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Sanchez-Burgos I, Espinosa JR. Direct Calculation of the Interfacial Free Energy between NaCl Crystal and Its Aqueous Solution at the Solubility Limit. PHYSICAL REVIEW LETTERS 2023; 130:118001. [PMID: 37001068 DOI: 10.1103/physrevlett.130.118001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 11/07/2022] [Accepted: 01/30/2023] [Indexed: 06/19/2023]
Abstract
Salty water is the most abundant electrolyte aqueous mixture on Earth, however, very little is known about the NaCl-saturated solution interfacial free energy (γ_{s}). Here, we provide the first direct estimation of γ_{s} for several NaCl crystallographic planes by means of the mold integration technique, a highly efficient computational method to evaluate interfacial free energies with anisotropic crystal resolution. Making use of the JC-SPC/E model, one of the most benchmarked force fields for NaCl water solutions, we measure γ_{s} of four different crystal planes, (100), (110), (111), and (112[over ¯]) with the saturated solution at normal conditions. We find high anisotropy between the different crystal orientations with values ranging from 100 to 150 mJ m^{-2}, and the average value of the distinct planes being γ[over ¯]_{s}=137(20) mJ m^{-2}. This value for the coexistence interfacial free energy is in reasonable agreement with previous extrapolations from nucleation studies. Our Letter represents a milestone in the computational calculation of interfacial free energies between ionic crystals and aqueous solutions.
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Affiliation(s)
- Ignacio Sanchez-Burgos
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, United Kingdom
| | - Jorge R Espinosa
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, United Kingdom
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2
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Yeandel S, Freeman C, Harding J. A General Method for Calculating Solid/Liquid Interfacial Free Energies from Atomistic Simulations: Application to CaSO 4.xH 2O. J Chem Phys 2022; 157:084117. [DOI: 10.1063/5.0095130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present a general method for computing interfacial free energies from atomistic simulations, which is particularly suitable for solid/liquid interfaces. Our method uses an Einstein crystal as a universal reference state and is more flexible than previous approaches. Surfaces with dipoles, complex reconstructions, and partially dissolved species are all easily accommodated within the framework. It may also be extended to calculating the relative free energies of different phases and other types of defect. We have applied our method to interfaces of bassanite and gypsum with water and obtained interfacial free energies of the order of 0.15 J/m2, of which approximately 50 % is due to entropic contributions. Our calculations of the interfacial free energy of NaCl with water obtained a value of 0.13 J/m2 of which only 19 % is from entropic contributions. We have also predicted equilibrium morphologies for bassanite and gypsum that compare well with experiments and previous calculations.
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Affiliation(s)
- Stephen Yeandel
- Materials Science and Engineering, The University of Sheffield Department of Materials Science and Engineering, United Kingdom
| | - Colin Freeman
- Materials Science and Engineering, University of Sheffield, United Kingdom
| | - John Harding
- Materials Science and Engineering, University of Sheffield Department of Materials Science and Engineering, United Kingdom
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Sanchez-Burgos I, Sanz E, Vega C, Espinosa JR. Fcc vs. hcp competition in colloidal hard-sphere nucleation: on their relative stability, interfacial free energy and nucleation rate. Phys Chem Chem Phys 2021; 23:19611-19626. [PMID: 34524277 DOI: 10.1039/d1cp01784e] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hard-sphere crystallization has been widely investigated over the last six decades by means of colloidal suspensions and numerical methods. However, some aspects of its nucleation behaviour are still under debate. Here, we provide a detailed computational characterisation of the polymorphic nucleation competition between the face-centered cubic (fcc) and the hexagonal-close packed (hcp) hard-sphere crystal phases. By means of several state-of-the-art simulation techniques, we evaluate the melting pressure, chemical potential difference, interfacial free energy and nucleation rate of these two polymorphs, as well as of a random stacking mixture of both crystals. Our results highlight that, despite the fact that both polymorphs have very similar stability, the interfacial free energy of the hcp phase could be marginally higher than that of the fcc solid, which in consequence, mildly decreases its propensity to nucleate from the liquid compared to the fcc phase. Moreover, we analyse the abundance of each polymorph in grown crystals from different types of inserted nuclei: fcc, hcp and stacking disordered fcc/hcp seeds, as well as from those spontaneously emerged from brute force simulations. We find that post-critical crystals fundamentally grow maintaining the polymorphic structure of the critical nucleus, at least until moderately large sizes, since the only crystallographic orientation that allows stacking close-packed disorder is the fcc (111) plane, or equivalently the hcp (0001) one. Taken together, our results contribute with one more piece to the intricate puzzle of colloidal hard-sphere crystallization.
