1
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Foreseeing the future of green Technology. Molecular dynamic investigation on passive membrane penetration by the products of the CO2 and 1,3-butadiene reaction. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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2
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Rózsa ZB, Szőri-Dorogházi E, Viskolcz B, Szőri M. Transmembrane penetration mechanism of cyclic pollutants inspected by molecular dynamics and metadynamics: the case of morpholine, phenol, 1,4-dioxane and oxane. Phys Chem Chem Phys 2021; 23:15338-15351. [PMID: 34254082 DOI: 10.1039/d1cp01521d] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The presence of industrially produced chemicals in water is often not monitored, while their passive transport and accumulation can cause serious damage in living cells. Molecular dynamics simulations are an effective way to understand the mechanism of the action of these pollutants. In this paper, the passive membrane transport of 1,4-dioxane, phenol, oxane and morpholine was investigated and analyzed thoroughly from structural and energetic points of view. Free energy profiles for pollutant and water penetration into the bilayer were obtained from well-tempered metadynamics (WT-MD) simulations and a mass density-based approach. It was found that all four investigated compounds can penetrate biological membranes and affect the free energy profile of water penetration. Out of the investigated species, oxane has the thermodynamically most preferred position in the bilayer center, leading to a lower free energy barrier of water molecules by 3 kJ mol-1, resulting in 5 times more water molecules in the bilayer center. The concentration dependence of free energy was tested at two different phenol concentrations using WT-MD, and it was found that the higher phenol concentration lowers the main barrier by 3 kJ mol-1. Density-based free energy calculations were found to reproduce the results of WT-MD within the limits of chemical accuracy.
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Affiliation(s)
- Zsófia Borbála Rózsa
- Institute of Chemistry, University of Miskolc, Egyetemváros A/2, H-3515 Miskolc, Hungary.
| | - Emma Szőri-Dorogházi
- Centre for Higher Education and Industrial Cooperation, University of Miskolc, Egyetemváros A/2, H-3515 Miskolc, Hungary
| | - Béla Viskolcz
- Institute of Chemistry, University of Miskolc, Egyetemváros A/2, H-3515 Miskolc, Hungary.
| | - Milán Szőri
- Institute of Chemistry, University of Miskolc, Egyetemváros A/2, H-3515 Miskolc, Hungary.
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3
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Duignan TT, Kathmann SM, Schenter GK, Mundy CJ. Toward a First-Principles Framework for Predicting Collective Properties of Electrolytes. Acc Chem Res 2021; 54:2833-2843. [PMID: 34137593 DOI: 10.1021/acs.accounts.1c00107] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Given the universal importance of electrolyte solutions, it is natural to expect that we have a nearly complete understanding of the fundamental properties of these solutions (e.g., the chemical potential) and that we can therefore explain, predict, and control the phenomena occurring in them. In fact, reality falls short of these expectations. But, recent advances in the simulation and modeling of electrolyte solutions indicate that it should soon be possible to make progress toward these goals. In this Account, we will discuss the use of first-principles interaction potentials based in quantum mechanics (QM) to enhance our understanding of electrolyte solutions. Specifically, we will focus on the use of quantum density functional theory (DFT) combined with molecular dynamics simulation (DFT-MD) as the foundation for our approach. The overarching concept is to understand and accurately reproduce the balance between local or short-ranged (SR) structural details and long-range (LR) correlations, allowing the prediction of the thermodynamics of both single ions in solution as well as the collective interactions characterized by activity/osmotic coefficients. In doing so, relevant collective motions and driving forces characterized by chemical potentials can be determined.In this Account, we will make the case that understanding electrolyte solutions requires a faithful QM representation of the SR nature of the ion-ion, ion-water, and water-water interactions. However, the number of molecules that is required for collective behavior makes the direct application of high-level QM methods that contain the best SR physics untenable, making methods that balance accuracy and efficiency a practical goal. Alternatives such as continuum solvent models (CSMs) and empirically based classical molecular dynamics have been extensively employed to resolve this problem but without yet overcoming the fundamental issue of SR accuracy. We will demonstrate that accurately describing the SR interaction is imperative for predicting both intrinsic properties, namely, at infinite dilution, and collective properties of electrolyte solutions.DFT has played an important role in our understanding of condensed phase systems, e.g., bulk liquid water, the air-water interface, ions in bulk, and at the air-water interface. This approach holds huge promise to provide benchmark calculations of electrolyte solution properties that will allow for the development and improvement of more efficient methods, as well as an enhanced understanding of fundamental phenomena. However, the standard protocol using the generalized gradient approximation with van der Waals (vdW) correction requires improvement in order to achieve a high level of quantitative accuracy. Simply simulating with higher level DFT functionals may not be the best route considering the significant computational cost. Alternative methods of incorporating information from higher levels of QM should be explored; e.g., using force matching techniques on small clusters, where high level benchmark calculations are possible, to develop ideal correction terms to the DFT functional is a promising possibility. We argue that DFT with statistical mechanics is becoming an increasingly useful framework enabling the prediction of collective electrolyte properties.
