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Li S, Zhang X, Su J. Enhanced Rectification Performance in Bipolar Janus Graphene Oxide Channels by Lateral Electric Fields. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2024; 40:5488-5498. [PMID: 38423602 DOI: 10.1021/acs.langmuir.4c00021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Improving the ionic rectification in nanochannels enables versatile applications such as biosensors, energy harvesting, and fluidic diodes. While previous work mostly focused on the effect of channel geometry and surface charge, in this work via a series of molecular dynamics simulations, we find a striking phenomenon that the ionic current rectification (ICR) ratio in Janus graphene oxide (GO) channels can be tremendously promoted by lateral electric fields. First, under a given axial electric field, an additional lateral electric field can improve the ICR ratio by several times to an order, depending on the channel symmetry. The symmetric channel has an obviously greater ICR ratio because it maintains a more pronounced ion transport disparity at opposite axial fields. The underlying mechanism for the function of the lateral electric field is that it promotes the lateral migration of ions and thus amplifies the ion-residue electrostatic interaction at opposite axial fields, enlarging the ion dynamical difference. Furthermore, for different axial electric fields, the ICR ratio can always be improved by lateral electric fields (up to two orders), suggesting that the ICR improvement is universal. Our results demonstrate that applying a lateral electric field could be a new method to improve the rectification performance of nanochannels, providing valuable guidance for the design of efficient ionic diode devices.
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Affiliation(s)
- Shuang Li
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing and Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Xinke Zhang
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing and Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Jiaye Su
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing and Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
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2
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Li S, Zhang X, Su J. Desalination Performance in Janus Graphene Oxide Channels: Geometric Asymmetry vs Charge Polarity. ACS APPLIED MATERIALS & INTERFACES 2024; 16:2659-2671. [PMID: 38166374 DOI: 10.1021/acsami.3c16592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
Improving the desalination performance of membranes is always in the spotlight of scientific research; however, Janus channels with polarized surface charge as nanofiltration membranes are still unexplored. In this work, using molecular dynamics simulations, we demonstrate that Janus graphene oxide (GO) channels with appropriate geometry and surface charge can serve as highly efficient nanofiltration membranes. We observe that the water permeability of symmetric Janus GO channels is significantly superior to that of asymmetric channels without sacrificing much ion rejection, owing to weakened ion blockage and electrostatic effects. Furthermore, in symmetric Janus GO channels, the transport of water and ions is sensitive to the charge polarity of the channel inner surface, which is realized by tuning the ratio of cationic and anionic functionalization. Specifically, with the increase in cationic functionalization, the water flux decreases monotonously, while ion rejection displays an interesting maximum behavior that indicates desalination optimization. Moreover, the trade-off between water permeability and ion rejection suggests that the Janus GO channels have an excellent desalination potential and are highly tunable according to the specific water treatment requirements. Our work sheds light on the key role of channel geometry and charge polarity in the desalination performance of Janus GO channels, which paves the way for the design of novel desalination devices.
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Affiliation(s)
- Shuang Li
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, and Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Xinke Zhang
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, and Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Jiaye Su
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, and Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
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3
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de Izarra A, Coudert FX, Fuchs AH, Boutin A. Molecular Simulation of the Impact of Defects on Electrolyte Intrusion in Zeolites. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:19056-19063. [PMID: 38088342 DOI: 10.1021/acs.langmuir.3c03306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
We have investigated through molecular simulation the intrusion of electrolytes in two representative pure-silica zeolites, silicalite-1 and chabazite, in which point defects were introduced in varying amounts. We distinguish between two types of defects, considering either "weak" or "strong" silanol nest defects, resulting in different hydration behaviors. In the presence of weak defects, the hydration process occurs through a homogeneous nucleation process, while with strong defects, we observe an initial adsorption followed by a filling of the nanoporous volume at a higher pressure. However, we show that electrolytes do not penetrate the zeolites, and these defects appear to have only marginal influence on the thermodynamics of electrolyte intrusion. While replacing pure water by the electrolyte solution shifts the intrusion pressure toward higher values because of the drop of water saturation vapor pressure, an increase in hydrophilicity of the framework due to point defects has the opposite effect, showing that controlling the amount of defects in zeolites is crucial for storage energy applications.
