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Fei L, Wang M, Qiao M, Zhang Y, Wang A, Zhao Y, Liu J, Wang S, Guo X, Wang J, Bi J, Zhang P, Guo Z, Yue Y, Yuan J, Di Tommaso D, Li F, Ji Z. Comparative Investigation of the Microstructure of MgCl 2 Aqueous Solutions Using Different X-ray Scattering Sources, Raman Spectroscopy, and Atomistic Simulations. J Phys Chem B 2024; 128:208-221. [PMID: 38113228 DOI: 10.1021/acs.jpcb.3c05763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2023]
Abstract
Aqueous solutions of magnesium chloride (MgCl2(aq)) are often used to test advances in the theory of electrolyte solutions because they are considered an ideal strong 2:1 electrolyte. However, there is evidence that some ion association occurs in these solutions, even at low concentrations. Even a small ion-pairing constant can have a significant impact on the chemical speciation of ions, so it is important to determine whether ion pairing actually occurs. In this study, MgCl2(aq) with concentrations ranging from 1 to 35% was studied using three methods: X-ray scattering (XRS) with the Shanghai Synchrotron Radiation Facility (SSRF) and silver-anode laboratory sources, Raman spectroscopy, and molecular dynamics (MD) simulations with the COMPASS-II and Madrid force fields. XRS results were analyzed in the framework of PDF theory to obtain the reduced structure function F(Q) and the reduced pair distribution function G(r). The F(Q) values from synchrotron radiation and laboratory sources both showed that the tetrahedral hydrogen bonds in bulk water were destroyed with the increased MgCl2 concentration. The results of G(r) indicated that the main peaks centered at 2.05 and 2.80 Å can be ascribed to the interactions of Mg-O and O-O, respectively. The peak at 3.10 Å is attributed to the combined effect of O-O and Cl-O. By comparing the structural information on MgCl2 solution obtained from the two light sources, it was found that both SSRF and silver-anode laboratory sources can reflect the above-mentioned structural information on MgCl2 solution. The radial distribution function (RDF) obtained from MD simulations of MgCl2 solutions assigned the peaks at 2.0, 2.8, and 3.2 Å to the Mg-O, O-O, and Cl-O interatomic pairs, respectively. The decrease in the O-O coordination number confirms that the hydrogen-bonding network of water is disrupted by increasing MgCl2 observed by X-ray scattering. The proportion of Mg-Cl contact ion pairs gradually increases with MgCl2 concentration as does the coordination number. Raman spectroscopy results show that the bond type changes from double donor double acceptor (DDAA) to single donor-single acceptor (DA) with increasing concentration, providing explicit details of the hydrogen-bond evolution in the aqueous solution.
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Affiliation(s)
- Liting Fei
- Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
| | - Meiling Wang
- Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
| | - Mengdan Qiao
- Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
| | - Yu Zhang
- Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
| | - Ao Wang
- Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
| | - Yingying Zhao
- Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- National-Local Joint Engineering Laboratory of Chemical Energy Saving Process Integration and Resource Utilization, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- Tianjin Key Laboratory of Intrinsically Safe Chemical Technology, Tianjin 300130, China
- Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin 300401, China
| | - Jie Liu
- Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- National-Local Joint Engineering Laboratory of Chemical Energy Saving Process Integration and Resource Utilization, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- Tianjin Key Laboratory of Intrinsically Safe Chemical Technology, Tianjin 300130, China
- Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin 300401, China
| | - Shizhao Wang
- Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- National-Local Joint Engineering Laboratory of Chemical Energy Saving Process Integration and Resource Utilization, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- Tianjin Key Laboratory of Intrinsically Safe Chemical Technology, Tianjin 300130, China
- Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin 300401, China
| | - Xiaofu Guo
- Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- National-Local Joint Engineering Laboratory of Chemical Energy Saving Process Integration and Resource Utilization, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- Tianjin Key Laboratory of Intrinsically Safe Chemical Technology, Tianjin 300130, China
- Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin 300401, China
| | - Jing Wang
- Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- National-Local Joint Engineering Laboratory of Chemical Energy Saving Process Integration and Resource Utilization, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- Tianjin Key Laboratory of Intrinsically Safe Chemical Technology, Tianjin 300130, China
- Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin 300401, China
| | - Jingtao Bi
- Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- National-Local Joint Engineering Laboratory of Chemical Energy Saving Process Integration and Resource Utilization, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- Tianjin Key Laboratory of Intrinsically Safe Chemical Technology, Tianjin 300130, China
- Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin 300401, China
| | - Panpan Zhang
- Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- National-Local Joint Engineering Laboratory of Chemical Energy Saving Process Integration and Resource Utilization, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- Tianjin Key Laboratory of Intrinsically Safe Chemical Technology, Tianjin 300130, China
- Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin 300401, China
| | - Zhiyuan Guo
- Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- National-Local Joint Engineering Laboratory of Chemical Energy Saving Process Integration and Resource Utilization, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- Tianjin Key Laboratory of Intrinsically Safe Chemical Technology, Tianjin 300130, China
- Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin 300401, China
| | - Yajun Yue
- China Spallation Neutron Source, Dongguan, Guangdong 523000, China
| | - Junsheng Yuan
- Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- National-Local Joint Engineering Laboratory of Chemical Energy Saving Process Integration and Resource Utilization, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- Tianjin Key Laboratory of Intrinsically Safe Chemical Technology, Tianjin 300130, China
- Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin 300401, China
| | - Devis Di Tommaso
- Department of Chemistry, School of Physical and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, U.K
- Digital Environment Research Institute, Queen Mary University of London, Empire House, 67-75 New Road, London E1 1HH, U.K
| | - Fei Li
- Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- National-Local Joint Engineering Laboratory of Chemical Energy Saving Process Integration and Resource Utilization, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- Tianjin Key Laboratory of Intrinsically Safe Chemical Technology, Tianjin 300130, China
- Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin 300401, China
| | - Zhiyong Ji
- Engineering Research Center of Seawater Utilization Technology of Ministry of Education, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- National-Local Joint Engineering Laboratory of Chemical Energy Saving Process Integration and Resource Utilization, School of Chemical Engineering and Technology, Hebei University of Technology, Tianjin 300130, China
- Tianjin Key Laboratory of Intrinsically Safe Chemical Technology, Tianjin 300130, China
- Hebei Collaborative Innovation Center of Modern Marine Chemical Technology, Tianjin 300401, China
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2
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Boyn JN, Carter EA. Characterizing the Mechanisms of Ca and Mg Carbonate Ion-Pair Formation with Multi-Level Molecular Dynamics/Quantum Mechanics Simulations. J Phys Chem B 2023; 127:10824-10832. [PMID: 38086172 DOI: 10.1021/acs.jpcb.3c05369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
The carbonate minerals of Ca and Mg are abundant throughout the lithosphere and have recently garnered significant research interest as possible long-term carbon sinks in the sequestration of atmospheric carbon dioxide. Nonetheless, an understanding of the atomic-level processes comprising their mineralization remains limited. Here, we characterize and contrast the mechanisms of contact ion-pair formation in aqueous Ca and Mg carbonate systems, which represents the most fundamental step leading to the formation of their mineral solids. Utilizing multilevel embedded correlated wavefunction-based ab initio molecular dynamics/quantum mechanics simulations, we characterize not only the dynamics of these processes but also factors arising from the electronic structure of the involved species, revealing further details of the fundamentally different mechanisms for the interconversion between the contact ion-pairs and solvent-shared ion-pairs of Ca versus Mg carbonate.
