1
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Berlinger SA, Küpers V, Dudenas PJ, Schinski D, Flagg L, Lamberty ZD, McCloskey BD, Winter M, Frechette J. Cation valency in water-in-salt electrolytes alters the short- and long-range structure of the electrical double layer. Proc Natl Acad Sci U S A 2024; 121:e2404669121. [PMID: 39047037 PMCID: PMC11295052 DOI: 10.1073/pnas.2404669121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 06/20/2024] [Indexed: 07/27/2024] Open
Abstract
Highly concentrated aqueous electrolytes (termed water-in-salt electrolytes, WiSEs) at solid-liquid interfaces are ubiquitous in myriad applications including biological signaling, electrosynthesis, and energy storage. This interface, known as the electrical double layer (EDL), has a different structure in WiSEs than in dilute electrolytes. Here, we investigate how divalent salts [zinc bis(trifluoromethylsulfonyl)imide, Zn(TFSI)2], as well as mixtures of mono- and divalent salts [lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) mixed with Zn(TFSI)2], affect the short- and long-range structure of the EDL under confinement using a multimodal combination of scattering, spectroscopy, and surface forces measurements. Raman spectroscopy of bulk electrolytes suggests that the cation is closely associated with the anion regardless of valency. Wide-angle X-ray scattering reveals that all bulk electrolytes form ion clusters; however, the clusters are suppressed with increasing concentration of the divalent ion. To probe the EDL under confinement, we use a Surface Forces Apparatus and demonstrate that the thickness of the adsorbed layer of ions at the interface grows with increasing divalent ion concentration. Multiple interfacial layers form following this adlayer; their thicknesses appear dependent on anion size, rather than cation. Importantly, all electrolytes exhibit very long electrostatic decay lengths that are insensitive to valency. It is likely that in the WiSE regime, electrostatic screening is mediated by the formation of ion clusters rather than individual well-solvated ions. This work contributes to understanding the structure and charge-neutralization mechanism in this class of electrolytes and the interfacial behavior of mixed-electrolyte systems encountered in electrochemistry and biology.
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Affiliation(s)
- Sarah A. Berlinger
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA94720
| | - Verena Küpers
- Münster Electrochemical Energy Technology, University of Münster, Münster48149, Germany
| | - Peter J. Dudenas
- Polymer Processing Group, Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD20899
| | - Devin Schinski
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA94720
| | - Lucas Flagg
- Polymer Processing Group, Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD20899
| | - Zachary D. Lamberty
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA94720
| | - Bryan D. McCloskey
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA94720
- Energy Storage and Distributed Resources Division, Lawrence Berkeley National Laboratory, Berkeley, CA94720
| | - Martin Winter
- Münster Electrochemical Energy Technology, University of Münster, Münster48149, Germany
- Helmholtz-Institute Münster Ionics in Energy Storage, Münster48149, Germany
| | - Joelle Frechette
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, CA94720
- Energy Storage and Distributed Resources Division, Lawrence Berkeley National Laboratory, Berkeley, CA94720
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2
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Forsman J, Ribar D, Woodward CE. An efficient method to establish electrostatic screening lengths of restricted primitive model electrolytes. Phys Chem Chem Phys 2024; 26:19921-19933. [PMID: 38990567 DOI: 10.1039/d4cp00546e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/12/2024]
Abstract
We present a novel, and computationally cheap, way to estimate electrostatic screening lengths from simulations of restricted primitive model (RPM) electrolytes. We demonstrate that the method is accurate by comparisons with simulated long-ranged parts of the charge density, at various Bjerrum lengths, salt concentrations and ion diameters. We find substantial underscreening in low dielectric solvent, but with an "aqueous" solvent, there is instead overscreening, the degree of which increases with ion size. Our method also offers a possible path to (future) more accurate classical density functional treatments of ionic fluids.
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Affiliation(s)
- Jan Forsman
- Computational Chemistry, Lund University, P.O. Box 124, S-221 00 Lund, Sweden.
| | - David Ribar
- Computational Chemistry, Lund University, P.O. Box 124, S-221 00 Lund, Sweden.
| | - Clifford E Woodward
- School of Physical, Environmental and Mathematical Sciences University College, University of New South Wales, ADFA Canberra ACT 2600, Australia
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3
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Wang S, Tao H, Yang J, Cheng J, Liu H, Lian C. Structure and Screening in Confined Electrolytes: The Role of Ion Association. J Phys Chem Lett 2024; 15:7147-7153. [PMID: 38959446 DOI: 10.1021/acs.jpclett.4c01698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
The effect of ionic association on the structure and property of confined electrolytes is investigated using the classical density functional theory. We find that ionic association strongly affects the ion distribution, surface force, and screening behavior of confined electrolytes. The decay length ξ, which can describe the screening effect of high-concentration electrolytes, satisfies a scaling relationship ξ/λD ∼ (σ/λD)n, with λD being the Debye length and σ representing the ion diameter. We find that n = 1.5 in the nonassociation model, which is contributed by the charge correlation, but n = 3 in the association model, which is contributed by the density correlation. The ion association changes the concentration-dependent characteristics of the screening length by promoting the shift of the decay behavior from the charge-dominated regime to the density-dominated regime. Our result reveals the importance of ion association for electrolyte structure and screening behaviors.
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Affiliation(s)
- Sijie Wang
- State Key Laboratory of Chemical Engineering and School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Haolan Tao
- State Key Laboratory of Chemical Engineering and School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Jie Yang
- State Key Laboratory of Chemical Engineering and School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Jin Cheng
- State Key Laboratory of Chemical Engineering and School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Honglai Liu
- State Key Laboratory of Chemical Engineering and School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Cheng Lian
- State Key Laboratory of Chemical Engineering and School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China
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4
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Gurina DL, Odintsova EG, Budkov YA. Disjoining Pressure Decay Length in Room-Temperature Ionic Liquids: A Molecular Simulation Study. J Phys Chem B 2024; 128:2215-2218. [PMID: 38387067 DOI: 10.1021/acs.jpcb.3c08425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
We present all-atom molecular simulations to investigate the behavior of 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) in negatively charged carbon nanopores of different widths (h = 5÷15 nm) and lengths (l = 4÷10 nm). The goal of our study was to determine how the disjoining pressure varies as a function of the pore width at different lengths and to understand the influence of edge effects. Our results show that the edge effect decreases as the pore length increases. Using an exponential function, we can approximate the disjoining pressure at large pore widths and use this approximation to estimate the decay length that can correlate with the electrostatic screening length. The results agreed well with those of previous experimental studies.
