1
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Huang X, Ji C, Ma X, Hao L, Guo F, Yang G, Huang J, Wen Y, Qiao Z. Size-dependent shock response mechanisms in nanogranular RDX: a reactive molecular dynamics study. Phys Chem Chem Phys 2024. [PMID: 39189793 DOI: 10.1039/d4cp01696c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/28/2024]
Abstract
Understanding the shock initiation mechanisms of explosives is pivotal for advancing physicochemical theories and enhancing experimental methodologies. This study delves into the size-dependent shock responses of nanogranular hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) through nonequilibrium reactive molecular dynamics simulations. Utilizing the ReaxFF-lg force field, we examine the influence of the particle size on the decomposition dynamics of RDX under varying shock velocities. Our findings reveal that larger particles promote more significant RDX decomposition at lower velocities due to fluid jet formation and gas compression during void collapse. Conversely, smaller particles exhibit a higher average temperature and a faster decomposition rate under high-velocity shocks, attributed to their increased specific surface area. Detailed chemical reaction pathways are analyzed to elucidate the growth and initiation of reactions during shock waves. The results contribute to resolving the discrepancies observed in experimental studies of shocked granular explosives and provide a deeper understanding of the underlying mechanisms governing their behavior. This research offers valuable insights into the design and control of nano- and submicron-sized explosives with tailored sensitivity to external stimuli.
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Affiliation(s)
- Xiaona Huang
- Institute of Chemical Materials, China Academy of Engineering Physics (CAEP), NO. 64, Mianshan Road, Youxian, Mianyang, Sichuan 621900, China.
- School of Power and Mechanical Engineering, Wuhan University, Wuhan, Hubei 430072, China
| | - Chunliang Ji
- Institute of Chemical Materials, China Academy of Engineering Physics (CAEP), NO. 64, Mianshan Road, Youxian, Mianyang, Sichuan 621900, China.
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
- Norinco Group Air Ammunition Research Institute Co., Ltd, Harbin 150030, China
| | - Xiaoxia Ma
- School of Mechatronical Engineering, Beijing Institute of Technology, Beijing 100081, China
| | - Lixiao Hao
- Institute of Chemical Materials, China Academy of Engineering Physics (CAEP), NO. 64, Mianshan Road, Youxian, Mianyang, Sichuan 621900, China.
| | - Feng Guo
- School of Physical Science and Information Technology, Liaocheng University, Liaocheng 252000, China
| | - Guangcheng Yang
- Institute of Chemical Materials, China Academy of Engineering Physics (CAEP), NO. 64, Mianshan Road, Youxian, Mianyang, Sichuan 621900, China.
| | - Jichun Huang
- Institute of Chemical Materials, China Academy of Engineering Physics (CAEP), NO. 64, Mianshan Road, Youxian, Mianyang, Sichuan 621900, China.
| | - Yushi Wen
- Institute of Chemical Materials, China Academy of Engineering Physics (CAEP), NO. 64, Mianshan Road, Youxian, Mianyang, Sichuan 621900, China.
| | - Zhiqiang Qiao
- Institute of Chemical Materials, China Academy of Engineering Physics (CAEP), NO. 64, Mianshan Road, Youxian, Mianyang, Sichuan 621900, China.
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2
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Gao Y, Lin H, Zhu X. General Aqueous System Simulation through an AI-Embedded Metaverse Chemistry Laboratory. J Phys Chem Lett 2024; 15:5978-5984. [PMID: 38814104 DOI: 10.1021/acs.jpclett.4c01111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
Recent decades have witnessed the rapid development of autonomous laboratories and artificial intelligence, where experiments can be automatically run and optimized. Although human work is reduced, the total time of experimental optimization is still consuming due to limitations of the current ab metaverse framework, which accurately predicts the future state of the system by receiving and analyzing in situ experimental data. To substitute for traditional simulation methods, we designed a physically endorsed deep learning model to predict the future system picture ranging from atomic image to bulk appearance, intensively using the correlations between properties of the system. Through this framework, we studied the general aqueous system, covering 100+ common ionic solutions. We can accurately simulate properties for a general aqueous system as well as predict the time of solvation of ionic compounds ahead of real experiments. In this way, the experiments can be optimized more efficiently without waiting for the end of a bad iteration. We hope our work offers a fresh direction for the digitization of chemical information, enhancing access to and use of experimental data in advancing the field of physical chemistry.