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Affiliation(s)
- Jan-Niklas Boyn
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544-5263, United States
| | - Emily A Carter
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544-5263, United States
- Andlinger Center for Energy and the Environment and Program in Applied and Computational Mathematics, Princeton University, Princeton, New Jersey 08544-5263, United States
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3
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Seepma SYMH, Kuipers BWM, Wolthers M. Impact of Solution {Ba 2+}:{SO 42-} on Charge Evolution of Forming and Growing Barite (BaSO 4) Crystals: A ζ-Potential Measurement Investigation. ACS OMEGA 2023; 8:43521-43537. [PMID: 38027339 PMCID: PMC10666142 DOI: 10.1021/acsomega.3c03727] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 10/06/2023] [Accepted: 10/12/2023] [Indexed: 12/01/2023]
Abstract
The impact of solution stoichiometry on formation of BaSO4 (barite) crystals and the development of surface charge was investigated at various predefined stoichiometries (raq = 0.01, 0.1, 1, 10, and 100, where raq = {Ba2+}:{SO42-}). Synthesis experiments and zeta potential (ζ-potential) measurements were conducted at a fixed initial degree of supersaturation (Ωbarite = 1000, where Ωbarite = {Ba2+}{SO42-}/Ksp), at circumneutral pH of ∼6, 0.02 M NaCl, and ambient temperature and pressure. Mixed-mode measurement-phase analysis light scattering (M3-PALS) showed that the particles stayed negative for raq < 1 during barite crystal formation and positive for raq > 1. At raq = 1, two populations with a positive or negative ζ-potential prevailed for ∼2.5 h before a population with a circumneutral ζ-potential (-10 to +10 mV) remained. We relate the observations of particle charge evolution to particle size and morphology evolution under the experimental conditions. Furthermore, we showed that the ζ-potential became more negative when the pH was increased for every raq. In addition, our results demonstrated that the type of monovalent background electrolyte did not influence the ζ-potential of barite crystals significantly, although NaCl showed slightly different behavior compared to KCl and NaNO3. Our results show the important role of surface charge (evolution) during ionic crystal formation under nonstoichiometric conditions. Moreover, our combined scanning electron microscopy and ζ-potential results imply that the surface charge during particle formation can be influenced by solution stoichiometry, besides the pH and ionic strength, and may aid in predicting the fate of barite in environmental settings and in understanding and improving industrial barite (surface chemistry) processes.
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Affiliation(s)
- Sergěj Y. M. H. Seepma
- Department
of Earth Sciences, Utrecht University, Princetonlaan 8A, Utrecht 3584 CB, The Netherlands
| | - Bonny W. M. Kuipers
- Van
‘t Hoff Laboratory for Physical and Colloid Chemistry, Debye
Institute for Nanomaterials Science, Utrecht
University, Padualaan
8, Utrecht 3584 CH, The Netherlands
| | - Mariëtte Wolthers
- Department
of Earth Sciences, Utrecht University, Princetonlaan 8A, Utrecht 3584 CB, The Netherlands
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4
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Kelland MA, Rønning KW. Effect of Divalent Cations and Other Ions on the Tetrahydrofuran Crystal Inhibition of Quaternary Ammonium Salts-Relevance to the Efficiency of Gas Hydrate Quaternary Anti-agglomerants. ACS OMEGA 2023; 8:24495-24502. [PMID: 37457459 PMCID: PMC10339423 DOI: 10.1021/acsomega.3c02487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 06/16/2023] [Indexed: 07/18/2023]
Abstract
Gas hydrate anti-agglomerants (AAs) are a class of low-dosage hydrate inhibitor that are used to prevent plugging of gas hydrates in oil and condensate upstream flow lines. Industrial AAs are mostly cationic surfactants which are "hydrate-philic", i.e., they are designed to interact with and modify gas hydrate crystal growth. Tetrahydrofuran (THF) hydrate crystal growth studies have been used for many years to determine useful functional groups to incorporate into AA surfactants. In particular, quaternary ammonium and phosphonium salts with optimized alkyl groups show good THF crystal growth inhibition, which is a key property for AAs. AAs are often screened and tested in model brines containing sodium chloride despite the produced water containing various divalent cations. Recent studies have shown that AAs performed better when tested in brines containing both sodium and calcium ions rather than just sodium ions. Here, we present THF hydrate crystal growth studies on quaternary ammonium and phosphonium salts and other related molecules including guanidinium salts and amine oxides. Tests were carried out with a variety of cations including sodium, calcium, magnesium, and lithium at identical pre-determined subcooling, in order to investigate the effect of the ion size and charge density on the crystal growth inhibition. We also investigate the effect of using the more polarizable iodide ions compared to chloride ions. Our results show that crystal growth inhibition in solutions with calcium ions is somewhat greater than that with sodium ions, in agreement with past studies on the effect of AA performance with mono- and divalent cations. However, the variation does not seem to be primarily related to the charge density and polarizing ability of the cations. This study therefore provides evidence that AAs should be tested in brines containing all the ions present in the produced water and not just sodium chloride brine.
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5
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Qin L, Mao X, Cui Y, Bao J, Sant G, Chen T, Zhang P, Gao X, Bauchy M. New insights into the early stage nucleation of calcium carbonate gels by reactive molecular dynamics simulations. J Chem Phys 2022; 157:234501. [PMID: 36550033 DOI: 10.1063/5.0127240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The precipitation of calcium carbonate (CaCO3) is a key mechanism in carbon capture applications relying on mineralization. In that regard, Ca-rich cementitious binders offer a unique opportunity to act as a large-scale carbon sink by immobilizing CO2 as calcium carbonate by mineralization. However, the atomistic mechanism of calcium carbonate formation is still not fully understood. Here, we study the atomic scale nucleation mechanism of an early stage amorphous CaCO3 gel based on reactive molecular dynamics (MD) simulations. We observe that reactive MD offers a notably improved description of this reaction as compared to classical MD, which allows us to reveal new insights into the structure of amorphous calcium carbonate gels and formation kinetics thereof.
