1
|
del Río F, Vargas LD, Chapela GA, Guzmán O. Thermodynamic perturbation theory of square-well dimers of variable width. Mol Phys 2022. [DOI: 10.1080/00268976.2022.2109525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Affiliation(s)
- Fernando del Río
- Departamento de Física, Universidad Autonónoma Metropolitana, Iztapalapa, Ciudad de México, México
| | - Luis D. Vargas
- Departamento de Física, Universidad Autonónoma Metropolitana, Iztapalapa, Ciudad de México, México
| | - Gustavo A. Chapela
- Departamento de Física, Universidad Autonónoma Metropolitana, Iztapalapa, Ciudad de México, México
| | - Orlando Guzmán
- Departamento de Física, Universidad Autonónoma Metropolitana, Iztapalapa, Ciudad de México, México
| |
Collapse
|
2
|
Perdomo-Hurtado L, Valadez-Pérez NE, Millan-Malo B, Castañeda-Priego R. Generalized equation of state for fluids: From molecular liquids to colloidal dispersions. J Chem Phys 2021; 154:084902. [PMID: 33639744 DOI: 10.1063/5.0037630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
In this work, a new parameterization for the Statistical Association Fluid Theory for potentials of Variable Range (SAFT-VR) is coupled to the discrete potential theory to represent the thermodynamic properties of several fluids, ranging from molecular liquids to colloidal-like dispersions. In this way, this version of the SAFT-VR approach can be straightforwardly applied to any kind of either simple or complex fluid. In particular, two interaction potentials, namely, the Lennard-Jones and the hard-core attractive Yukawa potentials, are discretized to study the vapor-liquid equilibrium properties of both molecular and complex liquids, respectively. Our results are assessed with Monte Carlo computer simulations and available and accurate theoretical results based on the self-consistent Ornstein-Zernike approximation.
Collapse
Affiliation(s)
- Luis Perdomo-Hurtado
- Grupo de Investigación Diseño Mecánico y Desarrollo Industrial, Universidad Autónoma de Manizales, Antigua Estación del Ferrocarril, Manizales, Caldas, Colombia
| | - Néstor Enrique Valadez-Pérez
- Facultad de Ciencias en Física y Matemáticas, Universidad Autónoma de Chiapas, Tuxtla Gutiérrez, Chiapas, Mexico
| | - Beatriz Millan-Malo
- Centro de Física Aplicada y Tecnología Avanzada, Universidad Nacional Autónoma de México, A.P. 1-1010, Querétaro 76000, Mexico
| | - Ramón Castañeda-Priego
- Departamento de Ingeniería Física, División de Ciencias e Ingenierías, Campus León, Universidad de Guanajuato, Loma del Bosque 103, Lomas del Campestre, 37150 León, Guanajuato, Mexico
| |
Collapse
|
3
|
Santos A, Yuste SB, López de Haro M. Structural and thermodynamic properties of hard-sphere fluids. J Chem Phys 2020; 153:120901. [PMID: 33003724 DOI: 10.1063/5.0023903] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
This Perspective article provides an overview of some of our analytical approaches to the computation of the structural and thermodynamic properties of single-component and multicomponent hard-sphere fluids. For the structural properties, they yield a thermodynamically consistent formulation, thus improving and extending the known analytical results of the Percus-Yevick theory. Approximate expressions linking the equation of state of the single-component fluid to the one of the multicomponent mixtures are also discussed.
Collapse
Affiliation(s)
- Andrés Santos
- Departamento de Física and Instituto de Computación Científica Avanzada (ICCAEx), Universidad de Extremadura, Badajoz E-06006, Spain
| | - Santos B Yuste
- Departamento de Física and Instituto de Computación Científica Avanzada (ICCAEx), Universidad de Extremadura, Badajoz E-06006, Spain
| | - Mariano López de Haro
- Instituto de Energías Renovables, Universidad Nacional Autónoma de México (U.N.A.M.), Temixco, Morelos 62580, Mexico
| |
Collapse
|
4
|
Solana JR, Akhouri BP. The role of higher-order terms in perturbation approaches to the monomer and bonding contributions in a SAFT-type equation of state for square-well chain fluids. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1444802] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- J. R. Solana
- Departamento de Física Aplicada, Universidad de Cantabria, Santander, Spain
| | - B. P. Akhouri
- Department of Physics, Birsa College, Khunti, Jharkhand, India
| |
Collapse
|
5
|
Trinh TKH, Passarello JP, de Hemptinne JC, Lugo R, Lachet V. A non-additive repulsive contribution in an equation of state: The development for homonuclear square well chains equation of state validated against Monte Carlo simulation. J Chem Phys 2016; 144:124902. [PMID: 27036474 DOI: 10.1063/1.4944068] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
This work consists of the adaptation of a non-additive hard sphere theory inspired by Malakhov and Volkov [Polym. Sci., Ser. A 49(6), 745-756 (2007)] to a square-well chain. Using the thermodynamic perturbation theory, an additional term is proposed that describes the effect of perturbing the chain of square well spheres by a non-additive parameter. In order to validate this development, NPT Monte Carlo simulations of thermodynamic and structural properties of the non-additive square well for a pure chain and a binary mixture of chains are performed. Good agreements are observed between the compressibility factors originating from the theory and those from molecular simulations.