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Affiliation(s)
- Darya L Gurina
- Laboratory of Multiscale Modeling of Molecular Systems, G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Akademicheskaya St. 1, 153045 Ivanovo, Russian Federation
- Laboratory of Computational Physics, HSE University, Tallinskaya St. 34, 123458 Moscow, Russian Federation
| | - Ekaterina G Odintsova
- Laboratory of Multiscale Modeling of Molecular Systems, G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Akademicheskaya St. 1, 153045 Ivanovo, Russian Federation
| | - Yury A Budkov
- Laboratory of Multiscale Modeling of Molecular Systems, G.A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, Akademicheskaya St. 1, 153045 Ivanovo, Russian Federation
- Laboratory of Computational Physics, HSE University, Tallinskaya St. 34, 123458 Moscow, Russian Federation
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5
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Reinertsen RJE, Kewalramani S, Jiménez-Ángeles F, Weigand SJ, Bedzyk MJ, Olvera de la Cruz M. Reexpansion of charged nanoparticle assemblies in concentrated electrolytes. Proc Natl Acad Sci U S A 2024; 121:e2316537121. [PMID: 38289958 PMCID: PMC10861876 DOI: 10.1073/pnas.2316537121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 12/27/2023] [Indexed: 02/01/2024] Open
Abstract
Electrostatic forces in solutions are highly relevant to a variety of fields, ranging from electrochemical energy storage to biology. However, their manifestation in concentrated electrolytes is not fully understood, as exemplified by counterintuitive observations of colloidal stability and long-ranged repulsions in molten salts. Highly charged biomolecules, such as DNA, respond sensitively to ions in dilute solutions. Here, we use non-base-pairing DNA-coated nanoparticles (DNA-NP) to analyze electrostatic interactions in concentrated salt solutions. Despite their negative charge, these conjugates form colloidal crystals in solutions of sufficient divalent cation concentration. We utilize small-angle X-ray scattering (SAXS) to study such DNA-NP assemblies across the full accessible concentration ranges of aqueous CaCl2, MgCl2, and SrCl2 solutions. SAXS shows that the crystallinity and phases of the assembled structures vary with cation type. For all tested salts, the aggregates contract with added ions at low salinities and then begin expanding above a cation-dependent threshold salt concentration. Wide-angle X-ray scattering (WAXS) reveals enhanced positional correlations between ions in the solution at high salt concentrations. Complementary molecular dynamics simulations show that these ion-ion interactions reduce the favorability of dense ion configurations within the DNA brushes below that of the bulk solution. Measurements in solutions with lowered permittivity demonstrate a simultaneous increase in ion coupling and decrease in the concentration at which aggregate expansion begins, thus confirming the connection between these phenomena. Our work demonstrates that interactions between charged objects continue to evolve considerably into the high-concentration regime, where classical theories project electrostatics to be of negligible consequence.
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Affiliation(s)
- Roger J. E. Reinertsen
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL60208
| | - Sumit Kewalramani
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL60208
| | - Felipe Jiménez-Ángeles
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL60208
| | - Steven J. Weigand
- DuPont-Northwestern-Dow Collaborative Access Team, Northwestern University Synchrotron Research Center, Advanced Photon Source, Argonne, IL60439
| | - Michael J. Bedzyk
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL60208
- Department of Physics and Astronomy, Northwestern University, Evanston, IL60208
| | - Monica Olvera de la Cruz
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL60208
- Department of Physics and Astronomy, Northwestern University, Evanston, IL60208
- Department of Chemical and Biological Engineering, Northwestern University, Evanston, IL60208
- Department of Chemistry, Northwestern University, Evanston, IL60208
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6
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Fiuza T, Sarkar M, Riedl JC, Beaughon M, Torres Bautista BE, Bhattacharya K, Cousin F, Barruet E, Demouchy G, Depeyrot J, Dubois E, Gélébart F, Geertsen V, Mériguet G, Michot L, Nakamae S, Perzynski R, Peyre V. Ion specific tuning of nanoparticle dispersion in an ionic liquid: a structural, thermoelectric and thermo-diffusive investigation. Phys Chem Chem Phys 2023; 25:28911-28924. [PMID: 37855156 DOI: 10.1039/d3cp02399k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
Dispersions of charged maghemite nanoparticles (NPs) in EAN (ethylammonium nitrate) a reference Ionic Liquid (IL) are studied here using a number of static and dynamical experimental techniques; small angle scattering (SAS) of X-rays and of neutrons, dynamical light scattering and forced Rayleigh scattering. Particular insight is provided regarding the importance of tuning the ionic species present at the NP/IL interface. In this work we compare the effect of Li+, Na+ or Rb+ ions. Here, the nature of these species has a clear influence on the short-range spatial organisation of the ions at the interface and thus on the colloidal stability of the dispersions, governing both the NP/NP and NP/IL interactions, which are both evaluated here. The overall NP/NP interaction is either attractive or repulsive. It is characterised by determining, thanks to the SAS techniques, the second virial coefficient A2, which is found to be independent of temperature. The NP/IL interaction is featured by the dynamical effective charge ξeff0 of the NPs and by their entropy of transfer ŜNP (or equivalently their heat of transport ) determined here thanks to thermoelectric and thermodiffusive measurements. For repulsive systems, an activated process rules the temperature dependence of these two latter quantities.
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Affiliation(s)
- T Fiuza
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
- Grupo de Fluidos Complexos, Inst. de Fisíca, Univ. de Brasília, Brasília (DF), Brazil
| | - M Sarkar
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - J C Riedl
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - M Beaughon
- Service de Physique de l'état condensé, SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif sur Yvette, CEDEX, France
| | - B E Torres Bautista
- Service de Physique de l'état condensé, SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif sur Yvette, CEDEX, France
| | - K Bhattacharya
- Service de Physique de l'état condensé, SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif sur Yvette, CEDEX, France
| | - F Cousin
- Lab. Léon Brillouin-UMR 12 CNRS-CEA CEA-Saclay, 91191 Gif-sur-Yvette, France
| | - E Barruet
- Univ. Paris-Saclay, CEA, CNRS, NIMBE-LIONS, 91191 Gif sur Yvette, CEDEX, France
| | - G Demouchy
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
- Univ. de Cergy Pontoise-Dpt de physique, 33 Bd du Port, 95011 Cergy-Pontoise, France
| | - J Depeyrot
- Grupo de Fluidos Complexos, Inst. de Fisíca, Univ. de Brasília, Brasília (DF), Brazil
| | - E Dubois
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - F Gélébart
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - V Geertsen
- Univ. Paris-Saclay, CEA, CNRS, NIMBE-LIONS, 91191 Gif sur Yvette, CEDEX, France
| | - G Mériguet
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - L Michot
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - S Nakamae
- Service de Physique de l'état condensé, SPEC, CEA, CNRS, Université Paris-Saclay, CEA Saclay, 91191 Gif sur Yvette, CEDEX, France
| | - R Perzynski
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
| | - V Peyre
- Sorbonne Université, CNRS, Lab. PHENIX, 4 Place Jussieu, F-75005 Paris, France.
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7
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Fung YKC, Perkin S. Structure and anomalous underscreening in ethylammonium nitrate solutions confined between two mica surfaces. Faraday Discuss 2023; 246:370-386. [PMID: 37458200 PMCID: PMC10568257 DOI: 10.1039/d3fd00042g] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 03/02/2023] [Indexed: 10/13/2023]
Abstract
The observation of long-range interactions across ionic liquids and highly concentrated electrolytes, extending far beyond the Debye-Hückel prediction and beyond the range predicted in liquid state theory, has been called 'anomalous underscreening'. A number of theoretical and experimental works have explored this phenomenon over recent years, although its origin is not yet fully understood. Most of the experimental studies of anomalous underscreening until now involved aprotic ionic liquids, and so it is of interest to explore interactions in protic ionic liquids where the distribution of charge in the fluid is different in nature. Here we present direct measurements of the interaction force as a function of separation distance, measured using a surface force balance, across solutions of a protic ionic liquid ethylammonium nitrate (EAN) and its mixtures with water over a range of volume fractions from 10 vol% to 100 vol% EAN. The results reveal intricate details about near-surface ordering and dynamics at the EAN-mica interface as well as anomalous underscreening consistent with that observed in the past with aprotic ionic liquids.
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Affiliation(s)
- Y K Catherine Fung
- Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK.
| | - Susan Perkin
- Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK.
