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Tiburtini GA, Bertarini L, Bersani M, Dragani TA, Rolando B, Binello A, Barge A, Spyrakis F. In silico prediction of the interaction of legacy and novel per- and poly-fluoroalkyl substances (PFAS) with selected human transporters and of their possible accumulation in the human body. Arch Toxicol 2024; 98:3035-3047. [PMID: 38884658 PMCID: PMC11324760 DOI: 10.1007/s00204-024-03797-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 05/23/2024] [Indexed: 06/18/2024]
Abstract
Per- and poly-fluorinated compounds constitute a wide group of fluorocarbon chemicals with widespread industrial applications, ranging from non-stick coating in cookware to water surfactants, from fire-fighting foams to water-repellent coatings on textiles. Presently, over 12,000 PFAS are known worldwide. In recent years, extensive research has focused on investigating the biological effects of these molecules on various organisms, including humans. Here, we conducted in silico simulations to examine the potential binding of a representative selection of PFAS to various human proteins known to be involved in chemical transportation and accumulation processes. Specifically, we targeted human serum albumin (HSA), transthyretin (TTR), thyroxine binding protein (TBG), fatty acid binding proteins (FABPs), organic anion transporters (OATs), aiming to assess the potential for bioaccumulation. Molecular docking simulations were employed for this purpose, supplemented by molecular dynamics (MD) simulations to account for protein flexibility, when necessary. Our findings indicate that so-called "legacy PFAS" such as PFOA or PFOS exhibit a higher propensity for interaction with the analysed human protein targets compared to newly formulated PFAS, characterised by higher branching and hydrophilicity, and possibly a higher accumulation in the human body.
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Affiliation(s)
- G A Tiburtini
- Department of Drug Science and Technology, University of Turin, Turin, Italy
| | - L Bertarini
- Department of Drug Science and Technology, University of Turin, Turin, Italy
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - M Bersani
- Department of Drug Science and Technology, University of Turin, Turin, Italy
| | | | - B Rolando
- Department of Drug Science and Technology, University of Turin, Turin, Italy
| | - A Binello
- Department of Drug Science and Technology, University of Turin, Turin, Italy
| | - A Barge
- Department of Drug Science and Technology, University of Turin, Turin, Italy
| | - F Spyrakis
- Department of Drug Science and Technology, University of Turin, Turin, Italy.
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2
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de Souza BB, Meegoda J. Insights into PFAS environmental fate through computational chemistry: A review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 926:171738. [PMID: 38494023 DOI: 10.1016/j.scitotenv.2024.171738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 02/28/2024] [Accepted: 03/14/2024] [Indexed: 03/19/2024]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are widely used chemicals that exhibit exceptional chemical and thermal stability. However, their resistance to degradation has led to their widespread environmental contamination. PFAS also negatively affect the environment and other organisms, highlighting the need for effective remediation methods to mitigate their presence and prevent further contamination. Computational chemistry methods, such as Density Functional Theory (DFT) and Molecular Dynamics (MD) offer valuable tools for studying PFAS and simulating their interactions with other molecules. This review explores how computational chemistry methods contribute to understanding and tackling PFAS in the environment. PFAS have been extensively studied using DFT and MD, each method offering unique advantages and computational limitations. MD simulates large macromolecules systems however it lacks the ability model chemical reactions, while DFT provides molecular insights however at a high computational cost. The integration of DFT with MD shows promise in predicting PFAS behavior in different environments. This work summarizes reported studies on PFAS compounds, focusing on adsorption, destruction, and bioaccumulation, highlighting contributions of computational methods while discussing the need for continued research. The findings emphasize the importance of computational chemistry in addressing PFAS contamination, guiding risk assessments, and informing future research and innovations in this field.
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Affiliation(s)
- Bruno Bezerra de Souza
- John A. Reif, Jr. Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA
| | - Jay Meegoda
- John A. Reif, Jr. Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA.
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3
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Burrows SA, Shon JW, Peychev B, Slavchov RI, Smoukov SK. Phase transitions of fluorotelomer alcohols at the water|alkane interface studied via molecular dynamics simulation. SOFT MATTER 2024; 20:2243-2257. [PMID: 38351894 DOI: 10.1039/d3sm01444d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
Fluorosurfactants are long-lasting environmental pollutants that accumulate at interfaces ranging from aerosol droplet surfaces to cell membranes. Modeling of adsorption-based removal technologies for fluorosurfactants requires accurate simulation methods which can predict their adsorption isotherm and monolayer structure. Fluorotelomer alcohols with one or two methylene groups adjacent to the alcohol (7 : 1 FTOH and 6 : 2 FTOH, respectively) are investigated using the OPLS-AA force field at the water|hexane interface, varying the interfacial area per surfactant. The acquired interfacial pressure isotherms and monolayer phase behavior are compared with previous experimental results. The results are consistent with the experimental data inasmuch as, at realistic adsorption densities, only 7 : 1 FTOH shows a phase transition between liquid-expanded (LE) and 2D crystalline phases. Structures of the LE and crystalline phases are in good agreement with the sticky disc and Langmuir defective crystal models, respectively, used previously to interpret experimental data. Interfacial pressure of the LE phase agrees well with experiment, and sticky disc interaction parameters indicate no 2D LE-gas transition is present for either molecule. Conformation analysis reveals 7 : 1 FTOH favors conformers where the OH dipole is perpendicular to the molecular backbone, such that the crystalline phase is stabilized when these dipoles align.
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Affiliation(s)
- Stephen A Burrows
- Centre for Sustainable Engineering, School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK.
| | - Jang Won Shon
- Centre for Sustainable Engineering, School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK.
| | - Boyan Peychev
- Centre for Sustainable Engineering, School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK.
| | - Radomir I Slavchov
- Centre for Sustainable Engineering, School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK.
| | - Stoyan K Smoukov
- Centre for Sustainable Engineering, School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London, E1 4NS, UK.
