1
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Wang M, Chen F, Tan J, Ye S. Segregation of Chemical Groups at PMMA/H 2O Interface Leads to Different Local Hydrophobicity. J Phys Chem Lett 2025:5334-5340. [PMID: 40395004 DOI: 10.1021/acs.jpclett.5c00569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2025]
Abstract
The local hydrophilicity of polymer surfaces is essential for many applications, such as coatings and biocompatibility, but revealing its structural origin is challenging. Here, we used poly(methyl methacrylate) (PMMA) film as a model and excavated several SFG spectral features, generated by femtosecond sum-frequency generation vibrational spectroscopy (SFG-VS), to elucidate the nature of microscopic hydrophilicity of a polymer/H2O interface. For the first time, we successfully probed the SFG spectra of the bend-libration combination band of interfacial water, which exhibits high sensitivity to solvent-water interactions. Two local hydrophilic domains are observed at the PMMA/H2O interface. The segregation of -OCH3 and -CH3 groups to the PMMA/H2O interface results in the formation of a local hydrophobic domain, where weak solvent-water interactions, slow vibrational dynamics of OH stretching, and no ice-like interfacial water are detected. In contrast, when both C═O and -OCH3 groups segregate to the PMMA/water interface, a local hydrophilic domain is formed, leading to strong solvent-water interactions, fast vibrational dynamics of OH stretching, and the presence of ice-like interfacial water. The water molecules around the hydrophobic domains of the PMMA surface are mainly liquid-like water rather than ice-like water. This work contributes to a molecular-level understanding of the local hydrophilicity of polymer surfaces.
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Affiliation(s)
- Mengmeng Wang
- Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Feixiang Chen
- Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Junjun Tan
- Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230088, China
| | - Shuji Ye
- Hefei National Research Center for Physical Sciences at the Microscale, Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei, Anhui 230088, China
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2
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Yadav HOS. Three-body interaction of gold nanoparticles: the role of solvent density and ligand shell orientation. Phys Chem Chem Phys 2024; 26:11558-11569. [PMID: 38533797 DOI: 10.1039/d3cp06334h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
Molecular dynamics simulations are used to study the effective interactions of alkanethiol passivated gold nanoparticles in supercritical ethane at two- and three-particle levels with different solvent densities. Effective interaction is calculated as the potential of mean force (PMF) between two nanoparticles, and the three-body effect is estimated as the difference in PMFs calculated at the two- and three-particle levels. The variation in the three-body effect is examined as a function of solvent density. It is found that effective interaction, which is completely repulsive at very high solvent concentrations, progressively turns attractive as solvent density declines. On the other hand, the three-body effect turns out to be repulsive and increases exponentially with decreasing solvent density. Further, the structure of the ligand shell is analyzed as a function of nanoparticle separation, and its relationship with the three-body effect is investigated. It is observed that the three-body effect arises when the ligand shell begins to deform due to van der Waals repulsion between ligand shells. The study provides a deep insight into good understanding of the solvent evaporation-assisted nanoparticle self-assembly and can aid in experiments.
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Affiliation(s)
- Hari O S Yadav
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi, 110067, India.
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3
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Roy M, Dahmani R, Vallet V, Masella M. Early Steps in the O 2 Scavenger Process in the Aqueous Phase: Hydrazine vs DEHA. J Phys Chem A 2023; 127:10104-10117. [PMID: 37988629 DOI: 10.1021/acs.jpca.3c05383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
We investigate the first direct proton abstraction reactions from reducing agents (RAHs) hydrazine and diethyl hydroxylamine (DEHA), toward dioxygen (O2) in the aqueous phase, spanning ambient to high-temperature conditions. Quantum chemistry methods and molecular dynamics simulations are employed in this study. Quantum chemistry methods are used to analyze the quasi-equilibrium between a reactive conformation and a transition state in the [RAH,O2] cluster. On the other hand, molecular dynamics simulations estimate the probability of observing a reactive conformation of the [RAH,O2] cluster in the solution. In this study, we assume that the energy barrier of the quasi-equilibrium is sufficiently high for the RAH/O2 association process to be at equilibrium. Our findings indicate that the first proton abstraction process from a reactive conformation cluster by DEHA is energetically favored compared to hydrazine. Conversely, the association process of hydrazine and O2 in solution is more favorable than that of DEHA. Consequently, the rate constant for the first proton abstraction process is similar for both hydrazine and DEHA, particularly at high temperatures, with activation energies of approximately 21.5 ± 1.5 kcal mol-1 for both compounds. These results align with recent experiments investigating the complete O2 scavenger process in liquid water with hydrazine and DEHA. Therefore, our findings support the assumption that first proton abstraction reactions are the rate-determining steps in O2 scavenger processes in the aqueous phase.
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Affiliation(s)
- Marion Roy
- Service de Physico-Chimie, Université Paris-Saclay, CEA, Gif-sur-Yvette 91190, France
| | - Rahma Dahmani
- Laboratoire de Biologie Structurale et Radiobiologie, Service de Bioénergétique, Biologie Structurale et Mécanismes, Institut de Biologie et de Technologies de Saclay, CEA Saclay, Gif sur Yvette Cedex F-91191, France
| | - Valérie Vallet
- Univ. Lille, CNRS, UMR 8523─PhLAM─Physique des Lasers Atomes et Molécules, Lille F-59000, France
| | - Michel Masella
- Laboratoire de Biologie Structurale et Radiobiologie, Service de Bioénergétique, Biologie Structurale et Mécanismes, Institut de Biologie et de Technologies de Saclay, CEA Saclay, Gif sur Yvette Cedex F-91191, France
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4
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Zhang W, Zhou L, Yan T, Chen M. Speciation of La 3+-Cl - Complexes in Hydrothermal Fluids from Deep Potential Molecular Dynamics. J Phys Chem B 2023; 127:8926-8937. [PMID: 37812657 DOI: 10.1021/acs.jpcb.3c05428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/11/2023]
Abstract
The stability of rare earth element (REE) complexes plays a crucial role in quantitatively assessing their hydrothermal migration and transformation. However, reliable data are lacking under high-temperature hydrothermal conditions, which hampers our understanding of the association behavior of REE. Here a deep learning potential model for the LaCl3-H2O system in hydrothermal fluids is developed based on the first-principles density functional theory calculations. The model accurately predicts the radial distribution functions compared to ab initio molecular dynamics (AIMD) simulations. Furthermore, species of La-Cl complexes, the dissociation pathway of the La-Cl complexes dissociation process, and the potential of mean forces and corresponding association constants (logK) for LaCln3-n (n = 1-4) are extensively investigated under a wide range of temperatures and pressures. Empirical density models for logK calculation are fitted with these data and can accurately predict logK data from both experimental results and AIMD simulations. The distribution of La-Cl species is also evaluated across a wide range of temperatures, pressures, and initial chloride concentration conditions. The results show that La-Cl complexes are prone to forming in a low-density solution, and the number of bonded Cl- ions increases with rising temperature. In contrast, in a high-density solution, La3+ dominates and becomes the more prevalent species.
