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Horváth B, Decsi P, Szalai I. Nonlinear contributions to the dynamic magnetic susceptibility of magnetic fluids. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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2
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Thoms E, Richert R. New experimental approach to nonlinear dielectric effects in the static limit. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117107] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Richert R, Matyushov DV. Quantifying dielectric permittivities in the nonlinear regime. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:385101. [PMID: 34198283 DOI: 10.1088/1361-648x/ac108f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 07/01/2021] [Indexed: 06/13/2023]
Abstract
In contrast to the static dielectric permittivity,ε, associated with linear response, its high-field counterpart,εE, is not a material specific quantity, but rather depends on the experimental method used to determine the nonlinear dielectric effect (NDE). Here, we defineεEin a manner consistent with how high field permittivities are typically derived from a capacitance measurement using high voltages. Based upon characterizing the materials nonlinear behavior via its third order susceptibility,χ3, the relations between a givenχ3and the observableεEis calculated for six different experimental or theoretical approaches to NDEs in the static limit. It is argued that the quantityχ3is superior overεEor the Piekara factor, (εE-ε)/E2, because it facilitates an unambiguous comparison among different experimental techniques and it provides a more robust connection between experiment and theory.
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Affiliation(s)
- Ranko Richert
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, United States of America
| | - Dmitry V Matyushov
- Department of Physics and School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, United States of America
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Speck T. Modeling non-linear dielectric susceptibilities of supercooled molecular liquids. J Chem Phys 2021; 155:014506. [PMID: 34241396 DOI: 10.1063/5.0056657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Advances in high-precision dielectric spectroscopy have enabled access to non-linear susceptibilities of polar molecular liquids. The observed non-monotonic behavior has been claimed to provide strong support for theories of dynamic arrest based on the thermodynamic amorphous order. Here, we approach this question from the perspective of dynamic facilitation, an alternative view focusing on emergent kinetic constraints underlying the dynamic arrest of a liquid approaching its glass transition. We derive explicit expressions for the frequency-dependent higher-order dielectric susceptibilities exhibiting a non-monotonic shape, the height of which increases as temperature is lowered. We demonstrate excellent agreement with the experimental data for glycerol, challenging the idea that non-linear response functions reveal correlated relaxation in supercooled liquids.
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Affiliation(s)
- Thomas Speck
- Institut für Physik, Johannes Gutenberg-Universität Mainz, Staudingerweg 7-9, 55128 Mainz, Germany
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Drab M, Gongadze E, Kralj-Iglič V, Iglič A. Electric Double Layer and Orientational Ordering of Water Dipoles in Narrow Channels within a Modified Langevin Poisson-Boltzmann Model. ENTROPY (BASEL, SWITZERLAND) 2020; 22:E1054. [PMID: 33286823 PMCID: PMC7597128 DOI: 10.3390/e22091054] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/04/2020] [Accepted: 09/18/2020] [Indexed: 02/05/2023]
Abstract
The electric double layer (EDL) is an important phenomenon that arises in systems where a charged surface comes into contact with an electrolyte solution. In this work we describe the generalization of classic Poisson-Boltzmann (PB) theory for point-like ions by taking into account orientational ordering of water molecules. The modified Langevin Poisson-Boltzmann (LPB) model of EDL is derived by minimizing the corresponding Helmholtz free energy functional, which includes also orientational entropy contribution of water dipoles. The formation of EDL is important in many artificial and biological systems bound by a cylindrical geometry. We therefore numerically solve the modified LPB equation in cylindrical coordinates, determining the spatial dependencies of electric potential, relative permittivity and average orientations of water dipoles within charged tubes of different radii. Results show that for tubes of a large radius, macroscopic (net) volume charge density of coions and counterions is zero at the geometrical axis. This is attributed to effective electrolyte charge screening in the vicinity of the inner charged surface of the tube. For tubes of small radii, the screening region extends into the whole inner space of the tube, leading to non-zero net volume charge density and non-zero orientational ordering of water dipoles near the axis.
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Affiliation(s)
- Mitja Drab
- Faculty of Electrical Engineering, Tržaška Cesta 25, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (M.D.); (E.G.)
| | - Ekaterina Gongadze
- Faculty of Electrical Engineering, Tržaška Cesta 25, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (M.D.); (E.G.)
| | - Veronika Kralj-Iglič
- Faculty of Health Sciences, Zdravstvena Pot 5, University of Ljubljana, SI-1000 Ljubljana, Slovenia;
| | - Aleš Iglič
- Faculty of Electrical Engineering, Tržaška Cesta 25, University of Ljubljana, SI-1000 Ljubljana, Slovenia; (M.D.); (E.G.)
