1
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Frielinghaus H, Dubey PS, Saha D, Shin E, Holderer O, Sengers JV, Förster S. Random Field Ising Model Criticality in a Complex Binary Liquid System. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:1125. [PMID: 38998729 PMCID: PMC11243101 DOI: 10.3390/nano14131125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Accepted: 06/28/2024] [Indexed: 07/14/2024]
Abstract
While Ising criticality in classical liquids has been firmly established both theoretically and experimentally, much less is known about criticality in liquids in which the growth of the correlation length is frustrated by finite-size effects. A theoretical approach for dealing with this issue is the random-field Ising model (RFIM). While experimental critical-exponent values have been reported for magnetic samples (here, we consider γ, ν and η), little experimental information is available for critical fluctuations in corresponding liquid systems. In this paper, we present a study on a binary liquid consisting of 3-methyl pyridine and heavy water in a very light-weight porous gel. We find that the experimental results are in agreement with the theoretical predictions from the RFIM.
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Affiliation(s)
- Henrich Frielinghaus
- Forschungszentrum Jülich GmbH, Jülich Center for Neutron Scattering JCNS-4 at MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Purushottam S. Dubey
- Forschungszentrum Jülich GmbH, Jülich Center for Neutron Scattering JCNS-4 at MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Debasish Saha
- Forschungszentrum Jülich GmbH, Jülich Center for Neutron Scattering JCNS-4 at MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Eunjoo Shin
- Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 34057, Republic of Korea
| | - Olaf Holderer
- Forschungszentrum Jülich GmbH, Jülich Center for Neutron Scattering JCNS-4 at MLZ, Lichtenbergstrasse 1, 85747 Garching, Germany
| | - Jan V. Sengers
- Institute for Physical Science and Technology, University of Maryland, College Park, MD 20742, USA
| | - Stephan Förster
- Forschungszentrum Jülich GmbH, Jülich Center for Neutron Scattering JCNS-1, Leo-Brandt Str., 52425 Jülich, Germany
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2
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Kumar A, Safran SA. Fluctuations and Shape Dependence of Microphase Separation in Systems with Long-Range Interactions. PHYSICAL REVIEW LETTERS 2023; 131:258401. [PMID: 38181373 DOI: 10.1103/physrevlett.131.258401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 11/14/2023] [Indexed: 01/07/2024]
Abstract
The combination of phase separation and long-ranged, effective, Coulomb interactions results in microphase separation. We predict the sizes and shapes of such microdomains and uniquely their dependence on the macroscopic sample shape which also affects the effective interfacial tension of fluctuations of the lamellar phase. These are applied to equilibrium salt solutions and block copolymers. Nonequilibrium phase separation in the presence of chemical reactions (e.g., cellular condensates) is mapped to the Coulomb theory to which our predictions apply. In some cases, the effective interfacial tension can be ultralow.
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Affiliation(s)
- Amit Kumar
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
| | - Samuel A Safran
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel
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3
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Kawano M, Tashiro A, Imamura Y, Yamada M, Sadakane K, Iwase H, Matsugami M, Marekha BA, Idrissi A, Takamuku T. Effects of self-hydrogen bonding among formamide molecules on the UCST-type liquid-liquid phase separation of binary solutions with imidazolium-based ionic liquid, [C nmim][TFSI], studied by NMR, IR, MD simulations, and SANS. Phys Chem Chem Phys 2022; 24:13698-13712. [PMID: 35612374 DOI: 10.1039/d2cp01006b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The upper critical solution temperature (UCST)-type liquid-liquid phase separation of imidazolium-based ionic liquids (ILs), 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([Cnmim][TFSI], where n represents the alkyl chain length of the cation, n = 6, 8, 10, and 12) binary solutions with formamide (FA) was examined as a function of temperature and the FA mole fraction xFA. The two-phase region (immiscible region) of the solutions is much larger and expands more with the increase in n, in comparison with the previous [Cnmim][TFSI]-1,4-dioxane (1,4-DIO) systems. An array of spectroscopic techniques, including 1H and 13C NMR and IR combined with molecular dynamics (MD) simulations, was conducted on the present binary systems to clarify the microscopic interactions that contribute to the phase-separation mechanism. The hydrogen-bonding interactions of the imidazolium ring H atoms are more favorable with the O atoms of the FA molecules than with 1,4-DIO molecules, whereas the latter interact more favorably with the alkyl chain of the cation. Upon lowering the temperature, the FA molecules gradually self-aggregate through self-hydrogen bonding to form FA clusters. Concomitantly, clusters of ILs are formed via the electrostatic interaction between the counter ions and the dispersion force among the IL alkyl chains. Small-angle neutron scattering (SANS) experiments on the [C6mim][TFSI]-FA-d2 and [C8mim][TFSI]-FA-d2 systems revealed, similarly to [Cnmim][TFSI]-1,4-DIO systems, the crossover of the mechanism from the 3D-Ising mechanism around the UCST xFA to the mean-field mechanism at both sides of the mole fraction. Interestingly, the xFA range of the 3D-Ising mechanism for the FA systems is wider compared with the range of the 1,4-DIO systems. In this way, the self-hydrogen bonding among FA molecules most significantly governs the phase equilibria of the [Cnmim][TFSI]-FA systems.
