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Lopes JT, Franco LF. A possible way to explicitly account for different molecular geometries with an equation of state. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.115676] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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2
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Gámez F, Rodríguez-Almeida LF, Trejos VM. Thermodynamics of two-dimensional molecular fluids: Discrete perturbation theory and Monte Carlo simulations. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2019.112293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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3
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Lopes JT, M. Franco LF. New Thermodynamic Approach for Nonspherical Molecules Based on a Perturbation Theory for Ellipsoids. Ind Eng Chem Res 2019. [DOI: 10.1021/acs.iecr.9b00766] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Joyce T. Lopes
- School of Chemical Engineering, University of Campinas, Av. Albert Einstein 500, 13083-852 Campinas, Brazil
| | - Luís F. M. Franco
- School of Chemical Engineering, University of Campinas, Av. Albert Einstein 500, 13083-852 Campinas, Brazil
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4
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Sastre F, Moreno-Hilario E, Sotelo-Serna MG, Gil-Villegas A. Microcanonical-ensemble computer simulation of the high-temperature expansion coefficients of the Helmholtz free energy of a square-well fluid. Mol Phys 2017. [DOI: 10.1080/00268976.2017.1392051] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Francisco Sastre
- Departamento de Ingeniería Física, División de Ciencias e Ingenierías, Campus León de la Universidad de Guanajuato, AP E-143, 37150, Leon, Mexico
| | - Elizabeth Moreno-Hilario
- División de Ciencias e Ingenierías, Campus León de la Universidad de Guanajuato, AP E-143, 37150, Leon, Mexico
| | | | - Alejandro Gil-Villegas
- Departamento de Ingeniería Física, División de Ciencias e Ingenierías, Campus León de la Universidad de Guanajuato, AP E-143, 37150, Leon, Mexico
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Wu L, Müller EA, Jackson G. Understanding and Describing the Liquid-Crystalline States of Polypeptide Solutions: A Coarse-Grained Model of PBLG in DMF. Macromolecules 2014. [DOI: 10.1021/ma401230x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Liang Wu
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - Erich A. Müller
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
| | - George Jackson
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
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Wu L, Jackson G, Müller EA. Liquid crystal phase behaviour of attractive disc-like particles. Int J Mol Sci 2013; 14:16414-42. [PMID: 23965962 PMCID: PMC3759919 DOI: 10.3390/ijms140816414] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Revised: 07/24/2013] [Accepted: 07/25/2013] [Indexed: 11/17/2022] Open
Abstract
We employ a generalized van der Waals-Onsager perturbation theory to construct a free energy functional capable of describing the thermodynamic properties and orientational order of the isotropic and nematic phases of attractive disc particles. The model mesogen is a hard (purely repulsive) cylindrical disc particle decorated with an anisotropic square-well attractive potential placed at the centre of mass. Even for isotropic attractive interactions, the resulting overall inter-particle potential is anisotropic, due to the orientation-dependent excluded volume of the underlying hard core. An algebraic equation of state for attractive disc particles is developed by adopting the Onsager trial function to characterize the orientational order in the nematic phase. The theory is then used to represent the fluid-phase behaviour (vapour-liquid, isotropic-nematic, and nematic-nematic) of the oblate attractive particles for varying values of the molecular aspect ratio and parameters of the attractive potential. When compared to the phase diagram of their athermal analogues, it is seen that the addition of an attractive interaction facilitates the formation of orientationally-ordered phases. Most interestingly, for certain aspect ratios, a coexistence between two anisotropic nematic phases is exhibited by the attractive disc-like fluids.
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Affiliation(s)
- Liang Wu
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK; E-Mails: (L.W.); (G.J.)
| | - George Jackson
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK; E-Mails: (L.W.); (G.J.)
| | - Erich A. Müller
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK; E-Mails: (L.W.); (G.J.)