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8
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Zheng Q, Goodwin ZAH, Gopalakrishnan V, Hoane AG, Han M, Zhang R, Hawthorne N, Batteas JD, Gewirth AA, Espinosa-Marzal RM. Water in the Electrical Double Layer of Ionic Liquids on Graphene. ACS NANO 2023; 17:9347-9360. [PMID: 37163519 DOI: 10.1021/acsnano.3c01043] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The performance of electrochemical devices using ionic liquids (ILs) as electrolytes can be impaired by water uptake. This work investigates the influence of water on the behavior of hydrophilic and hydrophobic ILs─with ethylsulfate and tris(perfluoroalkyl)trifluorophosphate or bis(trifluoromethyl sulfonyl)imide (TFSI) anions, respectively─on electrified graphene, a promising electrode material. The results show that water uptake slightly reduces the IL electrochemical stability and significantly influences graphene's potential of zero charge, which is justified by the extent of anion depletion from the surface. Experiments confirm the dominant contribution of graphene's quantum capacitance (CQ) to the total interfacial capacitance (Cint) near the PZC, as expected from theory. Combining theory and experiments reveals that the hydrophilic IL efficiently screens surface charge and exhibits the largest double layer capacitance (CIL ∼ 80 μF cm-2), so that CQ governs the charge stored. The hydrophobic ILs are less efficient in charge screening and thus exhibit a smaller capacitance (CIL ∼ 6-9 μF cm-2), which governs Cint already at small potentials. An increase in the total interfacial capacitance is observed at positive voltages for humid TFSI-ILs relative to dry ones, consistent with the presence of a satellite peak. Short-range surface forces reveal the change of the interfacial layering with potential and water uptake owing to reorientation of counterions, counterion binding, co-ion repulsion, and water enrichment. These results are consistent with the charge being mainly stored in a ∼2 nm-thick double layer, which implies that ILs behave as highly concentrated electrolytes. This knowledge will advance the design of IL-graphene-based electrochemical devices.
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Affiliation(s)
- Qianlu Zheng
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Zachary A H Goodwin
- Department of Materials, Imperial College London, London SW7 2AZ, United Kingdom
- John A. Paulson School of Engineering and Applied Science, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Varun Gopalakrishnan
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Alexis G Hoane
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Mengwei Han
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Ruixian Zhang
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Nathaniel Hawthorne
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - James D Batteas
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
- Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Andrew A Gewirth
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
| | - Rosa M Espinosa-Marzal
- Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
- Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, United States
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9
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Härtel A, Bültmann M, Coupette F. Anomalous Underscreening in the Restricted Primitive Model. PHYSICAL REVIEW LETTERS 2023; 130:108202. [PMID: 36962045 DOI: 10.1103/physrevlett.130.108202] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 12/19/2022] [Accepted: 02/08/2023] [Indexed: 06/18/2023]
Abstract
Underscreening is a collective term for charge correlations in electrolytes decaying slower than the Debye length. Anomalous underscreening refers to phenomenology that cannot be attributed alone to steric interactions. Experiments with concentrated electrolytes and ionic fluids report anomalous underscreening, which so far has not been observed in simulation. We present Molecular Dynamics simulation results exhibiting anomalous underscreening that can be connected to cluster formation. A theory that accounts for ion pairing confirms the trend. Our results challenge the classic understanding of dense electrolytes impacting the design of technologies for energy storage and conversion.
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Affiliation(s)
- Andreas Härtel
- Institute of Physics, University of Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
| | - Moritz Bültmann
- Institute of Physics, University of Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
| | - Fabian Coupette
- Institute of Physics, University of Freiburg, Hermann-Herder-Straße 3, 79104 Freiburg, Germany
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10
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Kumar S, Cats P, Alotaibi MB, Ayirala SC, Yousef AA, van Roij R, Siretanu I, Mugele F. Absence of anomalous underscreening in highly concentrated aqueous electrolytes confined between smooth silica surfaces. J Colloid Interface Sci 2022; 622:819-827. [PMID: 35561602 DOI: 10.1016/j.jcis.2022.05.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 04/08/2022] [Accepted: 05/01/2022] [Indexed: 10/18/2022]
Abstract
Recent surface forces apparatus experiments that measured the forces between two mica surfaces and a series of subsequent theoretical studies suggest the occurrence of universal underscreening in highly concentrated electrolyte solutions. We performed a set of systematic Atomic Force Spectroscopy measurements for aqueous salt solutions in a concentration range from 1 mM to 5 M using chloride salts of various alkali metals as well as mixed concentrated salt solutions (involving both mono- and divalent cations and anions), that mimic concentrated brines typically encountered in geological formations. Experiments were carried out using flat substrates and submicrometer-sized colloidal probes made of smooth oxidized silicon immersed in salt solutions at pH values of 6 and 9 and temperatures of 25 °C and 45 °C. While strong repulsive forces were observed for the smallest tip-sample separations, none of the conditions explored displayed any indication of anomalous long range electrostatic forces as reported for mica surfaces. Instead, forces are universally dominated by attractive van der Waals interactions at tip-sample separations of ≈2 nm and beyond for salt concentrations of 1 M and higher. Complementary calculations based on classical density functional theory for the primitive model support these experimental observations and display a consistent decrease in screening length with increasing ion concentration.
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Affiliation(s)
- Saravana Kumar
- Physics of Complex Fluids Group and MESA+ Institute, Faculty of Science and Technology, University of Twente, PO Box 217, 7500 AE Enschede, the Netherlands
| | - Peter Cats
- Institute for Theoretical Physics, Center for Extreme Matter and Emergent Phenomena, Utrecht University, Princetonplein 5, 3584 CC Utrecht, the Netherlands
| | - Mohammed B Alotaibi
- The Exploration and Petroleum Engineering Center - Advanced Research Center (EXPEC ARC), Saudi Aramco, Dhahran 34465, Saudi Arabia
| | - Subhash C Ayirala
- The Exploration and Petroleum Engineering Center - Advanced Research Center (EXPEC ARC), Saudi Aramco, Dhahran 34465, Saudi Arabia
| | - Ali A Yousef
- The Exploration and Petroleum Engineering Center - Advanced Research Center (EXPEC ARC), Saudi Aramco, Dhahran 34465, Saudi Arabia
| | - René van Roij
- Institute for Theoretical Physics, Center for Extreme Matter and Emergent Phenomena, Utrecht University, Princetonplein 5, 3584 CC Utrecht, the Netherlands
| | - Igor Siretanu
- Physics of Complex Fluids Group and MESA+ Institute, Faculty of Science and Technology, University of Twente, PO Box 217, 7500 AE Enschede, the Netherlands
| | - Frieder Mugele
- Physics of Complex Fluids Group and MESA+ Institute, Faculty of Science and Technology, University of Twente, PO Box 217, 7500 AE Enschede, the Netherlands
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11
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Goodwin ZA, Kornyshev AA. Cracking Ion Pairs in the Electrical Double Layer of Ionic Liquids. Electrochim Acta 2022. [DOI: 10.1016/j.electacta.2022.141163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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12
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An R, Laaksonen A, Wu M, Zhu Y, Shah FU, Lu X, Ji X. Atomic force microscopy probing interactions and microstructures of ionic liquids at solid surfaces. NANOSCALE 2022; 14:11098-11128. [PMID: 35876154 DOI: 10.1039/d2nr02812c] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Ionic liquids (ILs) are room temperature molten salts that possess preeminent physicochemical properties and have shown great potential in many applications. However, the use of ILs in surface-dependent processes, e.g. energy storage, is hindered by the lack of a systematic understanding of the IL interfacial microstructure. ILs on the solid surface display rich ordering, arising from coulombic, van der Waals, solvophobic interactions, etc., all giving near-surface ILs distinct microstructures. Therefore, it is highly important to clarify the interactions of ILs with solid surfaces at the nanoscale to understand the microstructure and mechanism, providing quantitative structure-property relationships. Atomic force microscopy (AFM) opens a surface-sensitive way to probe the interaction force of ILs with solid surfaces in the layers from sub-nanometers to micrometers. Herein, this review showcases the recent progress of AFM in probing interactions and microstructures of ILs at solid interfaces, and the influence of IL characteristics, surface properties and external stimuli is thereafter discussed. Finally, a summary and perspectives are established, in which, the necessities of the quantification of IL-solid interactions at the molecular level, the development of in situ techniques closely coupled with AFM for probing IL-solid interfaces, and the combination of experiments and simulations are argued.