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Richert R. Nonlinear dielectric effects in liquids: a guided tour. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2017; 29:363001. [PMID: 28665294 DOI: 10.1088/1361-648x/aa7cc4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Dielectric relaxation measurements probe how the polarization of a material responds to the application of an external electric field, providing information on structure and dynamics of the sample. In the limit of small fields and thus linear response, such experiments reveal the properties of the material in the same thermodynamic state it would have in the absence of the external field. At sufficiently high fields, reversible changes in enthalpy and entropy of the system occur even at constant temperature, and these will in turn alter the polarization responses. The resulting nonlinear dielectric effects feature field induced suppressions (saturation) and enhancements (chemical effect) of the amplitudes, as well as time constant shifts towards faster (energy absorption) and slower (entropy reduction) dynamics. This review focuses on the effects of high electric fields that are reversible and observed at constant temperature for single component glass-forming liquids. The experimental challenges involved in nonlinear dielectric experiments, the approaches to separating and identifying the different sources of nonlinear behavior, and the current understanding of how high electric fields affect dielectric materials will be discussed. Covering studies from Debye's initial approach to the present state-of-the-art, it will be emphasized what insight can be gained from the nonlinear responses that are not available from dielectric relaxation results obtained in the linear regime.
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Affiliation(s)
- Ranko Richert
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287-1604, United States of America
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Soo H, Dean DS, Krüger M. Particles with nonlinear electric response: Suppressing van der Waals forces by an external field. Phys Rev E 2017; 95:012151. [PMID: 28208347 DOI: 10.1103/physreve.95.012151] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Indexed: 11/07/2022]
Abstract
We study the classical thermal component of Casimir, or van der Waals, forces between point particles with highly anharmonic dipole Hamiltonians when they are subjected to an external electric field. Using a model for which the individual dipole moments saturate in a strong field (a model that mimics the charges in a neutral, perfectly conducting sphere), we find that the resulting Casimir force depends strongly on the strength of the field, as demonstrated by analytical results. For a certain angle between the external field and center-to-center axis, the fluctuation force can be tuned and suppressed to arbitrarily small values. We compare the forces between these particles with those between particles with harmonic Hamiltonians and also provide a simple formula for asymptotically large external fields, which we expect to be generally valid for the case of saturating dipole moments.
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Affiliation(s)
- Heino Soo
- 4th Institute for Theoretical Physics, Universität Stuttgart, D-70569 Stuttgart, Germany.,Max Planck Institute for Intelligent Systems, D-70569 Stuttgart, Germany
| | - David S Dean
- Université Bordeaux and CNRS, Laboratoire Ondes et Matière d'Aquitaine (LOMA), UMR 5798, F-33400 Talence, France
| | - Matthias Krüger
- 4th Institute for Theoretical Physics, Universität Stuttgart, D-70569 Stuttgart, Germany.,Max Planck Institute for Intelligent Systems, D-70569 Stuttgart, Germany
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Solovyova AY, Goldina OA, Ivanov AO, Lebedev AV, Elfimova EA. The initial magnetic susceptibility of polydisperse ferrofluids: A comparison between experiment and theory over a wide range of concentration. J Chem Phys 2016; 145:084909. [DOI: 10.1063/1.4961405] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Anna Y. Solovyova
- Institute of Mathematics and Computer Sciences, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
| | - Olga A. Goldina
- Institute of Mathematics and Computer Sciences, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
| | - Alexey O. Ivanov
- Institute of Mathematics and Computer Sciences, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
| | - Aleksandr V. Lebedev
- Institute of Continuous Media Mechanics, UB RAS, 1 Korolyov st., Perm 614013, Russia
| | - Ekaterina A. Elfimova
- Institute of Mathematics and Computer Sciences, Ural Federal University, 51 Lenin Avenue, Ekaterinburg 620000, Russia
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Szalai I, Nagy S, Dietrich S. Linear and nonlinear magnetic properties of ferrofluids. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:042314. [PMID: 26565247 DOI: 10.1103/physreve.92.042314] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Indexed: 06/05/2023]
Abstract
Within a high-magnetic-field approximation, employing Ruelle's algebraic perturbation theory, a field-dependent free-energy expression is proposed which allows one to determine the magnetic properties of ferrofluids modeled as dipolar hard-sphere systems. We compare the ensuing magnetization curves, following from this free energy, with those obtained by Ivanov and Kuznetsova [Phys. Rev. E 64, 041405 (2001)] as well as with new corresponding Monte Carlo simulation data. Based on the power-series expansion of the magnetization, a closed expression for the magnetization is also proposed, which is a high-density extension of the corresponding equation of Ivanov and Kuznetsova. From both magnetization equations the zero-field susceptibility expression due to Tani et al. [Mol. Phys. 48, 863 (1983)] can be obtained, which is in good agreement with our MC simulation results. From the closed expression for the magnetization the second-order nonlinear magnetic susceptibility is also derived, which shows fair agreement with the corresponding MC simulation data.