Collapse
Affiliation(s)
- Thi-Kim-Hoang Trinh
- IFP Energies nouvelles, 1 et 4 avenue de Bois-Préau, 92852 Rueil-Malmaison, France
| | - Jean-Philippe Passarello
- Laboratoire de Science des Procédés et des Matériaux (LSPM), Université Paris 13, CNRS, 99 avenue Jean-Baptiste Clément, 93430 Villetaneuse, France
| | | | - Rafael Lugo
- IFP Energies nouvelles, 1 et 4 avenue de Bois-Préau, 92852 Rueil-Malmaison, France
| | - Veronique Lachet
- IFP Energies nouvelles, 1 et 4 avenue de Bois-Préau, 92852 Rueil-Malmaison, France
| |
Collapse
|
6
|
de Haro ML, Yuste SB, Santos A. Theoretical approaches to the structural properties of the square-shoulder fluid. Mol Phys 2016. [DOI: 10.1080/00268976.2016.1154199] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- M. López de Haro
- Departamento de Termociencias, Instituto de Energías Renovables, Universidad Nacional Autónoma de México (U.N.A.M.), Temixco, Mexico
| | - S. B. Yuste
- Departamento de Física and Instituto de Computación Científica Avanzada (ICCAEx), Universidad de Extremadura, Badajoz, Spain
| | - A. Santos
- Departamento de Física and Instituto de Computación Científica Avanzada (ICCAEx), Universidad de Extremadura, Badajoz, Spain
| |
Collapse
|
7
|
Elliott JR, Schultz AJ, Kofke DA. Combined temperature and density series for fluid-phase properties. I. Square-well spheres. J Chem Phys 2015; 143:114110. [DOI: 10.1063/1.4930268] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- J. Richard Elliott
- Chemical and Biomolecular Engineering Department, The University of Akron, Akron, Ohio 44325-3906, USA
| | - Andrew J. Schultz
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260-4200, USA
| | - David A. Kofke
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260-4200, USA
| |
Collapse
|
8
|
Orea P, Varga S, Odriozola G. A heuristic rule for classification of classical fluids: Master curves for Mie, Yukawa and square-well potentials. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2015.04.025] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
9
|
Guérin H. Unified SAFT-VR theory for simple and chain fluids formed of square-well, triangular-well, Sutherland and Mie segments. J Mol Liq 2015. [DOI: 10.1016/j.molliq.2015.01.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
10
|
Structure of discrete-potential fluids interacting via two piece-wise constant potentials with a hard-core. J Mol Liq 2013. [DOI: 10.1016/j.molliq.2013.08.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
11
|
Rivera-Torres S, del Río F, Espíndola-Heredia R, Kolafa J, Malijevský A. Molecular dynamics simulation of the free-energy expansion of the square-well fluid of short ranges. J Mol Liq 2013. [DOI: 10.1016/j.molliq.2012.12.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
12
|
Ramana ASV. Generalized coupling parameter expansion: Application to square well and Lennard-Jones fluids. J Chem Phys 2013; 139:044106. [DOI: 10.1063/1.4813797] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
13
|
Piasecki J, Szymczak P, Kozak JJ. Stability of phases of a square-well fluid within superposition approximation. J Chem Phys 2013; 138:164506. [PMID: 23635156 DOI: 10.1063/1.4801329] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The analytic and numerical methods introduced previously to study the phase behavior of hard sphere fluids starting from the Yvon-Born-Green (YBG) equation under the Kirkwood superposition approximation (KSA) are adapted to the square-well fluid. We are able to show conclusively that the YBG equation under the KSA closure when applied to the square-well fluid: (i) predicts the existence of an absolute stability limit corresponding to freezing where undamped oscillations appear in the long-distance behavior of correlations, (ii) in accordance with earlier studies reveals the existence of a liquid-vapor transition by the appearance of a "near-critical region" where monotonically decaying correlations acquire very long range, although the system never loses stability.