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Affiliation(s)
- Wei Zhang
- School of Geography and Environmental Science (School of Karst Science), Guizhou Normal University, Guiyang 550025, China
- State Engineering Technology Institute for Karst Desertification Control, Guiyang 550025, China
- Research Center of Karst Ecological Civilization, Guizhou Normal University, Guiyang 550025, China
| | - Li Zhou
- School of Geography and Environmental Science (School of Karst Science), Guizhou Normal University, Guiyang 550025, China
| | - Tinggui Yan
- School of Chemistry and Chemical Engineering, Guizhou University, Guiyang 550025, China
| | - Mohan Chen
- HEDPS, CAPT, College of Engineering and School of Physics, Peking University, Beijing 100871, China
- AI for Science Institute, Beijing 100080, China
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5
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Lanza G. Water model for hydrophobic cavities: structure and energy from quantum-chemical calculations. Phys Chem Chem Phys 2023; 25:6902-6913. [PMID: 36799662 DOI: 10.1039/d2cp05195h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This ab initio study aims to design a series of large water clusters having a hollow clathrate-like cage able to host hydrophobic solutes of various sizes. Starting from the (H2O)n (n = 18, 20, 24 and 28) hollow cages, water layers have been added in a stepwise manner in order to model the configuration of water molecules beyond the primary shell. The large (H2O)100, (H2O)120 and (H2O)140 clusters complete the hydrogen bonding network of the cage with optimal and regular tiling of the do-, tetra-decahedron and hexa-decahedron, respectively. This study is corroborated by an investigation of dense water clusters up to the (H2O)123 one, being highly consistent with experimental data on ice concerning the electronic and zero-point energies for aggregate formation at 0 K and enthalpy and entropy at 273 K. The cavity creation profoundly alters the orientation of water molecules compared with those found in dense clusters. Nevertheless, such a large reorganization is necessary to maximize the water-water attraction by making it similar to the one found in dense clusters. The cage formation is an endothermic process; however, the computed values are large compared with previous reports for hydrocarbon aqueous solutions. Larger clusters are required for a more fruitful comparison.
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Affiliation(s)
- Giuseppe Lanza
- Dipartimento di Scienze del Farmaco e della Salute, Università di Catania, Viale A. Doria 6, Catania, 95125, Italy.
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6
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Chen W, Sanders SE, Özdamar B, Louaas D, Brigiano FS, Pezzotti S, Petersen PB, Gaigeot MP. On the Trail of Molecular Hydrophilicity and Hydrophobicity at Aqueous Interfaces. J Phys Chem Lett 2023; 14:1301-1309. [PMID: 36724059 DOI: 10.1021/acs.jpclett.2c03300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Uncovering microscopic hydrophilicity and hydrophobicity at heterogeneous aqueous interfaces is essential as it dictates physico/chemical properties such as wetting, the electrical double layer, and reactivity. Several molecular and spectroscopic descriptors were proposed, but a major limitation is the lack of connections between them. Here, we combine density functional theory-based MD simulations (DFT-MD) and SFG spectroscopy to explore how interfacial water responds in contact with self-assembled monolayers (SAM) of tunable hydrophilicity. We introduce a microscopic metric to track the transition from hydrophobic to hydrophilic interfaces. This metric combines the H/V descriptor, a structural descriptor based on the preferential orientation within the water network in the topmost binding interfacial layer (BIL) and spectroscopic fingerprints of H-bonded and dangling OH groups of water carried by BIL-resolved SFG spectra. This metric builds a bridge between molecular descriptors of hydrophilicity/hydrophobicity and spectroscopically measured quantities and provides a recipe to quantitatively or qualitatively interpret experimental SFG signals.
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Affiliation(s)
- Wanlin Chen
- Université Paris-Saclay, Université Evry, CNRS, LAMBE UMR8587, 91025Evry-Courcouronnes, France
| | - Stephanie E Sanders
- Department of Chemistry and Biochemistry, Ruhr University Bochum, 44801Bochum, Germany
| | - Burak Özdamar
- Université Paris-Saclay, Université Evry, CNRS, LAMBE UMR8587, 91025Evry-Courcouronnes, France
| | - Dorian Louaas
- Université Paris-Saclay, Université Evry, CNRS, LAMBE UMR8587, 91025Evry-Courcouronnes, France
| | - Flavio Siro Brigiano
- Université Paris-Saclay, Université Evry, CNRS, LAMBE UMR8587, 91025Evry-Courcouronnes, France
- Laboratoire de Chimie Théorique, Sorbonne Université, UMR 7616 CNRS, 4 Place Jussieu, 75005Paris, France
| | - Simone Pezzotti
- Université Paris-Saclay, Université Evry, CNRS, LAMBE UMR8587, 91025Evry-Courcouronnes, France
- Department of Physical Chemistry II, Ruhr University Bochum, D-44801Bochum, Germany
| | - Poul B Petersen
- Department of Chemistry and Biochemistry, Ruhr University Bochum, 44801Bochum, Germany
| | - Marie-Pierre Gaigeot
- Université Paris-Saclay, Université Evry, CNRS, LAMBE UMR8587, 91025Evry-Courcouronnes, France
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7
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Molecular dynamics simulations of LiCl ion pairs in high temperature aqueous solutions by deep learning potential. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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8
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Sujith K. Effect of methanol as an amphiphile on water structuring around a hydrate forming gas molecule: Insights from molecular dynamics simulations. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Pavlov S, Danilova V, Sivakov V, Kislenko S. The effect of a mixture of an ionic liquid and organic solvent on oxygen reduction reaction kinetics. Phys Chem Chem Phys 2022; 24:16746-16754. [PMID: 35771039 DOI: 10.1039/d2cp00698g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Li-O2 batteries attract great attention due to their promising theoretical energy density. One of the main obstacles on the way to achieving high energy density and good cyclability is positive electrode passivation by the Li2O2 discharge product as well as the presence of parasitic reactions that degrade electrode and electrolyte materials. To overcome these issues new electrolytes are being extensively searched for to ensure the bulk-mediated mechanism of the oxygen reduction reaction and inhibition of parasitic reactions. Different additives to organic solvents can significantly change the properties of electrolytes. This work is devoted to the effect of ionic liquids (ILs), which are proposed as an additive to the solvent due to their excellent solvation properties, high stability, low volatility and flammability. Using molecular dynamics simulations we investigate mixtures of the Pyr14TFSI ionic liquid and dimethoxyethane (DME) with different volume fractions of the IL. Our calculations show that the presence of the ionic liquid in the electrolyte stabilises solvation shells around the ions, both involved in the oxygen reduction and parasitic reactions, slowing down the kinetics of Li+ and O2- association. This makes the usage of such mixtures promising for electrolyte design for Li-O2 batteries.
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Affiliation(s)
- Sergey Pavlov
- Joint Institute for High Temperatures of RAS, Izhorskaya 13/2, 125412 Moscow, Russian Federation. .,Skolkovo Institute of Science and Technology, Skolkovo Innovation Center, Nobel St. 3, Moscow, 143026, Russian Federation
| | - Valentina Danilova
- Joint Institute for High Temperatures of RAS, Izhorskaya 13/2, 125412 Moscow, Russian Federation.
| | - Vyacheslav Sivakov
- Joint Institute for High Temperatures of RAS, Izhorskaya 13/2, 125412 Moscow, Russian Federation.
| | - Sergey Kislenko
- Joint Institute for High Temperatures of RAS, Izhorskaya 13/2, 125412 Moscow, Russian Federation.