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Affiliation(s)
- Yuechen Gao
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Shenzhen, Guangdong, China 518172
| | - Haoxiang Lin
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Shenzhen, Guangdong, China 518172
| | - Xi Zhu
- School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen, Shenzhen, Guangdong, China 518172
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3
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Dumortier L, Chizallet C, Creton B, de Bruin T, Verstraelen T. Managing Expectations and Imbalanced Training Data in Reactive Force Field Development: An Application to Water Adsorption on Alumina. J Chem Theory Comput 2024; 20:3779-3797. [PMID: 38639642 DOI: 10.1021/acs.jctc.3c01009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
ReaxFF is a computationally efficient model for reactive molecular dynamics simulations that has been applied to a wide variety of chemical systems. When ReaxFF parameters are not yet available for a chemistry of interest, they must be (re)optimized, for which one defines a set of training data that the new ReaxFF parameters should reproduce. ReaxFF training sets typically contain diverse properties with different units, some of which are more abundant (by orders of magnitude) than others. To find the best parameters, one conventionally minimizes a weighted sum of squared errors over all of the data in the training set. One of the challenges in such numerical optimizations is to assign weights so that the optimized parameters represent a good compromise among all the requirements defined in the training set. This work introduces a new loss function, called Balanced Loss, and a workflow that replaces weight assignment with a more manageable procedure. The training data are divided into categories with corresponding "tolerances", i.e., acceptable root-mean-square errors for the categories, which define the expectations for the optimized ReaxFF parameters. Through the Log-Sum-Exp form of Balanced Loss, the parameter optimization is also a validation of one's expectations, providing meaningful feedback that can be used to reconfigure the tolerances if needed. The new methodology is demonstrated with a nontrivial parametrization of ReaxFF for water adsorption on alumina. This results in a new force field that reproduces both the rare and frequent properties of a validation set not used for training. We also demonstrate the robustness of the new force field with a molecular dynamics simulation of water desorption from a γ-Al2O3 slab model.
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Affiliation(s)
- Loïc Dumortier
- IFP Energies nouvelles, 1 et 4 Avenue de Bois-Préau, 92852 Rueil-Malmaison, France
- Center for Molecular Modeling (CMM), Ghent University, Technologiepark-Zwijnaarde 46, Zwijnaarde, B-9052 Ghent, Belgium
| | - Céline Chizallet
- IFP Energies nouvelles, Rond-point de l'échangeur de Solaize, BP3, 69360 Solaize, France
| | - Benoit Creton
- IFP Energies nouvelles, 1 et 4 Avenue de Bois-Préau, 92852 Rueil-Malmaison, France
| | - Theodorus de Bruin
- IFP Energies nouvelles, 1 et 4 Avenue de Bois-Préau, 92852 Rueil-Malmaison, France
| | - Toon Verstraelen
- Center for Molecular Modeling (CMM), Ghent University, Technologiepark-Zwijnaarde 46, Zwijnaarde, B-9052 Ghent, Belgium
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4
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Zhang Y, Liu X, van Duin ACT, Lu X, Meijer EJ. Development and validation of a general-purpose ReaxFF reactive force field for earth material modeling. J Chem Phys 2024; 160:094103. [PMID: 38426512 DOI: 10.1063/5.0194486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Accepted: 02/13/2024] [Indexed: 03/02/2024] Open
Abstract
ReaxFF reactive force field bridges the gap between nonreactive molecular simulations and quantum mechanical calculations and has been widely applied during the past two decades. However, its application to earth materials, especially those under high T-P conditions relevant to Earth's interior, is still limited due to the lack of available parameters. Here, we present the development and validation of a ReaxFF force field containing several of the most common elements in Earth's crust, i.e., Si/Al/O/H/Na/K. The force field was trained against a large data set obtained from density functional theory (DFT) calculations, including charges, bond/angle distortion curves, equation of states, ion migration energy profiles, and condensation reaction energies. Different coordination environments were considered in the training set. The fitting results showed that the current force field can well reproduce the DFT data (the Pearson correlation coefficient, Rp, is 0.95). We validated the force field on mineral-water interfaces, hydrous melts/supercritical geofluids, and bulk crystals. It was found that the current force field performed excellently in predicting the structural, thermodynamic, and transport properties of various systems (Rp = 0.95). Moreover, possible applications and future development have been discussed. The results obtained in this study suggest that the current force field holds good promise to model a wide range of processes and thus open opportunities to advance the application of ReaxFF in earth material modeling.