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4
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Bezerra de Souza B, Aluthgun Hewage S, A Kewalramani J, Ct van Duin A, N Meegoda J. A ReaxFF-based molecular dynamics study of the destruction of PFAS due to ultrasound. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 333:122026. [PMID: 37315883 DOI: 10.1016/j.envpol.2023.122026] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 06/05/2023] [Accepted: 06/10/2023] [Indexed: 06/16/2023]
Abstract
This work uses a computational approach to provide a mechanistic explanation for the experimentally observed destruction of per- and polyfluoroalkyl substances (PFAS) in water due to ultrasound. The PFAS compounds have caused a strong public and regulatory response due to their ubiquitous presence in the environment and toxicity to humans. In this research, ReaxFF -based Molecular Dynamics simulation under several temperatures ranging from 373 K to 5,000 K and different environments such as water vapor, O2, N2, and air were performed to understand the mechanism of PFAS destruction. The simulation results showed greater than 98% PFAS degradation was observed within 8 ns under a temperature of 5,000 K in a water vapor phase, replicating the observed micro/nano bubbles implosion and PFAS destruction during the application of ultrasound. Additionally, the manuscript discusses the reaction pathways and how PFAS degradation evolves providing a mechanistic basis for the destruction of PFAS in water due to ultrasound. The simulation showed that small chain molecules C1 and C2 fluoro-radical products are the most dominant species over the simulated period and are the impediment to an efficient degradation of PFAS. Furthermore, this research confirms the empirical findings observations that the mineralization of PFAS molecules occurs without the generation of byproducts. These findings highlight the potential of virtual experiments in complementing laboratory experiments and theoretical projections to enhance the understanding of PFAS mineralization during the application of ultrasound.
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Affiliation(s)
- Bruno Bezerra de Souza
- Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ, USA
| | - Shaini Aluthgun Hewage
- Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ, USA
| | - Jitendra A Kewalramani
- Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ, USA
| | - Adri Ct van Duin
- Department of Mechanical Engineering, The Pennsylvania State University, State College, PA, USA
| | - Jay N Meegoda
- Department of Civil and Environmental Engineering, New Jersey Institute of Technology, Newark, NJ, USA.
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5
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Dong D, Kancharla S, Hooper J, Tsianou M, Bedrov D, Alexandridis P. Controlling the self-assembly of perfluorinated surfactants in aqueous environments. Phys Chem Chem Phys 2021; 23:10029-10039. [PMID: 33870993 DOI: 10.1039/d1cp00049g] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Surface active per- and polyfluoroalkyl substances (PFAS) released in the environment generate great concern in the US and worldwide. The sequestration of PFAS amphiphiles from aqueous media can be limited by their strong tendency to form micelles that plug the pores in the adsorbent material, rendering most of the active surface inaccessible. A joint experimental and simulation approach has been used to investigate the structure of perfluorooctanoate ammonium (PFOA) micelles in aqueous solutions, focusing on the understanding of ethanol addition on PFOA micelle formation and structure. Structurally compact and slightly ellipsoidal in shape, PFOA micelles in pure water become more diffuse with increasing ethanol content, and break into smaller PFOA clusters in aqueous solutions with high ethanol concentration. A transition from a co-surfactant to a co-solvent behavior with the increase of ethanol concentration has been observed by both experiments and simulations, while the latter also provide insight on how to achieve co-solvent conditions with other additives. An improved understanding of how to modulate PFAS surfactant self-assembly in water can inform the fate and transport of PFAS in the environment and the PFAS sequestration from aqueous media.
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Affiliation(s)
- Dengpan Dong
- Department of Materials Science and Engineering, University of Utah, 122 South Central Campus Drive, Room 304, Salt Lake City, UT 84112, USA.
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6
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Martin Somer A, Macaluso V, Barnes GL, Yang L, Pratihar S, Song K, Hase WL, Spezia R. Role of Chemical Dynamics Simulations in Mass Spectrometry Studies of Collision-Induced Dissociation and Collisions of Biological Ions with Organic Surfaces. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2020; 31:2-24. [PMID: 32881516 DOI: 10.1021/jasms.9b00062] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In this article, a perspective is given of chemical dynamics simulations of collisions of biological ions with surfaces and of collision-induced dissociation (CID) of ions. The simulations provide an atomic-level understanding of the collisions and, overall, are in quite good agreement with experiment. An integral component of ion/surface collisions is energy transfer to the internal degrees of freedom of both the ion and the surface. The simulations reveal how this energy transfer depends on the collision energy, incident angle, biological ion, and surface. With energy transfer to the ion's vibration fragmentation may occur, i.e. surface-induced dissociation (SID), and the simulations discovered a new fragmentation mechanism, called shattering, for which the ion fragments as it collides with the surface. The simulations also provide insight into the atomistic dynamics of soft-landing and reactive-landing of ions on surfaces. The CID simulations compared activation by multiple "soft" collisions, resulting in random excitation, versus high energy single collisions and nonrandom excitation. These two activation methods may result in different fragment ions. Simulations provide fragmentation products in agreement with experiments and, hence, can provide additional information regarding the reaction mechanisms taking place in experiment. Such studies paved the way on using simulations as an independent and predictive tool in increasing fundamental understanding of CID and related processes.
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Affiliation(s)
- Ana Martin Somer
- Departamento de Química, Facultad de Ciencias, Módulo 13 Universidad Autónoma de Madrid, Campus de Excelencia UAM-CSIC Cantoblanco, 28049 Madrid, Spain
| | - Veronica Macaluso
- LAMBE, Univ Evry, CNRS, CEA, Université Paris-Saclay, 91025 Evry, France
| | - George L Barnes
- Department of Chemistry and Biochemistry, Siena College, Loudonville, New York 12211, United States
| | - Li Yang
- MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, P.R. China
| | - Subha Pratihar
- Department of Chemistry and Biochemistry Texas Tech University, Lubbock, Texas 79409, United States
| | - Kihyung Song
- Department of Chemistry, Korea National University of Education, Chungbuk 28644, Republic of Korea
| | - William L Hase
- Department of Chemistry and Biochemistry Texas Tech University, Lubbock, Texas 79409, United States
| | - Riccardo Spezia
- Sorbonne Université, CNRS, Laboratoire de Chimie Théorique, LCT, 4, Place Jussieu, Paris, 75252 Cedex 05, France
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7
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Molecular Dynamics Simulation of the Superspreading of Surfactant-Laden Droplets. A Review. FLUIDS 2019. [DOI: 10.3390/fluids4040176] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Superspreading is the rapid and complete spreading of surfactant-laden droplets on hydrophobic substrates. This phenomenon has been studied for many decades by experiment, theory, and simulation, but it has been only recently that molecular-level simulation has provided significant insights into the underlying mechanisms of superspreading thanks to the development of accurate force-fields and the increase of computational capabilities. Here, we review the main advances in this area that have surfaced from Molecular Dynamics simulation of all-atom and coarse-grained models highlighting and contrasting the main results and discussing various elements of the proposed mechanisms for superspreading. We anticipate that this review will stimulate further research on the interpretation of experimental results and the design of surfactants for applications requiring efficient spreading, such as coating technology.