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10
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Robinson VN, Ghosh R, Egan CK, Riera M, Knight C, Paesani F, Hassanali A. The behavior of methane-water mixtures under elevated pressures from simulations using many-body potentials. J Chem Phys 2022; 156:194504. [PMID: 35597630 DOI: 10.1063/5.0089773] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Non-polarizable empirical potentials have been proven to be incapable of capturing the mixing of methane-water mixtures at elevated pressures. Although density functional theory-based ab initio simulations may circumvent this discrepancy, they are limited in terms of the relevant time and length scales associated with mixing phenomena. Here, we show that the many-body MB-nrg potential, designed to reproduce methane-water interactions with coupled cluster accuracy, successfully captures this phenomenon up to 3 GPa and 500 K with varying methane concentrations. Two-phase simulations and long time scales that are required to fully capture the mixing, affordable due to the speed and accuracy of the MBX software, are assessed. Constructing the methane-water equation of state across the phase diagram shows that the stable mixtures are denser than the sum of their parts at a given pressure and temperature. We find that many-body polarization plays a central role, enhancing the induced dipole moments of methane by 0.20 D during mixing under pressure. Overall, the mixed system adopts a denser state, which involves a significant enthalpic driving force as elucidated by a systematic many-body energy decomposition analysis.
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Affiliation(s)
- Victor Naden Robinson
- The 'Abdus Salam' International Centre for Theoretical Physics, I-34151 Trieste, Italy
| | - Raja Ghosh
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, USA
| | - Colin K Egan
- The 'Abdus Salam' International Centre for Theoretical Physics, I-34151 Trieste, Italy
| | - Marc Riera
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, USA
| | - Christopher Knight
- Computational Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Lemont, Illinois 60439, USA
| | - Francesco Paesani
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, USA
| | - Ali Hassanali
- The 'Abdus Salam' International Centre for Theoretical Physics, I-34151 Trieste, Italy
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11
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Hu W, Chen C, Sun J, Zhang N, Zhao J, Liu Y, Ling Z, Li W, Liu W, Song Y. Three-body aggregation of guest molecules as a key step in methane hydrate nucleation and growth. Commun Chem 2022; 5:33. [PMID: 36697657 PMCID: PMC9814777 DOI: 10.1038/s42004-022-00652-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2021] [Accepted: 02/16/2022] [Indexed: 02/01/2023] Open
Abstract
Gas hydrates have an important role in environmental and astrochemistry, as well as in energy materials research. Although it is widely accepted that gas accumulation is an important and necessary process during hydrate nucleation, how guest molecules aggregate remains largely unknown. Here, we have performed molecular dynamics simulations to clarify the nucleation path of methane hydrate. We demonstrated that methane gather with a three-body aggregate pattern corresponding to the free energy minimum of three-methane hydrophobic interaction. Methane molecules fluctuate around one methane which later becomes the central gas molecule, and when several methanes move into the region within 0.8 nm of the potential central methane, they act as directional methane molecules. Two neighbor directional methanes and the potential central methane form a three-body aggregate as a regular triangle with a distance of ~6.7 Å which is well within the range of typical methane-methane distances in hydrates or in solution. We further showed that hydrate nucleation and growth is inextricably linked to three-body aggregates. By forming one, two, and three three-body aggregates, the possibility of hydrate nucleation at the aggregate increases from 3/6, 5/6 to 6/6. The results show three-body aggregation of guest molecules is a key step in gas hydrate formation.
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Affiliation(s)
- Wenfeng Hu
- School of Energy and Power Engineering, Dalian University of Technology, 116024, Dalian, P. R. China
| | - Cong Chen
- School of Energy and Power Engineering, Dalian University of Technology, 116024, Dalian, P. R. China.
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, 116024, Dalian, P. R. China.
| | - Jingyue Sun
- School of Energy and Power Engineering, Dalian University of Technology, 116024, Dalian, P. R. China
| | - Ning Zhang
- School of Petroleum and Chemical Engineering, Dalian University of Technology, 124221, Panjin, P. R. China
| | - Jiafei Zhao
- School of Energy and Power Engineering, Dalian University of Technology, 116024, Dalian, P. R. China
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, 116024, Dalian, P. R. China
| | - Yu Liu
- School of Energy and Power Engineering, Dalian University of Technology, 116024, Dalian, P. R. China
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, 116024, Dalian, P. R. China
| | - Zheng Ling
- School of Energy and Power Engineering, Dalian University of Technology, 116024, Dalian, P. R. China
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, 116024, Dalian, P. R. China
| | - Weizhong Li
- School of Energy and Power Engineering, Dalian University of Technology, 116024, Dalian, P. R. China
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, 116024, Dalian, P. R. China
| | - Weiguo Liu
- School of Energy and Power Engineering, Dalian University of Technology, 116024, Dalian, P. R. China
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, 116024, Dalian, P. R. China
| | - Yongchen Song
- School of Energy and Power Engineering, Dalian University of Technology, 116024, Dalian, P. R. China.
- Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, 116024, Dalian, P. R. China.
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12
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Prasad S, Gupta M. Solvation of gold nanoparticles passivated with functionalized alkylthiols: A molecular dynamics study. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2021.118342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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13
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Lanza G, Chiacchio MA. On the size, shape and energetics of the hydration shell around alkanes. Phys Chem Chem Phys 2021; 23:24852-24865. [PMID: 34723301 DOI: 10.1039/d1cp02888j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
A large number of clathrate-like cages have been proposed as the very first hydration shell of alkanes. The cages include canonical structures commonly found in clathrate hydrates and many others, not previously reported, derived from the carbon fullerene cavities. These structures have a rich and variegated form, which can adapt to the shape and conformation of the solute. They avoid "wasting" hydrogen bonds, while minimizing the volume cage and maximizing the solute-solvent van der Waals interactions. DFT/M06-2X and MP2 ab initio calculations give comparable structural and energetic results although the latter predicts slightly larger cages for a given solute. It is shown that the van der Waals interactions are substantial and the large exoenergetic values found for isobutane and cyclopentane provide an explanation for the surprising high melting points of related hydrates at room pressure. The encaging enthalpy for various hydrocarbons is similar to the enthalpy of solution measured at a temperature just above the melting point of aqueous hydrocarbon solutions, thus indicating that water molecules should not deviate too much from the configuration with O-H bonds tangentially oriented with respect to the solute surface. The computed trend differs from the enthalpy of solution measured at room temperature, thus the very first hydration shell departs, up to a certain degree, from the clathrate-like structures.
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Affiliation(s)
- Giuseppe Lanza
- A Dipartimento di Scienze del Farmaco e della Salute, Università di Catania, Viale A. Doria 6, Catania, Italy.
| | - Maria Assunta Chiacchio
- A Dipartimento di Scienze del Farmaco e della Salute, Università di Catania, Viale A. Doria 6, Catania, Italy.
