studied mixtures. This work proves the value of having an accurate theory for isolating the effect of polarity, especially for the design of ad hoc polar solvents.
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Affiliation(s)
- Ismail I I Alkhatib
- Chemical Engineering Department, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates
| | - Lourdes F Vega
- Chemical Engineering Department, Khalifa University of Science and Technology, P.O. Box 127788, Abu Dhabi, United Arab Emirates
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Furlan AP, Almarza NG, Barbosa MC. Lattice model for water-solute mixtures. J Chem Phys 2017; 145:144501. [PMID: 27782509 DOI: 10.1063/1.4964396] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A lattice model for the study of mixtures of associating liquids is proposed. Solvent and solute are modeled by adapting the associating lattice gas (ALG) model. The nature of interaction of solute/solvent is controlled by tuning the energy interactions between the patches of ALG model. We have studied three set of parameters, resulting in, hydrophilic, inert, and hydrophobic interactions. Extensive Monte Carlo simulations were carried out, and the behavior of pure components and the excess properties of the mixtures have been studied. The pure components, water (solvent) and solute, have quite similar phase diagrams, presenting gas, low density liquid, and high density liquid phases. In the case of solute, the regions of coexistence are substantially reduced when compared with both the water and the standard ALG models. A numerical procedure has been developed in order to attain series of results at constant pressure from simulations of the lattice gas model in the grand canonical ensemble. The excess properties of the mixtures, volume and enthalpy as the function of the solute fraction, have been studied for different interaction parameters of the model. Our model is able to reproduce qualitatively well the excess volume and enthalpy for different aqueous solutions. For the hydrophilic case, we show that the model is able to reproduce the excess volume and enthalpy of mixtures of small alcohols and amines. The inert case reproduces the behavior of large alcohols such as propanol, butanol, and pentanol. For the last case (hydrophobic), the excess properties reproduce the behavior of ionic liquids in aqueous solution.
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Affiliation(s)
- A P Furlan
- Instituto de Física, Unversidade Federal do Rio Grande do Sul, Caixa Postal 15051, 91501-570, Porto Alegre, Rio Grande do Sul, Brazil
| | - N G Almarza
- Instituto de Química Física Rocasolano, CSIC, Serrano 119, E-28006 Madrid, Spain
| | - M C Barbosa
- Instituto de Física, Unversidade Federal do Rio Grande do Sul, Caixa Postal 15051, 91501-570, Porto Alegre, Rio Grande do Sul, Brazil
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Martins LFG, Palace Carvalho AJ, Prates Ramalho JP, Filipe EJM. Excess Thermodynamic Properties of Mixtures Involving Xenon and Light Alkanes: A Study of Their Temperature Dependence by Computer Simulation. J Phys Chem B 2011; 115:9745-65. [DOI: 10.1021/jp2026384] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Luís F. G. Martins
- Centro de Química de Évora, University of Évora, Rua Romão Ramalho, 59, 7000−671 Évora, Portugal
| | - A. J. Palace Carvalho
- Centro de Química de Évora, University of Évora, Rua Romão Ramalho, 59, 7000−671 Évora, Portugal
| | - J. P. Prates Ramalho
- Centro de Química de Évora, University of Évora, Rua Romão Ramalho, 59, 7000−671 Évora, Portugal
| | - Eduardo J. M. Filipe
- Centro de Química Estrutural, Instituto Superior Técnico, Avenida Rovisco Pais, 1049-001, Lisbon, Portugal
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Bessières D, Piñeiro MM, De Ferron G, Plantier F. Analysis of the orientational order effect on n-alkanes: Evidences on experimental response functions and description using Monte Carlo molecular simulation. J Chem Phys 2010; 133:074507. [DOI: 10.1063/1.3472283] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- D Bessières
- Laboratoire des Fluides Complexes, Faculté des Sciences, Université de Pau, UMR CNRS 5150, BP 1155, Pau Cedex F-64013, France