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8
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Tamir E, Sidess A, Srebnik S. Thermodynamic, structural, and mechanical properties of fluoropolymers from molecular dynamics simulation: Comparison of force fields. Chem Eng Sci 2019. [DOI: 10.1016/j.ces.2019.05.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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9
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Gu M, Yang L, Hase WL, Sun J, Zhang J. Energy Transfer of Peptide Ions Colliding with a Self‐Assembled Monolayer Surface. The Influence of Peptide Ion Size. CHINESE J CHEM 2019. [DOI: 10.1002/cjoc.201800544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Meng Gu
- MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology Harbin Heilongjiang 150001 China
| | - Li Yang
- MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology Harbin Heilongjiang 150001 China
| | - William L Hase
- Department of Chemistry and BiochemistryTexas Tech University Lubbock TX 79401 USA
| | - Jianmin Sun
- MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology Harbin Heilongjiang 150001 China
| | - Jiaxu Zhang
- MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology Harbin Heilongjiang 150001 China
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10
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Morgado P, Lobanova O, Müller EA, Jackson G, Almeida M, Filipe EJM. SAFT-γ force field for the simulation of molecular fluids: 8. Hetero-segmented coarse-grained models of perfluoroalkylalkanes assessed with new vapour–liquid interfacial tension data. Mol Phys 2016. [DOI: 10.1080/00268976.2016.1218077] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Pedro Morgado
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - Olga Lobanova
- Department of Chemical Engineering, Centre for Process Systems Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Erich A. Müller
- Department of Chemical Engineering, Centre for Process Systems Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - George Jackson
- Department of Chemical Engineering, Centre for Process Systems Engineering, Imperial College London, London SW7 2AZ, United Kingdom
| | - Miguel Almeida
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - Eduardo J. M. Filipe
- Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
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11
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Pratihar S, Kim N, Kohale SC, Hase WL. Mechanistic details of energy transfer and soft landing in ala2-H(+) collisions with a F-SAM surface. Phys Chem Chem Phys 2016. [PMID: 26214056 DOI: 10.1039/c5cp03214h] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Previous chemical dynamics simulations (Phys. Chem. Chem. Phys., 2014, 16, 23769-23778) were analyzed to delineate atomistic details for collision of N-protonated dialanine (ala2-H(+)) with a C8 perfluorinated self-assembled monolayer (F-SAM) surface. Initial collision energies Ei of 5-70 eV and incident angles θi of 0° and 45°, with the surface normal, were considered. Four trajectory types were identified: (1) direct scattering; (2) temporary sticking/physisorption on top of the surface; (3) temporary penetration of the surface with additional physisorption on the surface; and (4) trapping on/in the surface, by physisorption or surface penetration, when the trajectory is terminated. Direct scattering increases from 12 to 100% as Ei is increased from 5 to 70 eV. For the direct scattering at 70 eV, at least one ala2-H(+) heavy atom penetrated the surface for all of the trajectories. For ∼33% of the trajectories all eleven of the ala2-H(+) heavy atoms penetrated the F-SAM at the time of deepest penetration. The importance of trapping decreased with increase in Ei, decreasing from 84 to 0% with Ei increase from 5 to 70 eV at θi = 0°. Somewhat surprisingly, the collisional energy transfers to the F-SAM surface and ala2-H(+) are overall insensitive to the trajectory type. The energy transfer to ala2-H(+) is primarily to vibration, with the transfer to rotation ∼10% or less. Adsorption and then trapping of ala2-H(+) is primarily a multi-step process, and the following five trapping mechanisms were identified: (i) physisorption-penetration-physisorption (phys-pen-phys); (ii) penetration-physisorption-penetration (pen-phys-pen); (iii) penetration-physisorption (pen-phys); (iv) physisorption-penetration (phys-pen); and (v) only physisorption (phys). For Ei = 5 eV, the pen-phys-pen, pen-phys, phys-pen, and phys trapping mechanisms have similar probabilities. For 13.5 eV, the phys-pen mechanism, important at 5 eV, is unimportant. The radius of gyration of ala2-H(+) was calculated once it is trapped on/in the F-SAM surface and trapping decreases the ion's compactness, in part by breaking hydrogen bonds. The ala2-H(+) + F-SAM simulations are compared with the penetration and trapping dynamics found in previous simulations of projectile + organic surface collisions.
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Affiliation(s)
- S Pratihar
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061, USA.
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12
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Kuritz N, Murat M, Balaish M, Ein-Eli Y, Natan A. PFC and Triglyme for Li-Air Batteries: A Molecular Dynamics Study. J Phys Chem B 2016; 120:3370-7. [PMID: 26982570 DOI: 10.1021/acs.jpcb.5b12075] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this work, we present an all-atom molecular dynamics (MD) study of triglyme and perfluorinated carbons (PFCs) using classical atomistic force fields. Triglyme is a typical solvent used in nonaqueous Li-air battery cells. PFCs were recently reported to increase oxygen availability in such cells. We show that O2 diffusion in two specific PFC molecules (C6F14 and C8F18) is significantly faster than in triglyme. Furthermore, by starting with two very different initial configurations for our MD simulation, we demonstrate that C8F18 and triglyme do not mix. The mutual solubility of these molecules is evaluated both theoretically and experimentally, and a qualitative agreement is found. Finally, we show that the solubility of O2 in C8F18 is considerably higher than in triglyme. The significance of these results to Li-air batteries is discussed.
