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Mkanya A, Pellicane G, Ramos FS, Ramos AM, Lee LL. On the structure, property, and phase behaviour of the symmetric Yukawa mixtures: testing of the consistent integral equation theories. Mol Phys 2019. [DOI: 10.1080/00268976.2018.1542165] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Anele Mkanya
- School of Chemistry and Physics, University of Kwazulu-Natal, Pietermaritzburg, South Africa
- National Institute for Theoretical Physics (NITheP), KZN node, Pietermaritzburg, South Africa
| | - Giuseppe Pellicane
- School of Chemistry and Physics, University of Kwazulu-Natal, Pietermaritzburg, South Africa
- National Institute for Theoretical Physics (NITheP), KZN node, Pietermaritzburg, South Africa
| | - Franklin S. Ramos
- Department of Chemical and Materials Engineering, California State University, Pomona, CA, USA
| | - Ana M. Ramos
- Department of Chemical and Materials Engineering, California State University, Pomona, CA, USA
| | - Lloyd L. Lee
- School of Chemistry and Physics, University of Kwazulu-Natal, Pietermaritzburg, South Africa
- Department of Chemical and Materials Engineering, California State University, Pomona, CA, USA
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2
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Sokołowski S, Pizio O. Density functional theory for the microscopic structure of nanoparticles at the liquid-liquid interface. Phys Chem Chem Phys 2019; 21:3073-3082. [PMID: 30672936 DOI: 10.1039/c8cp07449f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We propose an extension of the density functional approach to study the structure and thermodynamic properties of a system comprising a certain amount of nanoparticles at the interface between two partially miscible liquids. Model calculations have been carried out for a binary symmetric mixture of Yukawa fluids and hard-sphere nanoparticles. Despite its simplicity, the model captures the principal features of this type of system. The results indicate that nanoparticles form layers and the number of layers depends on the amount of nanoparticles and on their diameters. For the systems studied the formation of the layers evidences strong localization of the nanoparticles at the interface.
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Affiliation(s)
- Stefan Sokołowski
- Department for the Modelling of Physico-Chemical Processes, Maria Curie-Sklodowska University, Lublin 20-031, Poland.
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3
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Sokołowski S, Pizio O. Density functional approach to the description of the structure of dimer nanoparticles at liquid–liquid interfaces. Phys Chem Chem Phys 2019; 21:11181-11192. [DOI: 10.1039/c9cp01087d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A density functional approach to the description of the structure of dimer nanoparticles at liquid–liquid interfaces.
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Affiliation(s)
- Stefan Sokołowski
- Department for the Modelling of Physico-Chemical Processes
- Maria Curie-Sklodowska University
- Lublin 20-031
- Poland
| | - Orest Pizio
- Instituto de Química
- Universidad Nacional Autónoma de México
- Circuito Exterior
- Mexico
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4
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Ojeda-Mendoza GJ, Moncho-Jordá A, González-Mozuelos P, Haro-Pérez C, Rojas-Ochoa LF. Evidence of electrostatic-enhanced depletion attraction in the structural properties and phase behavior of binary charged colloidal suspensions. SOFT MATTER 2018; 14:1355-1364. [PMID: 29379934 DOI: 10.1039/c7sm02220d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
In this paper we study the structure and phase behavior of binary mixtures of charged particles at low ionic strength. Due to the large size asymmetry between both species, light scattering measurements give us access only to the partial static structure factor that corresponds to the big particles. We observe that the addition of small charged colloids produces a decrease of the main peak of the measured static structure factor and a shift to larger scattering vector values. This finding is in agreement with theory based on integral equations with the Hypernetted-Chain Closure (HNC) relation. The effective interaction between two big particles due to the presence of small particles is obtained by a HNC inversion scheme and used in numerical simulations that adequately reproduce the experiments. We find that the presence of small particles induces an electrostatic depletion screening among the big colloids, creating around them an exclusion zone for the small charged colloids greater than that caused in the case of neutral small colloids, which in turn augments the depletion effect.
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Affiliation(s)
- G J Ojeda-Mendoza
- Departamento de Física, CINVESTAV-IPN, Av. Instituto Politécnico Nacional 2508, 07360 Ciudad de México, Mexico.