Collapse
Affiliation(s)
- Jarosław Piasecki
- Institute of Theoretical Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland
| | | | | |
Collapse
|
14
|
Ramana ASV, Menon SVG. Coupling-parameter expansion in thermodynamic perturbation theory. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2013; 87:022101. [PMID: 23496454 DOI: 10.1103/physreve.87.022101] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Revised: 12/15/2012] [Indexed: 06/01/2023]
Abstract
An approach to the coupling-parameter expansion in the liquid state theory of simple fluids is presented by combining the ideas of thermodynamic perturbation theory and integral equation theories. This hybrid scheme avoids the problems of the latter in the two phase region. A method to compute the perturbation series to any arbitrary order is developed and applied to square well fluids. Apart from the Helmholtz free energy, the method also gives the radial distribution function and the direct correlation function of the perturbed system. The theory is applied for square well fluids of variable ranges and compared with simulation data. While the convergence of perturbation series and the overall performance of the theory is good, improvements are needed for potentials with shorter ranges. Possible directions for further developments in the coupling-parameter expansion are indicated.
Collapse
Affiliation(s)
- A Sai Venkata Ramana
- Theoretical Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India
| | | |
Collapse
|
15
|
Pavlyukhin YT. Thermodynamic perturbation theory of simple liquids: Monte Carlo simulation of a hard sphere system and the Helmholtz free energy of SW fluids. J STRUCT CHEM+ 2012. [DOI: 10.1134/s0022476612030092] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
16
|
Rohrmann RD, Zurbriggen E. Conditional pair distributions in many-body systems: exact results for Poisson ensembles. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 85:051109. [PMID: 23004705 DOI: 10.1103/physreve.85.051109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Revised: 02/03/2012] [Indexed: 06/01/2023]
Abstract
We introduce a conditional pair distribution function (CPDF) which characterizes the probability density of finding an object (e.g., a particle in a fluid) to within a certain distance of each other, with each of these two having a nearest neighbor to a fixed but otherwise arbitrary distance. This function describes special four-body configurations, but also contains contributions due to the so-called mutual nearest neighbor (two-body) and shared neighbor (three-body) configurations. The CPDF is introduced to improve a Helmholtz free energy method based on space partitions. We derive exact expressions of the CPDF and various associated quantities for randomly distributed, noninteracting points at Euclidean spaces of one, two, and three dimensions. Results may be of interest in many diverse scientific fields, from fluid physics to social and biological sciences.
Collapse
Affiliation(s)
- René D Rohrmann
- Instituto de Ciencias Astronómicas, de la Tierra y del Espacio, UNSJ-CONICET, Av. España 1512 Sur, 5400 San Juan, Argentina.
| | | |
Collapse
|
17
|
Nigro B, Grimaldi C, Miller MA, Ryser P, Schilling T. Tunneling conductivity in composites of attractive colloids. J Chem Phys 2012; 136:164903. [DOI: 10.1063/1.4705307] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
18
|
Pini D, Parola A, Colombo J, Reatto L. An investigation of the SCOZA for narrow square-well potentials and in the sticky limit. Mol Phys 2011. [DOI: 10.1080/00268976.2011.558028] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
19
|
|
20
|
Khanpour M. Perturbation theory of liquids for short-ranged hard-core potentials: structure and thermodynamics of short-ranged square-well fluids. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 83:021203. [PMID: 21405836 DOI: 10.1103/physreve.83.021203] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 11/01/2010] [Indexed: 05/30/2023]
Abstract
A new method is devised to derive a thermodynamic perturbation theory that is suitable for short-ranged potentials. We have calculated structure and thermodynamic of short-ranged square-well potential with good agreement with computer simulation data even at low temperatures. We have also compared the results with other perturbation theories. It is found that the proposed theory gives better results when used to compute the structure and thermodynamic of short-ranged hard-core potentials.