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Affiliation(s)
- Ambroise de Izarra
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
- Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris, 75005 Paris, France
| | - François-Xavier Coudert
- Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris, 75005 Paris, France
| | - Alain H Fuchs
- Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris, 75005 Paris, France
| | - Anne Boutin
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005 Paris, France
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4
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Ding C, Su J. Ionic transport through a bilayer nanoporous graphene with cationic and anionic functionalization. J Chem Phys 2023; 159:174502. [PMID: 37909454 DOI: 10.1063/5.0170313] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 10/11/2023] [Indexed: 11/03/2023] Open
Abstract
Understanding the ionic transport through multilayer nanoporous graphene (NPG) holds great promise for the design of novel nanofluidic devices. Bilayer NPG with different structures, such as nanopore offset and interlayer space, should be the most simple but representative multilayer NPG. In this work, we use molecular dynamics simulations to systematically investigate the ionic transport through a functionalized bilayer NPG, focusing on the effect of pore functionalization, offset, applied pressure and interlayer distance. For a small interlayer space, the fluxes of water and ions exhibit a sudden reduction to zero with the increase in offset that indicates an excellent on-off gate, which can be deciphered by the increasing potential of mean force barriers. With the increase in pressure, the fluxes increase almost linearly for small offsets while always maintain zero for large offsets. Finally, with the increase in interlayer distance, the fluxes increase drastically, resulting in the reduction in ion rejection. Notably, for a specific interlayer distance with monolayer water structure, the ion rejection maintains high levels (almost 100% for coions) with considerable water flux, which could be the best choice for desalination purpose. The dynamics of water and ions also exhibit an obvious bifurcation for cationic and anionic functionalization. Our work comprehensively addresses the ionic transport through a bilayer NPG and provides a route toward the design of novel desalination devices.
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Affiliation(s)
- Chuxuan Ding
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, and Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
| | - Jiaye Su
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, and Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China
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5
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Li S, Zhang X, Su J. Surface charge density governs the ionic current rectification direction in asymmetric graphene oxide channels. Phys Chem Chem Phys 2023; 25:7477-7486. [PMID: 36852635 DOI: 10.1039/d2cp05137k] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
Charged asymmetric channels are extensively investigated for the design of artificial biological channels, ionic diodes, artificial separation films, etc. These applications are attributed to the unique ionic current rectification phenomenon, where the surface charge density of the channel has a deep influence. In this work, we use molecular dynamics simulations to study the rectification phenomenon in asymmetric graphene oxide channels. A fascinating finding is that the ionic current rectification direction reverses from the negative to positive electric field direction with an increase in surface charge density. Specifically, at low charge density, the ionic flux reaches greater values in the negative electric field due to the enrichment of cations and anions, which provides a sufficient electrostatic shielding effect inside the channel and increases the possibility of ion release by the residues. However, at high charge density, the extremely strong residue attraction induces a Coulomb blockade effect in the negative electric field, which seriously impedes the ion transport and eventually leads to a smaller ionic current. Consequently, this ionic current order transition ultimately results in the rectification reversion phenomenon, providing a new route for the design of some novel nanofluidic devices.
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Affiliation(s)
- Shuang Li
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, and Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China.
| | - Xinke Zhang
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, and Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China.
| | - Jiaye Su
- MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, and Department of Applied Physics, Nanjing University of Science and Technology, Nanjing 210094, China.
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6
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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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7
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Wang L, Morita A, North NM, Baumler SM, Springfield EW, Allen HC. Identification of Ion Pairs in Aqueous NaCl and KCl Solutions in Combination with Raman Spectroscopy, Molecular Dynamics, and Quantum Chemical Calculations. J Phys Chem B 2023; 127:1618-1627. [PMID: 36757371 DOI: 10.1021/acs.jpcb.2c07923] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
This work summarizes a theoretical analysis of the perturbation on Raman spectra in aqueous NaCl and KCl solutions with the aim to detect ion pairs. The experimental Raman spectra, both polarized and depolarized, are perturbed by these ions to a comparable extent or somewhat less by KCl than NaCl. This result appears to be contrary to the molecular dynamics (MD) simulation showing that the isolated and separated ions of KCl should have a larger perturbation than NaCl, as the solvation shell of K+ is larger than that of Na+. The apparent discrepancy signifies the ion pair formation which is more substantial for KCl than NaCl. The MD simulations and quantum chemical calculations revealed that KCl forms ion pairs more than NaCl and that the ion pair formation reduces the perturbation on the Raman spectra more for KCl. The present analysis shows that the perturbed Raman spectra provide a useful sign to evaluate the ion pair formation in aqueous solutions.