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Affiliation(s)
- Yingchun Zhang
- State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu 210023, People's Republic of China
- Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing, Jiangsu 210023, People's Republic of China
- Department of Mechanical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Xiandong Liu
- State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu 210023, People's Republic of China
- Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing, Jiangsu 210023, People's Republic of China
| | - Adri C T van Duin
- Department of Mechanical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Xiancai Lu
- State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, Nanjing, Jiangsu 210023, People's Republic of China
- Frontiers Science Center for Critical Earth Material Cycling, Nanjing University, Nanjing, Jiangsu 210023, People's Republic of China
| | - Evert Jan Meijer
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam 1012 WX, The Netherlands
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5
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Fan H, Liu Z, Gan LH, Wang CR. The formation mechanism of Sc-based metallofullerenes: a molecular dynamics simulation study. Phys Chem Chem Phys 2024; 26:5499-5507. [PMID: 38282470 DOI: 10.1039/d3cp05587f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2024]
Abstract
The practical applications of endohedral metallofullerenes (EMFs) are mainly constrained by their low yields. Understanding the formation mechanisms is therefore crucial for developing methods for high-yield and selective synthesis. To address this, a novel force-field parameter set, "CSc.ff", was created using a single-parameter search optimization method, then molecular dynamics simulations of various systems with a carbon-to-scandium atomic ratio of 12.5 were carried out. The simulations were run under a constant atomic number, volume, and energy (NVE) ensemble. The influence of the working gas, helium, as well as temperature gradients on the formation process was examined. Our simulations reveal that the cage growth patterns of Sc-based EMFs (Sc-EMFs) closely resemble those of hollow fullerenes, evolving from free carbon atoms to chains, rings, and, ultimately, to cage-shaped clusters. Importantly, the Sc-EMFs formed in the simulation frequently exhibit structural defects or under-coordinated carbon atoms. Scandium atoms, whether at the periphery or on the surface of these cages, can be incorporated into the cages, forming Sc-EMFs. Helium was found to not only promote the formation of carbon cages but also facilitate the encapsulation of scandium atoms, playing a crucial role in the formation of cluster fullerenes. Moreover, cooling effectively inhibits the uncontrollable growth of the carbon cage and is essential for forming stable, appropriate-sized cages. This study enhances our understanding of the formation of Sc-EMFs and provides valuable insights for developing more efficient synthetic methods.
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Affiliation(s)
- Huichen Fan
- School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
| | - Zhenyu Liu
- School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
| | - Li-Hua Gan
- School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, China.
| | - Chun-Ru Wang
- Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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6
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Brugnoli L, Miyatani K, Akaji M, Urata S, Pedone A. New Atomistic Insights on the Chemical Mechanical Polishing of Silica Glass with Ceria Nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:5527-5541. [PMID: 37029752 PMCID: PMC10116594 DOI: 10.1021/acs.langmuir.3c00304] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 03/29/2023] [Indexed: 06/19/2023]
Abstract
Reactive molecular dynamics simulations have been used to simulate the chemical mechanical polishing (CMP) process of silica glass surfaces with the ceria (111) and (100) surfaces, which are predominantly found in ceria nanoparticles. Since it is known that an alteration layer is formed at the glass surface as a consequence of the chemical interactions with the slurry solutions used for polishing, we have created several glass surface models with different degrees of hydroxylation and porosity for investigating their morphology and chemistry after the interaction with acidic, neutral, and basic water solutions and the ceria surfaces. Both the chemical and mechanical effects under different pressure and temperature conditions have been studied and clarified. According to the simulation results, we have found that the silica slab with a higher degree of hydroxylation (thicker alteration layer) is more reactive, suggesting that proper chemical treatment is fundamental to augment the polishing efficiency. The reactivity between the silica and ceria (111) surfaces is higher at neutral pH since more OH groups present at the two surfaces increased the Si-O-Ce bonds formed at the interface. Usually, an outermost tetrahedral silicate unit connected to the rest of the silicate network through a single bond was removed during the polishing simulations. We observed that higher pressure and temperature accelerated the removal of more SiO4 units. However, excessively high pressure was found to be detrimental since the heterogeneous detachment of SiO4 units led to rougher surfaces and breakage of the Si-O-Si bond, even in the bulk of the glass. Despite the lower concentration of Ce ions at the surface resulting in the lower amount of Si-O-Ce formed, the (100) ceria surface was intrinsically more reactive than (111). The different atomic-scale mechanisms of silica removal at the two ceria surfaces were described and discussed.
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Affiliation(s)
- Luca Brugnoli
- Department
of Chemical and Geological Sciences, University
of Modena and Reggio Emilia, via G. Campi 103, 41125 Modena, Italia
| | - Katsuaki Miyatani
- Innovative
Technology Laboratories, AGC Inc., Yokohama, Kanagawa 230-0045, Japan
| | - Masatoshi Akaji
- Electronics
Company, AGC Inc., Yokohama, Kanagawa 230-0045, Japan
| | - Shingo Urata
- Innovative
Technology Laboratories, AGC Inc., Yokohama, Kanagawa 230-0045, Japan
| | - Alfonso Pedone
- Department
of Chemical and Geological Sciences, University
of Modena and Reggio Emilia, via G. Campi 103, 41125 Modena, Italia
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7
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Faraji F, Neek-Amal M, Neyts EC, Peeters FM. Cation-controlled permeation of charged polymers through nanocapillaries. Phys Rev E 2023; 107:034501. [PMID: 37073056 DOI: 10.1103/physreve.107.034501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Accepted: 02/28/2023] [Indexed: 04/20/2023]
Abstract
Molecular dynamics simulations are used to study the effects of different cations on the permeation of charged polymers through flat capillaries with heights below 2 nm. Interestingly, we found that, despite being monovalent, Li^{+}, Na^{+}, and K^{+} cations have different effects on polymer permeation, which consequently affects their transmission speed throughout those capillaries. We attribute this phenomenon to the interplay of the cations' hydration free energies and the hydrodynamic drag in front of the polymer when it enters the capillary. Different alkali cations exhibit different surface versus bulk preferences in small clusters of water under the influence of an external electric field. This paper presents a tool to control the speed of charged polymers in confined spaces using cations.