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dos Ramos MC, Blas FJ. Examination of the Excess Thermodynamic Properties of n-Alkane Binary Mixtures: A Molecular Approach. J Phys Chem B 2005; 109:12145-53. [PMID: 16852498 DOI: 10.1021/jp0507142] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A modification of the statistical associating fluid theory, the so-called Soft-SAFT equation of state, is proposed to predict the excess thermodynamic properties of binary mixtures of n-alkanes. n-Alkane molecules are modeled as fully flexible Lennard-Jones chains. This molecular model accounts for the most important microscopic features of real chainlike molecules: attractive and repulsive interactions between different chemical groups and the connectivity of the segments that form the molecules. In this work we consider an additional microscopic effect that can profoundly affect certain thermodynamic properties, namely, the conformational changes when two different n-alkane molecules are mixed. We propose, following the work of Vega and co-workers [J. Chem. Phys. 1999, 111, 3192], a simple model to account for the conformational changes in molecules. The resulting free energy is combined with the SAFT free energy to describe the excess thermodynamic properties of binary mixtures of n-alkanes. Predictions from the theory are compared with experimental data taken from the literature. The agreement between the experiments and the theoretical predictions is excellent in all cases. This work shows that although minor microscopic effects, such as the conformational changes in the molecules that form the mixtures, have only a very small effect on the usual thermodynamic properties, such as pressure, chemical potential, phase equilibria, and excess volumes, they can contribute significantly to other thermodynamic properties. In fact, one of the main conclusions of this work is that it is essential that conformational effects be taken into account in molecular-based theories if an accurate description of certain excess properties (excess enthalpy for instance) is desired.
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Affiliation(s)
- María Carolina dos Ramos
- Departamento de Física Aplicada, Facultad de Ciencias Experimentales, Universidad de Huelva, 21071 Huelva, Spain
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Duque D, Pàmies JC, Vega LF. Interfacial properties of Lennard-Jones chains by direct simulation and density gradient theory. J Chem Phys 2004; 121:11395-401. [PMID: 15634099 DOI: 10.1063/1.1818679] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We perform a series of molecular dynamics simulations of Lennard-Jones chains systems, up to tetramers, in order to investigate the influence of temperature and chain length on their phase separation and interfacial properties. Simulation results serve as a test to check the accuracy of a statistical associated fluid theory (soft-SAFT) coupled with the density gradient theory. We focus on surface tension and density profiles. The simulations allow us to discuss the success and limitations of the theory and how to estimate the only adjustable parameter, the influence parameter. This parameter is obtained by fitting the surface tension, and then used to obtain the density profiles in a predictive manner. A good agreement is found if the temperature dependence of this parameter is neglected.(c) 2004 American Institute of Physics.
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Affiliation(s)
- Daniel Duque
- Institut de Ciència de Materials de Barcelona, Consejo Superior de Investigaciones Científicas, Campus de la Universitat, Autònoma de Barcelona, 08193 Bellaterra, Spain.
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BLAS FELIPEJ. Excess thermodynamic properties of chainlike mixtures. II. Self-associating systems: predictions from soft-SAFT and molecular simulation. Mol Phys 2002. [DOI: 10.1080/00268970210130209] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Galindo A, Blas FJ. Theoretical Examination of the Global Fluid Phase Behavior and Critical Phenomena in Carbon Dioxide + n-Alkane Binary Mixtures. J Phys Chem B 2002. [DOI: 10.1021/jp013402h] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Amparo Galindo
- Department of Chemical Engineering and Chemical Technology, Imperial College of Science, Technology and Medicine, Prince Consort Road, London SW7 2BY, U.K., and Departamento de Física Aplicada, Escuela Politécnica Superior, Universidad de Huelva, 21819 La Rábida, Huelva, Spain
| | - Felipe J. Blas
- Department of Chemical Engineering and Chemical Technology, Imperial College of Science, Technology and Medicine, Prince Consort Road, London SW7 2BY, U.K., and Departamento de Física Aplicada, Escuela Politécnica Superior, Universidad de Huelva, 21819 La Rábida, Huelva, Spain
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Blas FJ, Vega LF. Thermodynamic properties and phase equilibria of branched chain fluids using first- and second-order Wertheim’s thermodynamic perturbation theory. J Chem Phys 2001. [DOI: 10.1063/1.1388544] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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