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Affiliation(s)
- Timothy T. Duignan
- School of Chemical Engineering, The University of Queensland, St Lucia, Brisbane 4072, Australia
| | - Shawn M. Kathmann
- Physical Science Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
| | - Gregory K. Schenter
- Physical Science Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
| | - Christopher J. Mundy
- Physical Science Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99352, United States
- Affiliate Professor, Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, United States
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4
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Adel T, Ng KC, Vazquez de Vasquez MG, Velez-Alvarez J, Allen HC. Insight into the Ionizing Surface Potential Method and Aqueous Sodium Halide Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:7863-7874. [PMID: 34152764 DOI: 10.1021/acs.langmuir.1c00465] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Complementing the microscopic picture of the surface structure of electrolyte solutions set out by previous theoretical and experimental studies, the ionizing surface potential technique offers a unique approach to quantifying the impact of aqueous inorganic ions upon the interfacial electric field of the air-aqueous interface. In this Feature Article, we review the vulnerability of theoretical and empirically derived χwater values as a normative reference for aqueous ion surface potentials. Instead, we recognize and evaluate aqueous ion surface potentials relative to well-known ionic surfactants cetyltrimethylammonium bromide (CTAB) and sodium dodecyl sulfate (SDS). Additionally, we also explore factors that impact the magnitude of the measured surface potentials using the ionizing method, particularly in the type of reference electrode and ionizing gas environment. With potential measurements of sodium halide solutions, we show that iodide has a dominant effect on the air-aqueous electric field. Compared to chloride and bromide, iodide is directly observed with a net negatively charged surface electric field at all salt concentrations measured (0.2 to 3.0 mol/kg water). Also, above the 2 M region, bromide is observed with a net negatively charged surface. Although several scenarios contribute to this effect, it is most likely due to the surface enrichment of bromide and iodide. While the results of this study are pertinent to determining the specific interfacial reactivity of aqueous halides, these anions seldom transpire as single-halide systems in the natural environment. Therefore, we also provide an outlook on future research concerning surface potential methods and more complex aqueous electrolyte systems.
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Affiliation(s)
- Tehseen Adel
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Ka Chon Ng
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Maria G Vazquez de Vasquez
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Juan Velez-Alvarez
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Heather C Allen
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
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5
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Cox SJ, Mandadapu KK, Geissler PL. Quadrupole-mediated dielectric response and the charge-asymmetric solvation of ions in water. J Chem Phys 2021; 154:244502. [PMID: 34241373 DOI: 10.1063/5.0051399] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Treating water as a linearly responding dielectric continuum on molecular length scales allows very simple estimates of the solvation structure and thermodynamics for charged and polar solutes. While this approach can successfully account for basic length and energy scales of ion solvation, computer simulations indicate not only its quantitative inaccuracies but also its inability to capture some basic and important aspects of microscopic polarization response. Here, we consider one such shortcoming, a failure to distinguish the solvation thermodynamics of cations from that of otherwise-identical anions, and we pursue a simple, physically inspired modification of the dielectric continuum model to address it. The adaptation is motivated by analyzing the orientational response of an isolated water molecule whose dipole is rigidly constrained. Its free energy suggests a Hamiltonian for dipole fluctuations that accounts implicitly for the influence of higher-order multipole moments while respecting constraints of molecular geometry. We propose a field theory with the suggested form, whose nonlinear response breaks the charge symmetry of ion solvation. An approximate variational solution of this theory, with a single adjustable parameter, yields solvation free energies that agree closely with simulation results over a considerable range of solute size and charge.
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Affiliation(s)
- Stephen J Cox
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Kranthi K Mandadapu
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Phillip L Geissler
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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6
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Herboth R, Gopakumar G, Caleman C, Wohlert M. Charge State Dependence of Amino Acid Propensity at Water Surface: Mechanisms Elucidated by Molecular Dynamics Simulations. J Phys Chem A 2021; 125:4705-4714. [PMID: 34042438 PMCID: PMC8279654 DOI: 10.1021/acs.jpca.0c10963] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 04/19/2021] [Indexed: 11/28/2022]
Abstract
Atmospheric aerosols contain a variety of compounds, among them free amino acids and salt ions. The pH of the aerosol droplets depends on their origin and environment. Consequently, compounds like free amino acids found in the droplets will be at different charge states, since these states to a great extent depend on the surrounding pH condition. In droplets of marine origin, amino acids are believed to drive salt ions to the water surface and a pH-dependent amino acid surface propensity will, therefore, indirectly affect many processes in atmospheric chemistry and physics such as for instance cloud condensation. To understand the surface propensity of glycine, valine, and phenylalanine at acidic, neutral, and basic pH, we used molecular dynamics (MD) simulations to investigate them at three different charge states in water. Their respective surface propensities were obtained by the means of a potential of mean force (PMF) in an umbrella sampling approach. Glycine was found to have no preference for the surface, while both valine and phenylalanine showed high propensities. Among the charge states of the surface-enriched ones, the cation, representing the amino acids at low pH, was found to have the highest affinity. Free energy decomposition revealed that the driving forces depend strongly on the nature of the amino acid and its charge state. In phenylalanine, the main factor was found to be a substantial entropy gain, likely related to the side chain, whereas in valine, hydrogen bonding to the functional groups leads to favorable energies and, in turn, affects the surface propensity. A significant gain in water-water enthalpy was seen for both valine and phenylalanine.