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Affiliation(s)
- I Szalai
- Institute of Physics and Mechatronics, University of Pannonia, 8200 Veszprém, Hungary
| | - S Nagy
- Institute of Mechanics and Mechatronics, The University of West Hungary, H-9401 Sopron, P. O. Box 132, Hungary
| | - S Dietrich
- Max-Planck-Institut für Intelligente Systeme, Heisenbergstr. 3, D-70569 Stuttgart, Germany
- IV. Institut für Theoretische Physik, Universität Stuttgart, Pfaffenwaldring 57, D-70569 Stuttgart, Germany
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Gongadze E, Velikonja A, Perutkova Š, Kramar P, Maček-Lebar A, Kralj-Iglič V, Iglič A. Ions and water molecules in an electrolyte solution in contact with charged and dipolar surfaces. Electrochim Acta 2014. [DOI: 10.1016/j.electacta.2013.07.147] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Horváth B, Szalai I. Linear and nonlinear dielectric properties of chloroform–bromoform and chloroform–dichloromethane liquid mixtures. J Mol Liq 2014. [DOI: 10.1016/j.molliq.2013.04.028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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12
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The quadrupole moment of water molecules and the permittivity of water near a charged surface. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.07.126] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Iglič A, Gongadze E. On the orientational ordering of water and finite size of molecules in the mean-field description of the electric double layer – a mini review. ACTA ACUST UNITED AC 2012. [DOI: 10.1088/1742-6596/398/1/012004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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14
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Gongadze E, Iglič A. Decrease of permittivity of an electrolyte solution near a charged surface due to saturation and excluded volume effects. Bioelectrochemistry 2011; 87:199-203. [PMID: 22209491 DOI: 10.1016/j.bioelechem.2011.12.001] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2011] [Revised: 10/22/2011] [Accepted: 12/01/2011] [Indexed: 11/17/2022]
Abstract
The dipole moment of a water molecule in liquid water differs from that of an isolated one because each molecule is further polarized by the electric field of its neighbours. In this work a formula for the spatial dependence of the relative permittivity of an electrolyte near a highly charged surface is obtained in which the mutual influence of the water molecules is taken into account by means of the cavity field. The orientational ordering of water dipoles is considered in the saturation regime. It is predicted that the relative permittivity of an electrolyte solution near the highly charged surface (i.e. in saturation regime) may be substantially decreased due to orientational ordering of water (saturation effect) and depletion of water molecules (excluded volume effect) due to accumulation of counterions.
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Affiliation(s)
- Ekaterina Gongadze
- Faculty of Electrical Engineering, University of Ljubljana, Ljubljana, Slovenia
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Johnson LE, Barnes R, Draxler TW, Eichinger BE, Robinson BH. Dielectric constants of simple liquids: stockmayer and ellipsoidal fluids. J Phys Chem B 2010; 114:8431-40. [PMID: 20527870 DOI: 10.1021/jp1010605] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Coarse-grained models of molecular interactions are of interest because they convey the essence of molecular interactions in simple and easy to understand form. However, coarse-grained models fail to adequately predict some material properties, such as the failure of the Stockmayer model to reproduce the dielectric behavior of highly polar liquids. We examine the behavior of the Stockmayer fluid over a range of dipole densities that covers known organic solvents, as well as that of an ellipsoidal Stockmayer-like fluid, using NVT rigid-body Monte Carlo simulations. Both fluids are examined under different electrostatic boundary conditions and ensemble sizes. While the Stockmayer model predicts that liquids of similar dipole density to acetonitrile would be ferroelectric and have a dielectric constant far higher than shown by experiment, the ellipsoidal model provides a better accounting of dielectric behavior. This result bodes well for the use of coarse-grained solvent models for large-scale simulations.
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Affiliation(s)
- Lewis E Johnson
- Department of Chemistry, P.O. Box 351700, University of Washington, Seattle, Washington 98195-1700, USA
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