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Affiliation(s)
- Ling Qin
- School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China
| | - Xingtai Mao
- School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China
| | - Yifei Cui
- School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China
| | - Jiuwen Bao
- School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China
| | - Gaurav Sant
- Institute for Carbon Management (ICM), University of California, Los Angeles, California 90095, USA
| | - Tiefeng Chen
- School of Civil Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Peng Zhang
- School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China
| | - Xiaojian Gao
- School of Civil Engineering, Harbin Institute of Technology, Harbin 150090, China
| | - Mathieu Bauchy
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
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6
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Liu XC, Skibsted LH. Citrate in calcium transport and biomineralisation. Int Dairy J 2022. [DOI: 10.1016/j.idairyj.2022.105561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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7
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Broad A, Darkins R, Duffy DM, Ford IJ. Calcite Kinks Grow via a Multistep Mechanism. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2022; 126:15980-15985. [PMID: 36185702 PMCID: PMC9514807 DOI: 10.1021/acs.jpcc.2c04116] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/18/2022] [Indexed: 06/16/2023]
Abstract
The classical model of crystal growth assumes that kinks grow via a sequence of independent adsorption events where each solute transitions from the solution directly to the crystal lattice site. Here, we challenge this view by showing that some calcite kinks grow via a multistep mechanism where the solute adsorbs to an intermediate site and only transitions to the lattice site upon the adsorption of a second solute. We compute the free energy curves for Ca and CO3 ions adsorbing to a large selection of kink types, and we identify kinks terminated both by Ca ions and by CO3 ions that grow in this multistep way.
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8
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Toroz D, Song F, Uddin A, Chass GA, Di Tommaso D. A Database of Solution Additives Promoting Mg 2+ Dehydration and the Onset of MgCO 3 Nucleation. CRYSTAL GROWTH & DESIGN 2022; 22:3080-3089. [PMID: 35529066 PMCID: PMC9073943 DOI: 10.1021/acs.cgd.1c01525] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 03/22/2022] [Indexed: 06/14/2023]
Abstract
Formed via aqueous carbonation of Mg2+ ions, the crystallization of magnesite (MgCO3) is a promising route to carbon capture and reuse, albeit limited by the slow precipitation of MgCO3. Although magnesite is naturally abundant, forming at low temperature conditions, its industrial production is an energy-intensive process due to the temperatures required to prevent the formation of hydrated phases. The principal difficulty in aqueous conditions arises from the very strong Mg2+···H2O interaction, with high barriers to Mg2+ dehydration. Using atomistic simulations, we have investigated the influence of 30 additive anions (X n-, n = 1-3), ranging from simple halides to more complex molecules, on the first two steps of MgCO3 aggregation from solution, as follows: Mg2+ dehydration and subsequent prenucleative Mg2+···CO3 2- pairing. We have computed the thermodynamic stabilities of solvent shared ion pairs (Mg2+···H2O···X n-) and contact ion pairs (Mg2+···X n-) to reveal the propensity of solution additives to inhibit or promote Mg2+···CO3 2- formation. We have determined the stabilization of undercoordinated hydrated Mg2+ states with a vacant coordination site to which CO3 2- can bind, subsequently initiating MgCO3 nucleation or Mg2+ incorporation into the crystal lattice. Extensive molecular dynamics simulations of electrolyte solutions containing Na2CO3 with different sources of Mg2+ (i.e., MgCl2, MgSO4, and Mg(CH3COO)2) further show that the degree of dehydration of Mg2+ and the structure of prenucleation MgCO3 clusters change depending on the counterion identity. Through a fundamental understanding of the role of solution additives in the mechanism of Mg2+ dehydration, our results help to rationalize previously reported experimental observation of the effect of solvation environments on the growth of magnesite. This understanding may contribute to identifying the solution composition and conditions that could promote the low-temperature CO2 conversion into MgCO3 at industrially relevant scales.
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Affiliation(s)
- Dimitrios Toroz
- Department
of Chemistry, Queen Mary University of London, Mile End Road, London, E1 4NS, United
Kingdom
| | - Fu Song
- Department
of Chemistry, Queen Mary University of London, Mile End Road, London, E1 4NS, United
Kingdom
| | - Amira Uddin
- Department
of Chemistry, Queen Mary University of London, Mile End Road, London, E1 4NS, United
Kingdom
| | - Gregory A. Chass
- Department
of Chemistry, Queen Mary University of London, Mile End Road, London, E1 4NS, United
Kingdom
- Department
of Chemistry and Chemical Biology, McMaster
University, Hamilton, Ontario L8S 4M1, Canada
- Faculty
of Land and Food Systems, The University
of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Devis Di Tommaso
- Department
of Chemistry, Queen Mary University of London, Mile End Road, London, E1 4NS, United
Kingdom
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9
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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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10
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Orekhov M. Effect of divalent ion coordination on ion diffusion in organic liquids. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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11
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Zhang N, Tang J, Luo Q, Wang S, Zeng D. Computational and solubility equilibrium experimental insight into Ca 2+-fluoride complexation and their dissociation behaviors in aqueous solutions: implication for the association constant measured using fluoride ion selective electrodes. Phys Chem Chem Phys 2021; 23:24711-24725. [PMID: 34709252 DOI: 10.1039/d1cp02087k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Although the Ca2+-F- association is of great importance for aqueous environments and industrial systems containing F-, as well as for defluorination processes, many details of the association solvation structures and behavior remain unclear. Herein, a combination of classical/ab initio molecular dynamics simulations and density functional theory calculations was used to investigate the structure and hydration of CaFx2-x (x = 1, 2) and the association/dissociation behavior of Ca2+-F- in aqueous CaF2 solutions. The primary shell of Ca2+ is found to be very flexible in the association of Ca2+-F-, with coordination numbers dynamically oscillating in the range of 6-9, with 6 and 7 being the most favorable. The calculations show that for CaF(H2O)14+, the contact ion pair (CIP) is more favorable and occurs with no energy barrier, whereas the formation of CaF2(aq.) must overcome a ∼3.6 kJ mol-1 energy barrier; moreover, the CIP and solvent shared ion pair (SSIP) dynamically coexist for CaF2(H2O)14 in aqueous CaF2 solutions. Calculations for the dissociation process of CaF(H2O)6+ show a dramatic energy increase going from SSIP to free Ca2+ and F-, ascribed to the surprisingly long-range electrostatic attraction between Ca2+ and F- rather than to special F⋯H interactions. The energy increase results in the estimated association constant of CaF+ being larger than that previously measured using fluoride ion selective electrodes. This is attributed to the fact that the latter value might correspond to the ligand reaction of free Ca2+ and F- to form the Ca2+-F- SSIP. The combination of these results with CaF2(s) solubility measurements suggests that the higher-order Ca2+-F- complexes are absent in aqueous CaF2 solutions.
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Affiliation(s)
- Ning Zhang
- College of Science, Central South University of Forestry and Technology, Changsha 410004, Hunan, P. R. China.
| | - Jianfeng Tang
- College of Science, Central South University of Forestry and Technology, Changsha 410004, Hunan, P. R. China.
| | - Qiongqiong Luo
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, P. R. China
| | - Shaoheng Wang
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, P. R. China
| | - Dewen Zeng
- College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, Hunan, P. R. China
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12
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Orekhov MA. Coordination Numbers of Bivalent Ions in Organic Solvents. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2021. [DOI: 10.1134/s0036024421100204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract
Molecular dynamic models are created for properties of bivalent ions in organic solvents. It is shown that molecules of the considered solvents bound to ions via oxygen atoms. A theoretical model is developed that describes the ion coordination number. The coordination number in this model is determined by the ratio between the sizes of the ion and the atom organic molecule bound to it. It is shown that the coordination number depends weakly on the solvent and strongly on the type of ion. A value of 0.13 nm is obtained for the effective size of an oxygen atom bound to a bivalent ion. The constructed theoretical model agrees with the results from molecular dynamic calculations and the available experimental data.