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Affiliation(s)
- Lin Wang
- Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku Sendai 980-8578, Japan
| | - Akihiro Morita
- Department of Chemistry, Graduate School of Science, Tohoku University, Aoba-ku Sendai 980-8578, Japan
| | - Nicole M North
- Department of Chemistry and Biochemistry, Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Stephen M Baumler
- Department of Chemistry and Biochemistry, Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Elliot W Springfield
- Department of Chemistry and Biochemistry, Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
| | - Heather C Allen
- Department of Chemistry and Biochemistry, Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States
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Izarra AD, Coudert FX, Fuchs AH, Boutin A. Alchemical Osmostat for Monte Carlo Simulation: Sampling Aqueous Electrolyte Solution in Open Systems. J Phys Chem B 2023; 127:766-776. [PMID: 36634303 DOI: 10.1021/acs.jpcb.2c07902] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Molecular simulations involving electrolytes are usually performed at a fixed amount of salt ions in the simulation box, reproducing macroscopic concentration. Although this statement is valid in the bulk, the concentration of an electrolyte confined in nanoporous materials such as MOFs or zeolites is greatly affected and remains a priori unknown. The nanoporous material in equilibrium with the bulk electrolyte exchange water and ions at a given chemical potential Δμ in the semi-grand-canonical ensemble, that must be calibrated in order to determine the concentration in the nanoporous material. In this work, we propose an algorithm based on nonequilibrium candidate Monte Carlo (NCMC) moves to ultimately perform MC simulations in contact with a saline reservoir. First, we adapt the Widom insertion technique to calibrate the chemical potential by alchemically transmuting water molecules into ions by using NCMC moves. The chemical potential defines a Monte Carlo osmostat in the semi-grand-constant volume and temperature ensemble (Δμ, N, V, T) to be added in a Monte Carlo simulation where the number of ions fluctuates. In order to validate the method, we adapted the NCMC move to determine the free energy of water solvation and subsequently explore thermodynamics of electrolyte solvation at infinite dilution in water. Finally, we implemented the osmostat in MC simulations initialized with bulk water that are driven toward electrolyte solutions of similar concentration as the saline reservoir. Our results demonstrate that alchemical osmostat for MC simulation is a promising tool for use to sample electrolyte insertion in nanoporous materials.
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Affiliation(s)
- Ambroise de Izarra
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France.,Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris, Paris75005, France
| | - François-Xavier Coudert
- Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris, Paris75005, France
| | - Alain H Fuchs
- Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris, Paris75005, France
| | - Anne Boutin
- PASTEUR, Département de Chimie, École Normale Supérieure, PSL University, Sorbonne Université, CNRS, 75005, Paris, France
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9
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Effect of alkali metal ions on water structure: insights into the pressure-like effect. Struct Chem 2022. [DOI: 10.1007/s11224-022-02101-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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10
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Zhang X, Li S, Su J. Enhanced Ion Rejection in Carbon Nanotubes by a Lateral Electric Field. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:10065-10074. [PMID: 35921520 DOI: 10.1021/acs.langmuir.2c01780] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Reverse osmosis membranes hold great promise for dealing with global water scarcity. However, the trade-off between ion selectivity and water permeability is a serious obstacle to desalination. Herein, we introduce an effective strategy to enhance the desalination performance of the membrane. A series of molecular dynamics simulations manifest that an additional lateral electric field significantly promotes ion rejection in carbon nanotubes (CNTs) under the drive of longitudinal pressure. Specifically, with the increase in the electric field, the ion flux shows a deep linear decay, while the water flux decreases only slightly, resulting in a linear increase in ion rejection. The energy barriers of ions around the CNT inlet are obtained by calculating the potentials of mean force to explain enhanced ion rejection. The lateral electric field uniformly raises the energy barriers of ions by pushing them away from the CNT inlet, corresponding to the enhanced ion velocity in the field direction. Furthermore, with the increase in CNT diameter, there is a significant increase in the flux of both ions and water; however, the lateral electric field can also obviously enhance the ion rejection in wider CNTs. Consequently, the enhancement of ion rejection by lateral electric fields should be universal for different CNT diameters, which opens a new avenue for selective permeation and may have broad implications for desalination devices with large pore sizes.