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Affiliation(s)
- Natalia Kuritz
- Department of Physical Electronics, Tel-Aviv University , Tel-Aviv 69978, Israel
| | - Michael Murat
- Department of Physical Electronics, Tel-Aviv University , Tel-Aviv 69978, Israel
| | - Moran Balaish
- The Grand Technion Energy Program, Technion - Israel Institute of Technology , Haifa 32000, Israel
| | - Yair Ein-Eli
- The Grand Technion Energy Program, Technion - Israel Institute of Technology , Haifa 32000, Israel
| | - Amir Natan
- Department of Physical Electronics, Tel-Aviv University , Tel-Aviv 69978, Israel
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13
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Ishizuka R, Matubayasi N. Self-Consistent Determination of Atomic Charges of Ionic Liquid through a Combination of Molecular Dynamics Simulation and Density Functional Theory. J Chem Theory Comput 2016; 12:804-11. [PMID: 26735302 DOI: 10.1021/acs.jctc.5b00885] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A self-consistent scheme is developed to determine the atomic partial charges of ionic liquid. Molecular dynamics (MD) simulation was conducted to sample a set of ion configurations, and these configurations were subject to density functional theory (DFT) calculations to determine the partial charges. The charges were then averaged and used as inputs for the subsequent MD simulation, and MD and DFT calculations were repeated until the MD results are not altered any more. We applied this scheme to 1,3-dimethylimidazolium bis(trifluoromethylsulfonyl) imide ([C1mim][NTf2]) and investigated its structure and dynamics as a function of temperature. At convergence, the average ionic charges were ±0.84 e at 350 K due to charge transfer among ions, where e is the elementary charge, while the reduced ionic charges do not affect strongly the density of [C1mim][NTf2] and radial distribution function. Instead, major effects are found on the energetics and dynamics, with improvements of the overestimated heat of vaporization and the too slow motions of ions observed in MD simulations using commonly used force fields.
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Affiliation(s)
- Ryosuke Ishizuka
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka 560-8531, Japan.,Elements Strategy Initiative for Catalysts and Batteries, Kyoto University , Katsura, Kyoto 615-8520, Japan
| | - Nobuyuki Matubayasi
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University , Toyonaka, Osaka 560-8531, Japan.,Elements Strategy Initiative for Catalysts and Batteries, Kyoto University , Katsura, Kyoto 615-8520, Japan
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14
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Pratihar S, Barnes GL, Hase WL. Chemical dynamics simulations of energy transfer, surface-induced dissociation, soft-landing, and reactive-landing in collisions of protonated peptide ions with organic surfaces. Chem Soc Rev 2016; 45:3595-608. [DOI: 10.1039/c5cs00482a] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Different simulation approaches like MM, QM + MM, and QM/MM, were used to study surface-induced dissociation, soft-landing, and reactive-landing for the peptide-H+ + surface collisions.
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Affiliation(s)
- Subha Pratihar
- Department of Chemistry and Biochemistry
- Texas Tech University
- Lubbock
- USA
| | - George L. Barnes
- Department of Chemistry and Biochemistry
- Siena College
- Loudonville
- USA
| | - William L. Hase
- Department of Chemistry and Biochemistry
- Texas Tech University
- Lubbock
- USA
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15
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Nikitin A, Milchevskiy Y, Lyubartsev A. AMBER-ii: New Combining Rules and Force Field for Perfluoroalkanes. J Phys Chem B 2015; 119:14563-73. [DOI: 10.1021/acs.jpcb.5b07233] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Alexei Nikitin
- Engelhardt
Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | - Yury Milchevskiy
- Engelhardt
Institute of Molecular Biology, Russian Academy of Sciences, Moscow 119991, Russia
| | - Alexander Lyubartsev
- Division
of Physical Chemistry, Department of Materials and Environmental Chemistry, Stockholm University, Stockholm SE-10691, Sweden
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16
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Isele-Holder RE, Berkels B, Ismail AE. Smoothing of contact lines in spreading droplets by trisiloxane surfactants and its relevance for superspreading. SOFT MATTER 2015; 11:4527-4539. [PMID: 25955355 DOI: 10.1039/c4sm02298j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Superspreading, the greatly enhanced spreading of aqueous solutions of trisiloxane surfactants on hydrophobic substrates, is of great interest in fundamental physics and technical applications. Despite numerous studies in the last 20 years, the superspreading mechanism is still not well understood, largely because the molecular scale cannot be resolved appropriately either experimentally or using continuum simulations. The absence of molecular-scale knowledge has led to a series of conflicting hypotheses based on different assumptions of surfactant behavior. We report a series of large-scale molecular dynamics simulations of aqueous solutions of superspreading and non-superspreading surfactants on different substrates. We find that the transition from the liquid-vapor to the solid-liquid interface is smooth for superspreading conditions, allowing direct adsorption through the contact line. This finding complements a study [Karapetsas et al., J. Fluid Mech., 2011, 670, 5-37], which predicts that superspreading can occur if this adsorption path is possible. Based on the observed mechanism, we provide plausible explanations for the influence of the substrate hydrophobicity, the surfactant chain length, and the surfactant concentration on the superspreading phenomenon. We also briefly address that the observed droplet shape is a mechanism to overcome the Huh-Scriven paradox of infinite viscous dissipation at the contact line.
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Affiliation(s)
- Rolf E Isele-Holder
- Aachener Verfahrenstechnik, Molecular Simulations and Transformations, RWTH Aachen University, Schinkelstraße 2, 52062 Aachen, Germany.