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13
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Liu XC, Skibsted LH. Strontium increasing calcium accessibility from calcium citrate. Food Chem 2021; 367:130674. [PMID: 34343801 DOI: 10.1016/j.foodchem.2021.130674] [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: 02/18/2021] [Revised: 06/04/2021] [Accepted: 07/20/2021] [Indexed: 11/30/2022]
Abstract
Strontium chloride added to aqueous suspensions of metastable calcium citrate tetrahydrate increased calcium ion activity measured electrochemically without transition of metastable tetrahydrate to stable calcium citrate hexahydrate as shown by DSC. Calcium activity increase was explained by lower solubility of strontium citrate pentahydrate formed (8.9 × 10-4 M at 25 °C) increasing with temperature compared to calcium citrate tetrahydrate (1.6 × 10-3 M) decreasing with temperature. Strontium binding to citrate was found endothermic, ΔH0 = 45 kJ∙mol-1 at 25 °C, while calcium binding shows variation from ΔH0 = 94 kJ∙mol-1 at 10 °C becoming exothermic above physiological temperature with ΔH0 = -9 kJ∙mol-1 at 45 °C as determined from temperature and concentration variation in electric conductivity. These differences in solution thermodynamics and pH effect on complex formation between calcium and strontium citrate are discussed in relation to biomineralization.
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Affiliation(s)
- Xiao-Chen Liu
- Department of Food Science, University of Copenhagen, Rolighedsvej 26, DK-1958 Frederiksberg C, Denmark.
| | - Leif H Skibsted
- Department of Food Science, University of Copenhagen, Rolighedsvej 26, DK-1958 Frederiksberg C, Denmark.
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14
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First Steps towards Understanding the Non-Linear Impact of Mg on Calcite Solubility: A Molecular Dynamics Study. MINERALS 2021. [DOI: 10.3390/min11040407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Magnesium (Mg2+) is one of the most common impurities in calcite and is known to have a non-linear impact on the solubility of magnesian calcites. Using molecular dynamics (MD), we observed that Mg2+ impacts overall surface energies, local free energy profiles, interfacial water density, structure and dynamics and, at higher concentrations, it also causes crystal surface deformation. Low Mg concentrations did not alter the overall crystal structure, but stabilised Ca2+ locally and tended to increase the etch pit nucleation energy. As a result, Ca-extraction energies over a wide range of 39 kJ/mol were observed. Calcite surfaces with an island were less stable compared to flat surfaces, and the incorporation of Mg2+ destabilised the island surface further, increasing the surface energy and the calcium extraction energies. In general, Ca2+ is less stable in islands of high Mg2+ concentrations. The local variation in free energies depends on the amount and distance to nearest Mg in addition to local disruption of interfacial water and the flexibility of surface carbonate ions to rotate. The result is a complex interplay of these characteristics that cause variability in local dissolution energies. Taken together, these results illustrate molecular scale processes behind the non-linear impact of Mg2+ concentration on the solubility of magnesium-bearing calcites.
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15
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Na+/Mg2+ interactions on membrane distillation permeation flux and crystallization performance during high saline solution treatment. Sep Purif Technol 2021. [DOI: 10.1016/j.seppur.2020.118191] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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16
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Garcia AC, Hansen JS, Bailey N, Skibsted LH. Slow lactate gluconate exchange in calcium complexes during precipitation from supersaturated aqueous solutions. Food Res Int 2020; 137:109539. [PMID: 33233167 DOI: 10.1016/j.foodres.2020.109539] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 06/22/2020] [Accepted: 07/09/2020] [Indexed: 02/07/2023]
Abstract
Saturated solutions of calcium l-lactate in water or in deuterium oxide continuously dissolve calcium l-lactate by addition of solid sodium d-gluconate and become strongly supersaturated in calcium d-gluconate due to no or slow precipitation. The quantification of total dissolved calcium allied with the calcium complexes equilibrium constants allowed an ion speciation, which shows an initial non-thermal and spontaneous supersaturation of more than a factor of 50 at 25 °C only slowly decreasing after initiation of precipitation of calcium d-gluconate after a lag phase of several hours. A mathematical model is proposed, based on numerical solution of coupled differential equations of dynamics of l-lactate and d-gluconate exchange during the lag phase for precipitation and during precipitation. A slow exchange of l-lactate coordinated to calcium with d-gluconate is indicated with a time constant of 0.20 h-1 in water and of 0.15 h-1 in deuterium oxide and a kinetic deuterium/hydrogen isotope effect of 1.25. Such spontaneous non-thermal supersaturation and slow ligand exchange with a pseudo first order equilibration process with a half-life of 3.5 h in water for calcium hydroxycarboxylates can help to understand the higher calcium bioavailability from calcium hydroxycarboxylates compared to simple salts.
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Affiliation(s)
- André C Garcia
- Department of Food Science, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark; Instituto Federal de Educação, Ciência e Tecnologia de São Paulo, Campus Capivari. Avenida Doutor Ênio Pires de Camargo, 2971, São João Batista, CEP: 13360-000 Capivari, SP, Brazil
| | - Jesper S Hansen
- IMFUFA, Department of Science and Environment, Roskilde University, Universitetsvej 1, DK-4000 Roskilde, Denmark
| | - Nicholas Bailey
- IMFUFA, Department of Science and Environment, Roskilde University, Universitetsvej 1, DK-4000 Roskilde, Denmark
| | - Leif H Skibsted
- Department of Food Science, University of Copenhagen, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark.
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17
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Kim S, Wang X, Jang J, Eom K, Clegg SL, Park G, Di Tommaso D. Hydrogen-Bond Structure and Low-Frequency Dynamics of Electrolyte Solutions: Hydration Numbers from ab Initio Water Reorientation Dynamics and Dielectric Relaxation Spectroscopy. Chemphyschem 2020; 21:2334-2346. [PMID: 32866322 PMCID: PMC7702081 DOI: 10.1002/cphc.202000498] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 08/31/2020] [Indexed: 11/16/2022]
Abstract
We present an atomistic simulation scheme for the determination of the hydration number (h) of aqueous electrolyte solutions based on the calculation of the water dipole reorientation dynamics. In this methodology, the time evolution of an aqueous electrolyte solution generated from ab initio molecular dynamics simulations is used to compute the reorientation time of different water subpopulations. The value of h is determined by considering whether the reorientation time of the water subpopulations is retarded with respect to bulk-like behavior. The application of this computational protocol to magnesium chloride (MgCl2 ) solutions at different concentrations (0.6-2.8 mol kg-1 ) gives h values in excellent agreement with experimental hydration numbers obtained using GHz-to-THz dielectric relaxation spectroscopy. This methodology is attractive because it is based on a well-defined criterion for the definition of hydration number and provides a link with the molecular-level processes responsible for affecting bulk solution behavior. Analysis of the ab initio molecular dynamics trajectories using radial distribution functions, hydrogen bonding statistics, vibrational density of states, water-water hydrogen bonding lifetimes, and water dipole reorientation reveals that MgCl2 has a considerable influence on the hydrogen bond network compared with bulk water. These effects have been assigned to the specific strong Mg-water interaction rather than the Cl-water interaction.