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Affiliation(s)
- Rong An
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
| | - Aatto Laaksonen
- Energy Engineering, Division of Energy Science, Luleå University of Technology, 97187 Luleå, Sweden.
- Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, SE-10691 Stockholm, Sweden
- Center of Advanced Research in Bionanoconjugates and Biopolymers, "Petru Poni" Institute of Macromolecular Chemistry, Iasi 700469, Romania
- State Key Laboratory of Materials-Oriented and Chemical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Muqiu Wu
- Herbert Gleiter Institute of Nanoscience, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
| | - Yudan Zhu
- State Key Laboratory of Materials-Oriented and Chemical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Faiz Ullah Shah
- Chemistry of Interfaces, Luleå University of Technology, 97187 Luleå, Sweden
| | - Xiaohua Lu
- State Key Laboratory of Materials-Oriented and Chemical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Xiaoyan Ji
- Energy Engineering, Division of Energy Science, Luleå University of Technology, 97187 Luleå, Sweden.
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13
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Abstract
Recent experiments have shown that the repulsive force between atomically flat, like-charged surfaces confining room-temperature ionic liquids or concentrated electrolytes exhibits an anomalously large decay length. In our previous publication [J. Zeman, S. Kondrat, and C. Holm, Chem. Commun. 56, 15635 (2020)], we showed by means of extremely large-scale molecular dynamics simulations that this so-called underscreening effect might not be a feature of bulk electrolytes. Herein, we corroborate these findings by providing additional results with more detailed analyses and expand our investigations to ionic liquids under confinement. Unlike in bulk systems, where screening lengths are computed from the decay of interionic potentials of mean force, we extract such data in confined systems from cumulative charge distributions. At high concentrations, our simulations show increasing screening lengths with increasing electrolyte concentration, consistent with classical liquid state theories. However, our analyses demonstrate that-also for confined systems-there is no anomalously large screening length. As expected, the screening lengths determined for ionic liquids under confinement are in good quantitative agreement with the screening lengths of the same ionic systems in bulk. In addition, we show that some theoretical models used in the literature to relate the measured screening lengths to other observables are inapplicable to highly concentrated electrolytes.
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Affiliation(s)
- Johannes Zeman
- Institute for Computational Physics, University of Stuttgart, D-70569 Stuttgart, Germany
| | - Svyatoslav Kondrat
- Institute of Physical Chemistry, Polish Academy of Sciences, 01-224 Warsaw, Poland
| | - Christian Holm
- Institute for Computational Physics, University of Stuttgart, D-70569 Stuttgart, Germany
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14
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Riedl JC, Sarkar M, Fiuza T, Cousin F, Depeyrot J, Dubois E, Mériguet G, Perzynski R, Peyre V. Design of concentrated colloidal dispersions of iron oxide nanoparticles in ionic liquids: Structure and thermal stability from 25 to 200 °C. J Colloid Interface Sci 2021; 607:584-594. [PMID: 34509733 DOI: 10.1016/j.jcis.2021.08.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 08/02/2021] [Accepted: 08/03/2021] [Indexed: 11/19/2022]
Abstract
HYPOTHESIS Some of the most promising fields of application of ionic liquid-based colloids imply elevated temperatures. Their careful design and analysis is therefore essential. We assume that tuning the structure of the nanoparticle-ionic liquid interface through its composition can ensure colloidal stability for a wide temperature range, from room temperature up to 200 °C. EXPERIMENTS The system under study consists of iron oxide nanoparticles (NPs) dispersed in ethylmethylimidazolium bistriflimide (EMIM TFSI). The key parameters of the solid-liquid interface, tuned at room temperature, are the surface charge density and the nature of the counterions. The thermal stability of these nanoparticle dispersions is then analysed on the short and long term up to 200 °C. A multiscale analysis is performed combining dynamic light scattering (DLS), small angle X-ray/neutron scattering (SAXS/SANS) and thermogravimetric analysis (TGA). FINDINGS Following the proposed approach with a careful choice of the species at the solid-liquid interface, ionic liquid-based colloidal dispersions of iron oxide NPs in EMIM TFSI stable over years at room temperature can be obtained, also stable at least over days up to 200 °C and NPs concentrations up to 12 vol% (≈30 wt%) thanks to few near-surface ionic layers.
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Affiliation(s)
- J C Riedl
- Sorbonne Université, CNRS, Laboratoire PHENIX, 4 place Jussieu, case 51, 75005 Paris, France.
| | - M Sarkar
- Sorbonne Université, CNRS, Laboratoire PHENIX, 4 place Jussieu, case 51, 75005 Paris, France.
| | - T Fiuza
- Sorbonne Université, CNRS, Laboratoire PHENIX, 4 place Jussieu, case 51, 75005 Paris, France; Inst. de Fisica, Complex Fluid Group, Universidade de Brasília, Brasília, Brazil.
| | - F Cousin
- Laboratoire Léon Brillouin, UMR 12 CNRS-CEA, CEA-Saclay, 91191 Gif-sur-Yvette, France.
| | - J Depeyrot
- Inst. de Fisica, Complex Fluid Group, Universidade de Brasília, Brasília, Brazil
| | - E Dubois
- Sorbonne Université, CNRS, Laboratoire PHENIX, 4 place Jussieu, case 51, 75005 Paris, France.
| | - G Mériguet
- Sorbonne Université, CNRS, Laboratoire PHENIX, 4 place Jussieu, case 51, 75005 Paris, France.
| | - R Perzynski
- Sorbonne Université, CNRS, Laboratoire PHENIX, 4 place Jussieu, case 51, 75005 Paris, France.
| | - V Peyre
- Sorbonne Université, CNRS, Laboratoire PHENIX, 4 place Jussieu, case 51, 75005 Paris, France.
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15
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Shmukler L, Fedorova I, Fadeeva YA, Safonova L. The physicochemical properties and structure of alkylammonium protic ionic liquids of RnH4-nNX (n = 1–3) family. A mini–review. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.114350] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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16
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Kiratidis AL, Miklavcic SJ. Density functional theory of confined ionic liquids: the influence of power-law attractions on molecule distributions and surface forces. RSC Adv 2021; 11:17498-17513. [PMID: 35479724 PMCID: PMC9032692 DOI: 10.1039/d1ra02761a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 04/28/2021] [Indexed: 12/13/2022] Open
Abstract
Interaction energies and density profiles for two model ionic liquids, [C4mim+][BF4−] and [C4mim+][TFSI−], confined between charged planar walls are studied within a density functional theory framework. The results of these simulations are also compared with results assuming a simpler linear hexamer–monomer, cation–anion system. We focus attention on the effect on the atom site distributions and the surface forces of an additional, specific attractive potential between oppositely charged molecules. We consider both short- and long-ranged attractive potentials in order to span the degree to which the ionic counterions associate. Independent of its strength, we interpret the results found with the short-ranged potential to be a manifestation of limited molecular association. In contrast, depending on its strength, the results found with the long-ranged potential suggest a much stronger and possibly longer ranged associations of ionic groups. Both potentials are found to influence the behavior of the surface force at small separations, while the long-ranged attractive potential has the greater influence of the two on the long-ranged behavior of the surface force. Interaction energies and density profiles for two model ionic liquids, [C4mim+][BF4−] and [C4mim+][TFSI−], confined between charged planar walls are studied within a density functional theory framework.![]()
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Affiliation(s)
- Adrian L. Kiratidis
- Phenomics and Bioinformatics Research Centre
- UniSA STEM
- University of South Australia
- Mawson Lakes
- Australia
| | - Stanley J. Miklavcic
- Phenomics and Bioinformatics Research Centre
- UniSA STEM
- University of South Australia
- Mawson Lakes
- Australia
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17
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Zeman J, Kondrat S, Holm C. Bulk ionic screening lengths from extremely large-scale molecular dynamics simulations. Chem Commun (Camb) 2020; 56:15635-15638. [PMID: 33283802 DOI: 10.1039/d0cc05023g] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recent experiments have reported anomalously large screening lengths of interactions between charged surfaces confining concentrated electrolytes and ionic liquids. Termed underscreening, this effect was ascribed to bulk properties of dense ionic systems. Herein, we study bulk ionic screening with extremely large-scale molecular dynamics simulations, allowing us to assess the range of distances relevant to the experiments. Our results yield two screening lengths satisfying distinct scaling relations. However, with an accuracy of 10-5kBT in interionic potentials of mean force, we find no signs of underscreening, suggesting that other than bulk effects might be at play in the experiments.