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Affiliation(s)
- Fahim Faraji
- PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium
- Condensed Matter Theory, Department of Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
- Center of Excellence NANOlab, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Mehdi Neek-Amal
- Condensed Matter Theory, Department of Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
- Department of Physics, Shahid Rajaee Teacher Training University, 16875-163 Tehran, Iran
| | - Erik C Neyts
- PLASMANT, Department of Chemistry, University of Antwerp, Universiteitsplein 1, 2610 Antwerp, Belgium
- Center of Excellence NANOlab, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - François M Peeters
- Condensed Matter Theory, Department of Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
- Center of Excellence NANOlab, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
- Departamento de Física, Universidade Federal do Ceará, Fortaleza-CE 60455-760, Brazil
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8
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Braunwarth L, Jung C, Jacob T. Potential-Dependent Pt(111)/Water Interface: Tackling the Challenge of a Consistent Treatment of Electrochemical Interfaces. Chemphyschem 2023; 24:e202200336. [PMID: 36123306 PMCID: PMC10092414 DOI: 10.1002/cphc.202200336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 09/19/2022] [Indexed: 01/04/2023]
Abstract
The interface between an electrode and an electrolyte is where electrochemical processes take place for countless technologically important applications. Despite its high relevance and intense efforts to elucidate it, a description of the interfacial structure and, in particular, the dynamics of the electric double layer at the atomic level is still lacking. Here we present reactive force-field molecular dynamics simulations of electrified Pt(111)/water interfaces, shedding light on the orientation of water molecules in the vicinity of the Pt(111) surface, taking into account the influence of potential, adsorbates, and ions simultaneously. We obtain a shift in the preferred orientation of water in the surface oxidation potential region, which breaks with the previously proclaimed strict correlation to the free charge density. Moreover, the characterization is complemented by course of the entropy and the intermolecular ordering in the interfacial region complements the characterization. Our work contributes to the ongoing process of understanding electric double layers and, in particular, the structure of the electrified Pt(111)/water interface, and aims to provide insights into the electrochemical processes occurring there.
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Affiliation(s)
- Laura Braunwarth
- Institute of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, D-89081, Ulm, Germany
| | - Christoph Jung
- Institute of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, D-89081, Ulm, Germany.,Karlsruhe Institute of Technology (KIT), P.O. Box 3640, D-76021, Karlsruhe, Germany.,Helmholtz Institute Ulm (HIU) Electrochemical Energy Storage, Helmholtzstr. 11, D-89081, Ulm, Germany
| | - Timo Jacob
- Institute of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, D-89081, Ulm, Germany.,Karlsruhe Institute of Technology (KIT), P.O. Box 3640, D-76021, Karlsruhe, Germany.,Helmholtz Institute Ulm (HIU) Electrochemical Energy Storage, Helmholtzstr. 11, D-89081, Ulm, Germany
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9
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Han Y, Wei B, Guo X, Jiao T. Improved hydroxyl radical production by electric-field-induced catalysis in O3/H2O2 process: A Reactive Molecular Dynamics Perspective. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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10
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Mineralization mechanism of carbon dioxide with illite interlayer cations using molecular dynamics simulation and experiments. J CO2 UTIL 2022. [DOI: 10.1016/j.jcou.2022.102161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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Hou D, Hong F, Dong B, Wang P, Zhang Y, Wang X, Wang M. Molecular Insights into the Reaction Process of Alkali-Activated Metakaolin by Sodium Hydroxide. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:11337-11345. [PMID: 36063092 DOI: 10.1021/acs.langmuir.2c01631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
When metakaolin (MK) is alkalized with an alkaline activator, it depolymerizes under the action of the alkali. However, the process of MK alkalinization is still unrevealed. Here, we supplied a molecular insight into the process of MK alkalinization through reaction molecular dynamics (MD) simulation. The structure, dynamics, and process of MK alkalinization are systematically investigated. The results showed that the layered structure of MK was destroyed and the silicates in MK were dissolved by sodium hydroxide solution during the alkalinization reaction of MK. The aluminates in MK are not dissolved, indicating that aluminates are more stable than silicates. Moreover, the equilibrium structures of MK with H2O and MK with NaOH solution show that only when both sodium hydroxide and water are involved in the alkalinization reaction, the silicates in MK undergo depolymerization. Also, the observed final state of MK alkalinization can be recognized as the precursor of alkali-activated materials (AAMs).