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Affiliation(s)
- Seonmyeong Kim
- Center for THz-driven Biomedical SystemDepartment of Physics and AstronomySeoul National UniversityGwanak-gu08826South Korea
- Advanced Institutes of Convergence TechnologySeoul National UniversitySuwon-SiGyeonggi-do16229South Korea
| | - Xiangwen Wang
- School of Biological and Chemical SciencesMaterials Research InstituteThomas Young CentreQueen Mary University of LondonMile End RoadLondonE1 4NSUnited Kingdom
| | - Jeongmin Jang
- Center for THz-driven Biomedical SystemDepartment of Physics and AstronomySeoul National UniversityGwanak-gu08826South Korea
- Advanced Institutes of Convergence TechnologySeoul National UniversitySuwon-SiGyeonggi-do16229South Korea
| | - Kihoon Eom
- Center for THz-driven Biomedical SystemDepartment of Physics and AstronomySeoul National UniversityGwanak-gu08826South Korea
- Advanced Institutes of Convergence TechnologySeoul National UniversitySuwon-SiGyeonggi-do16229South Korea
| | - Simon L. Clegg
- School of Environmental SciencesUniversity of East AngliaNorwichNR4 7TJUnited Kingdom
| | - Gun‐Sik Park
- Center for THz-driven Biomedical SystemDepartment of Physics and AstronomySeoul National UniversityGwanak-gu08826South Korea
- Advanced Institutes of Convergence TechnologySeoul National UniversitySuwon-SiGyeonggi-do16229South Korea
| | - Devis Di Tommaso
- School of Biological and Chemical SciencesMaterials Research InstituteThomas Young CentreQueen Mary University of LondonMile End RoadLondonE1 4NSUnited Kingdom
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18
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Wang X, Toroz D, Kim S, Clegg SL, Park GS, Di Tommaso D. Density functional theory based molecular dynamics study of solution composition effects on the solvation shell of metal ions. Phys Chem Chem Phys 2020; 22:16301-16313. [PMID: 32647838 DOI: 10.1039/d0cp01957g] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We present an ab initio molecular dynamics study of the alkali metal ions Li+, Na+, K+ and Cs+, and of the alkaline earth metal ions Mg2+ and Ca2+ in both pure water and electrolyte solutions containing the counterions Cl- and SO42-. Simulations were conducted using different density functional theory methods (PBE, BLYP and revPBE), with and without the inclusion of dispersion interactions (-D3). Analysis of the ion-water structure and interaction strength, water exchange between the first and second hydration shell, and hydrogen bond network and low-frequency reorientation dynamics around the metal ions have been used to characterise the influence of solution composition on the ionic solvation shell. Counterions affect the properties of the hydration shell not only when they are directly coordinated to the metal ion, but also when they are at the second coordination shell. Chloride ions reduce the sodium hydration shell and expand the calcium hydration shell by stabilizing under-coordinated hydrated Na(H2O)5+ complexes and over-coordinated Ca(H2O)72+. The same behaviour is observed in CaSO4(aq), where Ca2+ and SO42- form almost exclusively solvent-shared ion pairs. Water exchange between the first and second hydration shell around Ca2+ in CaSO4(aq) is drastically decelerated compared with the simulations of the hydrated metal ion (single Ca2+, no counterions). Velocity autocorrelation function analysis, used to probe the strength of the local ion-water interaction, shows a smoother decay of Mg2+ in MgCl2(aq), which is a clear indication of a looser inter-hexahedral vibration in the presence of chloride ions located in the second coordination shell of Mg2+. The hydrogen bond statistics and orientational dynamics in the ionic solvation shell show that the influence on the water-water network cannot only be ascribed to the specific cation-water interaction, but also to the subtle interplay between the level of hydration of the ions, and the interactions between ions, especially those of opposite charge. As many reactive processes involving solvated metal ions occur in environments that are far from pure water but rich in ions, this computational study shows how the solution composition can result in significant differences in behaviour and function of the ionic solvation shell.
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Affiliation(s)
- Xiangwen Wang
- School of Biological and Chemical Sciences, Materials Research Institute, Thomas Young Centre, Queen Mary University of London, Mile End Road, E1 4NS, London, UK.
| | - Dimitrios Toroz
- School of Biological and Chemical Sciences, Materials Research Institute, Thomas Young Centre, Queen Mary University of London, Mile End Road, E1 4NS, London, UK.
| | - Seonmyeong Kim
- Center for THz-driven Biological Systems, Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea and Advanced Institutes of Convergence Technology, Seoul National University, Suwon-Si, Gyeonggi-do 16229, Republic of Korea
| | - Simon L Clegg
- School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Gun-Sik Park
- Center for THz-driven Biological Systems, Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Republic of Korea and Advanced Institutes of Convergence Technology, Seoul National University, Suwon-Si, Gyeonggi-do 16229, Republic of Korea
| | - Devis Di Tommaso
- School of Biological and Chemical Sciences, Materials Research Institute, Thomas Young Centre, Queen Mary University of London, Mile End Road, E1 4NS, London, UK.
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19
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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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20
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Understanding Calcium-Dependent Conformational Changes in S100A1 Protein: A Combination of Molecular Dynamics and Gene Expression Study in Skeletal Muscle. Cells 2020; 9:cells9010181. [PMID: 31936886 PMCID: PMC7016722 DOI: 10.3390/cells9010181] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 01/08/2020] [Accepted: 01/08/2020] [Indexed: 12/12/2022] Open
Abstract
The S100A1 protein, involved in various physiological activities through the binding of calcium ions (Ca2+), participates in several protein-protein interaction (PPI) events after Ca2+-dependent activation. The present work investigates Ca2+-dependent conformational changes in the helix-EF hand-helix using the molecular dynamics (MD) simulation approach that facilitates the understanding of Ca2+-dependent structural and dynamic distinctions between the apo and holo forms of the protein. Furthermore, the process of ion binding by inserting Ca2+ into the bulk of the apo structure was simulated by molecular dynamics. Expectations of the simulation were demonstrated using cluster analysis and a variety of structural metrics, such as interhelical angle estimation, solvent accessible surface area, hydrogen bond analysis, and contact analysis. Ca2+ triggered a rise in the interhelical angles of S100A1 on the binding site and solvent accessible surface area. Significant configurational regulations were observed in the holo protein. The findings would contribute to understanding the molecular basis of the association of Ca2+ with the S100A1 protein, which may be an appropriate study to understand the Ca2+-mediated conformational changes in the protein target. In addition, we investigated the expression profile of S100A1 in myoblast differentiation and muscle regeneration. These data showed that S100A1 is expressed in skeletal muscles. However, the expression decreases with time during the process of myoblast differentiation.