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Affiliation(s)
- Ignacio Sanchez-Burgos
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, UK.
| | - Eduardo Sanz
- Departamento de Quimica Fisica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Carlos Vega
- Departamento de Quimica Fisica, Facultad de Ciencias Quimicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Jorge R Espinosa
- Maxwell Centre, Cavendish Laboratory, Department of Physics, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, UK.
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Richard D, Speck T. Classical nucleation theory for the crystallization kinetics in sheared liquids. Phys Rev E 2019; 99:062801. [PMID: 31330660 DOI: 10.1103/physreve.99.062801] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Indexed: 06/10/2023]
Abstract
While statistical mechanics provides a comprehensive framework for the understanding of equilibrium phase behavior, predicting the kinetics of phase transformations remains a challenge. Classical nucleation theory (CNT) provides a thermodynamic framework to relate the nucleation rate to thermodynamic quantities such as pressure difference and interfacial tension through the nucleation work necessary to spawn critical nuclei. However, it remains unclear whether such an approach can be extended to the crystallization of driven melts that are subjected to mechanical stresses and flows. Here, we demonstrate numerically for hard spheres that the impact of simple shear on the crystallization rate can be rationalized within the CNT framework by an additional elastic work proportional to the droplet volume. We extract the local stress and strain inside solid droplets, which yield size-dependent values for the shear modulus that are about half of the bulk value. Finally, we show that for a complete description one also has to take into account the change of interfacial work between the strained droplet and the sheared liquid. From scaling reasons, we expect this extra contribution to dominate the work formation of small nuclei but become negligible compared to the elastic work for droplets composed of a few hundreds of particles.
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Affiliation(s)
- David Richard
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7-9, 55128 Mainz, Germany
| | - Thomas Speck
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7-9, 55128 Mainz, Germany
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Richard D, Speck T. Crystallization of hard spheres revisited. II. Thermodynamic modeling, nucleation work, and the surface of tension. J Chem Phys 2018; 148:224102. [DOI: 10.1063/1.5025394] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- David Richard
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7-9, 55128 Mainz, Germany
| | - Thomas Speck
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7-9, 55128 Mainz, Germany
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Richard D, Speck T. Crystallization of hard spheres revisited. I. Extracting kinetics and free energy landscape from forward flux sampling. J Chem Phys 2018; 148:124110. [PMID: 29604868 DOI: 10.1063/1.5016277] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
We investigate the kinetics and the free energy landscape of the crystallization of hard spheres from a supersaturated metastable liquid though direct simulations and forward flux sampling. In this first paper, we describe and test two different ways to reconstruct the free energy barriers from the sampled steady state probability distribution of cluster sizes without sampling the equilibrium distribution. The first method is based on mean first passage times, and the second method is based on splitting probabilities. We verify both methods for a single particle moving in a double-well potential. For the nucleation of hard spheres, these methods allow us to probe a wide range of supersaturations and to reconstruct the kinetics and the free energy landscape from the same simulation. Results are consistent with the scaling predicted by classical nucleation theory although a quantitative fit requires a rather large effective interfacial tension.
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Affiliation(s)
- David Richard
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7-9, 55128 Mainz, Germany
| | - Thomas Speck
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7-9, 55128 Mainz, Germany
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Koß P, Statt A, Virnau P, Binder K. The phase coexistence method to obtain surface free energies and nucleation barriers: a brief review. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1463469] [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)
- Peter Koß
- Graduate School Materials Science in Mainz , Mainz, Germany
- Institut für Physik, Johannes Gutenberg-Universität , Mainz, Germany
| | - Antonia Statt
- Graduate School Materials Science in Mainz , Mainz, Germany
- Institut für Physik, Johannes Gutenberg-Universität , Mainz, Germany
- Department of Chemical and Biological Engineering, Princeton University , Princeton, NJ, USA
| | - Peter Virnau
- Institut für Physik, Johannes Gutenberg-Universität , Mainz, Germany
| | - Kurt Binder
- Institut für Physik, Johannes Gutenberg-Universität , Mainz, Germany
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Brumby PE, Wensink HH, Haslam AJ, Jackson G. Structure and Interfacial Tension of a Hard-Rod Fluid in Planar Confinement. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:11754-11770. [PMID: 28885848 DOI: 10.1021/acs.langmuir.7b02254] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The structural properties and interfacial tension of a fluid of rodlike hard-spherocylinder particles in contact with hard structureless flat walls are studied by means of Monte Carlo simulation. The calculated surface tension between the rod fluid and the substrate is characterized by a nonmonotonic trend as a function of the bulk concentration (density) over the range of isotropic bulk concentrations. As suggested by earlier theoretical studies, a surface-ordering scenario is confirmed by our simulations: the local orientational order close to the wall changes from uniaxial to biaxial nematic when the bulk concentration reaches about 85% of the value at the onset of the isotropic-nematic phase transition. The surface ordering coincides with a wetting transition whereby the hard wall is wetted by a nematic film. Accurate values of the fluid-solid surface tension, the adsorption, and the average particle-wall contact distance are reported (over a broad range of densities into the dense nematic region for the first time), which can serve as a useful benchmark for future theoretical and experimental studies on confined rod fluids. The simulation data are supplemented with predictions from second-virial density functional theory, which are in good qualitative agreement with the simulation results.