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Affiliation(s)
- Masahiro Kawano
- Department of Chemistry and Applied Chemistry, Graduate School of Science and Engineering, Saga University, Honjo-machi, Saga 840-8502, Japan
| | - Atsuya Tashiro
- Department of Chemistry and Applied Chemistry, Graduate School of Science and Engineering, Saga University, Honjo-machi, Saga 840-8502, Japan
| | - Yuki Imamura
- Department of Chemistry and Applied Chemistry, Faculty of Science and Engineering, Saga University, Honjo-machi, Saga 840-8502, Japan.
| | - Moeno Yamada
- Department of Chemistry and Applied Chemistry, Faculty of Science and Engineering, Saga University, Honjo-machi, Saga 840-8502, Japan.
| | - Koichiro Sadakane
- Faculty of Life and Medical Sciences, Doshisha University, 1-3 Tatara Miyakodani, Kyotanabe, Kyoto 610-0394, Japan
| | - Hiroki Iwase
- Comprehensive Research Organization for Science and Society (CROSS), 162-1 Shirakata, Tokai, Ibaraki 319-1106, Japan
| | - Masaru Matsugami
- Faculty of Liberal Arts, National Institute of Technology (KOSEN), Kumamoto College, 2659-2 Suya, Koshi, Kumamoto 861-1102, Japan
| | - Bogdan A Marekha
- Department of Biomolecular Mechanisms, Max Planck Institute for Medical Research, 29 Jahnstr., 69230 Heidelberg, Germany
| | - Abdenacer Idrissi
- University of Lille, CNRS, UMR 8516 - LASIRe - Laboratoire Avancé de Spectroscopie pour les Interactions la Réactivité et l'environnement, F-5900 Lille, France
| | - Toshiyuki Takamuku
- Department of Chemistry and Applied Chemistry, Faculty of Science and Engineering, Saga University, Honjo-machi, Saga 840-8502, Japan.
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4
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Patsahan O, Ciach A. Mesoscopic Inhomogeneities in Concentrated Electrolytes. ACS OMEGA 2022; 7:6655-6664. [PMID: 35252660 PMCID: PMC8892908 DOI: 10.1021/acsomega.1c06013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Accepted: 01/31/2022] [Indexed: 06/14/2023]
Abstract
A mesoscopic theory for water-in-salt electrolytes combining density functional and field-theoretic methods is developed in order to explain the unexpectedly large period of the oscillatory decay of the disjoining pressure observed in recent experiments for the lithium bis(trifluoromethylsulfonyl)-imide (LiTFSI) salt [T. S. Groves et al., J. Phys. Chem. Lett. 2021, 12, 1702]. We assumed spherical ions with different diameters and implicit solvent, inducing strong, short-range attraction between ions of the same sign. For this highly simplified model, we calculated correlation functions. Our results indicate that mesoscopic inhomogeneities can occur when the sum of the Coulomb and the water-mediated interactions between like ions is attractive at short and repulsive at large distances. We adjusted the attractive part of the potential to the water-in-LiTFSI electrolyte and obtained both the period and the decay rate of the correlations, in semiquantitative agreement with the experiment. In particular, the decay length of the correlations increases nearly linearly with the volume fraction of ions.