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11
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Zhang X, Liu Y, Su J. Promoting Electroosmotic Water Flow through a Carbon Nanotube by Weakening the Competition between Cations and Anions in a Lateral Electric Field. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:3530-3539. [PMID: 35259293 DOI: 10.1021/acs.langmuir.1c03473] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Understanding the electroosmotic flow through a nanochannel is essential to the design of novel nanofluidic devices, ranging from desalination to nanometer water pumps. Nonetheless, the competition between cation and anion in electric fields inevitably leads to a limited pumping of water, and thus weakening their competition could be a new avenue for the fundamental control of water transport. In this work, through a series of molecular dynamics simulations, we find a surprising phenomenon in which under the drive of a traditional longitudinal electric field, an additional lateral electric field can significantly weaken the competitive transport of a cation and anion through a carbon nanotube, which spontaneously leads to a massive increase in electroosmotic water flux. Specifically, with the increase in the lateral electric field, the anion flux exhibits an almost linear reduction, and the cation flux is stable and can even be enhanced. As a result, the net water flux along the cation direction increases significantly. The key to this unexpected phenomenon lies in the size and mobility difference between the cation and anion. The anion is larger and has greater mobility and is thus more susceptible to the lateral electric field, which ultimately leads to the reduction of its flux. For different ion types and CNT lengths, we can observe similar electropumping phenomenon, where the friction force induced by the lateral electric field becomes nontrivial for long CNTs. Our results provide a new route to tune the competitive transport of cations and anions and should be useful for the design of novel electroosmotic pumps.
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12
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Ding C, Zhao Y, Su J. Electropumping Phenomenon in Modified Carbon Nanotubes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:12318-12326. [PMID: 34644087 DOI: 10.1021/acs.langmuir.1c01793] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Controlling the water transport in a given direction is essential to the design of novel nanofluidic devices, which is still a challenge because of thermal fluctuations on the nanoscale. In this work, we find an interesting electropumping phenomenon for charge-modified carbon nanotubes (CNTs) through a series of molecular dynamics simulations. In electric fields, the flowing counterions on the CNT inner surface provide a direct driving force for water conduction. Specifically, the dynamics of cations and anions exhibit distinct behaviors that lead to thoroughly different water dynamics in positively and negatively charged CNTs. Because of the competition between the increased ion number and ion-CNT interaction, the cation flux displays an interesting maximum behavior with the increase in surface charge density; however, the anion flux rises further at higher charge density because it is less attractive to the surface. Thus, the anion flux is always several times larger than cation flux that induces a higher water flux in positive CNTs with nearly 100% pumping efficiency, which highly exceeds the efficiency of pristine CNTs. With the change in charge density, the translocation time, occupancy number, and radial density profiles for water and ions also demonstrate a nontrivial difference for positive and negative CNTs. Furthermore, the ion flux exhibits an excellent linear relationship with the field strength, leading to the same water flux behavior. For the change in salt concentration, the pumping efficiency for positive CNTs is also nearly 100%. Our results provide significant new insight into the ionic transport through modified CNTs and should be helpful for the design of nanometer water pumps.
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13
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Li S, Zhao Y, Zhang X, Ding C, Su J. Rectification Correlation between Water and Ions through Asymmetric Graphene Channels. J Phys Chem B 2021; 125:11232-11241. [PMID: 34597047 DOI: 10.1021/acs.jpcb.1c05255] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Rectification phenomena occurring in asymmetric channels are essential for the design of novel nanofluidic devices such as nanodiodes. Previous studies mostly focus on ion current rectification, while its correlations with water dynamics are rarely explored. In this work, we analyze the transport of water and ions through asymmetric graphene channels under the drive of electric fields using molecular dynamics simulations. A key observation is that the water flux also exists in the rectification phenomenon that follows the ion flux behaviors because of their dynamical coupling relation in electric fields, and both their rectification ratios exhibit maximum behaviors with the change of the channel opening ratio. This is because the ion dehydration is highly asymmetric for small opening ratios. In addition, the cations and anions have distinct rectification ratios that are strongly dependent on the field strength, where the values for anions can even be 1-2 orders larger. This can be attributed to their different hydration shell and dehydration processes in the graphene channel. The translocation time of ions displays a power law relation with the field strength, in agreement with the prediction by Langevin dynamics. Due to the exclude-volume effect, the occupancy of water and ions shows a clear competition and thus changes in an opposite trend with the field strength. Our results demonstrate the rectification correlations between water and ions, and tuning the geometry of graphene channels provides a simple and robust new route to achieve high rectification ratios.