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Affiliation(s)
- Dongshuai Hou
- Department of Civil Engineering, Qingdao University of Technology, Qingdao 266000, China
| | - Fen Hong
- Department of Civil Engineering, Qingdao University of Technology, Qingdao 266000, China
| | - Biqin Dong
- College of Civil and Transportation Engineering, Shenzhen University, Shenzhen 518060, China
| | - Pan Wang
- Department of Civil Engineering, Qingdao University of Technology, Qingdao 266000, China
| | - Yue Zhang
- Department of Civil Engineering, Qingdao University of Technology, Qingdao 266000, China
| | - Xinpeng Wang
- Department of Civil Engineering, Qingdao University of Technology, Qingdao 266000, China
| | - Muhan Wang
- Department of Civil Engineering, Qingdao University of Technology, Qingdao 266000, China
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12
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Zhou Y, Wang H. Molecular Dynamics Simulation of a Single Carbon Chain through an Asymmetric Double-Layer Graphene Nanopore for Prolonging the Translocation Time. ACS OMEGA 2022; 7:16422-16429. [PMID: 35601336 PMCID: PMC9118202 DOI: 10.1021/acsomega.2c00438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 04/13/2022] [Indexed: 06/15/2023]
Abstract
In recent years, sensing technology based on nanopores has become one of the trustworthy options for characterization and even identification of a single biomolecule. In nanopore based DNA sequencing technology, the DNA strand in the electrolyte solution passes through the nanopore under an applied bias electric field. Commonly, the ionic current signals carrying the sequence information are difficult to detect effectively due to the fast translocation speed of the DNA strand, so that slowing down the translocation speed is expected to make the signals easier to distinguish and improve the sequencing accuracy. Modifying the nanopore structure is one of the effective methods. Through all-atom molecular dynamics simulations, we designed an asymmetric double-layer graphene nanopore structure to regulate the translocation speed of a single carbon chain. The structure consists of two nanopores with different sizes located on two layers. The simulation results indicate that the asymmetric nanopore structure will affect the chain's translocation speed and the ionic current value. When the single carbon chain passes from the smaller pore to the larger pore, the translocation time is significantly prolonged, which is about three times as long as the chain passing from the larger pore to the smaller pore. These results provide a new idea for designing more accurate and effective single-molecule solid-state nanopore sensors.
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13
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Mabuchi T. Revealing the Anticorrelation Behavior Mechanism between the Grotthuss and Vehicular Diffusions for Proton Transport in Concentrated Acid Solutions. J Phys Chem B 2022; 126:3319-3326. [PMID: 35468285 DOI: 10.1021/acs.jpcb.1c09742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this study, we performed reactive molecular dynamics simulations to characterize proton solvation and transport in concentrated hydrochloric acid solutions. The correlation contribution to the total proton mean square displacement is found to be negative for all acid concentrations, indicating the anticorrelation between the Grotthuss and vehicular diffusions. For the vehicular diffusion, the hydronium ions tend to move freely toward the lone pair side independent of acid concentrations, whereas for the Grotthuss diffusion, the proton hopping direction is limited to one of the hydrogen-bonded water molecules on the opposite side of the lone pair region, which are specifically oriented with respect to the neighboring hydronium ion at higher acid concentrations. This result is justified by our findings of the higher fraction of proton rattling with the single hopping event and longer hydrogen bond lifetimes at higher acid concentrations. However, the angular distribution for both the vehicular and Grotthuss diffusions is found to be rather broad and comparable for all acid concentrations, and thus, the anticorrelation shows a minimal dependence on the acid concentration. Our results reveal that the anticorrelation behavior between the vehicle and Grotthuss diffusions is attributed to the amphiphilic nature of hydronium ions and thus is independent of the acid concentrations in solutions.