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Affiliation(s)
- Oksana Patsahan
- Institute
for Condensed Matter Physics of the National Academy of Sciences of
Ukraine, Lviv 79011, Ukraine
| | - Alina Ciach
- Institute
of Physical Chemistry, Polish Academy of
Sciences, 01-224 Warszawa, Poland
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5
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Jonas HJ, Stuij SG, Schall P, Bolhuis PG. A temperature-dependent critical Casimir patchy particle model benchmarked onto experiment. J Chem Phys 2021; 155:034902. [PMID: 34293902 DOI: 10.1063/5.0055012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Synthetic colloidal patchy particles immersed in a binary liquid mixture can self-assemble via critical Casimir interactions into various superstructures, such as chains and networks. Up to now, there are no quantitatively accurate potential models that can simulate and predict this experimentally observed behavior precisely. Here, we develop a protocol to establish such a model based on a combination of theoretical Casimir potentials and angular switching functions. Using Monte Carlo simulations, we optimize several material-specific parameters in the model to match the experimental chain length distribution and persistence length. Our approach gives a systematic way to obtain accurate potentials for critical Casimir induced patchy particle interactions and can be used in large-scale simulations.
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Affiliation(s)
- H J Jonas
- van 't Hoff Institute for Molecular Sciences, University of Amsterdam, P.O. Box 94157, 1090 GD Amsterdam, The Netherlands
| | - S G Stuij
- Institute of Physics, University of Amsterdam, P.O. Box 94157, 1090 GD Amsterdam, The Netherlands
| | - P Schall
- Institute of Physics, University of Amsterdam, P.O. Box 94157, 1090 GD Amsterdam, The Netherlands
| | - P G Bolhuis
- van 't Hoff Institute for Molecular Sciences, University of Amsterdam, P.O. Box 94157, 1090 GD Amsterdam, The Netherlands
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6
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Gradzielski M, Duvail M, de Molina PM, Simon M, Talmon Y, Zemb T. Using Microemulsions: Formulation Based on Knowledge of Their Mesostructure. Chem Rev 2021; 121:5671-5740. [PMID: 33955731 DOI: 10.1021/acs.chemrev.0c00812] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Microemulsions, as thermodynamically stable mixtures of oil, water, and surfactant, are known and have been studied for more than 70 years. However, even today there are still quite a number of unclear aspects, and more recent research work has modified and extended our picture. This review gives a short overview of how the understanding of microemulsions has developed, the current view on their properties and structural features, and in particular, how they are related to applications. We also discuss more recent developments regarding nonclassical microemulsions such as surfactant-free (ultraflexible) microemulsions or ones containing uncommon solvents or amphiphiles (like antagonistic salts). These new findings challenge to some extent our previous understanding of microemulsions, which therefore has to be extended to look at the different types of microemulsions in a unified way. In particular, the flexibility of the amphiphilic film is the key property to classify different microemulsion types and their properties in this review. Such a classification of microemulsions requires a thorough determination of their structural properties, and therefore, the experimental methods to determine microemulsion structure and dynamics are reviewed briefly, with a particular emphasis on recent developments in the field of direct imaging by means of electron microscopy. Based on this classification of microemulsions, we then discuss their applications, where the application demands have to be met by the properties of the microemulsion, which in turn are controlled by the flexibility of their amphiphilic interface. Another frequently important aspect for applications is the control of the rheological properties. Normally, microemulsions are low viscous and therefore enhancing viscosity has to be achieved by either having high concentrations (often not wished for) or additives, which do not significantly interfere with the microemulsion. Accordingly, this review gives a comprehensive account of the properties of microemulsions, including most recent developments and bringing them together from a united viewpoint, with an emphasis on how this affects the way of formulating microemulsions for a given application with desired properties.