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21
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Koskamp J, Ruiz-Hernandez SE, Di Tommaso D, Elena AM, De Leeuw NH, Wolthers M. Reconsidering Calcium Dehydration as the Rate-Determining Step in Calcium Mineral Growth. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2019; 123:26895-26903. [PMID: 31737161 PMCID: PMC6849658 DOI: 10.1021/acs.jpcc.9b06403] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 10/15/2019] [Indexed: 06/10/2023]
Abstract
The dehydration of cations is generally accepted as the rate-limiting step in many processes. Molecular dynamics (MD) can be used to investigate the dynamics of water molecules around cations, and two different methods exist to obtain trajectory-based water dehydration frequencies. Here, these two different post-processing methods (direct method versus survival function) have been implemented to obtain calcium dehydration frequencies from a series of trajectories obtained using a range of accepted force fields. None of the method combinations reproduced the commonly accepted experimental water exchange frequency of 10-8.2 s-1. Instead, our results suggest much faster water dynamics, comparable with more accurate ab initio MD simulations and with experimental values obtained using neutron scattering techniques. We obtained the best agreement using the survival function method to characterize the water dynamics, and we show that different method combinations significantly affect the outcome. Our work strongly suggests that the fast water exchange kinetics around the calcium ions is not rate-limiting for reactions involving dissolved/solvated calcium. Our results further suggest that, for alkali and most of the earth alkali metals, mechanistic rate laws for growth, dissolution, and adsorption, which are based on the principle of rate-limiting cation dehydration, need careful reconsideration.
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Affiliation(s)
- Janou
A. Koskamp
- Department
of Earth Sciences-Geochemistry, Utrecht
University, 3584 CB Utrecht, The Netherlands
| | | | - Devis Di Tommaso
- Materials
Research Institute and School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, E1 4NS London, United Kingdom
| | | | - Nora H. De Leeuw
- Department
of Earth Sciences-Geochemistry, Utrecht
University, 3584 CB Utrecht, The Netherlands
- School
of Chemistry, Cardiff University, Main Building Park Place, Cardiff CF10 3AT, United Kingdom
| | - Mariette Wolthers
- Department
of Earth Sciences-Geochemistry, Utrecht
University, 3584 CB Utrecht, The Netherlands
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22
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Lankin AV, Norman GE, Orekhov MA. Behavior of the Environment during Ion Diffusion in Liquids. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2019. [DOI: 10.1134/s003602441908017x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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23
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Pohl MN, Muchová E, Seidel R, Ali H, Sršeň Š, Wilkinson I, Winter B, Slavíček P. Do water's electrons care about electrolytes? Chem Sci 2019; 10:848-865. [PMID: 30774880 PMCID: PMC6346409 DOI: 10.1039/c8sc03381a] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 11/01/2018] [Indexed: 01/01/2023] Open
Abstract
Ions have a profound effect on the geometrical structure of liquid water and an aqueous environment is known to change the electronic structure of ions. Here we combine photoelectron spectroscopy measurements from liquid microjets with molecular dynamical and quantum chemical calculations to address the reverse question, to what extent do ions affect the electronic structure of liquid water? We study aqueous solutions of sodium iodide (NaI) over a wide concentration range, from nearly pure water to 8 M solutions, recording spectra in the 5 to 60 eV binding energy range to include all water valence and the solute Na+ 2p, I- 4d, and I- 5p orbital ionization peaks. We observe that the electron binding energies of the solute ions change only slightly as a function of electrolyte concentration, less than 150 ± 60 meV over an ∼8 M range. Furthermore, the photoelectron spectrum of liquid water is surprisingly mildly affected as we transform the sample from a dilute aqueous salt solution to a viscous, crystalline-like phase. The most noticeable spectral changes are a negative binding energy shift of the water 1b2 ionizing transition (up to -370 ± 60 meV) and a narrowing of the flat-top shape water 3a1 ionization feature (up to 450 ± 90 meV). A novel computationally efficient technique is introduced to calculate liquid-state photoemission spectra using small clusters from molecular dynamics (MD) simulations embedded in dielectric continuum. This theoretical treatment captured the characteristic positions and structures of the aqueous photoemission peaks, reproducing the experimentally observed narrowing of the water 3a1 feature and weak sensitivity of the water binding energies to electrolyte concentration. The calculations allowed us to attribute the small binding energy shifts to ion-induced disruptions of intermolecular electronic interactions. Furthermore, they demonstrate the importance of considering concentration-dependent screening lengths for a correct description of the electronic structure of solvated systems. Accounting for electronic screening, the calculations highlight the minimal effect of electrolyte concentration on the 1b1 binding energy reference, in accord with the experiments. This leads us to a key finding that the isolated, lowest-binding-energy, 1b1, photoemission feature of liquid water is a robust energetic reference for aqueous liquid microjet photoemission studies.
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Affiliation(s)
- Marvin N Pohl
- Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6 , D-14195 Berlin , Germany .
- Fachbereich Physik , Freie Universität Berlin , Arnimallee 14 , D-14195 Berlin , Germany
| | - Eva Muchová
- Department of Physical Chemistry , University of Chemistry and Technology , Technická 5 , 16628 Prague , Czech Republic .
| | - Robert Seidel
- Helmholtz-Zentrum Berlin für Materialien und Energie , Hahn-Meitner-Platz 1 , D-14109 Berlin , Germany .
- Humboldt-Universität zu Berlin , Department of Chemistry , Brook-Taylor-Str. 2 , D-12489 Berlin , Germany
| | - Hebatallah Ali
- Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6 , D-14195 Berlin , Germany .
- Fachbereich Physik , Freie Universität Berlin , Arnimallee 14 , D-14195 Berlin , Germany
| | - Štěpán Sršeň
- Department of Physical Chemistry , University of Chemistry and Technology , Technická 5 , 16628 Prague , Czech Republic .
| | - Iain Wilkinson
- Helmholtz-Zentrum Berlin für Materialien und Energie , Hahn-Meitner-Platz 1 , D-14109 Berlin , Germany .
| | - Bernd Winter
- Fritz-Haber-Institut der Max-Planck-Gesellschaft , Faradayweg 4-6 , D-14195 Berlin , Germany .
| | - Petr Slavíček
- Department of Physical Chemistry , University of Chemistry and Technology , Technická 5 , 16628 Prague , Czech Republic .