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Affiliation(s)
- Radost Herboth
- Department
of Materials Science and Engineering, Uppsala
University, Box 35, 751 03 Uppsala, Sweden
| | - Geethanjali Gopakumar
- Department
of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala, Sweden
| | - Carl Caleman
- Department
of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala, Sweden
- Center
for Free-Electron Laser Science, DESY, Notkestraße 85, 226 07 Hamburg, Germany
| | - Malin Wohlert
- Department
of Materials Science and Engineering, Uppsala
University, Box 35, 751 03 Uppsala, Sweden
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7
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Abstract
Electrostatic interactions near surfaces and interfaces are ubiquitous in many fields of science. Continuum electrostatics predicts that ions will be attracted to conducting electrodes but repelled by surfaces with lower dielectric constant than the solvent. However, several recent studies found that certain "chaotropic" ions have similar adsorption behavior at air/water and graphene/water interfaces. Here we systematically study the effect of polarization of the surface, the solvent, and solutes on the adsorption of ions onto the electrode surfaces using molecular dynamics simulation. An efficient method is developed to treat an electrolyte system between two parallel conducting surfaces by exploiting the mirror-expanded symmetry of the exact image-charge solution. With neutral surfaces, the image interactions induced by the solvent dipoles and ions largely cancel each other, resulting in no significant net differences in the ion adsorption profile regardless of the surface polarity. Under an external electric field, the adsorption of ions is strongly affected by the surface polarization, such that the charge separation across the electrolyte and the capacitance of the cell is greatly enhanced with a conducting surface over a low-dielectric-constant surface. While the extent of ion adsorption is highly dependent on the electrolyte model (the polarizability of solvent and solutes, as well as the van der Waals radii), we find the effect of surface polarization on ion adsorption is consistent throughout different electrolyte models.
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8
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Hantal G, Horváth RA, Kolafa J, Sega M, Jedlovszky P. Surface Affinity of Alkali and Halide Ions in Their Aqueous Solution: Insight from Intrinsic Density Analysis. J Phys Chem B 2020; 124:9884-9897. [PMID: 33084342 DOI: 10.1021/acs.jpcb.0c05547] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The surface tension of all aqueous alkali halide solutions is higher than that of pure water. According to the Gibbs adsorption equation, this indicates a net depletion of these ions in the interfacial region. However, simulations and experiments show that large, soft ions, such as I-, can accumulate at the liquid/vapor interface. The presence of a loose hydration shell is usually considered to be the reason for this behavior. In this work, we perform computer simulations to characterize the liquid-vapor interface of aqueous alkali chloride and sodium halide solutions systematically, considering all ions from Li+ to Cs+ and from F- to I-. Using computational methods for the removal of surface fluctuations, we analyze the structure of the interface at a dramatically enhanced resolution, showing that the positive excess originates in the very first molecular layer and that the next 3-4 layers account for the net negative excess. With the help of a fictitious system with charge-inverted ion pairs, we also show that it is not possible to rationalize the surface affinity of ions in solutions in terms of the properties of anions and cations separately. Moreover, the surface excess is generally dominated by the smaller of the two ions.
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Affiliation(s)
- György Hantal
- Institute of Physics and Materials Science, University of Natural Resources and Life Sciences, Peter Jordan Straße 82, A-1190 Vienna, Austria
| | - Réka A Horváth
- Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Szt. Gellért tér 4, H-1111 Budapest, Hungary
| | - Jiří Kolafa
- Department of Physical Chemistry, University of Chemistry and Technology, 166 28 Prague 6, Czech Republic
| | - Marcello Sega
- Forschungszentrum Jülich GmbH, Helmholtz Institute Erlangen-Nürnberg for Renewable Energy (IEK-11), Fürther Straße 248, D-90429 Nürnberg, Germany
| | - Pál Jedlovszky
- Department of Chemistry, Eszterházy Károly University, Leányka utca 6, H-3300 Eger, Hungary
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9
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Cox SJ, Thorpe DG, Shaffer PR, Geissler PL. Assessing long-range contributions to the charge asymmetry of ion adsorption at the air-water interface. Chem Sci 2020; 11:11791-11800. [PMID: 34094413 PMCID: PMC8162909 DOI: 10.1039/d0sc01947j] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Anions generally associate more favorably with the air–water interface than cations. In addition to solute size and polarizability, the intrinsic structure of the unperturbed interface has been discussed as an important contributor to this bias. Here we assess quantitatively the role that intrinsic charge asymmetry of water's surface plays in ion adsorption, using computer simulations to compare model solutes of various size and charge. In doing so, we also evaluate the degree to which linear response theory for solvent polarization is a reasonable approach for comparing the thermodynamics of bulk and interfacial ion solvation. Consistent with previous works on bulk ion solvation, we find that the average electrostatic potential at the center of a neutral, sub-nanometer solute at the air–water interface depends sensitively on its radius, and that this potential changes quite nonlinearly as the solute's charge is introduced. The nonlinear response closely resembles that of the bulk. As a result, the net nonlinearity of ion adsorption is weaker than in bulk, but still substantial, comparable to the apparent magnitude of macroscopically nonlocal contributions from the undisturbed interface. For the simple-point-charge model of water we study, these results argue distinctly against rationalizing ion adsorption in terms of surface potentials inherent to molecular structure of the liquid's boundary. Cations and anions have different affinities for the air-water interface. The intrinsic orientation of surface molecules suggests such an asymmetry, but the bias is dominated by solvent response that is spatially local and significantly nonlinear.![]()
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Affiliation(s)
- Stephen J Cox
- Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK
| | - Dayton G Thorpe
- Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley CA 94720 USA.,Department of Physics, University of California Berkeley CA 94720 USA
| | - Patrick R Shaffer
- Department of Chemistry, University of California Berkeley CA 94720 USA
| | - Phillip L Geissler
- Chemical Sciences Division, Lawrence Berkeley National Laboratory Berkeley CA 94720 USA.,Department of Chemistry, University of California Berkeley CA 94720 USA
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10
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Duignan TT, Peng M, Nguyen AV, Zhao XS, Baer MD, Mundy CJ. Detecting the undetectable: The role of trace surfactant in the Jones-Ray effect. J Chem Phys 2018; 149:194702. [DOI: 10.1063/1.5050421] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Timothy T. Duignan
- School of Chemical Engineering, The University of Queensland, St Lucia, Brisbane 4072, Australia
- Physical Science Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99354, USA
| | - Mengsu Peng
- School of Chemical Engineering, The University of Queensland, St Lucia, Brisbane 4072, Australia