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Affiliation(s)
- Paul E Brumby
- Department of Mechanical Engineering, Keio University , 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| | - Henricus H Wensink
- Laboratoire de Physique des Solides, Université Paris Sud & CNRS , 91405 Orsay Cedex, France
| | - Andrew J Haslam
- Department of Chemical Engineering and Qatar Carbonates and Carbon Storage Research Centre, Imperial College London , South Kensington Campus, London SW7 2AZ, United Kingdom
| | - George Jackson
- Department of Chemical Engineering and Qatar Carbonates and Carbon Storage Research Centre, Imperial College London , South Kensington Campus, London SW7 2AZ, United Kingdom
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Koß P, Statt A, Virnau P, Binder K. Free-energy barriers for crystal nucleation from fluid phases. Phys Rev E 2017; 96:042609. [PMID: 29347490 DOI: 10.1103/physreve.96.042609] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Indexed: 06/07/2023]
Abstract
Monte Carlo simulations of crystal nuclei coexisting with the fluid phase in thermal equilibrium in finite volumes are presented and analyzed, for fluid densities from dense melts to the vapor. Generalizing the lever rule for two-phase coexistence in the canonical ensemble to finite volume, "measurements" of the nucleus volume together with the pressure and chemical potential of the surrounding fluid allows us to extract the surface free energy of the nucleus. Neither the knowledge of the (in general nonspherical) nucleus shape nor of the angle-dependent interface tension is required for this task. The feasibility of the approach is demonstrated for a variant of the Asakura-Oosawa model for colloid-polymer mixtures, which form face-centered cubic colloidal crystals. For a polymer to colloid size ratio of 0.15, the colloid packing fraction in the fluid phase can be varied from melt values to zero by the variation of an effective attractive potential between the colloids. It is found that the approximation of spherical crystal nuclei often underestimates actual nucleation barriers significantly. Nucleation barriers are found to scale as ΔF^{*}=(4π/3)^{1/3}γ[over ¯](V^{*})^{2/3}+const with the nucleus volume V^{*}, and the effective surface tension γ[over ¯] that accounts implicitly for the nonspherical shape can be precisely estimated.
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Affiliation(s)
- Peter Koß
- Institut für Physik, Johannes Gutenberg-Universität, D-55128 Mainz, Staudinger Weg 9, Germany
- Graduate School Materials Science in Mainz, D-55128 Mainz, Staudinger Weg 9, Germany
| | - Antonia Statt
- Institut für Physik, Johannes Gutenberg-Universität, D-55128 Mainz, Staudinger Weg 9, Germany
- Graduate School Materials Science in Mainz, D-55128 Mainz, Staudinger Weg 9, Germany
- Department of Chemical and Biological Engineering, Princeton School of Engineering and Applied Science, Princeton, New Jersey 08544, USA
| | - Peter Virnau
- Institut für Physik, Johannes Gutenberg-Universität, D-55128 Mainz, Staudinger Weg 9, Germany
- Graduate School Materials Science in Mainz, D-55128 Mainz, Staudinger Weg 9, Germany
| | - Kurt Binder
- Institut für Physik, Johannes Gutenberg-Universität, D-55128 Mainz, Staudinger Weg 9, Germany
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Chen Q, Kozuch D, Milner ST. “Plunger” Method for Simulating Crystal–Melt Interfacial Free Energies. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b00421] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Qin Chen
- Department
of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Daniel Kozuch
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Scott T. Milner
- Department
of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
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11
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Qi X, Zhou Y, Fichthorn KA. Obtaining the solid-liquid interfacial free energy via multi-scheme thermodynamic integration: Ag-ethylene glycol interfaces. J Chem Phys 2016; 145:194108. [DOI: 10.1063/1.4967521] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Affiliation(s)
- Xin Qi
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Ya Zhou
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Kristen A. Fichthorn
- Department of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
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12
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Virnau P, Schmitz F, Binder K. The ensemble switch method and related approaches to obtain interfacial free energies between coexisting phases from simulations: a brief review. MOLECULAR SIMULATION 2015. [DOI: 10.1080/08927022.2015.1071810] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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