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Affiliation(s)
- Johannes Zeman
- Institute for Computational Physics, University of Stuttgart, D-70569 Stuttgart, Germany.
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18
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Yuan H, Liu G. Ionic effects on synthetic polymers: from solutions to brushes and gels. SOFT MATTER 2020; 16:4087-4104. [PMID: 32292998 DOI: 10.1039/d0sm00199f] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The ionic effects on synthetic polymers have attracted extensive attention due to the crucial role of ions in the determination of the properties of synthetic polymers. This review places the focus on specific ion effects, multivalent ion effects, and ionic hydrophilicity/hydrophobicity effects in synthetic polymer systems from solutions to brushes and gels. The specific ion effects on neutral polymers are determined by both the direct and indirect specific ion-polymer interactions, whereas the ion specificities of charged polymers are mainly dominated by the specific ion-pairing interactions. The ionic cross-linking effect exerted by the multivalent ions is widely used to tune the properties of polyelectrolytes, while the reentrant behavior of polyelectrolytes in the presence of multivalent ions still remains poorly understood. The ionic hydrophilicity/hydrophobicity effects not only can be applied to make strong polyelectrolytes thermosensitive, but also can be used to prepare polymeric nano-objects and to control the wettability of polyelectrolyte brush-modified surfaces. The not well-studied ionic hydrogen bond effects are also discussed in the last section of this review.
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Affiliation(s)
- Haiyang Yuan
- Hefei National Laboratory for Physical Sciences at the Microscale, Key Laboratory of Surface and Interface Chemistry and Energy Catalysis of Anhui Higher Education Institutes, Department of Chemical Physics, University of Science and Technology of China, No. 96, Jinzhai Road, Hefei 230026, P. R. China.
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19
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Fedorova IV, Safonova LP. Ion Pair Structures and Hydrogen Bonding in R nNH 4-n Alkylammonium Ionic Liquids with Hydrogen Sulfate and Mesylate Anions by DFT Computations. J Phys Chem A 2020; 124:3170-3179. [PMID: 32243166 DOI: 10.1021/acs.jpca.0c01282] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Density function theory calculations are employed to study the interaction of amines bearing different numbers of alkyl substituents of different sizes on the nitrogen atom with sulfuric and methanesulfonic acids. The proton affinities of the studied amines are calculated, and it is shown that the higher the value is, the more probable is its protonation. The most stable structures of the ion pairs resulting from the acid-base interaction are obtained and characterized. The geometric parameters of the ion pairs and the characteristics derived from the NBO and QTAIM analysis show that there are hydrogen bonding interactions between the cation and the anion. The hydrogen bonding character of the ion pairs and the strength of the interaction between the ions strongly depend on the nature of the cation itself. The interaction between the ions in the ion pairs weakens with the increase in the cation size. The trend of change in the structural parameters of the H-bonds and energetic characteristics in the cation series for the studied ion pairs is not dependent on the nature of the anion.
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Affiliation(s)
- Irina V Fedorova
- G. A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, 1 Akademicheskaya Street, Ivanovo 153045, Russia
| | - Lyubov P Safonova
- G. A. Krestov Institute of Solution Chemistry of the Russian Academy of Sciences, 1 Akademicheskaya Street, Ivanovo 153045, Russia
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20
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Coles SW, Park C, Nikam R, Kanduč M, Dzubiella J, Rotenberg B. Correlation Length in Concentrated Electrolytes: Insights from All-Atom Molecular Dynamics Simulations. J Phys Chem B 2020; 124:1778-1786. [PMID: 32031810 DOI: 10.1021/acs.jpcb.9b10542] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We study the correlation length of the charge-charge pair correlations in concentrated electrolyte solutions by means of all-atom, explicit-solvent molecular dynamics simulations. We investigate LiCl and NaI in water, which constitute highly soluble, prototypical salts for experiments, as well as two more complex, molecular electrolyte systems of lithium bis(trifluoromethane)sulfonimide (LiTFSI), a salt commonly employed in electrochemical storage systems, in water, and in an organic solvent mixture of dimethoxyethane and dioxolane. Our simulations support the recent experimental observations as well as theoretical predictions of a nonmonotonic behavior of the correlation length with increasing salt concentration. We observe a Debye-Hückel like regime at low concentration, followed by a minimum reached when d/λD ≃ 1, where λD is the Debye correlation length and d is the effective ionic diameter, and an increasing correlation length with salt concentration in very concentrated electrolytes. As in the experiments, we find that the screening length in the concentrated regime follows a universal scaling law as a function d/λD for all studied salts. However, the scaling exponent is significantly lower than the experimentally measured one and lies in the range of the theoretical predictions based on much simpler electrolyte models.
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Affiliation(s)
- Samuel W Coles
- Sorbonne Université, CNRS, Physicochimie des électrolytes et Nanosystèmes Interfaciaux, UMR PHENIX, 4 pl. Jussieu, F-75005 Paris, France
| | - Chanbum Park
- Research Group for Simulations of Energy Materials, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany.,Institut für Physik, Humboldt-Universität zu Berlin, Newtonstr. 15, D-12489 Berlin, Germany
| | - Rohit Nikam
- Research Group for Simulations of Energy Materials, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany.,Institut für Physik, Humboldt-Universität zu Berlin, Newtonstr. 15, D-12489 Berlin, Germany
| | - Matej Kanduč
- Research Group for Simulations of Energy Materials, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany.,Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Joachim Dzubiella
- Research Group for Simulations of Energy Materials, Hahn-Meitner-Platz 1, D-14109 Berlin, Germany.,Applied Theoretical Physics-Computational Physics, Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 3, D-79104 Freiburg, Germany
| | - Benjamin Rotenberg
- Sorbonne Université, CNRS, Physicochimie des électrolytes et Nanosystèmes Interfaciaux, UMR PHENIX, F-75005 Paris, France
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21
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Lhermerout R, Perkin S. A new methodology for a detailed investigation of quantized friction in ionic liquids. Phys Chem Chem Phys 2020; 22:455-466. [PMID: 31781711 DOI: 10.1039/c9cp05422g] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
When confined at the nanoscale between smooth surfaces, an ionic liquid forms a structured film responding to shear in a quantized way, i.e., with a friction coefficient indexed by the number of layers in the gap. So far, only a few experiments have been performed to study this phenomenon, because of the delicate nature of the measurements. We propose a new methodology to measure friction with a surface force balance, based on the simultaneous application of normal and lateral motions to the surfaces, allowing for a more precise, comprehensive and rapid determination of the friction response. We report on proof-of-concept experiments with an ionic liquid confined between mica surfaces in dry or wet conditions, showing the phenomenon of quantized friction with an unprecedented resolution. First, we show that the variation of the kinetic friction force with the applied load for a given layer is not linear, but can be quantitatively described by two additive contributions that are respectively proportional to the load and to the contact area. Then, we find that humidity improves the resistance of the layers to be squeezed-out and extends the range of loads in which the liquid behaves as a superlubricant, interpreted by an enhanced dissolution of the potassium ions on the mica leading to a larger surface charge. There, we note a liquid-like friction behavior, and observe in certain conditions a clear variation of the kinetic friction force over two decades of shearing velocities, that does not obey a simple Arrhenius dynamics.