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17
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Accurate equations of state for CF 4 , CF 4 –Ar, and CF 4 –CH 4 fluids using two-body and three-body intermolecular potentials from molecular dynamics simulation. J Fluor Chem 2014. [DOI: 10.1016/j.jfluchem.2014.09.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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18
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von Rudorff GF, Watermann T, Sebastiani D. Perfluoroalkane force field for lipid membrane environments. J Phys Chem B 2014; 118:12531-40. [PMID: 25275859 DOI: 10.1021/jp507464m] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In this work, we present atomic parameters of perfluoroalkanes for use within the CHARMM force field. Perfluorinated alkanes represent a special class of molecules. On the one hand, they are considerably more hydrophobic than lipids, but on the other hand, they are not lipophilic either. Instead, they represent an independent class of philicity, enabling a whole portfolio of applications within both materials science and biochemistry. We performed a thorough parametrization of all bonded and nonbonded parameters with a particular focus on van der Waals parameters. Here, the general framework of the CHARMM and CGenFF force fields has been followed. The van der Waals parameters have been fitted to experimental densities over a wide range of temperatures and pressures. This newly parametrized class of molecules will open the gate for a variety of simulations of biologically relevant systems within the CHARMM force field. A particular perspective for the present work is the influence of polyphilic transmembrane molecules on membrane properties, aggregation phenomena, and transmembrane channels.
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Affiliation(s)
- Guido Falk von Rudorff
- Dahlem Center for Complex Quantum Systems, Freie Universität Berlin , Arnimallee 14, 14195 Berlin, Germany
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19
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Pratihar S, Kohale SC, Bhakta DG, Laskin J, Hase WL. Dynamics of energy transfer and soft-landing in collisions of protonated dialanine with perfluorinated self-assembled monolayer surfaces. Phys Chem Chem Phys 2014; 16:23769-78. [PMID: 25274280 DOI: 10.1039/c4cp03535f] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chemical dynamics simulations are reported which provide atomistic details of collisions of protonated dialanine, ala2-H(+), with a perfluorinated octanethiolate self-assembled monolayer (F-SAM) surface. The simulations are performed at collision energies Ei of 5.0, 13.5, 22.5, 30.00, and 70 eV, and incident angles 0° (normal) and 45° (grazing). Excellent agreement with experiment (J. Am. Chem. Soc., 2000, 122, 9703-9714) is found for both the average fraction and distribution of the collision energy transferred to the ala2-H(+) internal degrees of freedom. The dominant pathway for this energy transfer is to ala2-H(+) vibration, but for Ei = 5.0 eV ∼20% of the energy transfer is to ala2-H(+) rotation. Energy transfer to ala2-H(+) rotation decreases with increase in Ei and becomes negligible at high Ei. Three types of collisions are observed in the simulations: i.e. those for which ala2-H(+) (1) directly scatters off the F-SAM surface; (2) sticks/physisorbs on/in the surface, but desorbs within the 10 ps numerical integration of the simulations; and (3) remains trapped (i.e. soft-landed) on/in the surface when the simulations are terminated. Penetration of the F-SAM by ala2-H(+) is important for the latter two types of events. The trapped trajectories are expected to have relatively long residence times on the surface, since a previous molecular dynamics simulation (J. Phys. Chem. B, 2014, 118, 5577-5588) shows that thermally accommodated ala2-H(+) ions have an binding energy with the F-SAM surface of at least ∼15 kcal mol(-1).
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Affiliation(s)
- Subha Pratihar
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409-1061, USA.
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20
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Drawe P, Lüttschwager N, Suhm M. The elastic modulus of isolated polytetrafluoroethylene filaments. SCIENCEOPEN RESEARCH 2014. [DOI: 10.14293/s2199-1006.1.sor-matsci.aka0j6.v2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We report vibrational Raman spectra of small extended perfluoro-n-alkanes (C{n}F{2n+2} with n=6, 8-10, 12-14) isolated in supersonic jet expansions and use wavenumbers of longitudinal acoustic vibrations to extrapolate the elastic modulus of cold, isolated polytetrafluoroethylene filaments. The derived value E = 209(10) GPa defines an upper limit for the elastic modulus of the perfectly crystalline, non-interacting polymer at low temperatures and serves as a benchmark for quantum chemical predictions.
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21
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Isele-Holder RE, Ismail AE. Atomistic potentials for trisiloxane, alkyl ethoxylate, and perfluoroalkane-based surfactants with TIP4P/2005 and application to simulations at the air-water interface. J Phys Chem B 2014; 118:9284-97. [PMID: 25003511 DOI: 10.1021/jp502975p] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The mechanism of superspreading, the greatly enhanced spreading of water droplets facilitated by trisiloxane surfactants, is still under debate, largely because the role and behavior of the surfactants cannot be sufficiently resolved by experiments or continuum simulations. Previous molecular dynamics studies have been performed with simple model molecules or inaccurate models, strongly limiting their explanatory power. Here we present a force field dedicated to superspreading, extending existing quantum-chemistry-based models for the surfactant and the TIP4P/2005 water model ( Abascal et al. J. Chem. Phys. , 2005 , 123 , 234505 ). We apply the model to superspreading trisiloxane surfactants and nonsuperspreading alkyl ethoxylate and perfluoroalkane surfactants at various concentrations at the air-water interface. We show that the developed model accurately predicts surface tensions, which are typically assumed important for superspreading. Significant differences between superspreading and traditional surfactants are presented and their possible relation to superspreading discussed. Although the force field has been developed for superspreading problems, it should also perform well for other simulations involving polymers or copolymers with water.
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Affiliation(s)
- Rolf E Isele-Holder
- Aachener Verfahrenstechnik: Molecular Simulations and Transformations and AICES Graduate School, RWTH Aachen University , Schinkelstraße 2, 52062 Aachen, Germany
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22
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The elastic modulus of isolated polytetrafluoroethylene filaments. SCIENCEOPEN RESEARCH 2014. [DOI: 10.14293/a2199-1006.01.sor-matsci.ka0j6.v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
We report vibrational Raman spectra of small extended perfluoro-n-alkanes (C{n}F{2n+2} with n=6, 8-10, 12-14) isolated in supersonic jet expansions and use wavenumbers of longitudinal acoustic vibrations to extrapolate the elastic modulus of cold, isolated polytetrafluoroethylene filaments. The derived value E = 209(10) GPa defines an upper limit for the elastic modulus of the perfectly crystalline, non-interacting polymer at low temperatures and serves as a benchmark for quantum chemical predictions.