| | - Anh V. Nguyen
- School of Chemical Engineering, The University of Queensland, St Lucia, Brisbane 4072, Australia
| | - X. S. Zhao
- School of Chemical Engineering, The University of Queensland, St Lucia, Brisbane 4072, Australia
| | - Marcel D. Baer
- Physical Science Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99354, USA
| | - Christopher J. Mundy
- Physical Science Division, Pacific Northwest National Laboratory, P.O. Box 999, Richland, Washington 99354, USA
- Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, USA
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11
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Cox SJ, Geissler PL. Interfacial ion solvation: Obtaining the thermodynamic limit from molecular simulations. J Chem Phys 2018; 148:222823. [DOI: 10.1063/1.5020563] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Stephen J. Cox
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
| | - Phillip L. Geissler
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
- Department of Chemistry, University of California, Berkeley, California 94720, USA
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12
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Remsing RC, Weeks JD. Alchemical free energy calculations and umbrella sampling with local molecular field theory. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2018. [DOI: 10.1142/s0219633618400035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Understanding the thermodynamic driving forces underlying any chemical process requires a description of the underlying free energy surface. However, computation of free energies is difficult, often requiring advanced sampling techniques. Moreover, these computations can be further complicated by the evaluation of any long-ranged interactions in the system of interest, such as Coulomb interactions in charged and polar media. Local molecular field theory is a promising approach to avoid many of the conceptual and computational difficulties associated with long-ranged interactions. We present frameworks for performing alchemical free energy calculations and non-Boltzmann sampling with local molecular field theory. We demonstrate that local molecular field theory can be used to perform these free energy calculations with accuracy comparable to traditional methodologies while eliminating the need for explicit treatment of long-ranged interactions in simulations.
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Affiliation(s)
- Richard C. Remsing
- Institute for Computational Molecular Science, Department of Chemistry, Temple University, Philadelphia, PA 19122, USA
| | - John D. Weeks
- Institute for Physical Science and Technology, Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
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13
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Wise PK, Ben-Amotz D. Interfacial Adsorption of Neutral and Ionic Solutes in a Water Droplet. J Phys Chem B 2018; 122:3447-3453. [PMID: 29244951 DOI: 10.1021/acs.jpcb.7b10488] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Direct (solute-water) and indirect (water-water) contributions to adsorption at an air-water interface are identified using the Widom potential distribution theorem and quantified using molecular dynamics simulations of a liquid water droplet containing either neopentane or iodide-like solutes with charges of 0 or ±1. The results are used to quantitatively compare direct and indirect energetic and entropic contributions to adsorption, as well as to critically test surface capillary wave, linear response (LR), and mean field (MF) predictions. The negative signs of the total adsorption energies and entropies of both the anionic and cationic solutes are found to result from indirect adsorption induced changes in water-water interactions, rather than from surface capillary wave perturbations, which are found to be asymmetric with respect to solute charge. The LR and MF approximations both accurately describe the adsorption of neutral (hydrophobic) solutes, while for ionic solutes the MF approximation is entirely inappropriate and LR predictions are qualitatively (but not quantitatively) accurate.
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Affiliation(s)
- Patrick K Wise
- Department of Chemistry , Purdue University , West Lafayette , Indiana 47907 United States
| | - Dor Ben-Amotz
- Department of Chemistry , Purdue University , West Lafayette , Indiana 47907 United States
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14
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Olivieri G, Parry KM, D’Auria R, Tobias DJ, Brown MA. Specific Anion Effects on Na+ Adsorption at the Aqueous Solution–Air Interface: MD Simulations, SESSA Calculations, and Photoelectron Spectroscopy Experiments. J Phys Chem B 2017; 122:910-918. [DOI: 10.1021/acs.jpcb.7b06981] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Giorgia Olivieri
- Department
of Materials, Laboratory for Surface Science and Technology, ETH Zürich, Vladimir-Prelog-Weg 5, CH-8093, Zürich, Switzerland
| | - Krista M. Parry
- Department
of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Raffaella D’Auria
- Department
of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Douglas J. Tobias
- Department
of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Matthew A. Brown
- Department
of Materials, Laboratory for Surface Science and Technology, ETH Zürich, Vladimir-Prelog-Weg 5, CH-8093, Zürich, Switzerland
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15
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Zhang H, Jiang Y, Yan H, Cui Z, Yin C. Comparative Assessment of Computational Methods for Free Energy Calculations of Ionic Hydration. J Chem Inf Model 2017; 57:2763-2775. [DOI: 10.1021/acs.jcim.7b00485] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Haiyang Zhang
- Department
of Biological Science and Engineering, School of Chemistry and Biological
Engineering, University of Science and Technology Beijing, 100083 Beijing, China
| | - Yang Jiang
- Beijing
Key Lab of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Box 53, 100029 Beijing, China
| | - Hai Yan
- Department
of Biological Science and Engineering, School of Chemistry and Biological
Engineering, University of Science and Technology Beijing, 100083 Beijing, China
| | - Ziheng Cui
- Beijing
Key Lab of Bioprocess, College of Life Science and Technology, Beijing University of Chemical Technology, Box 53, 100029 Beijing, China
| | - Chunhua Yin
- Department
of Biological Science and Engineering, School of Chemistry and Biological
Engineering, University of Science and Technology Beijing, 100083 Beijing, China
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16
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Specific cation effects at aqueous solution-vapor interfaces: Surfactant-like behavior of Li + revealed by experiments and simulations. Proc Natl Acad Sci U S A 2017; 114:13363-13368. [PMID: 29078311 DOI: 10.1073/pnas.1707540114] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
It is now well established by numerous experimental and computational studies that the adsorption propensities of inorganic anions conform to the Hofmeister series. The adsorption propensities of inorganic cations, such as the alkali metal cations, have received relatively little attention. Here we use a combination of liquid-jet X-ray photoelectron experiments and molecular dynamics simulations to investigate the behavior of K+ and Li+ ions near the interfaces of their aqueous solutions with halide ions. Both the experiments and the simulations show that Li+ adsorbs to the aqueous solution-vapor interface, while K+ does not. Thus, we provide experimental validation of the "surfactant-like" behavior of Li+ predicted by previous simulation studies. Furthermore, we use our simulations to trace the difference in the adsorption of K+ and Li+ ions to a difference in the resilience of their hydration shells.