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Mkanya A, Pellicane G, Pini D, Caccamo C. Theory and computer simulation of hard-core Yukawa mixtures: thermodynamical, structural and phase coexistence properties. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:365102. [PMID: 28661404 DOI: 10.1088/1361-648x/aa7c8b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report extensive calculations, based on the modified hypernetted chain (MHNC) theory, on the hierarchical reference theory (HRT), and on Monte Carlo simulations, of thermodynamical, structural and phase coexistence properties of symmetric binary hard-core Yukawa mixtures (HCYM) with attractive interactions at equal species concentration. The obtained results are throughout compared with those available in the literature for the same systems. It turns out that the MHNC predictions for thermodynamic and structural quantities are quite accurate in comparison with the MC data. The HRT is equally accurate for thermodynamics, and slightly less accurate for structure. Liquid-vapor (LV) and liquid-liquid (LL) consolute coexistence conditions as emerging from simulations, are also highly satisfactorily reproduced by both the MHNC and HRT for relatively long ranged potentials. When the potential range reduces, the MHNC faces problems in determining the LV binodal line; however, the LL consolute line and the critical end point (CEP) temperature and density turn out to be still satisfactorily predicted within this theory. The HRT also predicts with good accuracy the CEP position. The possibility of employing liquid state theories HCYM for the purpose of reliably determining phase equilibria in multicomponent colloidal fluids of current technological interest, is discussed.
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Affiliation(s)
- Anele Mkanya
- School of Chemistry and Physics, University of Kwazulu-Natal, Private Bag X01, Scottsville 3209, Pietermaritzburg, South Africa
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Pellicane G, Caccamo C. A thermodynamic self-consistent theory of asymmetric hard-core Yukawa mixtures. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:414009. [PMID: 27545096 DOI: 10.1088/0953-8984/28/41/414009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We perform structural and thermodynamic calculations in the framework of the modified hypernetted chain (MHNC) integral equation closure to the Ornstein-Zernike equation for binary mixtures of size-different particles interacting with hard-core Yukawa pair potentials. We use the Percus-Yevick (PY) bridge functions of a binary mixture of hard-sphere (HSM) particles. The hard-sphere diameters of the PY bridge functions of the HSM system are adjusted so to achieve thermodynamic consistency between the virial and compressibility equations of state. We show the benefit of thermodynamic consistency by comparing the MHNC results with the available computer simulation data reported in the literature, and we demonstrate that the self-consistent thermodynamic theory provides a better reproduction of the simulation data over other microscopic theories.
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Affiliation(s)
- Giuseppe Pellicane
- School of Chemistry and Physics, University of Kwazulu-Natal, Private Bag X01, Scottsville 3209, Pietermaritzburg, South Africa. National Institute for Theoretical Physics (NITheP), KZN Node, Pietermaritzburg, South Africa
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7
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Schöll-Paschinger E, Valadez-Pérez NE, Benavides AL, Castañeda-Priego R. Phase behavior of the modified-Yukawa fluid and its sticky limit. J Chem Phys 2013; 139:184902. [DOI: 10.1063/1.4827936] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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Valadez-Pérez NE, Benavides AL, Schöll-Paschinger E, Castañeda-Priego R. Phase behavior of colloids and proteins in aqueous suspensions: Theory and computer simulations. J Chem Phys 2012; 137:084905. [PMID: 22938263 DOI: 10.1063/1.4747193] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Affiliation(s)
- Néstor E Valadez-Pérez
- División de Ciencias e Ingenierías, Campus León, Universidad de Guanajuato, Loma del Bosque 103, Lomas del Campestre, 37150 León, Guanajuato, Mexico
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Gazzillo D, Giacometti A. Effects of polydispersity and anisotropy in colloidal and protein solutions: an integral equation approach. Interdiscip Sci 2011; 3:251-265. [PMID: 22179759 DOI: 10.1007/s12539-011-0106-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2010] [Revised: 04/06/2011] [Accepted: 04/06/2011] [Indexed: 05/31/2023]
Abstract
Application of integral equation theory to complex fluids is reviewed, with particular emphasis to the effects of polydispersity and anisotropy on their structural and thermodynamic properties. Both analytical and numerical solutions of integral equations are discussed within the context of a set of minimal potential models that have been widely used in the literature. While other popular theoretical tools, such as numerical simulations and density functional theory, are superior for quantitative and accurate predictions, we argue that integral equation theory still provides, as in simple fluids, an invaluable technique that is able to capture the main essential features of a complex system, at a much lower computational cost. In addition, it can provide a detailed description of the angular dependence in arbitrary frame, unlike numerical simulations where this information is frequently hampered by insufficient statistics. Applications to colloidal mixtures, globular proteins and patchy colloids are discussed, within a unified framework.