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Gámez F, Benavides AL. Perturbation theory for non-spherical fluids based on discretization of the interactions. J Chem Phys 2013; 138:124901. [DOI: 10.1063/1.4794783] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
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8
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Zheng YX, Yu YX, Li YF. An Equation of State for the Isotropic–Nematic Phase Transition of Semiflexible Polymers. Ind Eng Chem Res 2011. [DOI: 10.1021/ie102379h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yuan-Xiang Zheng
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Yang-Xin Yu
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
| | - Ying-Feng Li
- Department of Chemical Engineering, Tsinghua University, Beijing 100084, China
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Franco-Melgar M, Haslam AJ, Jackson G. Advances in generalised van der Waals approaches for the isotropic–nematic fluid phase equilibria of thermotropic liquid crystals–an algebraic equation of state for attractive anisotropic particles with the Onsager trial function. Mol Phys 2009. [DOI: 10.1080/00268970903352335] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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10
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Green MJ, Parra-Vasquez ANG, Behabtu N, Pasquali M. Modeling the phase behavior of polydisperse rigid rods with attractive interactions with applications to single-walled carbon nanotubes in superacids. J Chem Phys 2009; 131:084901. [DOI: 10.1063/1.3204024] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Varga S, Vesely FJ. A new generic model potential for mesogenic systems: Square well line potential of variable range. J Chem Phys 2009; 131:194506. [DOI: 10.1063/1.3264109] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Cortada M, Calero S, Lago S. A new insight on the structural changes of linear quadrupole liquids. J Chem Phys 2005; 123:184502. [PMID: 16292909 DOI: 10.1063/1.2102808] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Molecular-dynamics simulations for linear quadrupole liquids are presented. The study is carried out for two different molecular lengths at constant density and a number of temperatures and quadrupole moments. All the simulated thermodynamic states correspond to the condensed phases and some of them show typical features of a solid structure. Furthermore, a change on the preferred intermolecular orientation in the liquid phase is observed from a shifted parallel molecular arrangement to a perpendicular orientation as the quadrupole raises. This change depends on the quadrupole moment as well as on the molecular length and is put in relation with the solid structure of different "diatomic" molecules such as nitrogen, ethane, and acetylene. The appearance of a plastic solid phase at low quadrupole moment and density is also justified. A thoroughly discussion about the availability of classical perturbation theories for this kind of systems is presented.
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Affiliation(s)
- María Cortada
- Departamento Ciencias Ambientales, University Pablo de Olavide, Carretera de Utrera Km. 1, Seville 41013, Spain
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del Río EM, de Miguel E. Smectic phase in a system of hard ellipsoids with isotropic attractive interactions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 71:051710. [PMID: 16089554 DOI: 10.1103/physreve.71.051710] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2005] [Indexed: 05/03/2023]
Abstract
The smectic phase is studied for a thermotropic fluid model consisting of aligned hard ellipsoids with superimposed square-well attractive interactions of variable range. The system is analyzed using a density functional theory in which the hard-core contributions to the free-energy functional are treated within a nonlocal weighted density approximation and the attractive contributions are considered at a mean-field level. In the absence of attractions the model reduces, under appropriate scaling, to a fluid of hard spheres and therefore does not exhibit smectic ordering. It is shown that above a certain value of the square-well range, smectic ordering is stable relative to the nematic state at densities well inside the fluid region. The nematic-smectic-A transition is found to be continuous at high temperatures and first order at low temperatures, these two regimes being separated by a tricritical point at an intermediate temperature. These predictions have been confirmed by computer simulation of the model fluid. The results highlight that smectic ordering can be stabilized by coupling anisotropic short-range repulsions with the isotropic contribution of the soft attractive interactions. By increasing the pressure, the range of stability of the smectic phase is seen to decrease. At sufficiently high pressure, the smectic phase is suppressed, and the solid phase dominates. Our calculations show that smectic ordering is no longer stable if the range of the attractions is made too long ranged.
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Affiliation(s)
- Elvira Martín del Río
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, United Kingdom
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Martínez-Haya B, Cuetos A, Lago S. Solution of the Percus-Yevick equation for square well spherocylinders. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2003; 67:051201. [PMID: 12786138 DOI: 10.1103/physreve.67.051201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2002] [Revised: 01/13/2003] [Indexed: 05/24/2023]
Abstract
The Percus-Yevick equation for square-well spherocylinders has been numerically solved for some selected orientations following a methodology proposed previously for different fluids of elongated molecules. The equation is solved for particles of aspect ratios ranging from L/sigma=0.3 up to L/sigma=5.0, attractive range lambda/sigma=1.5, and packing fractions within eta=0.1-0.3. The resulting pair correlation functions are checked against isothermal-isobaric Monte Carlo simulations and good agreement is found for the short-range structure, at intermolecular distances within one molecular diameter sigma to contact for each of the selected orientations. At larger distances, the integral equation tends to overestimate the pair correlations. The results confirm the prediction of reference-system average Mayer-function perturbation theory for short aspect ratios, reaching the Onsager limit for the greater aspect ratios. Some instabilities of the solution for the longest models and higher densities are tentatively discussed in terms of their possible relation to frustration phenomena found in some polymer and complex systems.