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24
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Molecular dynamics simulation study on distinctive hydration characteristics of highly coordinated calcium chloride complexes. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2018.10.136] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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25
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Adhesive forces between two cleaved calcite surfaces in NaCl solutions: The importance of ionic strength and normal loading. J Colloid Interface Sci 2018; 532:605-613. [PMID: 30114650 DOI: 10.1016/j.jcis.2018.08.027] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 07/31/2018] [Accepted: 08/09/2018] [Indexed: 02/02/2023]
Abstract
The mechanical strength of calcite bearing rocks is influenced by pore fluid chemistry due to the variation in nano-scale surface forces acting at the grain contacts or close to the fracture tips. The adhesion of two contacting surfaces, which affects the macroscopic strength of the material, is not only influenced by the fluid chemistry but also by the surface topography. In this paper, we use Atomic Force Microscope (AFM) to measure the interfacial forces between two freshly cleaved calcite surfaces in CaCO3-saturated solutions with varying NaCl concentration. We show that calcite contacts become stronger with increasing NaCl concentration (>100 mM), as a result of progressively weaker secondary hydration and increasing attraction due to instantaneous ion-ion correlation. Moreover, we discuss the effect of normal applied force (Fn) and surface roughness on the measured adhesion forces (Fad). We show that the measured pull-off force (adhesion) is linearly correlated with the magnitude of Fn, where an increase in applied force results in increased adhesion. This is attributed to a larger number of contacting surface asperities and thus increase in real contact area and the contact-bond strength. We discuss that the possible variation in local topography at contacts, together with strong dependence on ionic strength of the solution, can explain the inconsistent behavior of calcite rocks in NaCl solutions.
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26
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Naleem N, Bentenitis N, Smith PE. A Kirkwood-Buff derived force field for alkaline earth halide salts. J Chem Phys 2018; 148:222828. [PMID: 29907021 DOI: 10.1063/1.5019454] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The activity and function of many macromolecules in cellular environments are coupled with the binding of divalent ions such as calcium or magnesium. In principle, computer simulations can be used to understand the molecular level aspects of how many important macromolecules interact with ions. However, most of the force fields currently available often fail to accurately reproduce the properties of divalent ions in aqueous environments. Here we develop classical non-polarizable force fields for the aqueous alkaline earth metal halides (MX2), where M = Mg2+, Ca2+, Sr2+, Ba2+ and X = Cl-, Br-, I-, which can be used in bimolecular simulations and which are compatible with the Simple Point Charge/Extended (SPC/E) water model. The force field parameters are specifically developed to reproduce the experimental Kirkwood-Buff integrals for aqueous solutions and thereby the experimental activity derivatives, partial molar volumes, and excess coordination numbers. This ensures that a reasonable balance between ion-ion, ion-water, and water-water distributions is obtained. However, this requires a scaling of the cation to water oxygen interaction strength in order to accurately reproduce the integrals. The scaling factors developed for chloride salts are successfully transferable to the bromide and iodide salts. Use of these new models leads to reasonable diffusion constants and dielectric decrements. However, the performance of the models decreases with increasing salt concentration (>4m), and simulations of the pure crystals exhibited unstable behavior.
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Affiliation(s)
- Nawavi Naleem
- Department of Chemistry, Kansas State University, 213 CBC Building, 1212 Mid Campus Dr. North, Manhattan, Kansas 66506-0401, USA
| | - Nikolaos Bentenitis
- Department of Chemistry, Kansas State University, 213 CBC Building, 1212 Mid Campus Dr. North, Manhattan, Kansas 66506-0401, USA
| | - Paul E Smith
- Department of Chemistry, Kansas State University, 213 CBC Building, 1212 Mid Campus Dr. North, Manhattan, Kansas 66506-0401, USA
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27
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Guardiani C, Fedorenko OA, Roberts SK, Khovanov IA. On the selectivity of the NaChBac channel: an integrated computational and experimental analysis of sodium and calcium permeation. Phys Chem Chem Phys 2018; 19:29840-29854. [PMID: 29090695 DOI: 10.1039/c7cp05928k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Ion channel selectivity is essential for their function, yet the molecular basis of a channel's ability to select between ions is still rather controversial. In this work, using a combination of molecular dynamics simulations and electrophysiological current measurements we analyze the ability of the NaChBac channel to discriminate between calcium and sodium. Our simulations show that a single calcium ion can access the Selectivity Filter (SF) interacting so strongly with the glutamate ring so as to remain blocked inside. This is consistent with the tiny calcium currents recorded in our patch-clamp experiments. Two reasons explain this scenario. The first is the higher free energy of ion/SF binding of Ca2+ with respect to Na+. The second is the strong electrostatic repulsion exerted by the resident ion that turns back a second potentially incoming Ca2+, preventing the knock-on permeation mechanism. Finally, we analyzed the possibility of the Anomalous Mole Fraction Effect (AMFE), i.e. the ability of micromolar Ca2+ concentrations to block Na+ currents. Current measurements in Na+/Ca2+ mixed solutions excluded the AMFE, in agreement with metadynamics simulations showing the ability of a sodium ion to by-pass and partially displace the resident calcium. Our work supports a new scenario for Na+/Ca2+ selectivity in the bacterial sodium channel, challenging the traditional notion of an exclusion mechanism strictly confining Ca2+ ions outside the channel.
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Affiliation(s)
- Carlo Guardiani
- School of Engineering, University of Warwick, Coventry CV4 7AL, UK.
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28
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Molecular Dynamics Simulations of Hydroxyapatite Nanopores in Contact with Electrolyte Solutions: The Effect of Nanoconfinement and Solvated Ions on the Surface Reactivity and the Structural, Dynamical, and Vibrational Properties of Water. CRYSTALS 2017. [DOI: 10.3390/cryst7020057] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Chizhik VI, Egorov AV, Pavlova MS, Egorova MI, Donets AV. Structure of hydration shell of calcium cation by NMR relaxation, Car-Parrinello molecular dynamics and quantum-chemical calculations. J Mol Liq 2016. [DOI: 10.1016/j.molliq.2016.10.035] [Citation(s) in RCA: 7] [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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Abstract
Little is known about the influence of nanoconfinement on calcium carbonate mineralization. Here, colloidal probe atomic force microscopy is used to confine the calcite-solution interface with a silica microsphere and to measure Derjaguin-Landau-Verwey-Overbeek (DLVO) and non-DLVO forces as a function of the calcium concentration, also after charge reversal of both surfaces occurs. Through the statistical analysis of the oscillatory component of a strong hydration force, the subnanometer interfacial structure of the confined atomically flat calcite is resolved in aqueous solution. By applying a mechanical work, both water and hydrated counterions are squeezed out from the nanoconfined solution, leaving the calcite surface more negatively charged than the analogous unconfined surfaces. Layer size and applied work allow a distinction between the hydration states of the counterions in the Stern layer; we propose counterions to be inner- and outer-sphere calcium ions, with a population of inner-sphere calcium ions larger than on unconfined calcite surfaces. It is also shown that the composition of the nanoconfined solution can be tuned by varying calcium concentration. This is a fundamental study of DLVO and hydration forces, and of their connection, on atomically flat calcite. More broadly, our work scrutinizes the greatly unexplored relation between surface science and confined mineralization, with implications for diverse areas of inquiry, such as nanoconfined biomineralization, CO2 sequestration in porous aquifers, and pressure solution and crystallization in confined hydrosystems.