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23
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Isele-Holder RE, Mitchell W, Hammond JR, Kohlmeyer A, Ismail AE. Reconsidering Dispersion Potentials: Reduced Cutoffs in Mesh-Based Ewald Solvers Can Be Faster Than Truncation. J Chem Theory Comput 2013; 9:5412-20. [DOI: 10.1021/ct4004614] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rolf E. Isele-Holder
- Aachener
Verfahrenstechnik: Molecular Simulations and Transformations and AICES
Graduate School, RWTH Aachen University, Schinkelstraße 2, 52062 Aachen, Germany
| | - Wayne Mitchell
- Aachener
Verfahrenstechnik: Molecular Simulations and Transformations and AICES
Graduate School, RWTH Aachen University, Schinkelstraße 2, 52062 Aachen, Germany
- Loyola University, 6363 Saint
Charles Avenue, New Orleans, Louisiana 70118, United States of America
| | - Jeff R. Hammond
- Leadership Computing Facility, Argonne National Laboratory, Argonne, Illinois 60439, United States of America
| | - Axel Kohlmeyer
- International
Centre for Theoretical Physics, Strada Costiera 11, 34151 Trieste, Italy
| | - Ahmed E. Ismail
- Aachener
Verfahrenstechnik: Molecular Simulations and Transformations and AICES
Graduate School, RWTH Aachen University, Schinkelstraße 2, 52062 Aachen, Germany
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24
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Chantawansri TL, Sirk TW, Byrd EFC, Andzelm JW, Rice BM. Shock Hugoniot calculations of polymers using quantum mechanics and molecular dynamics. J Chem Phys 2012. [DOI: 10.1063/1.4767394] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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25
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Nogueira JJ, Sánchez-Coronilla A, Marques JM, Hase WL, Martínez-Núñez E, Vázquez SA. Intermolecular potentials for simulations of collisions of SiNCS+ and (CH3)2SiNCS+ ions with fluorinated self-assembled monolayers. Chem Phys 2012. [DOI: 10.1016/j.chemphys.2011.02.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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26
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Hassan N, Ruso JM, Piñeiro Á. Hydrogenated/fluorinated catanionic surfactants as potential templates for nanostructure design. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:9719-9728. [PMID: 21728312 DOI: 10.1021/la2019346] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The structure and physicochemical properties of the nanoparticles spontaneously formed within aqueous mixtures of the hydrogenated/fluorinated catanionic surfactant cetyltrimetylammonium perfluorooctanoate in the absence of counterions as a function of its concentration are investigated by a combined experimental/computational study at room temperature. Apparent molar volumes, isentropic apparent molar compressibilities, and dynamic light scattering measurements together with transmission and cryo-scanning electron as well as confocal laser microscopy images, and computational molecular dynamics simulations indicate that a variety of structures of different sizes coexist in solution with vesicles of ∼160 nm diameter. Interestingly, the obtained nanostructures were observed to self-assemble from a random distribution of monomers in a time scale easily accessible by atomistic classical molecular dynamics simulations, allowing to provide a comprehensive structural and dynamic characterization of the surfactant molecules at atomic level within the different aggregates. Overall, it is demonstrated that the use of mixed fluorinated hydrogenated surfactant systems represents an easy strategy for the design of specific nanoscale structures. The detailed structural analysis provided in the present work is expected to be useful as a reference to guide the design of new nanoparticles based on different hydrogenated/fluorinated catanionic surfactants.
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Affiliation(s)
- Natalia Hassan
- Soft Matter and Molecular Biophysics Group, Department of Applied Physics, University of Santiago de Compostela, Campus Vida s/n, 15782, Santiago de Compostela, Spain
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27
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Michalkova A, Tulyani S, Beals J, Leszczynski J. Theoretical study of the surface properties of poly(dimethylsiloxane) and poly(tetrafluoroethylene). J Mol Model 2011; 18:239-50. [DOI: 10.1007/s00894-011-1058-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 03/22/2011] [Indexed: 11/27/2022]
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28
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Barnes GL, Young K, Yang L, Hase WL. Fragmentation and reactivity in collisions of protonated diglycine with chemically modified perfluorinated alkylthiolate-self-assembled monolayer surfaces. J Chem Phys 2011; 134:094106. [DOI: 10.1063/1.3558736] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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29
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Molecular simulations of intermediate and long alkanes adsorbed on graphite: Tuning of non-bond interactions. J Mol Model 2010; 17:811-6. [DOI: 10.1007/s00894-010-0770-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2010] [Accepted: 05/25/2010] [Indexed: 10/19/2022]
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30
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Ilott AJ, Palucha S, Batsanov AS, Wilson MR, Hodgkinson P. Elucidation of Structure and Dynamics in Solid Octafluoronaphthalene from Combined NMR, Diffraction, And Molecular Dynamics Studies. J Am Chem Soc 2010; 132:5179-85. [DOI: 10.1021/ja910526z] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andrew J. Ilott
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - Sebastian Palucha
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - Andrei S. Batsanov
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - Mark R. Wilson
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - Paul Hodgkinson
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom
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31
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Amat MA, Rutledge GC. Liquid-vapor equilibria and interfacial properties of n-alkanes and perfluoroalkanes by molecular simulation. J Chem Phys 2010; 132:114704. [DOI: 10.1063/1.3356219] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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32
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Soolo E, Brandell D, Liivat A, Kasemägi H, Tamm T, Aabloo A. Force field generation and molecular dynamics simulations of Li+–Nafion. Electrochim Acta 2010. [DOI: 10.1016/j.electacta.2009.03.039] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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33
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Rayne S, Forest K. Comparative semiempirical, ab initio, and density functional theory study on the thermodynamic properties of linear and branched perfluoroalkyl sulfonic acids/sulfonyl fluorides, perfluoroalkyl carboxylic acid/acyl fluorides, and perhydroalkyl sulfonic acids, alkanes, and alcohols. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.theochem.2009.11.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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34
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Fournier JA, Bohn RK. Microwave spectroscopy and structures of two conformers of 1H-heptafluoropropane. Dalton Trans 2010; 39:4575-8. [DOI: 10.1039/c000524j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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35
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Perkins, Jr. BG, Nesbitt DJ. High resolution Dopplerimetry of correlated angular and quantum state-resolved CO2 scattering dynamics at the gas–liquid interface. Phys Chem Chem Phys 2010; 12:14294-308. [DOI: 10.1039/c0cp00578a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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36
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Perkins BG, Nesbitt DJ. Stereodynamics at the Gas−Liquid Interface: Orientation and Alignment of CO2 Scattered from Perfluorinated Liquid Surfaces. J Phys Chem A 2009; 114:1398-410. [DOI: 10.1021/jp907022u] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Bradford G. Perkins
- JILA, University of Colorado and National Institute of Standards and Technology, and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0440
| | - David J. Nesbitt
- JILA, University of Colorado and National Institute of Standards and Technology, and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0440
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37
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Fournier JA, Bohn RK, Montgomery, Jr. JA, Onda M. Helical C2 Structure of Perfluoropentane and the C2v Structure of Perfluoropropane. J Phys Chem A 2009; 114:1118-22. [DOI: 10.1021/jp9093035] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Joseph A. Fournier
- Departments of Chemistry and Physics, University of Connecticut, Storrs, Connecticut 06269-3060, and Department of Chemistry, Faculty of Science and Technology, Sophia University, Kioicho 7-1, Chiyoda-ku, Tokyo 102-8554, Japan
| | - Robert K. Bohn
- Departments of Chemistry and Physics, University of Connecticut, Storrs, Connecticut 06269-3060, and Department of Chemistry, Faculty of Science and Technology, Sophia University, Kioicho 7-1, Chiyoda-ku, Tokyo 102-8554, Japan
| | - John A. Montgomery, Jr.