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14
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Li K, Wang W, Xiao F, Ge Y, Jin H, Yu Z, Gong J, Gao W, Peng Z. Atomic Force Microscopy Study of Non-DLVO Interactions between Drops and Bubbles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:6830-6837. [PMID: 34043914 DOI: 10.1021/acs.langmuir.1c00937] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The heterointeraction between liquid drops and air bubbles dispersed in another immiscible liquid is studied with the application of the atomic force microscopy (AFM) probe techniques. The tetradecane drops and air bubbles readily coalescence to form a lens-like structure in 100 mM sodium chloride aqueous solution, demonstrating strong hydrophobic (HB) attraction. The interaction range and strength of this hydrophobic attraction between oil drops and air bubbles is investigated by fine control of electrical double layer thicknesses related to specific electrolyte concentrations, and a midrange term in combination with a short-range term is found to present a proper characterization of this hydrophobic attraction. A further step is taken by introducing a triblock copolymer (Pluronic F68) into the aqueous solution, with results indicating that a relatively long-range steric hindrance (SH) furnished by a polymer "brush" surmounts the hydrophobic attraction. Finally, the interaction between a water drop and an air bubble in tetradecane is also measured as a comparison. The repelling action between a hydrophobic body (air bubble) and water drop indicates a strong repulsion. The present results show an interesting understanding of hydrophobic interactions between drops and bubbles, which is of potential application in controlling dispersion stability.
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Affiliation(s)
- Kai Li
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing, No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Wei Wang
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing, No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Fan Xiao
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing, No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Yuntong Ge
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing, No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Hang Jin
- Tianjin Research Institute for Water Transport Engineering, Key Laboratory of Environmental Protection Technology on Water Transport, Ministry of Transport, No. 2618 Xingang Second Road, Binhai New District, 300456 Tianjin, P. R. China
| | - Zhipeng Yu
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing, No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Jing Gong
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing, No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Weiwei Gao
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing, No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
| | - Zeheng Peng
- Beijing Key Laboratory of Urban Oil and Gas Distribution Technology, State Key Laboratory of Natural Gas Hydrates, MOE Key Laboratory of Petroleum Engineering, China University of Petroleum, Beijing, No. 18 Fuxue Road, Changping District, 102249 Beijing, P. R. China
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15
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Wills A, Fernández-Serra M. Role of water model on ion dissociation at ambient conditions. J Chem Phys 2021; 154:194502. [PMID: 34240899 DOI: 10.1063/5.0046188] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We study ion pair dissociation in water at ambient conditions using a combination of classical and ab initio approaches. The goal of this study is to disentangle the sources of discrepancy observed in computed potentials of mean force. In particular, we aim to understand why some models favor the stability of solvent-separated ion pairs vs contact ion pairs. We found that some observed differences can be explained by non-converged simulation parameters. However, we also unveil that for some models, small changes in the solution density can have significant effects on modifying the equilibrium balance between the two configurations. We conclude that the thermodynamic stability of contact and solvent-separated ion pairs is very sensitive to the dielectric properties of the underlying simulation model. In general, classical models are very robust in providing a similar estimation of the contact ion pair stability, while this is much more variable in density functional theory-based models. The barrier to transition from the solvent-separated to contact ion pair is fundamentally dependent on the balance between electrostatic potential energy and entropy. This reflects the importance of water intra- and inter-molecular polarizability in obtaining an accurate description of the screened ion-ion interactions.
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Affiliation(s)
- Alec Wills
- Physics and Astronomy Department, Stony Brook University. Stony Brook, New York 11794-3800, USA
| | - Marivi Fernández-Serra
- Physics and Astronomy Department, Stony Brook University. Stony Brook, New York 11794-3800, USA
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Liu SX, Lü G, Zhang H, Geng YZ, Ji Q. Origin of the Surprising Mechanical Stability of Kinesin's Neck Coiled Coil. J Chem Theory Comput 2021; 17:1017-1029. [PMID: 33512152 DOI: 10.1021/acs.jctc.0c00566] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Kinesin-1 is a motor protein moving along a microtubule with its two identical motor heads dimerized by two neck linkers and a coiled-coil stalk. When both motor heads bind the microtubule, an internal strain is built up between the two heads, which is indispensable to ensure proper coordination of the two motor heads during kinesin-1's mechanochemical cycle. The internal strain forms a tensile force along the neck linker that tends to unwind the neck coiled coil (NCC). Experiments showed that the kinesin-1's NCC has a high antiunwinding ability compared with conventional coiled coils, which was mainly attributed to the enhanced hydrophobic pressure arising from the unconventional sequence of kinesin-1's NCC. However, hydrophobic pressure cannot provide the shearing force which is needed to balance the tensile force on the interface between two helices. To find out the true origin of the mechanical stability of kinesin-1's NCC, we perform a novel and detailed mechanical analysis for the system based on molecular dynamics simulation at an atomic level. We find that the needed shearing force is provided by a buckle structure formed by two tyrosines which form effective steric hindrance in the presence of tensile forces. The tensile force is balanced by the tensile direction component of the contact force between the two tyrosines which forms the shearing force. The hydrophobic pressure balances the other component of the contact force perpendicular to the tensile direction. The antiunwinding strength of NCC is defined by the maximum shearing force, which is finally determined by the hydrophobic pressure. Kinesin-1 uses residues with plane side chains, tryptophans and tyrosines, to form the hydrophobic center and to shorten the interhelix distance so that a high antiunwinding strength is obtained. The special design of NCC ensures exquisite cooperation of steric hindrance and hydrophobic pressure that results in the surprising mechanical stability of NCC.
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Affiliation(s)
- Shu-Xia Liu
- Institute of Biophysics, Hebei University of Technology, Tianjin 300401, China
| | - Gang Lü
- Mathematical and Physical Science School, North China Electric Power University, Baoding 071003, China
| | - Hui Zhang
- School of Science, Hebei University of Technology, Tianjin 300401, China
| | - Yi-Zhao Geng
- Institute of Biophysics, Hebei University of Technology, Tianjin 300401, China.,School of Science, Hebei University of Technology, Tianjin 300401, China
| | - Qing Ji
- Institute of Biophysics, Hebei University of Technology, Tianjin 300401, China.,School of Science, Hebei University of Technology, Tianjin 300401, China.,State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China
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17
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Bui T, Monteiro D, Vo L, Striolo A. Synergistic and Antagonistic Effects of Aromatics on the Agglomeration of Gas Hydrates. Sci Rep 2020; 10:5496. [PMID: 32218443 PMCID: PMC7098976 DOI: 10.1038/s41598-020-62060-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 03/02/2020] [Indexed: 11/15/2022] Open
Abstract
Surfactants are often used to stabilize aqueous dispersions. For example, surfactants can be used to prevent hydrate particles from forming large plugs that can clog, and sometimes rupture pipelines. Changes in oil composition, however dramatically affect the performance of said surfactants. In this work we demonstrate that aromatic compounds, dissolved in the hydrocarbon phase, can have both synergistic and antagonistic effects, depending on their molecular structure, with respect to surfactants developed to prevent hydrate agglomerations. While monocyclic aromatics such as benzene were found to disrupt the structure of surfactant films at low surfactant density, they are expelled from the interfacial film at high surfactant density. On the other hand, polycyclic aromatics, in particular pyrene, are found to induce order and stabilize the surfactant films both at low and high surfactant density. Based on our simulation results, polycyclic aromatics could behave as natural anti-agglomerants and enhance the performance of the specific surfactants considered here, while monocyclic aromatics could, in some cases, negatively affect performance. Although limited to the conditions chosen for the present simulations, the results, explained in terms of molecular features, could be valuable for better understanding synergistic and antagonistic effects relevant for stabilizing aqueous dispersions used in diverse applications, ranging from foodstuff to processing of nanomaterials and advanced manufacturing.