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Tian KV, Chass GA, Di Tommaso D. Simulations reveal the role of composition into the atomic-level flexibility of bioactive glass cements. Phys Chem Chem Phys 2016; 18:837-45. [PMID: 26646505 DOI: 10.1039/c5cp05650k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Bioactive glass ionomer cements (GICs), the reaction product of a fluoro-alumino-silicate glass and polyacrylic acid, have been in effective use in dentistry for over 40 years and more recently in orthopaedics and medical implantation. Their desirable properties have affirmed GIC's place in the medical materials community, yet are limited to non-load bearing applications due to the brittle nature of the hardened composite cement, thought to arise from the glass component and the interfaces it forms. Towards helping resolve the fundamental bases of the mechanical shortcomings of GICs, we report the 1st ever computational models of a GIC-relevant component. Ab initio molecular dynamics simulations were employed to generate and characterise three fluoro-alumino-silicate glasses of differing compositions with focus on resolving the atomic scale structural and dynamic contributions of aluminium, phosphorous and fluorine. Analyses of the glasses revealed rising F-content leading to the expansion of the glass network, compression of Al-F bonding, angular constraint at Al-pivots, localisation of alumino-phosphates and increased fluorine diffusion. Together, these changes to the structure, speciation and dynamics with raised fluorine content impart an overall rigidifying effect on the glass network, and suggest a predisposition to atomic-level inflexibility, which could manifest in the ionomer cements they form.
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Affiliation(s)
- Kun Viviana Tian
- Materials Science Research Institute, Department of Oral Diagnostics, Faculty of Dentistry, Semmelweis University, Budapest 1088, Hungary and Global Institute of Computational Molecular and Materials Science (GIOCOMMS), Budapest (Hungary)/Beijing (China)/Toronto (Canada)
| | - Gregory A Chass
- Global Institute of Computational Molecular and Materials Science (GIOCOMMS), Budapest (Hungary)/Beijing (China)/Toronto (Canada) and School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK.
| | - Devis Di Tommaso
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK.
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Pathak AD, Nedea S, Zondag H, Rindt C, Smeulders D. A DFT-based comparative equilibrium study of thermal dehydration and hydrolysis of CaCl2 hydrates and MgCl2 hydrates for seasonal heat storage. Phys Chem Chem Phys 2016; 18:10059-69. [DOI: 10.1039/c6cp00926c] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
An equilibrium based comparative study of CaCl2 and MgCl2 hydrates reveals that CaCl2 hydrates have better resistance against hydrolysis compared to MgCl2 hydrates; therefore it can improve the durability of chloride based salt hydrates.
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Lopez-Berganza JA, Diao Y, Pamidighantam S, Espinosa-Marzal RM. Ab Initio Studies of Calcium Carbonate Hydration. J Phys Chem A 2015; 119:11591-600. [PMID: 26505205 DOI: 10.1021/acs.jpca.5b09006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Ab initio simulations of large hydrated calcium carbonate clusters are challenging due to the existence of multiple local energy minima. Extensive conformational searches around hydrated calcium carbonate clusters (CaCO3·nH2O for n = 1-18) were performed to find low-energy hydration structures using an efficient combination of Monte Carlo searches, density-functional tight binding (DFTB+) method, and density-functional theory (DFT) at the B3LYP level, or Møller-Plesset perturbation theory at the MP2 level. This multilevel optimization yields several low-energy structures for hydrated calcium carbonate. Structural and energetics analysis of the hydration of these clusters revealed a first hydration shell composed of 12 water molecules. Bond-length and charge densities were also determined for different cluster sizes. The solvation of calcium carbonate in bulk water was investigated by placing the explicitly solvated CaCO3·nH2O clusters in a polarizable continuum model (PCM). The findings of this study provide new insights into the energetics and structure of hydrated calcium carbonate and contribute to the understanding of mechanisms where calcium carbonate formation or dissolution is of relevance.
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Affiliation(s)
- Josue A Lopez-Berganza
- Smart Interfaces in Environmental Nanotechnology, Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , 205 North Matthews Avenue, Urbana, Illinois 61801, United States
| | - Yijue Diao
- Smart Interfaces in Environmental Nanotechnology, Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , 205 North Matthews Avenue, Urbana, Illinois 61801, United States
| | - Sudhakar Pamidighantam
- Science Gateways Group, Research Technologies, UITS, Indiana University , 2709 East 10th Street, Bloomington, Indiana 47408, United States
| | - Rosa M Espinosa-Marzal
- Smart Interfaces in Environmental Nanotechnology, Civil and Environmental Engineering, University of Illinois at Urbana-Champaign , 205 North Matthews Avenue, Urbana, Illinois 61801, United States
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Sarkar A, Tembe B. Molecular dynamics simulations of alkali metal halides in supercritical water. Chem Phys Lett 2015. [DOI: 10.1016/j.cplett.2015.08.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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35
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Azzaroli N, Lobello MG, Lapini A, Iagatti A, Bussotti L, Di Donato M, Calogero G, Pastore M, De Angelis F, Foggi P. Monitoring the intramolecular charge transfer process in the Z907 solar cell sensitizer: a transient Vis and IR spectroscopy and ab initio investigation. Phys Chem Chem Phys 2015. [DOI: 10.1039/c5cp03314d] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The excited state dynamics of Z907 in solution and on semiconductor substrates has been studied with ultrafast UV/Vis and IR spectroscopy and DFT/TDDFT calculations.
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Affiliation(s)
- Nicolò Azzaroli
- European Laboratory for Non Linear Spectroscopy (LENS)
- Università di Firenze
- Florence
- Italy
| | - Maria Grazia Lobello
- Computational Laboratory for Hybrid Organic Photovoltaics (CLHYO)
- Istituto CNR di Scienze e Tecnologie Molecolari
- I-06123 Perugia
- Italy
| | - Andrea Lapini
- European Laboratory for Non Linear Spectroscopy (LENS)
- Università di Firenze
- Florence
- Italy
- Dipartimento di Chimica “Ugo Schiff”
| | - Alessandro Iagatti
- European Laboratory for Non Linear Spectroscopy (LENS)
- Università di Firenze
- Florence
- Italy
- INO-CNR
| | - Laura Bussotti
- European Laboratory for Non Linear Spectroscopy (LENS)
- Università di Firenze
- Florence
- Italy
| | - Mariangela Di Donato
- European Laboratory for Non Linear Spectroscopy (LENS)
- Università di Firenze
- Florence
- Italy
- Dipartimento di Chimica “Ugo Schiff”
| | | | - Mariachiara Pastore
- Computational Laboratory for Hybrid Organic Photovoltaics (CLHYO)
- Istituto CNR di Scienze e Tecnologie Molecolari
- I-06123 Perugia
- Italy
| | - Filippo De Angelis
- Computational Laboratory for Hybrid Organic Photovoltaics (CLHYO)
- Istituto CNR di Scienze e Tecnologie Molecolari
- I-06123 Perugia
- Italy
| | - Paolo Foggi
- European Laboratory for Non Linear Spectroscopy (LENS)
- Università di Firenze
- Florence
- Italy
- INO-CNR
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