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17
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Mechanism of ion adsorption to aqueous interfaces: Graphene/water vs. air/water. Proc Natl Acad Sci U S A 2017; 114:13369-13373. [PMID: 28827359 DOI: 10.1073/pnas.1702760114] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The adsorption of ions to aqueous interfaces is a phenomenon that profoundly influences vital processes in many areas of science, including biology, atmospheric chemistry, electrical energy storage, and water process engineering. Although classical electrostatics theory predicts that ions are repelled from water/hydrophobe (e.g., air/water) interfaces, both computer simulations and experiments have shown that chaotropic ions actually exhibit enhanced concentrations at the air/water interface. Although mechanistic pictures have been developed to explain this counterintuitive observation, their general applicability, particularly in the presence of material substrates, remains unclear. Here we investigate ion adsorption to the model interface formed by water and graphene. Deep UV second harmonic generation measurements of the SCN- ion, a prototypical chaotrope, determined a free energy of adsorption within error of that for air/water. Unlike for the air/water interface, wherein repartitioning of the solvent energy drives ion adsorption, our computer simulations reveal that direct ion/graphene interactions dominate the favorable enthalpy change. Moreover, the graphene sheets dampen capillary waves such that rotational anisotropy of the solute, if present, is the dominant entropy contribution, in contrast to the air/water interface.
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18
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Shi Y, Beck T. Deconstructing Free Energies in the Law of Matching Water Affinities. J Phys Chem B 2017; 121:2189-2201. [DOI: 10.1021/acs.jpcb.7b00104] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yu Shi
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Thomas Beck
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
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19
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Ben-Amotz D. Interfacial solvation thermodynamics. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:414013. [PMID: 27545849 DOI: 10.1088/0953-8984/28/41/414013] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Previous studies have reached conflicting conclusions regarding the interplay of cavity formation, polarizability, desolvation, and surface capillary waves in driving the interfacial adsorptions of ions and molecules at air-water interfaces. Here we revisit these questions by combining exact potential distribution results with linear response theory and other physically motivated approximations. The results highlight both exact and approximate compensation relations pertaining to direct (solute-solvent) and indirect (solvent-solvent) contributions to adsorption thermodynamics, of relevance to solvation at air-water interfaces, as well as a broader class of processes linked to the mean force potential between ions, molecules, nanoparticles, proteins, and biological assemblies.
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Affiliation(s)
- Dor Ben-Amotz
- Department of Chemistry, Purdue University, West Lafayette, IN 47907, USA
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20
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Toward a quantitative theory of Hofmeister phenomena: From quantum effects to thermodynamics. Curr Opin Colloid Interface Sci 2016. [DOI: 10.1016/j.cocis.2016.06.015] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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21
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Chen Z, Beck TL. Free Energies of Ion Binding in the Bacterial CLC-ec1 Chloride Transporter with Implications for the Transport Mechanism and Selectivity. J Phys Chem B 2016; 120:3129-39. [DOI: 10.1021/acs.jpcb.6b01150] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zhihong Chen
- Department
of Physics, and ‡Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Thomas L. Beck
- Department
of Physics, and ‡Department of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
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22
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Specific ion interactions with aromatic rings in aqueous solutions: Comparison of molecular dynamics simulations with a thermodynamic solute partitioning model and Raman spectroscopy. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2015.06.061] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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23
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Arslanargin A, Powers A, Beck TL, Rick SW. Models of Ion Solvation Thermodynamics in Ethylene Carbonate and Propylene Carbonate. J Phys Chem B 2015; 120:1497-508. [DOI: 10.1021/acs.jpcb.5b06891] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ayse Arslanargin
- Department
of Physics, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - August Powers
- Department
of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Thomas L. Beck
- Department
of Physics, University of Cincinnati, Cincinnati, Ohio 45221, United States
- Department
of Chemistry, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Steven W. Rick
- Department
of Chemistry, University of New Orleans, New Orleans, Louisiana 70148, United States
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24
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Ou SC, Cui D, Patel S. Association of alkanes with the aqueous liquid-vapor interface: a reference system for interpreting hydrophobicity generally through interfacial fluctuations. Phys Chem Chem Phys 2014; 16:26779-85. [PMID: 25372502 DOI: 10.1039/c4cp03170a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report free energy calculations and fluctuation profiles of single alkanes (from methane to pentane) along the direction normal to the air-water interface. The induced fluctuations and the interfacial stabilities of alkanes are found to be correlated and similar to the results of inorganic monovalent ions (Ou et al., J. Phys. Chem. B, 2013, 117, 11732). This suggests that hydrophobic solvation of solutes and ions is important in determining the adsorption behavior.