Collapse
Affiliation(s)
- Mehrdad Khanpour
- Department of Chemistry, Islamic Azad University, Amol Branch, Amol, Iran.
| |
Collapse
|
21
|
Hansen-Goos H, Wettlaufer JS. A fundamental measure theory for the sticky hard sphere fluid. J Chem Phys 2011; 134:014506. [DOI: 10.1063/1.3528226] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
22
|
|
23
|
Bannerman MN, Lue L. Exact on-event expressions for discrete potential systems. J Chem Phys 2010; 133:124506. [DOI: 10.1063/1.3486567] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
|
24
|
Guérin H. A new simple analytic equation of state for square-well chain fluids with variable width, 1.1<λ<2, based on perturbation theory and an analytic representation of the hard-sphere radial distribution function gHS(r). J Mol Liq 2010. [DOI: 10.1016/j.molliq.2010.07.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
25
|
Guillén-Escamilla I, Schöll-Paschinger E, Castañeda-Priego R. A parametrisation of the direct correlation function for the square-shoulder fluid. Mol Phys 2010. [DOI: 10.1080/00268970903539592] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- I. Guillén-Escamilla
- a Departamento de Ciencias Naturales y Exactas, CU-Valles , Universidad de Guadalajara , Ameca, Mexico
| | - E. Schöll-Paschinger
- b Department für Materialwissenschaften und Prozesstechnik , Universität für Bodenkultu , Muthgase 107, A-1190 Vienna, Austria
| | - R. Castañeda-Priego
- c División de Ciencias e Ingenierías, Campus León , Universidad de Guanajuato , Loma del Bosque 103, Col. Lomas del Campestre, 37150 León, Guanajuato, Mexico
| |
Collapse
|
26
|
Apfelbaum EM, Vorob'ev VS. The confirmation of the critical point-Zeno-line similarity set from the numerical modeling data for different interatomic potentials. J Chem Phys 2009; 130:214111. [DOI: 10.1063/1.3151982] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
27
|
Zhou S, Solana JR. Progress in the Perturbation Approach in Fluid and Fluid-Related Theories. Chem Rev 2009; 109:2829-58. [DOI: 10.1021/cr900094p] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Shiqi Zhou
- State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083, China, and School of Physics Science and Technology, Central South University, Changsha, Hunan 410083, China
| | - J. R. Solana
- Applied Physics Department, University of Cantabria, 39005 Santander, Spain
| |
Collapse
|
28
|
Espíndola-Heredia R, del Río F, Malijevsky A. Optimized equation of the state of the square-well fluid of variable range based on a fourth-order free-energy expansion. J Chem Phys 2009; 130:024509. [DOI: 10.1063/1.3054361] [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
|
29
|
Zhou S. Thermodynamics and phase behavior of a triangle-well model and density-dependent variety. J Chem Phys 2009; 130:014502. [DOI: 10.1063/1.3049399] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
30
|
El Mendoub E, Wax JF, Charpentier I, Jakse N. Integral equation study of the square-well fluid for varying attraction range. Mol Phys 2008. [DOI: 10.1080/00268970802603499] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
31
|
|
32
|
|
33
|
Hu J, Duan Z, Shi X, Zhu J. A general local composition and coordination number model for square-well fluids with variable well width and diameter ratio. Mol Phys 2007. [DOI: 10.1080/00268970701262900] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
34
|
Adib AB. Algebraic perturbation theory for dense liquids with discrete potentials. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2007; 75:061204. [PMID: 17677248 DOI: 10.1103/physreve.75.061204] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2007] [Revised: 04/09/2007] [Indexed: 05/16/2023]
Abstract
A simple theory for the leading-order correction g{1}(r) to the structure of a hard-sphere liquid with discrete (e.g., square-well) potential perturbations is proposed. The theory makes use of a general approximation that effectively eliminates four-particle correlations from g{1}(r) with good accuracy at high densities. For the particular case of discrete perturbations, the remaining three-particle correlations can be modeled with a simple volume-exclusion argument, resulting in an algebraic and surprisingly accurate expression for g{1}(r). The structure of a discrete "core-softened" model for liquids with anomalous thermodynamic properties is reproduced as an application.
Collapse
Affiliation(s)
- Artur B Adib
- Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Bethesda, Maryland 20892-0520, USA.
| |
Collapse
|
35
|
Docherty H, Galindo A. A study of Wertheim's thermodynamic perturbation theory (TPT1) for associating fluids with dispersive interactions: the importance of the association range. Mol Phys 2006. [DOI: 10.1080/00268970601076467] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
36
|
López-Rendón R, Reyes Y, Orea P. Thermodynamic properties of short-range square well fluid. J Chem Phys 2006; 125:084508. [PMID: 16965030 DOI: 10.1063/1.2338307] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The interfacial properties of short-range square well fluid with lambda=1.15, 1.25, and 1.375 were determined by using single canonical Monte Carlo simulations. Simulations were carried out in the vapor-liquid region. The coexistence curves of these models were calculated and compared to those previously reported in the literature and good agreement was found among them. We found that the surface tension curves for any potential model of short range form a single master curve when we plot gamma* vs TT(c). It is demonstrated that the critical reduced second virial coefficient B(2)* as a function of interaction range or T(c)* is not constant.
