1
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Lindenberg EK, Patey GN. Melting point trends and solid phase behaviors of model salts with ion size asymmetry and distributed cation charge. J Chem Phys 2015; 143:024508. [DOI: 10.1063/1.4923344] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- E. K. Lindenberg
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - G. N. Patey
- Department of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
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2
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Frischknecht AL, Halligan DO, Parks ML. Electrical double layers and differential capacitance in molten salts from density functional theory. J Chem Phys 2014; 141:054708. [DOI: 10.1063/1.4891368] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | - Deaglan O. Halligan
- Department of Computer Science, Purdue University, West Lafayette, Indiana 47907, USA
| | - Michael L. Parks
- Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
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3
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Kłos J, Lamperski S. Monte Carlo study of molten salt with charge asymmetry near the electrode surface. J Chem Phys 2014; 140:054703. [PMID: 24511964 DOI: 10.1063/1.4862998] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Results of the Monte Carlo simulation of the electrode | molten salt or ionic liquid interface are reported. The system investigated is approximated by the primitive model of electrolyte being in contact with a charged hard wall. Ions differ in charges, namely anions are divalent and cations are monovalent but they are of the same diameter d = 400 pm. The temperature analysis of heat capacity at a constant volume Cv and the anion radial distribution function, g2-/2-, allowed the choice of temperature of the study, which is T = 2800 K and corresponds to T(*) = 0.34 (definition of reduced temperature T(*) in text). The differential capacitance curve of the interface with the molten salt or ionic liquid at c = 5.79 M has a distorted bell shape. It is shown that with increasing electrolyte concentration from c = 0.4 to 5 M the differential capacitance curves undergo transition from U shape to bell shape.
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Affiliation(s)
- Jacek Kłos
- Department of Physical Chemistry, Faculty of Chemistry, A. Mickiewicz University of Poznań, ul. Umultowska 89b, 61-614 Poznań, Poland
| | - Stanisław Lamperski
- Department of Physical Chemistry, Faculty of Chemistry, A. Mickiewicz University of Poznań, ul. Umultowska 89b, 61-614 Poznań, Poland
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4
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Lamperski S, Waśko M, Henderson D. Solidification of the charged hard-sphere fluid. MOLECULAR SIMULATION 2013. [DOI: 10.1080/08927022.2013.773432] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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5
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Rane KS, Errington JR. Using Monte Carlo Simulation to Compute Liquid–Vapor Saturation Properties of Ionic Liquids. J Phys Chem B 2013; 117:8018-30. [DOI: 10.1021/jp404207x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Kaustubh S. Rane
- Department of Chemical
and Biological Engineering, University at Buffalo, The State University of New
York, Buffalo, New York 14260-4200, United States
| | - Jeffrey R. Errington
- Department of Chemical
and Biological Engineering, University at Buffalo, The State University of New
York, Buffalo, New York 14260-4200, United States
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6
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Aragones JL, Sanz E, Valeriani C, Vega C. Calculation of the melting point of alkali halides by means of computer simulations. J Chem Phys 2012; 137:104507. [DOI: 10.1063/1.4745205] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
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7
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Patsahan O, Ciach A. Spatial inhomogeneities in ionic liquids, charged proteins, and charge stabilized colloids from collective variables theory. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 86:031504. [PMID: 23030920 DOI: 10.1103/physreve.86.031504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Indexed: 06/01/2023]
Abstract
Effects of size and charge asymmetry between oppositely charged ions or particles on spatial inhomogeneities are studied for a large range of charge and size ratios. We perform a stability analysis of the primitive model of ionic systems with respect to periodic ordering using the collective variables-based theory. We extend previous studies [Ciach et al., Phys. Rev. E 75, 051505 (2007)] in several ways. First, we employ a nonlocal approximation for the reference hard-sphere fluid which leads to the Percus-Yevick pair direct correlation functions for the uniform case. Second, we use the Weeks-Chandler-Anderson regularization scheme for the Coulomb potential inside the hard core. We determine the relevant order parameter connected with the periodic ordering and analyze the character of the dominant fluctuations along the λ lines. We show that the above-mentioned modifications produce large quantitative and partly qualitative changes in the phase diagrams obtained previously. We discuss possible scenarios of the periodic ordering for the whole range of size and charge ratios of the two ionic species, covering electrolytes, ionic liquids, charged globular proteins or nanoparticles in aqueous solutions, and charge-stabilized colloids.