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Affiliation(s)
- Domenico Gazzillo
- Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari Venezia, Venezia, Italy.
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Pizio O, Sokołowski S, Sokołowska Z. Phase behavior of binary symmetric mixtures in pillared slit-like pores: A density functional approach. J Chem Phys 2011; 134:214702. [DOI: 10.1063/1.3597773] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
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11
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Caillol JM, Verso FL, Schöll-Paschinger E, Weis JJ. Liquid–vapour transition of the long range Yukawa fluid. Mol Phys 2010. [DOI: 10.1080/00268970701420524] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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12
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Schwanzer DF, Coslovich D, Kurzidim J, Kahl G. Effects of porous confinement on the structural properties of the Gaussian core model. Mol Phys 2010. [DOI: 10.1080/00268970902845321] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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13
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Schöll-Paschinger E, Dellago C. Demixing of a binary symmetric mixture studied with transition path sampling. J Chem Phys 2010; 133:104505. [DOI: 10.1063/1.3486173] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Betancourt-Cárdenas F, Galicia-Luna L, Benavides A, Ramírez J, Schöll-Paschinger E. Thermodynamics of a long-range triangle-well fluid. Mol Phys 2008. [DOI: 10.1080/00268970701832397] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Yu YX, Jin L. Thermodynamic and structural properties of mixed colloids represented by a hard-core two-Yukawa mixture model fluid: Monte Carlo simulations and an analytical theory. J Chem Phys 2008; 128:014901. [DOI: 10.1063/1.2815802] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [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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Köfinger J, Wilding NB, Kahl G. Phase behavior of a symmetrical binary fluid mixture. J Chem Phys 2006; 125:234503. [PMID: 17190563 DOI: 10.1063/1.2393241] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have investigated the phase behavior of a symmetrical binary fluid mixture for the situation where the chemical potentials mu(1) and mu(2) of the two species differ. Attention is focused on the set of interparticle interaction strengths for which, when mu(1)=mu(2), the phase diagram exhibits both a liquid-vapor critical point and a tricritical point. The corresponding phase behavior for the case mu(1) not equalmu(2) is investigated via integral-equation theory calculations within the mean spherical approximation and grand canonical Monte Carlo (GCMC) simulations. We find that two possible subtypes of phase behavior can occur, these being distinguished by the relationship between the triple lines in the full phase diagram in the space of temperature, density, and concentration. We present the detailed form of the phase diagram for both subtypes and compare with the results from GCMC simulations, finding good overall agreement. The scenario via which one subtype evolves into the other is also studied, revealing interesting features.
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Affiliation(s)
- Jürgen Köfinger
- Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Wien, Austria
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Schöll-Paschinger E, Reiner A. Soft core thermodynamics from self-consistent hard core fluids. J Chem Phys 2006; 125:164503. [PMID: 17092101 DOI: 10.1063/1.2363385] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In an effort to generalize the self-consistent Ornstein-Zernike approximation (SCOZA)-an accurate liquid state theory that has been restricted so far to hard core systems-to arbitrary soft core systems we study a combination of SCOZA with a recently developed perturbation theory. The latter was constructed by Ben-Amotz and Stell [J. Phys. Chem. B 108, 6877 (2004)] as a reformulation of the Weeks-Chandler-Andersen [J. Chem. Phys. 54, 5237 (1971)] perturbation theory directly in terms of an arbitrary hard sphere reference system. We investigate the accuracy of the combined approach for the Lennard-Jones fluid in comparison with simulation data and pure perturbation theory predictions and determine the dependence of the thermodynamic properties and the phase behavior on the choice of the effective hard core diameter of the reference system.