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Affiliation(s)
- Tai Bui
- Department of Chemical Engineering, University College London, WC1 E7JE, London, UK
| | | | - Loan Vo
- Halliburton, Houston, Texas, USA
| | - Alberto Striolo
- Department of Chemical Engineering, University College London, WC1 E7JE, London, UK.
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18
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Ma YL, Li T, Jin YM, Geng YZ, Ji Q. Shaft Function of Kinesin-1's α4 Helix in the Processive Movement. Cell Mol Bioeng 2019; 12:345-354. [PMID: 31719918 PMCID: PMC6816713 DOI: 10.1007/s12195-019-00581-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2019] [Accepted: 06/17/2019] [Indexed: 10/26/2022] Open
Abstract
INTRODUCTION Kinesin-1 motor is a molecular walking machine constructed with amino acids. The understanding of how those structural elements play their mechanical roles is the key to the understanding of kinesin-1 mechanism. METHODS Using molecular dynamics simulations, we investigate the role of a helix structure, α4 (also called switch-II helix), of kinesin-1's motor domain in its processive movement along microtubule. RESULTS Through the analysis of the structure and the interactions between α4 and the surrounding residues in different nucleotide-binding states, we find that, mechanically, this helix functions as a shaft for kinesin-1's motor-domain rotation and, structurally, it is an amphipathic helix ensuring its shaft functioning. The hydrophobic side of α4 consists strictly of hydrophobic residues, making it behave like a lubricated surface in contact with the core β-sheet of kinesin-1's motor domain. The opposite hydrophilic side of α4 leans firmly against microtubule with charged residues locating at both ends to facilitate its positioning onto the intra-tubulin groove. CONCLUSIONS The special structural feature of α4 makes for an effective reduction of the conformational work in kinesin-1's force generation process.
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Affiliation(s)
- Yi-Long Ma
- Institute of Biophysics, Hebei University of Technology, Tianjin, 300401 China
- School of Science, Hebei University of Technology, Tianjin, 300401 China
| | - Tie Li
- State Key Laboratory of Reliability and Intelligence of Electrical Equipment, Hebei University of Technology, Tianjin, 300401 China
- School of Electrical Engineering, Hebei University of Technology, Tianjin, 300401 China
| | - Yu-Mei Jin
- Institute of Biophysics, Hebei University of Technology, Tianjin, 300401 China
- School of Science, Hebei University of Technology, Tianjin, 300401 China
| | - Yi-Zhao Geng
- Institute of Biophysics, Hebei University of Technology, Tianjin, 300401 China
- School of Science, Hebei University of Technology, Tianjin, 300401 China
| | - Qing Ji
- Institute of Biophysics, Hebei University of Technology, Tianjin, 300401 China
- School of Science, Hebei University of Technology, Tianjin, 300401 China
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19
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Akin-Ojo O, Szalewicz K. Does a pair of methane molecules aggregate in water? J Chem Phys 2019; 150:084501. [PMID: 30823769 DOI: 10.1063/1.5083826] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Molecular dynamics (MD) simulations of methane-water mixtures were performed using ab initio force fields for the CH4-H2O, H2O-H2O, and CH4-CH4 interactions. Both methane and water molecules were polarizable. From these calculations, the potential of mean force (PMF) between two methane molecules was extracted. Our results are compared with PMFs from a density-functional-theory (DFT) based Born-Oppenheimer type MD (BOMD) simulation, from a Monte Carlo (MC) simulation with ab initio-based force fields, and from MD simulations with empirical force fields. Our PMF is qualitatively similar to that obtained from the simulations with empirical force fields but differs significantly from those resulting from the DFT-BOMD and MC simulations. The depth of the PMF global minimum obtained in the present work is in a much better agreement with the experimental estimate than the result of the DFT-BOMD simulation, possibly due to the inability of DFT to describe the dispersion interactions and the lack of extensive sampling in the BOMD simulations. Our work indicates that, for a pair of methane molecules, there are configurations where the solvent increases the attraction between the solutes, but there are also conformations in which the solvent causes a weak net repulsion. On average, the methane molecules are more likely to be in the configuration where they are separated by a water molecule than in the one in which they are in contact even though the minimum of the PMF at the latter configuration is deeper than that at the former. Finally, we found that the water structure around methane solutes does not show a greater tetrahedral ordering than in neat bulk water.
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Affiliation(s)
- Omololu Akin-Ojo
- ICTP East Africa Institute for Fundamental Research, University of Rwanda, Rwanda
| | - Krzysztof Szalewicz
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716, USA
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20
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Escribano R, Gómez PC, Maté B, Molpeceres G, Artacho E. Prediction of the near-IR spectra of ices by ab initio molecular dynamics. Phys Chem Chem Phys 2019; 21:9433-9440. [DOI: 10.1039/c9cp00857h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Use of ab initio molecular dynamics to predict the near-IR spectra of ices and application to astronomical models.
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Affiliation(s)
- Rafael Escribano
- Instituto de Estructura de la Materia
- IEM-CSIC, and Unidad Asociada Physical Chemistry UCM-CSIC
- 28006 Madrid
- Spain
| | - Pedro C. Gómez
- Departamento de Química Física
- Facultad de C. Químicas
- Universidad Complutense, and Unidad Asociada Physical Chemistry UCM-CSIC
- 28040 Madrid
- Spain
| | - Belén Maté
- Instituto de Estructura de la Materia
- IEM-CSIC, and Unidad Asociada Physical Chemistry UCM-CSIC
- 28006 Madrid
- Spain
| | - Germán Molpeceres
- Instituto de Estructura de la Materia
- IEM-CSIC, and Unidad Asociada Physical Chemistry UCM-CSIC
- 28006 Madrid
- Spain
- Institut für Theoretische Chemie
| | - Emilio Artacho
- Theory of Condensed Matter
- Cavendish Laboratory
- University of Cambridge
- Cambridge
- UK
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21
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Dubey V, Daschakraborty S. Influence of glycerol on the cooling effect of pair hydrophobicity in water: relevance to proteins’ stabilization at low temperature. Phys Chem Chem Phys 2019; 21:800-812. [DOI: 10.1039/c8cp06513f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Glycerol reduces the cooling effect of pair hydrophobicity (reduction of hydrophobicity with decreasing temperature) in water.
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Affiliation(s)
- Vikas Dubey
- Department of Chemistry
- Indian Institute of Technology Patna
- Bihar 801106
- India
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22
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Yao Y, Kanai Y. Free Energy Profile of NaCl in Water: First-Principles Molecular Dynamics with SCAN and ωB97X-V Exchange–Correlation Functionals. J Chem Theory Comput 2018; 14:884-893. [DOI: 10.1021/acs.jctc.7b00846] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Yi Yao
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United States
| | - Yosuke Kanai
- Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599, United States
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23
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Lima Costa AH, Clemente WS, Bezerra KS, Lima Neto JX, Albuquerque EL, Fulco UL. Computational biochemical investigation of the binding energy interactions between an estrogen receptor and its agonists. NEW J CHEM 2018. [DOI: 10.1039/c8nj03521k] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We present the energy profiles of estrogen receptor–agonist ligand interactions in atomic detail using a quantum biochemical approach.