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Affiliation(s)
- O Patsahan
- Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine, 1 Svientsitskii Str., 79011 Lviv, Ukraine
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8
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Bastea S. Thermodynamics and diffusion in size-symmetric and asymmetric dense electrolytes. J Chem Phys 2011; 135:084515. [PMID: 21895207 DOI: 10.1063/1.3629782] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
MD simulation results for model size-symmetric and asymmetric electrolytes at high densities and temperatures (well outside the liquid-gas coexistence region) are generated and analyzed focusing on thermodynamic and diffusion properties. An extension of the mean spherical approximation for electrolytes originally derived for charged hard sphere fluids is adapted to these systems by exploiting the separation of short range and Coulomb interaction contributions intrinsic to these theoretical models and is found to perform well for predicting equation of state quantities. The diffusion coefficients of these electrolytes can also be reasonably well predicted using entropy scaling ideas suitably adapted to charged systems and mixtures. Thus, this approach may provide an avenue for studying dense electrolytes or complex molecular systems containing charged species at high pressures and temperatures.
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Affiliation(s)
- Sorin Bastea
- Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, California 94550, USA.
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9
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Troncoso J, Navia P, Romaní L, Bessieres D, Lafitte T. On the isobaric thermal expansivity of liquids. J Chem Phys 2011; 134:094502. [PMID: 21384980 DOI: 10.1063/1.3549828] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The temperature and pressure dependence of isobaric thermal expansivity, α(p), in liquids is discussed in this paper. Reported literature data allow general trends in this property that are consistent with experimental evidence to be established. Thus, a negative pressure dependence is to be expected except around the critical point. On the other hand, α(p) exhibits broad regions of negative and positive temperature dependence in the (T, p) plane depending on the nature of the particular liquid. These trends are rationalized here in terms of various molecular-based equations of state. The analysis of the Lennard-Jones, hard sphere square well and restricted primitive model equations allows understanding the differences in the α(p) behavior between liquids of diverse chemical nature (polar, nonpolar, and ionic): broader regions of negative temperature and positive pressure dependencies are obtained for liquids characterized by larger ranges of the interparticle potential. Also, using the statistical associating fluid theory (SAFT) allowed the behavior of more complex systems (basically, those potentially involving chain and association effects) to be described. The effect of chain length is rather simple: increasing it is apparently equivalent to raise the interaction range. By contrast, association presents a quite complex effect on α(p), which comes from a balance between the dispersive and associative parts of the interaction potential. Thus, if SAFT parameters are adjusted to obtain low association ability, α(p) is affected by each mechanism at clearly separate regions, one at low temperature, due to association, and the other to dispersive forces, which has its origin in fluctuations related with vapor-liquid transition.
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Affiliation(s)
- Jacobo Troncoso
- Departamento de Física Aplicada, Universidad de Vigo, Campus de As Lagoas, 32004 Ourense, Spain
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10
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Bier M, van Roij R, Dijkstra M. Phase diagrams of binary mixtures of oppositely charged colloids. J Chem Phys 2010; 133:124501. [DOI: 10.1063/1.3479883] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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11
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Janeček J, Netz RR. Effective screening length and quasiuniversality for the restricted primitive model of an electrolyte solution. J Chem Phys 2009; 130:074502. [DOI: 10.1063/1.3058777] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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Hynninen AP, Panagiotopoulos AZ. Simulations of phase transitions and free energies for ionic systems. Mol Phys 2008. [DOI: 10.1080/00268970802112160] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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13
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Caballero JB, Noya EG, Vega C. Complete phase behavior of the symmetrical colloidal electrolyte. J Chem Phys 2008; 127:244910. [PMID: 18163709 DOI: 10.1063/1.2816707] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We computed the complete phase diagram of the symmetrical colloidal electrolyte by means of Monte Carlo simulations. Thermodynamic integration, together with the Einstein-crystal method, and Gibbs-Duhem integration were used to calculate the equilibrium phase behavior. The system was modeled via the linear screening theory, where the electrostatic interactions are screened by the presence of salt in the medium, characterized by the inverse Debye length, kappa (in this work kappasigma=6). Our results show that at high temperature, the hard-sphere picture is recovered, i.e., the liquid crystallizes into a fcc crystal that does not exhibit charge ordering. In the low temperature region, the liquid freezes into a CsCl structure because charge correlations enhance the pairing between oppositely charged colloids, making the liquid-gas transition metastable with respect to crystallization. Upon increasing density, the CsCl solid transforms into a CuAu-like crystal and this one, in turn, transforms into a tetragonal ordered crystal near close packing. Finally, we have studied the ordered-disordered transitions finding three triple points where the phases in coexistence are liquid-CsCl-disordered fcc, CsCl-CuAu-disordered fcc, and CuAu-tetragonal-disordered fcc.