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Affiliation(s)
- B Martínez-Haya
- Departamento de Ciencias Ambientales, Facultad de Ciencias Experimentales, Universidad Pablo de Olavide, Ctra. de Utrera Km 1, 41013 Seville, Spain.
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Cuetos A, Martı́nez-Haya B, Rull LF, Lago S. Monte Carlo study of liquid crystal phases of hard and soft spherocylinders. J Chem Phys 2002. [DOI: 10.1063/1.1491872] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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16
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Fridrikh SV, Lipson JEG. Square-well fluids: The statistical and thermodynamic properties of short chains. J Chem Phys 2002. [DOI: 10.1063/1.1469615] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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17
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Taylor MP, Luettmer-Strathmann J, Lipson JEG. Structure and phase behavior of square-well dimer fluids. J Chem Phys 2001. [DOI: 10.1063/1.1338981] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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MARTÍNEZ-HAYA B, RULL LF, CUETOS A, LAGO S. Gibbs ensemble simulation of the vapour-liquid equilibrium of square well spherocylinders. Mol Phys 2001. [DOI: 10.1080/00268970010018675] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Calero S, Garzón B, Jorge S, Mejías, Tortajada J, Lago S. Suitability of the Kihara Potential To Predict Molecular Spectra of Linear Polyatomic Liquids. J Phys Chem B 2000. [DOI: 10.1021/jp993904j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- S. Calero
- Facultad de Ciencias Experimentales, Carretera de Utrera, Km 1, Universidad Pablo de Olavide, 41013 Seville, Spain; Departamento Química Física, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain; and Departamento Ciencias Básicas, Facultad de Ciencias Experimentales y Técnicas, Universidad San Pablo CEU, Urbanización Montepríncipe, Boadilla del Monte, 28660 Madrid, Spain
| | - B. Garzón
- Facultad de Ciencias Experimentales, Carretera de Utrera, Km 1, Universidad Pablo de Olavide, 41013 Seville, Spain; Departamento Química Física, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain; and Departamento Ciencias Básicas, Facultad de Ciencias Experimentales y Técnicas, Universidad San Pablo CEU, Urbanización Montepríncipe, Boadilla del Monte, 28660 Madrid, Spain
| | - S. Jorge
- Facultad de Ciencias Experimentales, Carretera de Utrera, Km 1, Universidad Pablo de Olavide, 41013 Seville, Spain; Departamento Química Física, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain; and Departamento Ciencias Básicas, Facultad de Ciencias Experimentales y Técnicas, Universidad San Pablo CEU, Urbanización Montepríncipe, Boadilla del Monte, 28660 Madrid, Spain
| | - Mejías
- Facultad de Ciencias Experimentales, Carretera de Utrera, Km 1, Universidad Pablo de Olavide, 41013 Seville, Spain; Departamento Química Física, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain; and Departamento Ciencias Básicas, Facultad de Ciencias Experimentales y Técnicas, Universidad San Pablo CEU, Urbanización Montepríncipe, Boadilla del Monte, 28660 Madrid, Spain
| | - J. Tortajada
- Facultad de Ciencias Experimentales, Carretera de Utrera, Km 1, Universidad Pablo de Olavide, 41013 Seville, Spain; Departamento Química Física, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain; and Departamento Ciencias Básicas, Facultad de Ciencias Experimentales y Técnicas, Universidad San Pablo CEU, Urbanización Montepríncipe, Boadilla del Monte, 28660 Madrid, Spain
| | - S. Lago
- Facultad de Ciencias Experimentales, Carretera de Utrera, Km 1, Universidad Pablo de Olavide, 41013 Seville, Spain; Departamento Química Física, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain; and Departamento Ciencias Básicas, Facultad de Ciencias Experimentales y Técnicas, Universidad San Pablo CEU, Urbanización Montepríncipe, Boadilla del Monte, 28660 Madrid, Spain
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GARCIA EDUARDO, WILLIAMSON DAVEC, MARTINEZ-RICHA ANTONIO. Effects of molecular geometry on liquid crystalline phase behaviour: isotropic-nematic transition. Mol Phys 2000. [DOI: 10.1080/00268970009483281] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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