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Affiliation(s)
- Shu-Ching Ou
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA.
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25
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Whitmer JK, Joshi AA, Carlton RJ, Abbott NL, de Pablo JJ. Surface Adsorption in Nonpolarizable Atomic Models. J Chem Theory Comput 2014; 10:5616-24. [DOI: 10.1021/ct5005406] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jonathan K. Whitmer
- Department
of Chemical and Biological Engineering, University of Wisconsin, Madison, Wisconsin 53706-1691, United States
- Institute for
Molecular Engineering, Argonne National Laboratory, Argonne, Illinois 60439, United States
- Institute
for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Abhijeet A. Joshi
- Department
of Chemical and Biological Engineering, University of Wisconsin, Madison, Wisconsin 53706-1691, United States
| | - Rebecca J. Carlton
- Department
of Chemical and Biological Engineering, University of Wisconsin, Madison, Wisconsin 53706-1691, United States
| | - Nicholas L. Abbott
- Department
of Chemical and Biological Engineering, University of Wisconsin, Madison, Wisconsin 53706-1691, United States
| | - Juan J. de Pablo
- Institute
for Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
- Institute for Molecular
Engineering, Argonne National Laboratory, Argonne, Illinois 60439, United States
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26
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Ion Interactions with the Air–Water Interface Using a Continuum Solvent Model. J Phys Chem B 2014; 118:8700-10. [DOI: 10.1021/jp502887e] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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27
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Pollard T, Beck TL. Quasichemical analysis of the cluster-pair approximation for the thermodynamics of proton hydration. J Chem Phys 2014; 140:224507. [DOI: 10.1063/1.4881602] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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28
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Levin Y, dos Santos AP. Ions at hydrophobic interfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2014; 26:203101. [PMID: 24769502 DOI: 10.1088/0953-8984/26/20/203101] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We review the present understanding of the behavior of ions at the air-water and oil-water interfaces. We argue that while the alkali metal cations remain strongly hydrated and are repelled from the hydrophobic surfaces, the anions must be classified into kosmotropes and chaotropes. The kosmotropes remain strongly hydrated in the vicinity of a hydrophobic surface, while the chaotropes lose their hydration shell and can become adsorbed to the interface. The mechanism of adsorption is still a subject of debate. Here, we argue that there are two driving forces for anionic adsorption: the hydrophobic cavitational energy and the interfacial electrostatic surface potential of water. While the cavitational contribution to ionic adsorption is now well accepted, the role of the electrostatic surface potential is much less clear. The difficulty is that even the sign of this potential is a subject of debate, with the ab initio and the classical force field simulations predicting electrostatic surface potentials of opposite sign. In this paper, we will argue that the strong anionic adsorption found in the polarizable force field simulations is the result of the artificial electrostatic surface potential present in the classical water models. We will show that if the adsorption of anions were as large as predicted by the polarizable force field simulations, the excess surface tension of the NaI solution would be strongly negative, contrary to the experimental measurements. While the large polarizability of heavy halides is a fundamental property and must be included in realistic modeling of the electrolyte solutions, we argue that the point charge water models, studied so far, are incompatible with the polarizable ionic force fields when the translational symmetry is broken. The goal for the future should be the development of water models with very low electrostatic surface potential. We believe that such water models will be compatible with the polarizable force fields, which can then be used to study the interaction of ions with hydrophobic surfaces and proteins.
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Affiliation(s)
- Yan Levin
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970, Porto Alegre, RS, Brazil
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29
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Ishiyama T, Imamura T, Morita A. Theoretical Studies of Structures and Vibrational Sum Frequency Generation Spectra at Aqueous Interfaces. Chem Rev 2014; 114:8447-70. [DOI: 10.1021/cr4004133] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- Tatsuya Ishiyama
- Department
of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Takako Imamura
- Department
of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
| | - Akihiro Morita
- Department
of Chemistry, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
- Elements
Strategy Initiative for Catalysts and Batteries, Kyoto University, Kyoto 615-8520, Japan
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30
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Vlcek L, Chialvo AA, Simonson JM. Correspondence between Cluster-Ion and Bulk Solution Thermodynamic Properties: On the Validity of the Cluster-Pair-Based Approximation. J Phys Chem A 2013; 117:11328-38. [DOI: 10.1021/jp408632e] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Lukas Vlcek
- Chemical
Sciences Division, Geochemistry & Interfacial Sciences Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110, United States
- Joint
Institute for Computational Sciences, Oak Ridge National Laboratory, Oak
Ridge, Tennessee 37831-6173, United States
| | - Ariel A. Chialvo
- Chemical
Sciences Division, Geochemistry & Interfacial Sciences Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110, United States
| | - J. Michael Simonson
- Chemical
& Engineering Materials Division, Oak Ridge National Laboratory, Oak
Ridge, Tennessee 37831-6475, United States
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31
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Stern AC, Baer MD, Mundy CJ, Tobias DJ. Thermodynamics of iodide adsorption at the instantaneous air-water interface. J Chem Phys 2013; 138:114709. [PMID: 23534655 DOI: 10.1063/1.4794688] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We performed molecular dynamics simulations using both polarizable and non-polarizable force fields to study the adsorption of iodide to the air-water interface. A novel aspect of our analysis is that the progress of ion adsorption is measured as the distance from the instantaneous interface, which is defined by a coarse-graining scheme proposed recently by Willard and Chandler ["Instantaneous liquid interfaces," J. Phys. Chem. B 114, 1954-1958 (2010)]. Referring structural and thermodynamic quantities to the instantaneous interface unmasks molecular-scale details that are obscured by thermal fluctuations when the same quantities are referred to an average measure of the position of the interface, such as the Gibbs dividing surface. Our results suggest that an ion adsorbed at the interface resides primarily in the topmost water layer, and the interfacial location of the ion is favored by enthalpy and opposed by entropy.