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Affiliation(s)
- José B Caballero
- Department of Applied Physics, University of Almeria, E-04120 Almeria, Spain.
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14
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Avendaño C, Gil-Villegas A, González-Tovar E. Computer simulation of charged hard spherocylinders. J Chem Phys 2008; 128:044506. [DOI: 10.1063/1.2823736] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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15
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Zhou S. Solid phase thermodynamic perturbation theory: Test and application to multiple solid phases. J Chem Phys 2007; 127:084512. [PMID: 17764274 DOI: 10.1063/1.2756836] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A simple procedure for the determination of hard sphere (HS) solid phase radial distribution function (rdf) is proposed, which, thanks to its physical foundation, allows for extension to other crystal structures besides the fcc structure. The validity of the procedure is confirmed by comparing (1) the predicted HS solid phase rdf's with corresponding simulation data and (2) the predicted non-HS solid phase Helmholtz free energy by the present solid phase first-order thermodynamic perturbation theory (TPT) whose numerical implementation depends on the HS solid phase rdf's as input, with the corresponding predictions also by the first-order TPT but the required HS solid phase rdf is given by an "exact" empirical simulation-fitted formula. The present solid phase first-order TPT predicts isostructural fcc-fcc transition of a hard core attractive Yukawa fluid, in very satisfactory agreement with the corresponding simulation data and is far more accurate than a recent thermodynamically consistent density functional perturbation theory. The present solid phase first-order TPT is employed to investigate multiple solid phases. It is found that a short-ranged potential, even if it is continuous and differentiable or is superimposed over a long-ranged potential, is sufficient to induce the multiple solid phases. When the potential range is short enough, not only isostructural fcc-fcc transition but also isostructural bcc-bcc transition, simple cubic (sc)-sc transition, or even fcc-bcc, fcc-sc, and bcc-sc transitions can be induced. Even triple point involving three solid phases becomes possible. The multiple solid phases can be stable or metastable depending on the potential parameters.
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Affiliation(s)
- Shiqi Zhou
- School of Physics Science and Technology, Central South University, Changsha, Hunan 410083, People's Republic of China.
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16
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17
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García Fernández R, Abascal JLF, Vega C. The melting point of ice Ih for common water models calculated from direct coexistence of the solid-liquid interface. J Chem Phys 2006; 124:144506. [PMID: 16626213 DOI: 10.1063/1.2183308] [Citation(s) in RCA: 283] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In this work we present an implementation for the calculation of the melting point of ice I(h) from direct coexistence of the solid-liquid interface. We use molecular dynamics simulations of boxes containing liquid water and ice in contact. The implementation is based on the analysis of the evolution of the total energy along NpT simulations at different temperatures. We report the calculation of the melting point of ice I(h) at 1 bar for seven water models: SPC/E, TIP4P, TIP4P-Ew, TIP4P/ice, TIP4P/2005, TIP5P, and TIP5P-E. The results for the melting temperature from the direct coexistence simulations of this work are in agreement (within the statistical uncertainty) with those obtained previously by us from free energy calculations. By taking into account the results of this work and those of our free energy calculations, recommended values of the melting point of ice I(h) at 1 bar for the above mentioned water models are provided.
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Affiliation(s)
- Ramón García Fernández
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense, 28040 Madrid, Spain
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18
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Fortini A, Hynninen AP, Dijkstra M. Gas-liquid phase separation in oppositely charged colloids: Stability and interfacial tension. J Chem Phys 2006; 125:094502. [PMID: 16965092 DOI: 10.1063/1.2335453] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We study the phase behavior and the interfacial tension of the screened Coulomb (Yukawa) restricted primitive model (YRPM) of oppositely charged hard spheres with diameter sigma using Monte Carlo simulations. We determine the gas-liquid and gas-solid phase transitions using free energy calculations and grand-canonical Monte Carlo simulations for varying inverse Debye screening length kappa. We find that the gas-liquid phase separation is stable for kappasigma<or=4, and that the critical temperature decreases upon increasing the screening of the interaction (decreasing the range of the interaction). In addition, we determine the gas-liquid interfacial tension using grand-canonical Monte Carlo simulations. The interfacial tension decreases upon increasing the range of the interaction. In particular, we find that simple scaling can be used to relate the interfacial tension of the YRPM to that of the restricted primitive model, where particles interact with bare Coulomb interactions.
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Affiliation(s)
- Andrea Fortini
- Soft Condensed Matter, Utrecht University, Princetonplein 5, 3584CC Utrecht, The Netherlands.