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Affiliation(s)
- Takuya Mabuchi
- Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan.,Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
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14
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Han Y, Gao Q, Guo X, Jiao T. Influence of external electric field on polymerization of Fe (III) flocculant in water: A reactive molecular dynamics and experiment study. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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15
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Dasgupta N, Chen C, van Duin ACT. Development and application of ReaxFF methodology for understanding the chemical dynamics of metal carbonates in aqueous solutions. Phys Chem Chem Phys 2022; 24:3322-3337. [PMID: 35060576 DOI: 10.1039/d1cp04790f] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
A new ReaxFF reactive force field has been developed for metal carbonate systems including Na+, Ca2+, and Mg2+ cations and the CO32- anion. This force field is fully transferable with previous ReaxFF water and water/electrolyte descriptions. The Me-O-C (Me = metal) three-body valence angle parameters and Me-C non-reactive parameters of the force field have been optimized against quantum mechanical calculations including equations of state, heats of formation, heats of reaction, angle distortions and vibrational frequencies. The new metal carbonate force field has been validated using molecular dynamics simulations to study the solvation and reactivity of metal and carbonate ions in water at 300 K and 700 K. The coordination radius and self-diffusion coefficient show good consistency with existing experimental and simulation results. The angular distribution analysis explains the structural preference of carbonate ions to form carbonates and bicarbonates, where Na+ predominantly forms carbonates due to weaker angular strain, while Ca2+ and Mg2+ prefer to form bicarbonate monodentate in nature. Residence time distribution analyses on different systems reveal the role of ions in accelerating and decelerating the dynamics of water and carbonate ions under different thermodynamic conditions. The formation and dissolution of bicarbonates and carbonates in solution were explored on the basis of the protonation capability in different systems. The nucleation phenomenon of metal carbonates at ambient and supercritical conditions is explained from the perspective of cluster formation over time: Ca2+ ions can form prenucleation clusters at ambient temperature but show saturation with increasing temperature, whereas Na+ and Mg2+ ions show a rapid increase in cluster size and amount upon increasing time and temperature.
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Affiliation(s)
- Nabankur Dasgupta
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA.
| | - Chen Chen
- Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Adri C T van Duin
- Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA. .,Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA.,Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA
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16
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Vaid R, Yildirim E, Pasquinelli MA, King MW. Hydrolytic Degradation of Polylactic Acid Fibers as a Function of pH and Exposure Time. Molecules 2021; 26:molecules26247554. [PMID: 34946629 PMCID: PMC8706057 DOI: 10.3390/molecules26247554] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 11/19/2021] [Accepted: 11/19/2021] [Indexed: 11/16/2022] Open
Abstract
Polylactic acid (PLA) is a widely used bioresorbable polymer in medical devices owing to its biocompatibility, bioresorbability, and biodegradability. It is also considered a sustainable solution for a wide variety of other applications, including packaging. Because of its widespread use, there have been many studies evaluating this polymer. However, gaps still exist in our understanding of the hydrolytic degradation in extreme pH environments and its impact on physical and mechanical properties, especially in fibrous materials. The goal of this work is to explore the hydrolytic degradation of PLA fibers as a function of a wide range of pH values and exposure times. To complement the experimental measurements, molecular-level details were obtained using both molecular dynamics (MD) simulations with ReaxFF and density functional theory (DFT) calculations. The hydrolytic degradation of PLA fibers from both experiments and simulations was observed to have a faster rate of degradation in alkaline conditions, with 40% of strength loss of the fibers in just 25 days together with an increase in the percent crystallinity of the degraded samples. Additionally, surface erosion was observed in these PLA fibers, especially in extreme alkaline environments, in contrast to bulk erosion observed in molded PLA grafts and other materials, which is attributed to the increased crystallinity induced during the fiber spinning process. These results indicate that spun PLA fibers function in a predictable manner as a bioresorbable medical device when totally degraded at end-of-life in more alkaline conditions.
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Affiliation(s)
- Radhika Vaid
- Fiber and Polymer Science Program, Wilson College of Textiles, NC State University, Raleigh, NC 27606, USA; (R.V.); (M.A.P.)
| | - Erol Yildirim
- Department of Chemistry, Middle East Technical University, 06800 Ankara, Turkey;
| | - Melissa A. Pasquinelli
- Fiber and Polymer Science Program, Wilson College of Textiles, NC State University, Raleigh, NC 27606, USA; (R.V.); (M.A.P.)
- Department of Forest Biomaterials, College of Natural Resources, NC State University, Raleigh, NC 27606, USA
| | - Martin W. King
- Fiber and Polymer Science Program, Wilson College of Textiles, NC State University, Raleigh, NC 27606, USA; (R.V.); (M.A.P.)
- College of Textiles, Donghua University, Shanghai 201620, China
- Correspondence: ; Tel.: +1-919-291-2563
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17
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Duong PHH, Shin YK, Kuehl VA, Afroz MM, Hoberg JO, Parkinson B, van Duin ACT, Li-Oakey KD. Molecular Interactions and Layer Stacking Dictate Covalent Organic Framework Effective Pore Size. ACS APPLIED MATERIALS & INTERFACES 2021; 13:42164-42175. [PMID: 34415136 DOI: 10.1021/acsami.1c10866] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Interactions among ions, molecules, and confining solid surfaces are universally challenging and intriguing topics. Lacking a molecular-level understanding of such interactions in complex organic solvents perpetuates the intractable challenge of simultaneously achieving high permeance and selectivity in selectively permeable barriers. Two-dimensional covalent organic frameworks (COFs) have demonstrated ultrahigh permeance, high selectivity, and stability in organic solvents. Using reactive force field molecular dynamics modeling and direct experimental comparisons of an imine-linked carboxylated COF (C-COF), we demonstrate that unprecedented organic solvent nanofiltration separation performance can be accomplished by the well-aligned, highly crystalline pores. Furthermore, we show that the effective, as opposed to designed, pore size and solvated solute radii can change dramatically with the solvent environment, providing insights into complex molecular interactions and enabling future application-specific material design and synthesis.