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Affiliation(s)
- Michael Gradzielski
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, D-10623 Berlin, Germany
| | - Magali Duvail
- ICSM, Université Montpellier, CEA, CNRS, ENSCM, 30207 Marcoule, France
| | - Paula Malo de Molina
- Centro de Física de Materiales (CFM) (CSIC-UPV/EHU)-Materials Physics Center (MPC), Paseo Manuel de Lardizabal 5, 20018 San Sebastián, Spain.,IKERBASQUE - Basque Foundation for Science, María Díaz de Haro 3, 48013 Bilbao, Spain
| | - Miriam Simon
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, D-10623 Berlin, Germany.,Department of Chemical Engineering and the Russell Berrie Nanotechnolgy Inst. (RBNI), Technion-Israel Institute of Technology, Haifa, IL-3200003, Israel
| | - Yeshayahu Talmon
- Department of Chemical Engineering and the Russell Berrie Nanotechnolgy Inst. (RBNI), Technion-Israel Institute of Technology, Haifa, IL-3200003, Israel
| | - Thomas Zemb
- Stranski-Laboratorium für Physikalische und Theoretische Chemie, Institut für Chemie, Technische Universität Berlin, D-10623 Berlin, Germany.,ICSM, Université Montpellier, CEA, CNRS, ENSCM, 30207 Marcoule, France
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7
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Jung D, Harting J, Sega M. Monolayer Structures of Supramolecular Antagonistic Salt Aggregates. J Phys Chem B 2021; 125:2351-2359. [PMID: 33634691 DOI: 10.1021/acs.jpcb.0c10005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The speculated presence of monomolecular lamellae of antagonistic salts in oil-water mixtures has left several open questions besides their hypothetical existence, including their microscopic structure and stabilization mechanism. Here, we simulate the spontaneous formation of supramolecular aggregates of the antagonistic salt sodium tetraphenylborate (NaBPh4) in water and 3-methylpyridine (3-MP) at the atomistic level. We show that, indeed, the lamellae are formed by a monomolecular layer of the anion, enveloped by 3-MP and hydrated sodium counterions. To understand which thermodynamic forces drive the aggregation, we compare the full-atomistic model with a simplified one for the salt and show that the strong hydrophobic effect granted by the large excluded volume of the anion, together with electrostatic repulsion, suffice to explain the stability of the monomolecular lamellae.
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Affiliation(s)
- David Jung
- Helmholtz Institute Erlangen-Nürnberg for Renewable Energy, Forschungszentrum Jülich, Fürther Straße 248, 90429 Nürnberg, Germany
| | - Jens Harting
- Helmholtz Institute Erlangen-Nürnberg for Renewable Energy, Forschungszentrum Jülich, Fürther Straße 248, 90429 Nürnberg, Germany
| | - Marcello Sega
- Helmholtz Institute Erlangen-Nürnberg for Renewable Energy, Forschungszentrum Jülich, Fürther Straße 248, 90429 Nürnberg, Germany
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8
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Onuki A. Long-range correlations of polarization and number densities in dilute electrolytes. J Chem Phys 2020; 153:234501. [DOI: 10.1063/5.0030763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Akira Onuki
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
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9
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Glende G, de Wijn AS, Pousaneh F. The Vanishing water/oil interface in the presence of antagonistic salt. J Chem Phys 2020; 152:124707. [DOI: 10.1063/1.5142811] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Affiliation(s)
- Gudrun Glende
- Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway
| | - Astrid S. de Wijn
- Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway
- Department of Physics, Stockholm University, Stockholm, Sweden
| | - Faezeh Pousaneh
- Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology, 7491 Trondheim, Norway
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10
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Jung D, Rivas N, Harting J. How antagonistic salts cause nematic ordering and behave like diblock copolymers. J Chem Phys 2019; 150:064912. [PMID: 30769987 DOI: 10.1063/1.5085660] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present simulation results and an explanatory theory on how antagonistic salts affect the spinodal decomposition of binary fluid mixtures. We find that spinodal decomposition is arrested and complex structures form only when electrostatic ion-ion interactions are small. In this case, the fluid and ion concentrations couple and the charge field can be approximated as a polynomial function of the relative fluid concentrations alone. When the solvation energy associated with transferring an ion from one fluid phase to the other is of the order of a few kBT, the coupled fluid and charge fields evolve according to the Ohta-Kawasaki free energy functional. This allows us to accurately predict structure sizes and reduce the parameter space to two dimensionless numbers. The lamellar structures induced by the presence of the antagonistic salt in our simulations exhibit a high degree of nematic ordering and the growth of ordered domains over time follows a power law. This power law carries a time exponent proportional to the salt concentration. We qualitatively reproduce and interpret neutron scattering data from previous experiments of similar systems. The dissolution of structures at high salt concentrations observed in these experiments agrees with our simulations, and we explain it as the result of a vanishing surface tension due to electrostatic contributions. We conclude by presenting 3D results showing the same morphologies as predicted by the Ohta-Kawasaki model as a function of volume fraction and suggesting that our findings from 2D systems remain valid in 3D.