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Affiliation(s)
- Aranthya H. Lima Costa
- Departamento de Biofísica e Farmacologia
- Universidade Federal do Rio Grande do Norte
- Natal-RN
- Brazil
| | - Washington S. Clemente
- Departamento de Biofísica e Farmacologia
- Universidade Federal do Rio Grande do Norte
- Natal-RN
- Brazil
| | - Katyanna S. Bezerra
- Departamento de Biofísica e Farmacologia
- Universidade Federal do Rio Grande do Norte
- Natal-RN
- Brazil
| | - José X. Lima Neto
- Departamento de Biofísica e Farmacologia
- Universidade Federal do Rio Grande do Norte
- Natal-RN
- Brazil
| | | | - Umberto L. Fulco
- Departamento de Biofísica e Farmacologia
- Universidade Federal do Rio Grande do Norte
- Natal-RN
- Brazil
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24
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Yadav HOS, Shrivastav G, Agarwal M, Chakravarty C. Effective interactions between nanoparticles: Creating temperature-independent solvation environments for self-assembly. J Chem Phys 2016; 144:244901. [DOI: 10.1063/1.4954325] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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25
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Affiliation(s)
- Dor Ben-Amotz
- Department of Chemistry, Purdue University, West Lafayette, Indiana 47907;
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26
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Gillan MJ, Alfè D, Manby FR. Energy benchmarks for methane-water systems from quantum Monte Carlo and second-order Møller-Plesset calculations. J Chem Phys 2015; 143:102812. [PMID: 26374005 DOI: 10.1063/1.4926444] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The quantum Monte Carlo (QMC) technique is used to generate accurate energy benchmarks for methane-water clusters containing a single methane monomer and up to 20 water monomers. The benchmarks for each type of cluster are computed for a set of geometries drawn from molecular dynamics simulations. The accuracy of QMC is expected to be comparable with that of coupled-cluster calculations, and this is confirmed by comparisons for the CH4-H2O dimer. The benchmarks are used to assess the accuracy of the second-order Møller-Plesset (MP2) approximation close to the complete basis-set limit. A recently developed embedded many-body technique is shown to give an efficient procedure for computing basis-set converged MP2 energies for the large clusters. It is found that MP2 values for the methane binding energies and the cohesive energies of the water clusters without methane are in close agreement with the QMC benchmarks, but the agreement is aided by partial cancelation between 2-body and beyond-2-body errors of MP2. The embedding approach allows MP2 to be applied without loss of accuracy to the methane hydrate crystal, and it is shown that the resulting methane binding energy and the cohesive energy of the water lattice agree almost exactly with recently reported QMC values.
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Affiliation(s)
- M J Gillan
- London Centre for Nanotechnology, University College London, Gordon St., London WC1H 0AH, United Kingdom
| | - D Alfè
- London Centre for Nanotechnology, University College London, Gordon St., London WC1H 0AH, United Kingdom
| | - F R Manby
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol BS8 1TS, United Kingdom
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27
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Ou SC, Cui D, Wezowicz M, Taufer M, Patel S. Free energetics of carbon nanotube association in aqueous inorganic NaI salt solutions: Temperature effects using all-atom molecular dynamics simulations. J Comput Chem 2015; 36:1196-212. [PMID: 25868455 PMCID: PMC4445429 DOI: 10.1002/jcc.23906] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 01/22/2015] [Accepted: 02/21/2015] [Indexed: 11/06/2022]
Abstract
In this study, we examine the temperature dependence of free energetics of nanotube association using graphical processing unit-enabled all-atom molecular dynamics simulations (FEN ZI) with two (10,10) single-walled carbon nanotubes in 3 m NaI aqueous salt solution. Results suggest that the free energy, enthalpy and entropy changes for the association process are all reduced at the high temperature, in agreement with previous investigations using other hydrophobes. Via the decomposition of free energy into individual components, we found that solvent contribution (including water, anion, and cation contributions) is correlated with the spatial distribution of the corresponding species and is influenced distinctly by the temperature. We studied the spatial distribution and the structure of the solvent in different regions: intertube, intratube and the bulk solvent. By calculating the fluctuation of coarse-grained tube-solvent surfaces, we found that tube-water interfacial fluctuation exhibits the strongest temperature dependence. By taking ions to be a solvent-like medium in the absence of water, tube-anion interfacial fluctuation shows similar but weaker dependence on temperature, while tube-cation interfacial fluctuation shows no dependence in general. These characteristics are discussed via the malleability of their corresponding solvation shells relative to the nanotube surface. Hydrogen bonding profiles and tetrahedrality of water arrangement are also computed to compare the structure of solvent in the solvent bulk and intertube region. The hydrophobic confinement induces a relatively lower concentration environment in the intertube region, therefore causing different intertube solvent structures which depend on the tube separation. This study is relevant in the continuing discourse on hydrophobic interactions (as they impact generally a broad class of phenomena in biology, biochemistry, and materials science and soft condensed matter research), and interpretations of hydrophobicity in terms of alternative but parallel signatures such as interfacial fluctuations, dewetting transitions, and enhanced fluctuation probabilities at interfaces.
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Affiliation(s)
- Shu-Ching Ou
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
| | - Di Cui
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
| | - Matthew Wezowicz
- Department of Computer and Information Sciences, University of Delaware, Newark, Delaware 19716, USA
| | - Michela Taufer
- Department of Computer and Information Sciences, University of Delaware, Newark, Delaware 19716, USA
| | - Sandeep Patel
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
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Abstract
Processes ranging from oil-water phase separation to the formation of solid clathrate hydrates send mixed messages regarding whether oil molecules hate or love to be surrounded by water. Recent experimental and theoretical results help decipher these mixed messages by illuminating the conditions under which the stability of a hydrophobic contact is expected to exceed thermal energy fluctuations - thus facilitating hydrophobic self-assembly and the emergence of structure from randomness. Important open questions remain regarding the dependence of hydrophobic interactions on molecular size and temperature, as well as the balance of direct and water-mediated interactions.
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Affiliation(s)
- Dor Ben-Amotz
- Purdue University, Department of Chemistry, West Lafayette, Indiana 47907, United States
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29
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Rankin BM, Ben-Amotz D, van der Post ST, Bakker HJ. Contacts Between Alcohols in Water Are Random Rather than Hydrophobic. J Phys Chem Lett 2015; 6:688-92. [PMID: 26262487 DOI: 10.1021/jz5027129] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Given the importance of water-mediated hydrophobic interactions in a wide range of biological and synthetic self-assembly processes, it is remarkable that both the sign and the magnitude of the hydrophobic interactions between simple amphiphiles, such as alcohols, remain unresolved. To address this question, we have performed Raman hydration-shell vibrational spectroscopy and polarization-resolved femtosecond infrared experiments, as well as random mixing and molecular dynamics simulations. Our results indicate that there are no more hydrophobic contacts in aqueous solutions of alcohols ranging from methanol to tertiary butyl alcohol than in random mixtures of the same concentration. This implies that the interaction between small hydrophobic groups is weaker than thermal energy fluctuations. Thus, the corresponding water-mediated hydrophobic interaction must be repulsive, with a magnitude sufficient to negate the attractive direct van der Waals interaction between the hydrophobic groups.