Collapse
Affiliation(s)
- R López-Rendón
- Departamento de Química UAM-Iztapalapa, Avenida San Rafael Atlixco 186, 09340 México D.F., México
| | | | | |
Collapse
|
37
|
Malijevský A, Yuste SB, Santos A. How “sticky” are short-range square-well fluids? J Chem Phys 2006; 125:074507. [PMID: 16942351 DOI: 10.1063/1.2244549] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The aim of this work is to investigate to what extent the structural properties of a short-range square-well (SW) fluid of range lambda at a given packing fraction eta and reduced temperature T* = kBT/epsilon can be represented by those of a sticky-hard-sphere (SHS) fluid at the same packing fraction and an effective stickiness parameter tau(T*,lambda). Such an equivalence cannot hold for the radial distribution function g(r) since this function has a delta singularity at contact (r = sigma) in the SHS case, while it has a jump discontinuity at r = lambda sigma in the SW case. Therefore, the equivalence is explored with the cavity function y(r), i.e., we assume that [formula: see text]. Optimization of the agreement between y(SW) and y(SHS) to first order in density suggests the choice tau(T*,lambda) = [12(e(1/T* - 1)(lambda - 1)](-1). We have performed Monte Carlo (MC) simulations of the SW fluid for lambda = 1.05, 1.02, and 1.01 at several densities and temperatures T* such that tau(T*,lambda) = 0.13, 0.2, and 0.5. The resulting cavity functions have been compared with MC data of SHS fluids obtained by Miller and Frenkel[J. Phys.: Condens. Matter 16, S4901 (2004)]. Although, at given values of eta and tau, some local discrepancies between y(SW) and y(SHS) exist (especially for lambda = 1.05), the SW data converge smoothly toward the SHS values as lambda-1 decreases. In fact, precursors of the singularities of y(SHS) at certain distances due to geometrical arrangements are clearly observed in y(SW). The approximate mapping y(SW)-->y(SHS) is exploited to estimate the internal energy and structure factor of the SW fluid from those of the SHS fluid. Taking for y(SHS) the solution of the Percus-Yevick equation as well as the rational-function approximation, the radial distribution function g(r) of the SW fluid is theoretically estimated and a good agreement with our MC simulations is found. Finally, a similar study is carried out for short-range SW fluid mixtures.
Collapse
Affiliation(s)
- Alexandr Malijevský
- E. Hála Laboratory of Thermodynamics, Academy of Science of the Czech Republic, 16502 Prague 6, Czech Republic.
| | | | | |
Collapse
|
38
|
Parsafar G, Khanpour M, Mohammadi A. Calculation of equilibrium and transport properties using modified hard-core potential models. Chem Phys 2006. [DOI: 10.1016/j.chemphys.2006.03.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
39
|
López de Haro M, Santos A, Yuste SB. On the radial distribution function of a hard-sphere fluid. J Chem Phys 2006; 124:236102. [PMID: 16821959 DOI: 10.1063/1.2201699] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
40
|
Schöll-Paschinger E, Benavides AL, Castañeda-Priego R. Vapor-liquid equilibrium and critical behavior of the square-well fluid of variable range: A theoretical study. J Chem Phys 2005; 123:234513. [PMID: 16392937 DOI: 10.1063/1.2137713] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The vapor-liquid phase behavior and the critical behavior of the square-well (SW) fluid are investigated as a function of the interaction range, lambdain [1.25, 3], by means of the self-consistent Ornstein-Zernike approximation (SCOZA) and analytical equations of state based on a perturbation theory [A. L. Benavides and F. del Rio, Mol. Phys. 68, 983 (1989); A. Gil-Villegas, F. del Rio, and A. L. Benavides, Fluid Phase Equilib. 119, 97 (1996)]. For this purpose the SCOZA, which has been restricted up to now to a few model systems, has been generalized to hard-core systems with arbitrary interaction potentials requiring a fully numerical solution of an integro-partial differential equation. Both approaches, in general, describe well the liquid-vapor phase diagram of the square-well fluid when compared with simulation data. SCOZA yields very precise predictions for the coexistence curves in the case of long ranged SW interaction (lambda>1.5), and the perturbation theory is able to predict the binodal curves and the saturated pressures, for all interaction ranges considered if one stays away from the critical region. In all cases, the SCOZA gives very good predictions for the critical temperatures and the critical pressures, while the perturbation theory approach tends to slightly overestimate these quantities. Furthermore, we propose analytical expressions for the critical temperatures and pressures as a function of the square-well range.
Collapse
|