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Affiliation(s)
- David Jung
- Forschungszentrum Jülich, Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (IEK-11), Fürther Straße 248, 90429 Nürnberg, Germany
| | - Nicolas Rivas
- Forschungszentrum Jülich, Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (IEK-11), Fürther Straße 248, 90429 Nürnberg, Germany
| | - Jens Harting
- Forschungszentrum Jülich, Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (IEK-11), Fürther Straße 248, 90429 Nürnberg, Germany
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11
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Sadakane K, Fujii K, Tsuzuki S, Watanabe H, Umebayashi Y. Solvation state of sodium tetraphenylborate in 3-methylpyridine and its aqueous solutions. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.10.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Tasios N, Samin S, van Roij R, Dijkstra M. Microphase Separation in Oil-Water Mixtures Containing Hydrophilic and Hydrophobic Ions. PHYSICAL REVIEW LETTERS 2017; 119:218001. [PMID: 29219402 DOI: 10.1103/physrevlett.119.218001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Indexed: 06/07/2023]
Abstract
We develop a lattice-based Monte Carlo simulation method for charged mixtures capable of treating dielectric heterogeneities. Using this method, we study oil-water mixtures containing an antagonistic salt, with hydrophilic cations and hydrophobic anions. Our simulations reveal several phases with a spatially modulated solvent composition, in which the ions partition between water-rich and water-poor regions according to their affinity. In addition to the recently observed lamellar phase, we find tubular and droplet phases, reminiscent of those found in block copolymers and surfactant systems. Interestingly, these structures stem from ion-mediated interactions, which allows for tuning of the phase behavior via the concentrations, the ionic properties, and the temperature.
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Affiliation(s)
- Nikos Tasios
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, Netherlands
| | - Sela Samin
- Institute for Theoretical Physics, Center for Extreme Matter and Emergent Phenomena, Utrecht University, Princetonplein 5, 3584 CC Utrecht, Netherlands
| | - René van Roij
- Institute for Theoretical Physics, Center for Extreme Matter and Emergent Phenomena, Utrecht University, Princetonplein 5, 3584 CC Utrecht, Netherlands
| | - Marjolein Dijkstra
- Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, Netherlands
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13
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Yabunaka S, Onuki A. Electric Double Layer Composed of an Antagonistic Salt in an Aqueous Mixture: Local Charge Separation and Surface Phase Transition. PHYSICAL REVIEW LETTERS 2017; 119:118001. [PMID: 28949213 DOI: 10.1103/physrevlett.119.118001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Indexed: 06/07/2023]
Abstract
We examine an electric double layer containing an antagonistic salt in an aqueous mixture, where the cations are small and hydrophilic but the anions are large and hydrophobic. In this situation, a strong coupling arises between the charge density and the solvent composition. As a result, the anions are trapped in an oil-rich adsorption layer on a hydrophobic wall. We then vary the surface charge density σ on the wall. For σ>0 the anions remain accumulated, but for σ<0 the cations are attracted to the wall with increasing |σ|. Furthermore, the electric potential drop Ψ(σ) is nonmonotonic when the solvent interaction parameter χ(T) exceeds a critical value χ_{c} determined by the composition and the ion density in the bulk. This leads to a first-order phase transition between two kinds of electric double layers with different σ and common Ψ. In equilibrium such two-layer regions can coexist. The steric effect due to finite ion sizes is crucial in these phenomena.