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19
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Diehl A, Panagiotopoulos AZ. Phase behavior of the lattice restricted primitive model with nearest neighbor exclusion. J Chem Phys 2006; 124:194509. [PMID: 16729827 DOI: 10.1063/1.2192498] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The global phase behavior of the lattice restricted primitive model with nearest neighbor exclusion has been studied by grand canonical Monte Carlo simulations. The phase diagram is dominated by a fluid (or charge-disordered solid) to charge-ordered solid transition that terminates at the maximum density rho*(max)= sqrt 2 and reduced temperature T* approximately equal to 0.29. At that point, there is a first-order phase transition between two phases of the same density, one charge-ordered, and the other charge-disordered. The liquid-vapor transition for the model is metastable, lying entirely within the fluid-solid phase envelope.
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Affiliation(s)
- Alexandre Diehl
- Departamento de Física, Universidade Federal do Ceará, Caixa Postal 6030, CEP 60455-760, Fortaleza, CE, Brazil
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20
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Avendaño C, Gil-Villegas A. Monte Carlo simulations of primitive models for ionic systems using the Wolf method. Mol Phys 2006. [DOI: 10.1080/00268970600551155] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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21
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Hynninen AP, Leunissen ME, van Blaaderen A, Dijkstra M. CuAu structure in the restricted primitive model and oppositely charged colloids. PHYSICAL REVIEW LETTERS 2006; 96:018303. [PMID: 16486528 DOI: 10.1103/physrevlett.96.018303] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2005] [Indexed: 05/06/2023]
Abstract
We study the phase behavior of oppositely charged equal-size hard spheres both theoretically and experimentally, using Monte Carlo simulations and confocal microscopy. In the simulations, two systems are considered: the restricted primitive model (RPM) and a system of screened Coulomb particles. We construct the phase diagrams of both systems by computer simulations and predict a novel solid phase that has the CuAu structure. In addition, the CuAu structure is observed experimentally in a system of oppositely charged colloids. The qualitative agreement between the RPM, the screened Coulomb system, and the experiments shows that colloids form a suitable model system to study phase behavior in ionic systems.
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Affiliation(s)
- A-P Hynninen
- Soft Condensed Matter, Debye Institute, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands
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22
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Bartlett P, Campbell AI. Three-dimensional binary superlattices of oppositely charged colloids. PHYSICAL REVIEW LETTERS 2005; 95:128302. [PMID: 16197118 DOI: 10.1103/physrevlett.95.128302] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2005] [Indexed: 05/04/2023]
Abstract
We report the equilibrium self-assembly of binary crystals of oppositely charged colloidal microspheres at high density. By varying the magnitude of the charge on near equal-sized spheres we show that the structure of the binary crystal may be switched between face-centered cubic, cesium chloride, and sodium chloride. We interpret these transformations in terms of a competition between entropic and Coulombic forces.
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Affiliation(s)
- Paul Bartlett
- School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
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23
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González-Melchor M, Bresme F, Alejandre J. Molecular dynamics simulations of the surface tension of ionic liquids. J Chem Phys 2005; 122:104710. [PMID: 15836348 DOI: 10.1063/1.1861878] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We report molecular dynamics computer simulations of the surface tension and interfacial thickness of ionic liquid-vapor interfaces modeled with a soft core primitive model potential. We find that the surface tension shows an anomalous oscillatory behavior with interfacial area. This observation is discussed in terms of finite size effects introduced by the periodic boundary conditions employed in computer simulations. Otherwise we show that the thickness of the liquid-vapor interface increases with surface area as predicted by the capillary wave theory. Data on the surface tension of size-asymmetric ionic liquids are reported and compared with experimental data of molten salts. Our data suggest that the surface tensions of size-asymmetric ionic liquids do not follow a corresponding states law.
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24
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Hanassab S, VanderNoot† T. Monte Carlo Simulations of Primitive Model (PM) Electrolytes in Non-Euclidean Geometries. MOLECULAR SIMULATION 2004. [DOI: 10.1080/08927020410001662624] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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25
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Zhou S. Formally Exact Truncated Nonuniform Excess Helmholtz Free Energy Density Functional: Test and Application. J Phys Chem B 2004. [DOI: 10.1021/jp0366318] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shiqi Zhou
- Research Institute of Modern Statistical Mechanics, Zhuzhou Institute of Technology, Wenhua Road, Zhuzhou City, 412008, P. R. China
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26
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Abascal JLF, Vega C, McBride C, Bresme F. Characterization of the order-disorder transition of a charged hard-sphere model. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2003; 68:052501. [PMID: 14682824 DOI: 10.1103/physreve.68.052501] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2003] [Indexed: 05/24/2023]
Abstract
Monte Carlo simulations at constant pressure are used to characterize the structure of the restricted primitive model in the tetragonal-ordered solid phase. A method to estimate the location of the order-disorder transition and the densities of the coexistence phases is discussed. The results support the weakly first-order character of the transition.