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Affiliation(s)
- Blake M Rankin
- †Purdue University, Department of Chemistry, West Lafayette, Indiana 47907, United States
| | - Dor Ben-Amotz
- †Purdue University, Department of Chemistry, West Lafayette, Indiana 47907, United States
| | | | - Huib J Bakker
- ‡FOM Institute AMOLF, Science Park 104, 1098 XG Amsterdam, The Netherlands
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30
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Galashev AE. Structure of water clusters with captured methane molecules. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY B 2015. [DOI: 10.1134/s1990793114110049] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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31
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32
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Brorsen KR, Pruitt SR, Gordon MS. Surface Affinity of the Hydronium Ion: The Effective Fragment Potential and Umbrella Sampling. J Phys Chem B 2014; 118:14382-7. [DOI: 10.1021/jp506906w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kurt R. Brorsen
- Ames
Laboratory, US-DOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
| | - Spencer R. Pruitt
- Ames
Laboratory, US-DOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
- Argonne Leadership
Computing Facility, Argonne, Illinois 60439, United States
| | - Mark S. Gordon
- Ames
Laboratory, US-DOE and Department of Chemistry, Iowa State University, Ames, Iowa 50011, United States
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33
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Chen JC, Reischl B, Spijker P, Holmberg N, Laasonen K, Foster AS. Ab initio Kinetic Monte Carlo simulations of dissolution at the NaCl-water interface. Phys Chem Chem Phys 2014; 16:22545-54. [PMID: 25227553 DOI: 10.1039/c4cp02375g] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have used ab initio molecular dynamics (AIMD) simulations to study the interaction of water with the NaCl surface. As expected, we find that water forms several ordered hydration layers, with the first hydration layer having water molecules aligned so that oxygen atoms are on average situated above Na sites. In an attempt to understand the dissolution of NaCl in water, we have then combined AIMD with constrained barrier searches, to calculate the dissolution energetics of Na(+) and Cl(-) ions from terraces, steps, corners and kinks of the (100) surface. We find that the barrier heights show a systematic reduction from the most stable flat terrace sites, through steps to the smallest barriers for corner and kink sites. Generally, the barriers for removal of Na(+) ions are slightly lower than for Cl(-) ions. Finally, we use our calculated barriers in a Kinetic Monte Carlo as a first order model of the dissolution process.
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Affiliation(s)
- Jian-Cheng Chen
- COMP Centre of Excellence and Department of Applied Physics, Aalto University, FI-00076 Helsinki, Finland.
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34
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Sa JH, Kwak GH, Lee BR, Ahn D, Lee KH. Abnormal incorporation of amino acids into the gas hydrate crystal lattice. Phys Chem Chem Phys 2014; 16:26730-4. [DOI: 10.1039/c4cp05056h] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Jabes BS, Yadav HOS, Kumar SK, Chakravarty C. Fluctuation-driven anisotropy in effective pair interactions between nanoparticles: Thiolated gold nanoparticles in ethane. J Chem Phys 2014; 141:154904. [DOI: 10.1063/1.4897541] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- B. Shadrack Jabes
- Department of Chemistry, Indian Institute of Technology-Delhi, New Delhi 110016, India
| | - Hari O. S. Yadav
- Department of Chemistry, Indian Institute of Technology-Delhi, New Delhi 110016, India
| | - Sanat K. Kumar
- Department of Chemical Engineering, Columbia University, 2960 Broadway, New York, New York 10027-6902, USA
| | - Charusita Chakravarty
- Department of Chemistry, Indian Institute of Technology-Delhi, New Delhi 110016, India
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36
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Aimoli CG, Maginn EJ, Abreu CRA. Transport properties of carbon dioxide and methane from molecular dynamics simulations. J Chem Phys 2014; 141:134101. [DOI: 10.1063/1.4896538] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- C. G. Aimoli
- Santos Basin Exploration and Production Operations Unit, Petróleo Brasileiro S.A., Av. Conselheiro Nébias 175, Santos, SP 11015-001, Brazil
- School of Chemical Engineering, State University of Campinas, Av. Albert Einstein 500, Campinas, SP 13083-852, Brazil
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, 182 Fitzpatrick Hall, Notre Dame, Indiana 46556, USA
| | - E. J. Maginn
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, 182 Fitzpatrick Hall, Notre Dame, Indiana 46556, USA
| | - C. R. A. Abreu
- School of Chemical Engineering, State University of Campinas, Av. Albert Einstein 500, Campinas, SP 13083-852, Brazil
- School of Chemistry, Federal University of Rio de Janeiro, Av. Athos da Silveira Ramos 149, Rio de Janeiro, RJ 21941-909, Brazil
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37
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Ou SC, Patel S. Electrostatic contribution from solvent in modulating single-walled carbon nanotube association. J Chem Phys 2014; 141:114906. [PMID: 25240371 PMCID: PMC4187323 DOI: 10.1063/1.4892566] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 07/28/2014] [Indexed: 11/14/2022] Open
Abstract
We perform all-atom molecular dynamics simulations to compute the potential of mean force (PMF) between two (10,10) single-walled carbon nanotubes solvated in pure nonpolarizable SPC/E and polarizable TIP4P-FQ water, at various temperatures. In general, the reversible work required to bring two nanotubes from a dissociated state (free energy reference) to contact state (free energy minimum) is more favorable and less temperature-dependent in TIP4P-FQ than in SPC/E water models. In contrast, molecular properties and behavior of water such as the spatially-resolved water number density (intertube, intratube, or outer regions), for TIP4P-FQ are more sensitive to temperature than SPC/E. Decomposition of the solvent-induced PMF into different spatial regions suggests that TIP4P-FQ has stronger temperature dependence; the opposing destabilizing/stabilizing contributions from intertube water and more distal water balance each other and suppress the temperature dependence of total association free energy. Further investigation of hydrogen bonding network in intertube water reveals that TIP4P-FQ retains fewer hydrogen bonds than SPC/E, which correlates with the lower water number density in this region. This reduction of hydrogen bonds affects the intertube water dipoles. As the intertube volume decreases, TIP4P-FQ dipole moment approaches the gas phase value; the distribution of dipole magnitude also becomes narrower due to less average polarization/perturbation from other water molecules. Our results imply that the reduction of water under confinement may seem trivial, but underlying effects to structure and free energetics are non-negligible.