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Affiliation(s)
- Shunsuke Yabunaka
- Fukui Institute for Fundamental Chemistry, Kyoto University, Kyoto 606-8103, Japan
| | - Akira Onuki
- Department of Physics, Kyoto University, Kyoto 606-8502, Japan
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14
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Bier M, Mars J, Li H, Mezger M. Salt-induced microheterogeneities in binary liquid mixtures. Phys Rev E 2017; 96:022603. [PMID: 28950527 DOI: 10.1103/physreve.96.022603] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Indexed: 11/07/2022]
Abstract
The salt-induced microheterogeneity (MH) formation in binary liquid mixtures is studied by small-angle x-ray scattering (SAXS) and liquid state theory. Previous experiments have shown that this phenomenon occurs for antagonistic salts, whose cations and anions prefer different components of the solvent mixture. However, so far the precise mechanism leading to the characteristic length scale of MHs has remained unclear. Here, it is shown that MHs can be generated by the competition of short-ranged interactions and long-ranged monopole-dipole interactions. The experimental SAXS patterns can be reproduced quantitatively by fitting to the derived correlation functions without assuming any specific model. The dependency of the MH structure with respect to ionic strength and temperature is analyzed. Close to the demixing phase transition, critical-like behavior occurs with respect to the spinodal line in the phase diagram.
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Affiliation(s)
- Markus Bier
- Max Planck Institute for Intelligent Systems, Heisenbergstrasse 3, 70569 Stuttgart, Germany.,Institute for Theoretical Physics IV, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - Julian Mars
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.,Institute of Physics and MAINZ Graduate School, Johannes Gutenberg University Mainz, Staudingerweg 7, 55128 Mainz, Germany
| | - Hailong Li
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Markus Mezger
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany.,Institute of Physics and MAINZ Graduate School, Johannes Gutenberg University Mainz, Staudingerweg 7, 55128 Mainz, Germany
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15
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Kawabata Y, Bradbury R, Kugizaki S, Weigandt K, Melnichenko YB, Sadakane K, Yamada NL, Endo H, Nagao M, Seto H. Effect of interlamellar interactions on shear induced multilamellar vesicle formation. J Chem Phys 2017; 147:034905. [PMID: 28734290 DOI: 10.1063/1.4994563] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Shear-induced multilamellar vesicle (MLV) formation has been studied by coupling the small-angle neutron scattering (SANS) technique with neutron spin echo (NSE) spectroscopy. A 10% mass fraction of the nonionic surfactant pentaethylene glycol dodecyl ether (C12E5) in water was selected as a model system for studying weak inter-lamellar interactions. These interactions are controlled either by adding an anionic surfactant, sodium dodecyl sulfate, or an antagonistic salt, rubidium tetraphenylborate. Increasing the charge density in the bilayer induces an enhanced ordering of the lamellar structure. The charge density dependence of the membrane bending modulus was determined by NSE and showed an increasing trend with charge. This behavior is well explained by a classical theoretical model. By considering the Caillé parameters calculated from the SANS data, the layer compressibility modulus B¯ is estimated and the nature of the dominant inter-lamellar interaction is determined. Shear flow induces MLV formation around a shear rate of 10 s-1, when a small amount of charge is included in the membrane. The flow-induced layer undulations are in-phase between neighboring layers when the inter-lamellar interaction is sufficiently strong. Under these conditions, MLV formation can occur without significantly changing the inter-lamellar spacing. On the other hand, in the case of weak inter-lamellar interactions, the flow-induced undulations are not in-phase, and greater steric repulsion leads to an increase in the inter-lamellar spacing with shear rate. In this case, MLV formation occurs as the amplitude of the undulations gets larger and the steric interaction leads to in-phase undulations between neighboring membranes.