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Affiliation(s)
- José L F Abascal
- Departamento de Química-Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, E-28040 Madrid, Spain
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27
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Vega C, Abascal JLF, McBride C, Bresme F. The fluid–solid equilibrium for a charged hard sphere model revisited. J Chem Phys 2003. [DOI: 10.1063/1.1576374] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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28
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Vega C, McBride C, de Miguel E, Blas FJ, Galindo A. The phase diagram of the two center Lennard-Jones model as obtained from computer simulation and Wertheim’s thermodynamic perturbation theory. J Chem Phys 2003. [DOI: 10.1063/1.1572811] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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29
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González-Melchor M, Alejandre J, Bresme F. Surface tension of the restrictive primitive model for ionic liquids. PHYSICAL REVIEW LETTERS 2003; 90:135506. [PMID: 12689306 DOI: 10.1103/physrevlett.90.135506] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2002] [Indexed: 05/24/2023]
Abstract
Hybrid molecular dynamics and Monte Carlo simulations are performed to study the liquid-vapor interface of the restricted primitive model (RPM) of ionic fluids. We report for the first time simulation results of the surface tension associated to this interface. The RPM accurately predicts experimental surface tensions of ionic salts and good agreement with theoretical predictions that include the idea of ion association is found. The simulation results indicate that the structure of an ionic liquid-vapor interface is rather rough. This is reflected in the interfacial thickness, larger than that observed in simple fluids and water.
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Affiliation(s)
- Minerva González-Melchor
- Departamento de Física, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, 07000 México Distrito Federal, México
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30
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31
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Guillot B, Guissani Y. Chemical reactivity and phase behavior of NH4Cl by molecular dynamics simulations. I. Solid–solid and solid–fluid equilibria. J Chem Phys 2002. [DOI: 10.1063/1.1431591] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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32
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Almarza NG, Enciso E. Critical behavior of ionic solids. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2001; 64:042501. [PMID: 11690066 DOI: 10.1103/physreve.64.042501] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2001] [Indexed: 05/23/2023]
Abstract
Phase transitions of lattice models of ionic crystals are studied by computer simulation. The nature of order-disorder transitions on different crystal structures is established and compared with the behavior of related Ising models. It is found that for both, continuous and first order transitions the basic features seem to be similar to those of Ising systems.
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Affiliation(s)
- N G Almarza
- Departamento de Química Física I, Facultad de Ciencias Químicas, Universidad Complutense, E-28040 Madrid, Spain
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33
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Bresme F, Vega C, Abascal JL. Order-disorder transition in the solid phase of a charged hard sphere model. PHYSICAL REVIEW LETTERS 2000; 85:3217-3220. [PMID: 11019305 DOI: 10.1103/physrevlett.85.3217] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2000] [Indexed: 05/23/2023]
Abstract
We investigate the solid phases of the restricted primitive model (RPM). Monte Carlo simulations show the existence of an order-disorder transition from a substitutionally disordered face centered cubic lattice (fcc) to a new ordered fcc structure which is proposed as the ground state of the RPM at the close packing density. Our results suggest that the new phase might turn out in a new triple point in the RPM phase diagram involving three solid phases: CsCl, fcc ordered and fcc disordered structures. The order-disorder transition is also studied using the cell theory. The theory shows good agreement with the simulation results and suggests that the transition is weakly first order.
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Affiliation(s)
- F Bresme
- Department of Chemistry, Imperial College of Science, Technology and Medicine, Exhibition Road, London SW7 2AY, United Kingdom
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Vega C, MacDowell LG, López-Rodríguez A. Excess properties of mixtures of n-alkanes from perturbation theory. J Chem Phys 1999. [DOI: 10.1063/1.479599] [Citation(s) in RCA: 7] [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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Vega C, Monson PA. Solid–fluid equilibrium for a molecular model with short ranged directional forces. J Chem Phys 1998. [DOI: 10.1063/1.477660] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Vlot MJ, Huitema HEA, de Vooys A, van der Eerden JP. Crystal structures of symmetric Lennard-Jones mixtures. J Chem Phys 1997. [DOI: 10.1063/1.474775] [Citation(s) in RCA: 22] [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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