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Affiliation(s)
- Abraham C Stern
- Department of Chemistry, University of California, Irvine, California 92697-2025, USA.
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32
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Sedlmeier F, Netz RR. Solvation thermodynamics and heat capacity of polar and charged solutes in water. J Chem Phys 2013; 138:115101. [PMID: 23534665 DOI: 10.1063/1.4794153] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The solvation thermodynamics and in particular the solvation heat capacity of polar and charged solutes in water is studied using atomistic molecular dynamics simulations. As ionic solutes we consider a F(-) and a Na(+) ion, as an example for a polar molecule with vanishing net charge we take a SPC/E water molecule. The partial charges of all three solutes are varied in a wide range by a scaling factor. Using a recently introduced method for the accurate determination of the solvation free energy of polar solutes, we determine the free energy, entropy, enthalpy, and heat capacity of the three different solutes as a function of temperature and partial solute charge. We find that the sum of the solvation heat capacities of the Na(+) and F(-) ions is negative, in agreement with experimental observations, but our results uncover a pronounced difference in the heat capacity between positively and negatively charged groups. While the solvation heat capacity ΔC(p) stays positive and even increases slightly upon charging the Na(+) ion, it decreases upon charging the F(-) ion and becomes negative beyond an ion charge of q = -0.3e. On the other hand, the heat capacity of the overall charge-neutral polar solute derived from a SPC/E water molecule is positive for all charge scaling factors considered by us. This means that the heat capacity of a wide class of polar solutes with vanishing net charge is positive. The common ascription of negative heat capacities to polar chemical groups might arise from the neglect of non-additive interaction effects between polar and apolar groups. The reason behind this non-additivity is suggested to be related to the second solvation shell that significantly affects the solvation thermodynamics and due to its large spatial extent induces quite long-ranged interactions between solvated molecular parts and groups.
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Affiliation(s)
- Felix Sedlmeier
- Fachbereich Physik, Freie Universität Berlin, 14195 Berlin, Germany
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33
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Duignan TT, Parsons DF, Ninham BW. A continuum model of solvation energies including electrostatic, dispersion, and cavity contributions. J Phys Chem B 2013; 117:9421-9. [PMID: 23837915 DOI: 10.1021/jp403596c] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Physically accurate continuum solvent models that can calculate solvation energies are crucial to explain and predict the behavior of solute particles in water. Here, we present such a model applied to small spherical ions and neutral atoms. It improves upon a basic Born electrostatic model by including a standard cavity energy and adding a dispersion component, consistent with the Born electrostatic energy and using the same cavity size parameter. We show that the well-known, puzzling differences between the solvation energies of ions of the same size is attributable to the neglected dispersion contribution. This depends on dynamic polarizability as well as size. Generally, a large cancellation exists between the cavity and dispersion contributions. This explains the surprising success of the Born model. The model accurately reproduces the solvation energies of the alkali halide ions, as well as the silver(I) and copper(I) ions with an error of 12 kJ mol(-1) (±3%). The solvation energy of the noble gases is also reproduced with an error of 2.6 kJ mol(-1) (±30%). No arbitrary fitting parameters are needed to achieve this. This model significantly improves our understanding of ionic solvation and forms a solid basis for the investigation of other ion-specific effects using a continuum solvent model.
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Affiliation(s)
- Timothy T Duignan
- Department of Applied Mathematics, Research School of Physical Sciences and Engineering, Australian National University, Canberra ACT 0200, Australia
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34
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Shi Y, Beck TL. Length scales and interfacial potentials in ion hydration. J Chem Phys 2013; 139:044504. [DOI: 10.1063/1.4814070] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
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35
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Ou S, Patel S. Temperature dependence and energetics of single ions at the aqueous liquid-vapor interface. J Phys Chem B 2013; 117:6512-23. [PMID: 23537166 DOI: 10.1021/jp401243m] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We investigate temperature-dependence of free energetics with two single halide anions, I(-) and Cl(-), crossing the aqueous liquid-vapor interface through molecular dynamics simulations. The result shows that I(-) has a modest surface stability of 0.5 kcal/mol at 300 K and the stability decreases as the temperature increases, indicating the surface adsorption process for the anion is entropically disfavored. In contrast, Cl(-) shows no such surface state at all temperatures. Decomposition of free energetics reveals that water-water interactions provide a favorable enthalpic contribution, while the desolvation of ion induces an increase in free energy. Calculations of surface fluctuations demonstrate that I(-) generates significantly greater interfacial fluctuations compared to Cl(-). The fluctuation is attributed to the malleability of the solvation shells, which allows for more long-ranged perturbations and solvent density redistribution induced by I(-) as the anion approaches the liquid-vapor interface. The increase in temperature of the solvent enhances the inherent thermally excited fluctuations and consequently reduces the relative contribution from anion to surface fluctuations, which is consistent with the decrease in surface stability of I(-). Our results indicate a strong correlation with induced interfacial fluctuations and anion surface stability; moreover, resulting temperature dependent behavior of induced fluctuations suggests the possibility of a critical level of induced fluctuations associated with surface stability.