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Affiliation(s)
- Y Kawabata
- Department of Chemistry, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan
| | - R Bradbury
- Center for Exploration of Energy and Matter, Department of Physics, Indiana University, Bloomington, Indiana 47408, USA
| | - S Kugizaki
- Department of Chemistry, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan
| | - K Weigandt
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, USA
| | - Y B Melnichenko
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6393, USA
| | - K Sadakane
- Faculty of Life and Medical Sciences, Doshisha University, Kyotanabe, Kyoto 610-0321, Japan
| | - N L Yamada
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tokai 319-1106, Japan
| | - H Endo
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tokai 319-1106, Japan
| | - M Nagao
- Center for Exploration of Energy and Matter, Department of Physics, Indiana University, Bloomington, Indiana 47408, USA
| | - H Seto
- Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tokai 319-1106, Japan
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Witala M, Lages S, Nygård K. Mesoscale ordering in binary aqueous solvents induced by ion size asymmetry. SOFT MATTER 2016; 12:4778-4782. [PMID: 27112965 DOI: 10.1039/c6sm00580b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Surprising weak assembly behavior has lately been found in binary aqueous solvents containing antagonistic salt. The underlying mechanism is still under debate, particularly the role of ion size asymmetry. Here we use small-angle X-ray scattering to study the effect of ion size asymmetry on the mesoscale ordering in a binary solvent composed of water and 2,6-dimethylpyridine with added symmetrical quaternary ammonium salt. By systematically elongating the hydrocarbon side-chain lengths, and hence developing cation-to-anion size asymmetry, we provide the first experimental evidence of a gradual build-up of the solvent's mesoscale ordering. These results are in qualitative agreement with model-independent theoretical predictions.
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Affiliation(s)
- Monika Witala
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-41296 Gothenburg, Sweden.
| | - Sebastian Lages
- MAX IV Laboratory, Lund University, PO Box 118, SE-22100 Lund, Sweden
| | - Kim Nygård
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-41296 Gothenburg, Sweden.
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Onuki A, Yabunaka S, Araki T, Okamoto R. Structure formation due to antagonistic salts. Curr Opin Colloid Interface Sci 2016. [DOI: 10.1016/j.cocis.2016.02.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Ciach A. Competition Between Electrostatic and Thermodynamic Casimir Potentials in Near-Critical Mixtures with Ions. ADVANCES IN BIOMEMBRANES AND LIPID SELF-ASSEMBLY 2016. [DOI: 10.1016/bs.abl.2015.12.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Pousaneh F, Ciach A. The effect of antagonistic salt on a confined near-critical mixture. SOFT MATTER 2014; 10:8188-8201. [PMID: 25171785 DOI: 10.1039/c4sm01264j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We consider a near-critical binary mixture with addition of antagonistic salt (hydrophilic cations and hydrophobic anions) confined between weakly charged and selective surfaces. A mesoscopic functional for this system is developed from a microscopic description by a systematic coarse-graining procedure. The functional reduces to the Landau-Brazovskii functional for amphiphilic systems for a sufficiently large ratio between the correlation length in the critical binary mixture and the screening length. Our theoretical result agrees with the experimental observation [Sadakane et al., J. Chem. Phys., 2013, 139, 234905] that the antagonistic salt and the surfactant both lead to a similar mesoscopic structure. For very low salt concentration ρion the Casimir potential is the same as in the presence of inorganic salt. For larger ρion the Casimir potential takes a minimum followed by a maximum for separations of order of tens of nanometers, and exhibits an oscillatory decay very close to the critical point. For separations of tens of nanometers the potential between surfaces with a linear size of hundreds of nanometers can be of order of kBT. We have verified that in the experimentally studied samples [Sadakane et al., J. Chem. Phys., 2013, 139, 234905, Leys et al., Soft Matter, 2013, 9, 9326] the decay length is too small compared to the period of oscillations of the Casimir potential, but the oscillatory force could be observed closer to the critical point.
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Affiliation(s)
- Faezeh Pousaneh
- Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, PL-01-224 Warsaw, Poland.
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Lamellar/Disorder Phase Transition in a Mixture of Water/2,6-Dimethylpyridine/Antagonistic Salt. J SOLUTION CHEM 2014. [DOI: 10.1007/s10953-014-0240-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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