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Affiliation(s)
- Phuoc H H Duong
- Department of Chemical Engineering, University of Wyoming, Laramie, Wyoming 82070, United States
| | - Yun Kyung Shin
- Department of Mechanical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Valerie A Kuehl
- Department of Chemistry, University of Wyoming, Laramie, Wyoming 82070, United States
| | - Mohammad M Afroz
- Department of Chemical Engineering, University of Wyoming, Laramie, Wyoming 82070, United States
| | - John O Hoberg
- Department of Chemistry, University of Wyoming, Laramie, Wyoming 82070, United States
| | - Bruce Parkinson
- Department of Chemistry, University of Wyoming, Laramie, Wyoming 82070, United States
| | - Adri C T van Duin
- Department of Mechanical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Katie D Li-Oakey
- Department of Chemical Engineering, University of Wyoming, Laramie, Wyoming 82070, United States
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18
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A Review of Recent Developments in Molecular Dynamics Simulations of the Photoelectrochemical Water Splitting Process. Catalysts 2021. [DOI: 10.3390/catal11070807] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
In this review, we provide a short overview of the Molecular Dynamics (MD) method and how it can be used to model the water splitting process in photoelectrochemical hydrogen production. We cover classical non-reactive and reactive MD techniques as well as multiscale extensions combining classical MD with quantum chemical and continuum methods. Selected examples of MD investigations of various aqueous semiconductor interfaces with a special focus on TiO2 are discussed. Finally, we identify gaps in the current state-of-the-art where further developments will be needed for better utilization of MD techniques in the field of water splitting.
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19
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Pols M, Vicent-Luna JM, Filot I, van Duin ACT, Tao S. Atomistic Insights Into the Degradation of Inorganic Halide Perovskite CsPbI 3: A Reactive Force Field Molecular Dynamics Study. J Phys Chem Lett 2021; 12:5519-5525. [PMID: 34096726 PMCID: PMC8215647 DOI: 10.1021/acs.jpclett.1c01192] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 06/02/2021] [Indexed: 06/12/2023]
Abstract
Halide perovskites make efficient solar cells but suffer from several stability issues. The characterization of these degradation processes is challenging because of the limited spatiotemporal resolution in experiments and the absence of efficient computational methods to study these reactive processes. Here, we present the first reactive force field for molecular dynamics simulations of the phase instability and the defect-induced degradation in CsPbI3. We find that the phase transitions are driven by the anharmonic fluctuations of the atoms in the perovskite lattice. At low temperatures, the Cs cations tend to move away from their preferential positions, resulting in worse contacts with the surrounding metal halide framework which initiates the conversion to a nonperovskite phase. Moreover, our simulations of defective structures reveal that, although both iodine vacancies and interstitials are mobile in the perovskite lattice, the vacancies have a detrimental effect on the stability, leading to the decomposition of perovskites to PbI2.
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Affiliation(s)
- Mike Pols
- Materials
Simulation & Modelling, Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
- Laboratory
of Inorganic Materials Chemistry, Schuit Institute of Catalysis, Department
of Chemical Engineering and Chemistry, Eindhoven
University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Center
for Computational Energy Research, Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - José Manuel Vicent-Luna
- Materials
Simulation & Modelling, Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
- Center
for Computational Energy Research, Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Ivo Filot
- Laboratory
of Inorganic Materials Chemistry, Schuit Institute of Catalysis, Department
of Chemical Engineering and Chemistry, Eindhoven
University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
- Center
for Computational Energy Research, Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Adri C. T. van Duin
- Department
of Mechanical Engineering, Pennsylvania
State University, University
Park, Pennsylvania 16802, United States
| | - Shuxia Tao
- Materials
Simulation & Modelling, Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
- Center
for Computational Energy Research, Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
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20
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Zhang X, Ponce V, Galvez-Aranda DE, Zhou G, Zhou H, Seminario JM. CS 2 Removal from C 5 Distillates by Reactive Molecular Dynamics Simulations. Ind Eng Chem Res 2021. [DOI: 10.1021/acs.iecr.1c00530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xiance Zhang
- College of New Energy and Materials, China University of Petroleum-Beijing, Beijing 102249, China
- Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Victor Ponce
- Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
- Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Diego E. Galvez-Aranda
- Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, United States
| | - Guanglin Zhou
- College of New Energy and Materials, China University of Petroleum-Beijing, Beijing 102249, China
| | - Hongjun Zhou
- College of New Energy and Materials, China University of Petroleum-Beijing, Beijing 102249, China
| | - Jorge M. Seminario
- Department of Chemical Engineering, Texas A&M University, College Station, Texas 77843, United States
- Department of Electrical and Computer Engineering, Texas A&M University, College Station, Texas 77843, United States