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Affiliation(s)
- Romain Lhermerout
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, OX1 3QZ, UK.
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22
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Ntim S, Sulpizi M. Role of image charges in ionic liquid confined between metallic interfaces. Phys Chem Chem Phys 2020; 22:10786-10791. [DOI: 10.1039/d0cp00409j] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Atomistic molecular dynamics simulations unveil a minor role of metal polarisation at ionic liquid/gold interface and provide a novel description of the interface where long range effects are seen in dynamical properties up to 10 nm from surface.
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Affiliation(s)
- Samuel Ntim
- Institut für Physik
- Johannes Gutenberg Universität
- 55128-Mainz
- Germany
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23
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Hjalmarsson N, Bergendal E, Wang YL, Munavirov B, Wallinder D, Glavatskih S, Aastrup T, Atkin R, Furó I, Rutland MW. Electro-Responsive Surface Composition and Kinetics of an Ionic Liquid in a Polar Oil. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:15692-15700. [PMID: 31581771 DOI: 10.1021/acs.langmuir.9b02119] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The quartz crystal microbalance (QCM) has been used to study how the interfacial layer of an ionic liquid dissolved in a polar oil at low weight percentages responds to changes in applied potential. The changes in surface composition at the QCM gold surface depend on both the magnitude and sign of the applied potential. The time-resolved response indicates that the relaxation kinetics are limited by the diffusion of ions in the interfacial region and not in the bulk, since there is no concentration dependence. The measured mass changes cannot be explained only in terms of simple ion exchange; the relative molecular volumes of the ions and the density changes in response to ion exclusion must be considered. The relaxation behavior of the potential between the electrodes upon disconnecting the applied potential is more complex than that observed for pure ionic liquids, but a measure of the surface charge can be extracted from the exponential decay when the rapid initial potential drop is accounted for. The adsorbed film at the gold surface consists predominantly of ionic liquid despite the low concentration, which is unsurprising given the surtactant-like structures of (some of) the ionic liquid ions. Changes in response to potential correspond to changes in the relative numbers of cations and anions, rather than a change in the oil composition. No evidence for an electric field induced change in viscosity is observed. This work shows conclusively that electric potentials can be used to control the surface composition, even in an oil-based system, and paves the way for other ion solvent studies.
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Affiliation(s)
| | | | | | | | | | - Sergei Glavatskih
- Department of Electrical Energy, Metals, Mechanical Constructions and Systems , Ghent University , B-9000 , Ghent , Belgium
| | | | - Rob Atkin
- School of Molecular Sciences , University of Western Australia , 6009 Perth , Australia
| | | | - Mark W Rutland
- Surfaces, Processes and Formulation , RISE Research Institutes of Sweden , SE-50115 Stockholm , Sweden
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24
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Kjellander R. The intimate relationship between the dielectric response and the decay of intermolecular correlations and surface forces in electrolytes. SOFT MATTER 2019; 15:5866-5895. [PMID: 31243425 DOI: 10.1039/c9sm00712a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A general, exact theory for the decay of interactions between any particles immersed in electrolytes, including surface forces between macroscopic bodies, is derived in a self-contained, physically transparent manner. It is valid for electrolytes at any density, including ionic gases, molten salts, ionic liquids, and electrolyte solutions with molecular solvent at any concentration. The ions, the solvent and any other particles in the system can have any sizes, any shapes and arbitrary internal charge distributions. The spatial propagation of the interactions in electrolytes has several decay modes with different decay lengths that are given by the solutions, κν, ν = 1, 2,…, to a general equation for the screening parameter κ; an equation that describes the dielectric response. There can exist simultaneous decay modes with plain exponential decay and modes with damped oscillatory exponential decay, as observed experimentally and theoretically. In the limit of zero ionic density, the decay length 1/κν of the mode with the longest range approaches the Debye length 1/κD. The coupling between fluctuations in number density and charge density, described by the density-charge correlation function HNQ(r), makes all decay modes of pair correlations and interaction free energies identical to those of the screened electrostatic potential, and hence they have the same values for the screening parameters. The density-density and charge-charge correlation functions, HNN(r) and HQQ(r), also have these decay modes. For the exceptional case of charge-inversion invariant systems, HNQ(r) is identically zero for symmetry reasons and HNN(r) and HQQ(r) have, instead, decay modes with different decay lengths.
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Affiliation(s)
- Roland Kjellander
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden.
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25
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Kiratidis AL, Miklavcic SJ. Density functional theory of confined ionic liquids: A survey of the effects of ion type, molecular charge distribution, and surface adsorption. J Chem Phys 2019; 150:184502. [DOI: 10.1063/1.5093552] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Adrian L. Kiratidis
- Phenomics and Bioinformatics Research Centre, School of Information Technology and Mathematical Sciences, University of South Australia, Mawson Lakes, SA, Australia
| | - Stanley J. Miklavcic
- Phenomics and Bioinformatics Research Centre, School of Information Technology and Mathematical Sciences, University of South Australia, Mawson Lakes, SA, Australia
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26
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Gaddam P, Ducker W. Electrostatic Screening Length in Concentrated Salt Solutions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:5719-5727. [PMID: 30945875 DOI: 10.1021/acs.langmuir.9b00375] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Thin films (0-30 nm) of very concentrated aqueous monovalent salt solutions (2-10 M of LiCl, NaCl, and CsCl) were examined to determine how ionic strength affects the screening length of the electrostatic potential. Measurements were consistent with a screening length in the range of 3-12 nm. The screening length increased monotonically as a function of salt concentration, and the rate of increase was a function of the monovalent salt type. The results were incompatible with the Debye length of Poisson-Boltzmann theory but consistent with previous measurements of surface forces. The screening length was determined from the surface excess of fluorescein, a dianion under basic conditions, which was present in trace amounts in the thin film and detected via its fluorescence emission. That is, we directly observed that the ion concentration in very concentrated solutions is perturbed far from an interface.
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Affiliation(s)
- Prudhvidhar Gaddam
- Department of Chemical Engineering and Center for Soft Matter, Biological Physics , Virginia Tech , Blacksburg , Virginia 24061 , United States
| | - William Ducker
- Department of Chemical Engineering and Center for Soft Matter, Biological Physics , Virginia Tech , Blacksburg , Virginia 24061 , United States
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27
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Miklavcic SJ, Fung C. Quantifying the force between mercury and mica across an ionic liquid using white light interferometry. J Colloid Interface Sci 2019; 538:218-227. [PMID: 30508742 DOI: 10.1016/j.jcis.2018.11.079] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 11/20/2018] [Accepted: 11/20/2018] [Indexed: 11/29/2022]
Abstract
HYPOTHESIS Under axisymmetric conditions, changes in the thickness of the thin film between a fluid drop and a solid revealed by white light interferometry can provide information about the interaction of the bodies. Thus, in principle one can quantify the force between the surfaces using interferometric information of film thickness profile. This is needed to quantify and analyze drop-solid interactions across complex fluids such as an ionic liquid to independently characterize new surface forces. EXPERIMENTS Interferometric fringes were obtained in experiments on the interaction between a mercury drop and mica across a film of room temperature ionic liquid. The data is analyzed using a novel formula giving the total force acting on the drop. The calculations are compared with two other approaches to estimating forces. Qualitative and quantitative differences are discussed. FINDINGS This is the first report of forces measured between mercury and mica across an ionic liquid. The system is subjected to different applied electric potentials. In each case a long ranged, exponentially decaying repulsive force is found. At small separations, the system becomes unstable and the surfaces jump into contact. The comparison of force calculation methods demonstrates the superiority of the force approach proposed here.