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Affiliation(s)
- Shuching Ou
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
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36
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Horváth L, Beu T, Manghi M, Palmeri J. The vapor-liquid interface potential of (multi)polar fluids and its influence on ion solvation. J Chem Phys 2013; 138:154702. [DOI: 10.1063/1.4799938] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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37
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Tobias DJ, Stern AC, Baer MD, Levin Y, Mundy CJ. Simulation and Theory of Ions at Atmospherically Relevant Aqueous Liquid-Air Interfaces. Annu Rev Phys Chem 2013; 64:339-59. [DOI: 10.1146/annurev-physchem-040412-110049] [Citation(s) in RCA: 133] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Douglas J. Tobias
- Department of Chemistry, University of California, Irvine, California 92697-2025; ,
| | - Abraham C. Stern
- Department of Chemistry, University of California, Irvine, California 92697-2025; ,
| | - Marcel D. Baer
- Chemical and Materials Science Division, Pacific Northwest National Laboratory, Richland, Washington 99352; ,
| | - Yan Levin
- Insituto de Física, Universidade Federal do Rio Grande do Sul, CEP 91501-970 Porto Alegre, RS, Brazil;
| | - Christopher J. Mundy
- Chemical and Materials Science Division, Pacific Northwest National Laboratory, Richland, Washington 99352; ,
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38
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Beck TL. The influence of water interfacial potentials on ion hydration in bulk water and near interfaces. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2013.01.008] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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39
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Abstract
Simulations are carried out for the ice/vapor and ice/liquid interfaces using models for water which include intermolecular charge transfer, as well as polarizability. The models transfer a small amount of charge for each hydrogen bond formed, as indicated from electronic structure calculations, from the molecule that accepts the hydrogen bond to the molecule that donates the hydrogen bond. Depending on distance from the interface, molecules can, on average, have more of one type (donor or acceptor) than the other. The asymmetric local environment leads to net charge transfer at the interface, with layers of molecules with small net charges. Molecules at the ice side of the interface tend to be positively charged, while molecules at the vapor or liquid side tend to be negatively charged.
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Affiliation(s)
- Alexis J Lee
- Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148, United States
| | - Steven W Rick
- Department of Chemistry, University of New Orleans, New Orleans, Louisiana 70148, United States
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40
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Verreault D, Hua W, Allen HC. From Conventional to Phase-Sensitive Vibrational Sum Frequency Generation Spectroscopy: Probing Water Organization at Aqueous Interfaces. J Phys Chem Lett 2012; 3:3012-3028. [PMID: 26292243 DOI: 10.1021/jz301179g] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Elucidation of water organization at aqueous interfaces has remained a challenging problem. Conventional vibrational sum frequency generation (VSFG) spectroscopy and its most recent extension, phase-sensitive VSFG (PS-VSFG), have emerged as powerful experimental methods for unraveling structural information at various aqueous interfaces. In this Perspective, we briefly describe the two possible VSFG detection modes, and we point out features that make these methods highly suited to address questions about water organization at air/aqueous interfaces. Several important aqueous interfacial systems are discussed to illustrate the versatility of these methods. Remaining challenges and exciting prospective directions are also presented.
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Affiliation(s)
- Dominique Verreault
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Wei Hua
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Heather C Allen
- Department of Chemistry and Biochemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
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41
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Rembert KB, Paterová J, Heyda J, Hilty C, Jungwirth P, Cremer PS. Molecular Mechanisms of Ion-Specific Effects on Proteins. J Am Chem Soc 2012; 134:10039-46. [DOI: 10.1021/ja301297g] [Citation(s) in RCA: 233] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Kelvin B. Rembert
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Jana Paterová
- Institute
of Organic Chemistry
and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
| | - Jan Heyda
- Institute
of Organic Chemistry
and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
| | - Christian Hilty
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Pavel Jungwirth
- Institute
of Organic Chemistry
and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 16610, Prague 6, Czech Republic
| | - Paul S. Cremer
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
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42
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Baer MD, Stern AC, Levin Y, Tobias DJ, Mundy CJ. Electrochemical Surface Potential Due to Classical Point Charge Models Drives Anion Adsorption to the Air-Water Interface. J Phys Chem Lett 2012; 3:1565-1570. [PMID: 26285639 DOI: 10.1021/jz300302t] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We demonstrate that the driving forces for ion adsorption to the air-water interface for point charge models result from both cavitation and a term that is of the form of a negative electrochemical surface potential. We carefully characterize the role of the free energy due to the electrochemical surface potential computed from simple empirical models and its role in ionic adsorption within the context of dielectric continuum theory. Our research suggests that the electrochemical surface potential due to point charge models provides anions with a significant driving force for adsoprtion to the air-water interface. This is contrary to the results of ab initio simulations that indicate that the average electrostatic surface potential should favor the desorption of anions at the air-water interface. The results have profound implications for the studies of ionic distributions in the vicinity of hydrophobic surfaces and proteins.
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Affiliation(s)
- Marcel D Baer
- †Chemical and Materials Science Division, Pacific Northwest National Laboratory, Richland 99352, Washington
| | - Abraham C Stern
- ‡Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Yan Levin
- §Instituto de Física, UFRGS Porto Alegre, RS, 91501-970, Brazil
| | - Douglas J Tobias
- ‡Department of Chemistry, University of California, Irvine, Irvine, California 92697-2025, United States
| | - Christopher J Mundy
- †Chemical and Materials Science Division, Pacific Northwest National Laboratory, Richland 99352, Washington
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