- Department of Materials Science and Engineering, Texas A&M University, College Station, Texas 77843, United States
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21
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Dasgupta N, Yilmaz DE, van Duin A. Simulations of the Biodegradation of Citrate-Based Polymers for Artificial Scaffolds Using Accelerated Reactive Molecular Dynamics. J Phys Chem B 2020; 124:5311-5322. [PMID: 32495628 DOI: 10.1021/acs.jpcb.0c03008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In this study, we investigate the reactivity and mechanical properties of poly(1,6-hexanediol-co-citric acid) via ReaxFF molecular dynamics simulations. We implement an accelerated scheme within the ReaxFF framework to study the hydrolysis reaction of the polymer which is provided with a sufficient amount of energy known as the restrain energy after a suitable pretransition-state configuration is obtained to overcome the activation energy barrier and the desired product is obtained. The validity of the ReaxFF force field is established by comparing the ReaxFF energy barriers of ester and ether hydrolysis with benchmark DFT values in the literature. We perform chemical and mechanical degradation of polymer chain bundles at 300 K. We find that ester hydrolyzes faster than ether because of the lower activation energy barrier of the reaction. The selectivity of the bond-boost scheme has been demonstrated by lowering the boost parameters of the accelerated simulation, which almost stops the ether hydrolysis. Mechanical degradation of prehydrolyzed and intermittent hydrolyzed polymer bundles is performed along the longitudinal direction at two different strain rates. We find that the tensile modulus of the polymers increases with increase in strain rates, which shows that polymers show a strain-dependent behavior. The tensile modulus of the polyester-ether is higher than polyester but reaches yield stress faster than polyester. This makes polyester more ductile than polyester-ether.
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Affiliation(s)
- Nabankur Dasgupta
- Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Dundar E Yilmaz
- Department of Mechanical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Adri van Duin
- Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania 16802, United States.,Department of Mechanical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, United States
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22
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Dasgupta N, Shin YK, Fedkin MV, van Duin A. ReaxFF molecular dynamics simulations of electrolyte-water systems at supercritical temperature. J Chem Phys 2020; 152:204502. [PMID: 32486685 DOI: 10.1063/5.0006676] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
We have performed ReaxFF molecular dynamics simulations of alkali metal-chlorine pairs in different water densities at supercritical temperature (700 K) to elucidate the structural and dynamical properties of the system. The radial distribution function and the angular distribution function explain the inter-ionic structural and orientational arrangements of atoms during the simulation. The coordination number of water molecules in the solvation shell of ions increases with an increase in the radius of ions. We find that the self-diffusion coefficient of metal ions increases with a decrease in density under supercritical conditions due to the formation of voids within the system. The hydrogen bond dynamics has been interpreted by the residence time distribution of various ions, which shows Li+ having the highest water retaining capability. The void distribution within the system has been analyzed by using the Voronoi polyhedra algorithm providing an estimation of void formation within the system at high temperatures. We observe the formation of salt clusters of Na+ and K+ at low densities due to the loss of dielectric constants of ions. The diffusion of ions gets altered dramatically due to the formation of voids and nucleation of ions in the system.
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Affiliation(s)
- Nabankur Dasgupta
- Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Yun Kyung Shin
- Department of Mechanical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Mark V Fedkin
- Department of Mechanical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Adri van Duin
- Department of Engineering Science and Mechanics, Pennsylvania State University, University Park, Pennsylvania 16802, USA
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23
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Gao Q, Han Y, Liang P, Meng J. Influence of an external electric field on the deprotonation reactions of an Fe3+-solvated molecule: a reactive molecular dynamics study. Phys Chem Chem Phys 2020; 22:6291-6299. [DOI: 10.1039/d0cp00072h] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
An EEF can promote deprotonation reactions of Fe3+using associated methods of MD simulations and experiments.
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Affiliation(s)
- Qiaofeng Gao
- Measurement Technology and Instrumentation Key Laboratory of Hebei Province
- School of Electrical Engineering
- Yanshan University
- Qinhuangdao 066004
- P. R. China
| | - Yong Han
- Measurement Technology and Instrumentation Key Laboratory of Hebei Province
- School of Electrical Engineering
- Yanshan University
- Qinhuangdao 066004
- P. R. China
| | - Pengyuan Liang
- Measurement Technology and Instrumentation Key Laboratory of Hebei Province
- School of Electrical Engineering
- Yanshan University
- Qinhuangdao 066004
- P. R. China
| | - Jie Meng
- Measurement Technology and Instrumentation Key Laboratory of Hebei Province
- School of Electrical Engineering
- Yanshan University
- Qinhuangdao 066004
- P. R. China
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