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Affiliation(s)
- S J Miklavcic
- Phenomics and Bioinformatics Research Centre, School of Information Technology and Mathematical Sciences, University of South Australia, Mawson Lakes, SA 5095, Australia.
| | - C Fung
- Phenomics and Bioinformatics Research Centre, School of Information Technology and Mathematical Sciences, University of South Australia, Mawson Lakes, SA 5095, Australia
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28
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Radiom M. Ionic liquid–solid interface and applications in lubrication and energy storage. Curr Opin Colloid Interface Sci 2019. [DOI: 10.1016/j.cocis.2019.01.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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29
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Sindoro M, Granick S. Ionic Janus Liquid Droplets Assembled and Propelled by Electric Field. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201810862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Melinda Sindoro
- School of Materials Science & EngineeringNanyang Technological University 50 Nanyang Ave Singapore 639798 Singapore
| | - Steve Granick
- IBS Center for Soft and Living MatterInstitute of Basic Science Ulsan 44919 Republic of Korea
- Departments of Chemistry and PhysicsUNIST Ulsan 44919 Republic of Korea
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30
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Sindoro M, Granick S. Ionic Janus Liquid Droplets Assembled and Propelled by Electric Field. Angew Chem Int Ed Engl 2018; 57:16773-16776. [PMID: 30378736 DOI: 10.1002/anie.201810862] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Indexed: 11/06/2022]
Affiliation(s)
- Melinda Sindoro
- School of Materials Science & EngineeringNanyang Technological University 50 Nanyang Ave Singapore 639798 Singapore
| | - Steve Granick
- IBS Center for Soft and Living MatterInstitute of Basic Science Ulsan 44919 Republic of Korea
- Departments of Chemistry and PhysicsUNIST Ulsan 44919 Republic of Korea
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31
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Anomalous Interfacial Structuring of a Non-Halogenated Ionic Liquid: Effect of Substrate and Temperature. COLLOIDS AND INTERFACES 2018. [DOI: 10.3390/colloids2040060] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We investigate the interfacial properties of the non-halogenated ionic liquid (IL), trihexyl(tetradecyl)phosphonium bis(mandelato)borate, [P6,6,6,14][BMB], in proximity to solid surfaces, by means of surface force measurement. The system consists of sharp atomic force microscopy (AFM) tips interacting with solid surfaces of mica, silica, and gold. We find that the force response has a monotonic form, from which a characteristic steric decay length can be extracted. The decay length is comparable with the size of the ions, suggesting that a layer is formed on the surface, but that it is diffuse. The long alkyl chains of the cation, the large size of the anion, as well as crowding of the cations at the surface of negatively charged mica, are all factors which are likely to oppose the interfacial stratification which has, hitherto, been considered a characteristic of ionic liquids. The variation in the decay length also reveals differences in the layer composition at different surfaces, which can be related to their surface charge. This, in turn, allows the conclusion that silica has a low surface charge in this aprotic ionic liquid. Furthermore, the effect of temperature has been investigated. Elevating the temperature to 40 °C causes negligible changes in the interaction. At 80 °C and 120 °C, we observe a layering artefact which precludes further analysis, and we present the underlying instrumental origin of this rather universal artefact.
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Kjellander R. Focus Article: Oscillatory and long-range monotonic exponential decays of electrostatic interactions in ionic liquids and other electrolytes: The significance of dielectric permittivity and renormalized charges. J Chem Phys 2018; 148:193701. [DOI: 10.1063/1.5010024] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Affiliation(s)
- Roland Kjellander
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden
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Hoque M, Thomas M, Miran MS, Akiyama M, Marium M, Ueno K, Dokko K, Watanabe M. Protic ionic liquids with primary alkylamine-derived cations: the dominance of hydrogen bonding on observed physicochemical properties. RSC Adv 2018; 8:9790-9794. [PMID: 35540830 PMCID: PMC9078737 DOI: 10.1039/c8ra00402a] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Accepted: 02/26/2018] [Indexed: 11/21/2022] Open
Abstract
The dominance of hydrogen bonds (networking) over the physicochemical features of primary alkylamine-PILs based on an amide acid.
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Affiliation(s)
- Mahfuzul Hoque
- Department of Chemistry and Biotechnology
- Yokohama National University
- Yokohama 240-8501
- Japan
| | - Morgan L. Thomas
- Department of Chemistry and Biotechnology
- Yokohama National University
- Yokohama 240-8501
- Japan
| | - Muhammed Shah Miran
- Department of Chemistry and Biotechnology
- Yokohama National University
- Yokohama 240-8501
- Japan
| | - Mio Akiyama
- Department of Chemistry and Biotechnology
- Yokohama National University
- Yokohama 240-8501
- Japan
| | - Mayeesha Marium
- Department of Chemistry and Biotechnology
- Yokohama National University
- Yokohama 240-8501
- Japan
| | - Kazuhide Ueno
- Department of Chemistry and Biotechnology
- Yokohama National University
- Yokohama 240-8501
- Japan
| | - Kaoru Dokko
- Department of Chemistry and Biotechnology
- Yokohama National University
- Yokohama 240-8501
- Japan
| | - Masayoshi Watanabe
- Department of Chemistry and Biotechnology
- Yokohama National University
- Yokohama 240-8501
- Japan
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Coles S, Smith AM, Fedorov MV, Hausen F, Perkin S. Interfacial structure and structural forces in mixtures of ionic liquid with a polar solvent. Faraday Discuss 2018; 206:427-442. [DOI: 10.1039/c7fd00168a] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Oscillatory and monotonic decay in mixtures of salt and solvent at interfaces with varying surface charge.
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Affiliation(s)
- Samuel W. Coles
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory
- University of Oxford
- Oxford OX1 3QZ
- UK
| | - Alexander M. Smith
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory
- University of Oxford
- Oxford OX1 3QZ
- UK
- Department of Inorganic and Analytical Chemistry
| | - Maxim V. Fedorov
- Department of Physics
- Scottish Universities Physics Alliance (SUPA)
- Strathclyde University
- Glasgow G4 0NG
- UK
| | - Florian Hausen
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory
- University of Oxford
- Oxford OX1 3QZ
- UK
- Institute of Energy and Climate Research
| | - Susan Perkin
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory
- University of Oxford
- Oxford OX1 3QZ
- UK
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35
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Sanchez-Fernandez A, Hammond OS, Jackson AJ, Arnold T, Doutch J, Edler KJ. Surfactant-Solvent Interaction Effects on the Micellization of Cationic Surfactants in a Carboxylic Acid-Based Deep Eutectic Solvent. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:14304-14314. [PMID: 29182879 DOI: 10.1021/acs.langmuir.7b03254] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Deep eutectic solvents have been demonstrated to support amphiphile self-assembly, providing potential alternatives as structure-directing agents in the synthesis of nanostructures, and drug delivery. Here we have expanded on this recent research to investigate the self-assembly of alkyltrimethylammonium bromide surfactants in choline chloride:malonic acid deep eutectic solvent and mixtures of the solvent with water. Surface tension and small-angle neutron scattering were used to determine the behavior of the amphiphiles. Surfactants were found to remain active in the solvent, and surface tension measurements revealed changes in the behavior of the surfactants with different levels of hydration. Small-angle neutron scattering shows that in this solvent the micelle shape depends on the surfactant chain length, varying from globular micelles (aspect ratio ∼2) for short chain surfactants to elongated micelles (aspect ratio ∼14) for long chain surfactants even at low surfactant concentration. We suggest that the formation of elongated micelles can be explained through the interaction of the solvent with the surfactant headgroup, since ion-ion interactions between surfactant headgroups and solvent may modify the morphology of the micelles. The presence of water in the deep eutectic solvents promotes an increase in the charge density at the micelle interface and therefore the formation of less elongated, globular micelles.