- Departments of Chemistry and Physics, University of Connecticut, Storrs, Connecticut 06269-3060, and Department of Chemistry, Faculty of Science and Technology, Sophia University, Kioicho 7-1, Chiyoda-ku, Tokyo 102-8554, Japan
| | - Masao Onda
- Departments of Chemistry and Physics, University of Connecticut, Storrs, Connecticut 06269-3060, and Department of Chemistry, Faculty of Science and Technology, Sophia University, Kioicho 7-1, Chiyoda-ku, Tokyo 102-8554, Japan
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38
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Potoff JJ, Bernard-Brunel DA. Mie Potentials for Phase Equilibria Calculations: Application to Alkanes and Perfluoroalkanes. J Phys Chem B 2009; 113:14725-31. [DOI: 10.1021/jp9072137] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Affiliation(s)
- Jeffrey J. Potoff
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202
| | - Damien A. Bernard-Brunel
- Department of Chemical Engineering and Materials Science, Wayne State University, Detroit, Michigan 48202
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39
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Borodin O. Polarizable Force Field Development and Molecular Dynamics Simulations of Ionic Liquids. J Phys Chem B 2009; 113:11463-78. [DOI: 10.1021/jp905220k] [Citation(s) in RCA: 518] [Impact Index Per Article: 34.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Oleg Borodin
- Wasatch Molecular Inc., 2141 St. Marys Drive, Ste 102, Salt Lake City, Utah 84108, and Department of Materials Science & Engineering, 122 South Central Campus Drive, Room 304, University of Utah, Salt Lake City, Utah 84112-0560
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40
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Blanco E, Piñeiro A, Miller R, Ruso JM, Prieto G, Sarmiento F. Langmuir monolayers of a hydrogenated/fluorinated catanionic surfactant: from the macroscopic to the nanoscopic size scale. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:8075-8082. [PMID: 19449890 DOI: 10.1021/la900593c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Langmuir monolayers of the hydrogenated/fluorinated catanionic surfactant cetyltrimethylammonium perfluorooctanoate at the air/water interface are studied at room temperature. Excess Gibbs energies of mixing, DeltaG(E), as well as transition areas and pressures, were obtained from the surface pressure-area isotherm. The DeltaG(E) curve indicates that tail-tail interactions are more important than head-head interactions at low pressures and vice versa. Atomic force microscopy and molecular dynamics simulations allowed a fine characterization of the monolayer structure as a function of the area per molecule at mesoscopic and nanoscopic size scales, respectively. A combined analysis of the techniques allow us to conclude that electrostatic interactions between the ionic head groups are dominant in the monolayer while hydrophobic parts are of secondary importance. Overall, results obtained from the different techniques complement to each other, giving a comprehensive characterization of the monolayer.
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Affiliation(s)
- Elena Blanco
- Department of Applied Physics, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
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41
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Perkins BG, Nesbitt DJ. Toward Three-Dimensional Quantum State-Resolved Collision Dynamics at the Gas−Liquid Interface: Theoretical Investigation of Incident Angle. J Phys Chem A 2009; 113:4613-25. [DOI: 10.1021/jp811322y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Bradford G. Perkins
- JILA, University of Colorado and National Institute of Standards and Technology, and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0440
| | - David J. Nesbitt
- JILA, University of Colorado and National Institute of Standards and Technology, and Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0440
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42
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Piñeiro Á, Prieto G, Ruso JM, Verdes PV, Sarmiento F. Surface films of short fluorocarbon–hydrocarbon diblocks studied by molecular dynamics simulations: Spontaneous formation of elongated hemimicelles. J Colloid Interface Sci 2009; 329:351-6. [DOI: 10.1016/j.jcis.2008.10.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 09/28/2008] [Accepted: 10/02/2008] [Indexed: 11/30/2022]
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43
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Burns DC, Ellis DA, Li H, McMurdo CJ, Webster E. Experimental pKa determination for perfluorooctanoic acid (PFOA) and the potential impact of pKa concentration dependence on laboratory-measured partitioning phenomena and environmental modeling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2008; 42:9283-8. [PMID: 19174905 DOI: 10.1021/es802047v] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
An accurately measured equilibrium acid dissociation constant (pKa) is essential for understanding and predicting the fate of perfluorocarboxylic acids (PFCAs) in the environment. The aqueous pKa of perfluorooctanoic acid (PFOA) has been determined potentiometrically using a standard water-methanol mixed solvent approach and was found to be 3.8 +/- 0.1. The acidity of PFOA is thus considerably weaker than its shorter-chain PFCA homologues. This was attributed to differences in molecular and electronic structure, coupled with solvation effects. The pKa of PFOA was suppressed to approximately 2.3 at higher concentrations because of the aggregation of perfluorooctanoate (PFO). Often, PFCA partion coefficients are determined at concentrations above those found in the environment. Thus, it was suggested that a pKa correction factor, which accounts for this concentration-dependent shift in acid/base equilibrium, should be applied to PFCA partition efficients before they are implemented in environmental fate models. A pKa of 3.8 +/- 0.1 suggests that a considerable concentration of the PFCA exists as the neutral species in the aqueous environment for example, in typical Ontario rainwater, it is approximately 17%. Transport, fate, and partitioning models have often ignored the presence this species completely. The environmental dissemination of PFCAs could, in part, be explained by considering the role of the neutral species.