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Patra CN, Smith GD. A self-consistent density-functional approach to the structure of nonuniform binary hard-core Yukawa mixtures. J Chem Phys 2006; 124:16101. [PMID: 16409061 DOI: 10.1063/1.2138690] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Chandra N Patra
- Department of Materials Science, University of Utah, 122 South Central Campus Drive, Room 304, Salt Lake City, UT 84112, USA.
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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.
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Diaz-Herrera E, Ramirez-Santiago G, Moreno-Razo JA. Phase and interfacial behavior of partially miscible symmetric Lennard-Jones binary mixtures. J Chem Phys 2005; 123:184507. [PMID: 16292914 DOI: 10.1063/1.2102787] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have carried out extensive equilibrium molecular-dynamics simulations to study quantitatively the topology of the temperature versus density phase diagrams and related interfacial phenomena in a partially miscible symmetric Lennard-Jones binary mixture. The topological features are studied as a function of miscibility parameter, alpha = epsilonAB/epsilonAA. Here epsilonAA = epsilonBB and epsilonAB stand for the parameters related to the attractive part of the intermolecular interactions for similar and dissimilar particles, respectively. When the miscibility varies in the range 0 < alpha < 1, a continuous critical line of consolute points Tcons(rho)--critical demixing transition line--appears. This line intersects the liquid-vapor coexistence curve at different positions depending on the values of alpha, yielding mainly three different topologies for the phase diagrams. These results are in qualitative agreement to those found previously for square-well and hard-core Yukawa binary mixtures. The main contributions of the present paper are (i) a quantitative analysis of the phase behavior and (ii) a detailed study of the liquid-liquid interfacial and liquid-vapor surface tensions, as function of temperature and miscibility as well as its relationship to the topological features of the phase diagrams.
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Affiliation(s)
- Enrique Diaz-Herrera
- Departamento de Fisica, Universidad Autonoma Metropolitana-Iztapalapa, Apdo. Postal 55-534, Mexico 09340, DF, Mexico
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Schöll-Paschinger E, Kahl G. Type-IV phase behavior in fluids with an internal degree of freedom. J Chem Phys 2005; 123:134508. [PMID: 16223315 DOI: 10.1063/1.2042447] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We have identified a fourth archetype of phase diagram in binary symmetrical mixtures, which is encountered when the ratio of the interaction between the unlike and the like particles is sufficiently small. This type of phase diagram is characterized by the fact that the lambda line (i.e., the line of the second-order demixing transition) intersects the first-order liquid-vapor curve at densities smaller than the liquid-vapor critical density.
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Giacometti A, Gazzillo D, Pastore G, Das TK. Numerical study of a binary Yukawa model in regimes characteristic of globular proteins in solutions. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2005; 71:031108. [PMID: 15903407 DOI: 10.1103/physreve.71.031108] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2004] [Indexed: 05/02/2023]
Abstract
The main goal of this paper is to assess the limits of validity, in the regime of low concentration and strong Coulomb coupling (high molecular charges), of a simple perturbative approximation to the radial distribution functions (RDF's), based upon a low-density expansion of the potential of mean force and proposed to describe protein-protein interactions in a recent small-angle-scattering (SAS) experimental study. A highly simplified Yukawa (screened Coulomb) model of monomers and dimers of a charged globular protein (beta-lactoglobulin) in solution is considered. We test the accuracy of the RDF approximation, as a necessary complementary part of the previous experimental investigation, by comparison with the fluid structure predicted by approximate integral equations and exact Monte Carlo (MC) simulations. In the MC calculations, an Ewald construction for Yukawa potentials has been used to take into account the long-range part of the interactions in the weakly screened cases. Our results confirm that the perturbative first-order approximation is valid for this system even at strong Coulomb coupling, provided that the screening is not too weak (i.e., for Debye length smaller than monomer radius). A comparison of the MC results with integral equation calculations shows that both the hypernetted-chain (HNC) and Percus-Yevick closures have a satisfactory behavior under these regimes, with the HNC being superior throughout. The relevance of our findings for interpreting SAS results is also discussed.
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Affiliation(s)
- Achille Giacometti
- Istituto Nazionale per la Fisica della Materia and Dipartimento di Chimica Fisica, Università di Venezia, Italy
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