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Affiliation(s)
- Adrian Sanchez-Fernandez
- Department of Chemistry, University of Bath , Claverton Down, Bath BA2 7AY, U.K
- European Spallation Source , Box 176, 22100 Lund, Sweden
| | - Oliver S Hammond
- Centre for Sustainable Chemical Technologies, University of Bath , Claverton Down, Bath BA2 7AY, U.K
| | - Andrew J Jackson
- European Spallation Source , Box 176, 22100 Lund, Sweden
- Department of Physical Chemistry, Lund University , SE-221 00 Lund, Sweden
| | - Thomas Arnold
- European Spallation Source , Box 176, 22100 Lund, Sweden
| | - James Doutch
- ISIS Neutron and Muon Source, Science and Technology Facilities Council, Rutherford Appleton Laboratory , Didcot OX11 0QX, U.K
| | - Karen J Edler
- Department of Chemistry, University of Bath , Claverton Down, Bath BA2 7AY, U.K
- Centre for Sustainable Chemical Technologies, University of Bath , Claverton Down, Bath BA2 7AY, U.K
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36
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37
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Lee AA, Perez-Martinez CS, Smith AM, Perkin S. Scaling Analysis of the Screening Length in Concentrated Electrolytes. PHYSICAL REVIEW LETTERS 2017; 119:026002. [PMID: 28753344 DOI: 10.1103/physrevlett.119.026002] [Citation(s) in RCA: 125] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2017] [Indexed: 05/23/2023]
Abstract
The interaction between charged objects in an electrolyte solution is a fundamental question in soft matter physics. It is well known that the electrostatic contribution to the interaction energy decays exponentially with object separation. Recent measurements reveal that, contrary to the conventional wisdom given by the classic Poisson-Boltzmann theory, the decay length increases with the ion concentration for concentrated electrolytes and can be an order of magnitude larger than the ion diameter in ionic liquids. We derive a simple scaling theory that explains this anomalous dependence of the decay length on the ion concentration. Our theory successfully collapses the decay lengths of a wide class of salts onto a single curve. A novel prediction of our theory is that the decay length increases linearly with the Bjerrum length, which we experimentally verify by surface force measurements. Moreover, we quantitatively relate the measured decay length to classic measurements of the activity coefficient in concentrated electrolytes, thus showing that the measured decay length is indeed a bulk property of the concentrated electrolyte as well as contributing a mechanistic insight into empirical activity coefficients.
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Affiliation(s)
- Alpha A Lee
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Carla S Perez-Martinez
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Alexander M Smith
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
- Department of Inorganic and Analytical Chemistry, University of Geneva, 1205 Geneva, Switzerland
| | - Susan Perkin
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
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38
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Rutland MW. Chemical physics of electroactive materials: concluding remarks. Faraday Discuss 2017; 199:615-630. [PMID: 28675400 DOI: 10.1039/c7fd00176b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
It is an honour to be charged with providing the concluding remarks for a Faraday Discussion. As many have remarked before, it is nonetheless a prodigious task, and what follows is necessarily a personal, and probably perverse, view of a watershed event in the Chemical Physics of Electroactive materials. The spirit of the conference was captured in a single sentence during the meeting itself."It is the nexus between rheology, electrochemistry, colloid science and energy storage". The current scientific climate is increasingly dominated by a limited number of global challenges, and there is thus a tendency for research to resemble a football match played by 6 year olds, where everyone on the field chases the (funding) ball instead of playing to their "discipline". It is thus reassuring to see how the application of rigorous chemical physics is leading to ingenious new solutions for both energy storage and harvesting, via, for example, nanoactuation, electrowetting, ionic materials and nanoplasmonics. In fact, the same language of chemical physics allows seamless transition between applications as diverse as mechano-electric energy generation, active moisture transport and plasmonic shutters - even the origins of life were addressed in the context of electro-autocatalysis!
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Affiliation(s)
- Mark W Rutland
- KTH Royal Institute of Technology, Surface and Corrosion Science, Drottning Kristinas väg 51, Stockholm 10044, Sweden. and RISE Research Institutes of Sweden AB, Chemistry Materials and Surfaces, Drottning Kristinas väg 45, Stockholm 11486, Sweden
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39
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Bier S, Gavish N, Uecker H, Yochelis A. From bulk self-assembly to electrical diffuse layer in a continuum approach for ionic liquids: The impact of anion and cation size asymmetry. Phys Rev E 2017; 95:060201. [PMID: 28709248 DOI: 10.1103/physreve.95.060201] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Indexed: 06/07/2023]
Abstract
Ionic liquids are solvent-free electrolytes, some of which possess an intriguing self-assembly at finite length scale due to Coulombic interactions. Using a continuum framework (based on Onsager's relations), it is shown that bulk nanostructures arise via linear (supercritical) and nonlinear (subcritical) bifurcations (morphological phase transitions), which also directly affect the electrical double layer structure. A Ginzburg-Landau amplitude equation is derived and the bifurcation type is related to model parameters, such as temperature, potential, and interactions. Specifically, the nonlinear bifurcation occurs for geometrically dissimilar ions and, surprisingly, is induced by perturbations on the order of thermal fluctuations. Finally, qualitative insights and comparisons to the experimentally decaying charge layers within the electrical double layer are discussed.
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Affiliation(s)
- Sariel Bier
- Department of Solar Energy and Environmental Physics, Swiss Institute for Dryland Environmental and Energy Research, Blaustein Institutes for Desert Research (BIDR), Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000 Midreshet Ben-Gurion, Israel
| | - Nir Gavish
- Department of Mathematics, Technion-IIT, 3200003 Haifa, Israel
| | - Hannes Uecker
- Institute for Mathematics, Carl von Ossietzky University of Oldenburg, P.F 2503, 26111 Oldenburg, Germany
| | - Arik Yochelis
- Department of Solar Energy and Environmental Physics, Swiss Institute for Dryland Environmental and Energy Research, Blaustein Institutes for Desert Research (BIDR), Ben-Gurion University of the Negev, Sede Boqer Campus, 8499000 Midreshet Ben-Gurion, Israel
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40
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Gebbie MA, Smith AM, Dobbs HA, Lee AA, Warr GG, Banquy X, Valtiner M, Rutland MW, Israelachvili JN, Perkin S, Atkin R. Long range electrostatic forces in ionic liquids. Chem Commun (Camb) 2017; 53:1214-1224. [DOI: 10.1039/c6cc08820a] [Citation(s) in RCA: 231] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Experimental evidence for long range surface forces in ionic liquids is collated and examined, key outstanding questions are identified, and possible mechanisms underpinning these long range forces are explored.
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Affiliation(s)
- Matthew A. Gebbie
- Geballe Laboratory for Advanced Materials
- Stanford University
- Stanford
- USA
| | - Alexander M. Smith
- Department of Chemistry
- Physical & Theoretical Chemistry Laboratory
- University of Oxford
- Oxford
- UK
| | - Howard A. Dobbs
- Department of Chemical Engineering
- University of California
- Santa Barbara
- UK
| | - Alpha A. Lee
- School of Engineering and Applied Sciences
- Harvard University
- Cambridge
- USA
| | - Gregory G. Warr
- School of Chemistry
- F11
- The University of Sydney
- NSW 2006
- Australia
| | - Xavier Banquy
- Faculty of Pharmacy
- Universite de Montreal
- Montreal
- Canada
| | - Markus Valtiner
- Interface Chemistry and Surface Engineering
- Max Planck Institut fur Eisenforschung GmbH
- Dusseldorf
- Germany
| | - Mark W. Rutland
- Surface and Corrosion Science
- KTH Royal Institute of Technology
- SE-10044 Stockholm
- Sweden
- SP Chemistry Materials and Surfaces
| | | | - Susan Perkin
- Department of Chemistry
- Physical & Theoretical Chemistry Laboratory
- University of Oxford
- Oxford
- UK
| | - Rob Atkin
- Priority Research Centre for Advanced Fluid Interfaces
- Newcastle Institute for Energy and Resources
- The University of Newcastle
- Australia
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