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Affiliation(s)
- Darcy C Burns
- Department of Chemistry, Centre for Environmental Modelling and Chemistry, Trent University, 1600 West Bank Drive, Peterborough, Ontario, K9J 7B8 Canada
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44
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Tsige M, Curro JG, Grest GS. Packing of poly(tetrafluoroethylene) in the liquid state: Molecular dynamics simulation and theory. J Chem Phys 2008; 129:214901. [DOI: 10.1063/1.3030610] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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45
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Firlej L, Kuchta B, Roth MW, Connolly MJ, Wexler C. Structural and phase properties of tetracosane (C24H50) monolayers adsorbed on graphite: an explicit hydrogen molecular dynamics study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008; 24:12392-12397. [PMID: 18828622 DOI: 10.1021/la802071a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
We discuss molecular dynamics (MD) computer simulations of a tetracosane (C24H50) monolayer physisorbed onto the basal plane of graphite. The adlayer molecules are simulated with explicit hydrogens, and the graphite substrate is represented as an all-atom structure having six graphene layers. The tetracosane dynamics modeled in the fully atomistic manner agree well with experiment. The low-temperature ordered solid organizes into a rectangularly centered structure that is not commensurate with underlying graphite. Above T=200 K, as the molecules start to lose their translational and orientational order via gauche defect formation a weak smectic mesophase (observed experimentally but never reproduced in united atom (UA) simulations) appears. The phase behavior of the adsorbed layer is critically sensitive to the way the electrostatic interactions are included in the model. If the electrostatic charges are set to zero (as for a UA force field), then the melting temperature increases by approximately 70 K with respect to the experimental value. When the nonbonded 1-4 interaction is not scaled, the melting temperature decreases by approximately 90 K. If the scaling factor is set to 0.5, then melting occurs at T=350 K, in very good agreement with experimental data.
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Affiliation(s)
- L Firlej
- LCVN, Université Montpellier 2, 34095 Montpellier, France
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46
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Pierce F, Tsige M, Perahia D, Grest GS. Liquid−Liquid Interfaces of Semifluorinated Alkane Diblock Copolymers with Water, Alkanes, and Perfluorinated Alkanes. J Phys Chem B 2008; 112:16012-20. [DOI: 10.1021/jp805574f] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Flint Pierce
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634, Department of Physics, Southern Illinois University, Carbondale, Illinois 62901, and Sandia National Laboratories, Albuquerque, New Mexico 87185
| | - Mesfin Tsige
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634, Department of Physics, Southern Illinois University, Carbondale, Illinois 62901, and Sandia National Laboratories, Albuquerque, New Mexico 87185
| | - Dvora Perahia
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634, Department of Physics, Southern Illinois University, Carbondale, Illinois 62901, and Sandia National Laboratories, Albuquerque, New Mexico 87185
| | - Gary S. Grest
- Department of Chemistry, Clemson University, Clemson, South Carolina 29634, Department of Physics, Southern Illinois University, Carbondale, Illinois 62901, and Sandia National Laboratories, Albuquerque, New Mexico 87185
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Pierce F, Tsige M, Borodin O, Perahia D, Grest GS. Interfacial properties of semifluorinated alkane diblock copolymers. J Chem Phys 2008; 128:214903. [DOI: 10.1063/1.2924120] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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Alexander WA, Day BS, Moore HJ, Lee TR, Morris JR, Troya D. Experimental and theoretical studies of the effect of mass on the dynamics of gas/organic-surface energy transfer. J Chem Phys 2008; 128:014713. [DOI: 10.1063/1.2815327] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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Vázquez SA, Morris JR, Rahaman A, Mazyar OA, Vayner G, Addepalli SV, Hase WL, Martínez-Núñez E. Inelastic Scattering Dynamics of Ar from a Perfluorinated Self-Assembled Monolayer Surface. J Phys Chem A 2007; 111:12785-94. [DOI: 10.1021/jp076431m] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Saulo A. Vázquez
- Departamento de Química Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain, Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and High Performance Computing Center, Texas Tech University, Lubbock, Texas 79409
| | - John R. Morris
- Departamento de Química Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain, Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and High Performance Computing Center, Texas Tech University, Lubbock, Texas 79409
| | - Asif Rahaman
- Departamento de Química Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain, Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and High Performance Computing Center, Texas Tech University, Lubbock, Texas 79409
| | - Oleg A. Mazyar
- Departamento de Química Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain, Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and High Performance Computing Center, Texas Tech University, Lubbock, Texas 79409
| | - Grigoriy Vayner
- Departamento de Química Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain, Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and High Performance Computing Center, Texas Tech University, Lubbock, Texas 79409
| | - Srirangam V. Addepalli
- Departamento de Química Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain, Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and High Performance Computing Center, Texas Tech University, Lubbock, Texas 79409
| | - William L. Hase
- Departamento de Química Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain, Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and High Performance Computing Center, Texas Tech University, Lubbock, Texas 79409
| | - Emilio Martínez-Núñez
- Departamento de Química Física, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain, Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, and High Performance Computing Center, Texas Tech University, Lubbock, Texas 79409
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Chen Q, Schmidt-Rohr K. Backbone Dynamics of the Nafion Ionomer Studied by19F-13C Solid-State NMR. MACROMOL CHEM PHYS 2007. [DOI: 10.1002/macp.200700200] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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