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Affiliation(s)
- Shu-Ching Ou
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
| | - Sandeep Patel
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
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38
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Zhang Q, Zhang R, Zhao Y, Li H, Gao YQ, Zhuang W. Pairing preferences of the model mono-valence mono-atomic ions investigated by molecular simulation. J Chem Phys 2014; 140:184504. [DOI: 10.1063/1.4874255] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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39
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Shvab I, Sadus RJ. Thermodynamic properties and diffusion of water + methane binary mixtures. J Chem Phys 2014; 140:104505. [DOI: 10.1063/1.4867282] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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40
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Graziano G. Hydrostatic pressure effect on hydrophobic hydration and pairwise hydrophobic interaction of methane. J Chem Phys 2014; 140:094503. [DOI: 10.1063/1.4866972] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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41
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Park JW, Shumaker-Parry JS. Structural Study of Citrate Layers on Gold Nanoparticles: Role of Intermolecular Interactions in Stabilizing Nanoparticles. J Am Chem Soc 2014; 136:1907-21. [DOI: 10.1021/ja4097384] [Citation(s) in RCA: 439] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Jong-Won Park
- Department of Chemistry, University of Utah, 1400 East 315 South
RM 2020, Salt Lake City, Utah 84112, United States
| | - Jennifer S. Shumaker-Parry
- Department of Chemistry, University of Utah, 1400 East 315 South
RM 2020, Salt Lake City, Utah 84112, United States
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42
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43
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Zhang Q, Zhang B, Jiang L, Zhuang W. Ion Pairing Kinetics Does not Necessarily Follow the Eigen‐Tamm Mechanism. CHINESE J CHEM PHYS 2013. [DOI: 10.1063/1674-0068/26/06/694-700] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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44
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Calero C, Martí J, Guàrdia E, Masia M. Characterization of the Methane-Graphene Hydrophobic Interaction in Aqueous Solution from Ab Initio Simulations. J Chem Theory Comput 2013; 9:5070-5. [PMID: 26583421 DOI: 10.1021/ct400554q] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this article, the interaction between a methane molecule and a graphene plane in liquid water has been characterized employing DFT-based free energy Molecular Dynamics calculations. This system represents a good model to understand the generic interaction between a small hydrophobic solute (methane molecule) and an extense hydrophobic surface (graphene plane). The structural and dynamical properties of graphene and methane hydration water are analyzed and found to be closely related to the main features of the potential of mean force. The results could be used in coarse-grained models to take into account the effect of the hydrophobic interaction in realistic systems relevant to experiment.
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Affiliation(s)
- C Calero
- Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya-Barcelona Tech , B5-209 Campus Nord., 08034 Barcelona, Spain
| | - J Martí
- Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya-Barcelona Tech , B5-209 Campus Nord., 08034 Barcelona, Spain
| | - E Guàrdia
- Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya-Barcelona Tech , B5-209 Campus Nord., 08034 Barcelona, Spain
| | - Marco Masia
- Institut für Physikalische und Theoretische Chemie, Goethe Universität Frankfurt Max von Laue , Str. 7, D-60438 Frankfurt am Main, Germany.,Dipartimento di Chimica e Farmacia, Università degli Studi di Sassari , Via Vienna 2, 07100 Sassari, Italy
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45
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Godec A, Smith JC, Merzel F. Soft collective fluctuations governing hydrophobic association. PHYSICAL REVIEW LETTERS 2013; 111:127801. [PMID: 24093302 DOI: 10.1103/physrevlett.111.127801] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 08/02/2013] [Indexed: 06/02/2023]
Abstract
The interaction between two associating hydrophobic particles has traditionally been explained in terms of the release of entropically frustrated hydration shell water molecules. However, this picture cannot account for the kinetics of hydrophobic association and is therefore not capable of providing a microscopic description of the hydrophobic interaction (HI). Here, Monte Carlo simulations of a pair of molecular-scale apolar solutes in aqueous solution reveal the critical role of collective fluctuations in the hydrogen bond (HB) network for the microscopic picture of the HI. The main contribution to the HI is the relaxation of solute-water translational correlations. The existence of a heat capacity maximum at the desolvation barrier is shown to arise from softening of non-HB water fluctuations and the relaxation of many-body correlations in the labile HB network. The microscopic event governing the kinetics of hydrophobic association has turned out to be a relatively large critical collective fluctuation in hydration water displacing a substantial fraction of HB clusters from the inner to the outer region of the first hydration shell.
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Affiliation(s)
- Aljaž Godec
- National Institute of Chemistry, Hajdrihova 19, 1000 Ljubljana, Slovenia and Institute for Physics and Astronomy, University of Potsdam, 14476 Potsdam-Golm, Germany
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46
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Molinero V. Thermodynamic and structural signatures of water-driven methane-methane attraction in coarse-grained mW water. J Chem Phys 2013; 139:054511. [DOI: 10.1063/1.4816005] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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47
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Ghosh MK, Uddin N, Choi CH. Hydrophobic and Hydrophilic Associations of a Methanol Pair in Aqueous Solution. J Phys Chem B 2012; 116:14254-60. [DOI: 10.1021/jp308936g] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Manik Kumer Ghosh
- Department of Chemistry and Green-Nano Materials Research
Center, College of Natural Sciences, Kyungpook National University, Taegu 702-701, South Korea
| | - Nizam Uddin
- Department of Chemistry and Green-Nano Materials Research
Center, College of Natural Sciences, Kyungpook National University, Taegu 702-701, South Korea
| | - Cheol Ho Choi
- Department of Chemistry and Green-Nano Materials Research
Center, College of Natural Sciences, Kyungpook National University, Taegu 702-701, South Korea
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48
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Zhang Q, Zhang X, Zhao DX. Ion disturbance and clustering in the NaCl water solutions. J Mol Model 2012; 19:661-72. [DOI: 10.1007/s00894-012-1581-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 08/22/2012] [Indexed: 10/27/2022]
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49
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Pan Z, Chen J, Lü G, Geng YZ, Zhang H, Ji Q. An ab initio molecular dynamics study on hydrogen bonds between water molecules. J Chem Phys 2012; 136:164313. [DOI: 10.1063/1.4705371] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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50
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Pham VT, Penfold TJ, van der Veen RM, Lima F, El Nahhas A, Johnson SL, Beaud P, Abela R, Bressler C, Tavernelli I, Milne CJ, Chergui M. Probing the Transition from Hydrophilic to Hydrophobic Solvation with Atomic Scale Resolution. J Am Chem Soc 2011; 133:12740-8. [DOI: 10.1021/ja203882y] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Van-Thai Pham
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB, Station 6, CH-1015 Lausanne, Switzerland
| | - Thomas J. Penfold
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB, Station 6, CH-1015 Lausanne, Switzerland
- Swiss Light Source, Paul-Scherrer-Institut, CH-5232 PSI-Villigen, Switzerland
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Chimie Et Biochimie Computationnelles, ISIC-FSB, CH-1015 Lausanne, Switzerland
| | - Renske M. van der Veen
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB, Station 6, CH-1015 Lausanne, Switzerland
- Swiss Light Source, Paul-Scherrer-Institut, CH-5232 PSI-Villigen, Switzerland
| | - Frederico Lima
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB, Station 6, CH-1015 Lausanne, Switzerland
| | - Amal El Nahhas
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB, Station 6, CH-1015 Lausanne, Switzerland
| | - Steve L. Johnson
- Swiss Light Source, Paul-Scherrer-Institut, CH-5232 PSI-Villigen, Switzerland
| | - Paul Beaud
- Swiss Light Source, Paul-Scherrer-Institut, CH-5232 PSI-Villigen, Switzerland
| | - Rafael Abela
- Swiss Light Source, Paul-Scherrer-Institut, CH-5232 PSI-Villigen, Switzerland
| | - Christian Bressler
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB, Station 6, CH-1015 Lausanne, Switzerland
| | - Ivano Tavernelli
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Chimie Et Biochimie Computationnelles, ISIC-FSB, CH-1015 Lausanne, Switzerland
| | - Christopher J. Milne
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB, Station 6, CH-1015 Lausanne, Switzerland
| | - Majed Chergui
- Ecole Polytechnique Fédérale de Lausanne, Laboratoire de Spectroscopie Ultrarapide, ISIC-FSB, Station 6, CH-1015 Lausanne, Switzerland
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