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Affiliation(s)
- Shuang Li
- Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Yunzhen Zhao
- Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Xinke Zhang
- Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Chuxuan Ding
- Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Jiaye Su
- Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.,MIIT Key Laboratory of Semiconductor Microstructure and Quantum Sensing, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
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14
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Wang M, Liu S, Ji H, Yang T, Qian T, Yan C. Salting-out effect promoting highly efficient ambient ammonia synthesis. Nat Commun 2021; 12:3198. [PMID: 34045462 PMCID: PMC8160333 DOI: 10.1038/s41467-021-23360-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2020] [Accepted: 04/18/2021] [Indexed: 02/04/2023] Open
Abstract
The electroreduction of nitrogen to ammonia offers a promising alternative to the energy-intensive Haber-Bosch process. Unfortunately, the reaction suffers from low activity and selectivity, owing to competing hydrogen evolution and the poor accessibility of nitrogen to the electrocatalyst. Here, we report that deliberately triggering a salting-out effect in a highly concentrated electrolyte can simultaneously tackle the above challenges and achieve highly efficient ammonia synthesis. The solute ions exhibit strong affinity for the surrounding H2O molecules, forming a hydration shell and limiting their efficacy as both proton sources and solvents. This not only effectively suppresses hydrogen evolution but also ensures considerable nitrogen flux at the reaction interface via heterogeneous nucleation of the precipitate, thus facilitating the subsequent reduction process in terms of both selectivity and activity. As expected, even when assembled with a metal-free electrocatalyst, a high Faradaic efficiency of 71 ± 1.9% is achieved with this proof-of-concept system.
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Affiliation(s)
- Mengfan Wang
- grid.263761.70000 0001 0198 0694College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou, China
| | - Sisi Liu
- grid.263761.70000 0001 0198 0694College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou, China
| | - Haoqing Ji
- grid.263761.70000 0001 0198 0694College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou, China
| | - Tingzhou Yang
- grid.263761.70000 0001 0198 0694College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou, China
| | - Tao Qian
- grid.263761.70000 0001 0198 0694College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou, China ,grid.260483.b0000 0000 9530 8833School of Chemistry and Chemical Engineering, Nantong University, Nantong, China
| | - Chenglin Yan
- grid.263761.70000 0001 0198 0694College of Energy, Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu Province, Soochow University, Suzhou, China
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15
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Salman S, Zhao Y, Zhang X, Su J. Effect of temperature on the coupling transport of water and ions through a carbon nanotube in an electric field. J Chem Phys 2020; 153:184503. [PMID: 33187400 DOI: 10.1063/5.0028077] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Temperature governs the motion of molecules at the nanoscale and thus should play an essential role in determining the transport of water and ions through a nanochannel, which is still poorly understood. This work devotes to revealing the temperature effect on the coupling transport of water and ions through a carbon nanotube by molecular dynamics simulations. A fascinating finding is that the ion flux order changes from cation > anion to anion > cation with the increase in field strength, leading to the same direction change of water flux. The competition between ion hydration strength and mobility should be a partial reason for this ion flux order transition. High temperatures significantly promote the transport of water and ions, stabilize the water flux direction, and enhance the critical field strength. The ion translocation time exhibits an excellent Arrhenius relation with the temperature and a power law relation with the field strength, yielding to the Langevin dynamics. However, because of self-diffusion, the water translocation time displays different behaviors without following the ions. The high temperature also leads to an abnormal maximum behavior of the ion flux, deciphered by the massive increase in water flow that inversely hinders the ion flux, suggesting the coexistence of water-ion coupling transport and competition. Our results shed deep light on the temperature dependence of coupling transport of water and ions, answering a fundamental question on the water flux direction during the ionic transport, and thus should have great implications in the design of high flux nanofluidic devices.
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Affiliation(s)
- Shabbir Salman
- Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Yunzhen Zhao
- Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Xingke Zhang
- Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
| | - Jiaye Su
- Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China
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16
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Banerjee P, Bagchi B. Role of local order in anomalous ion diffusion: Interrogation through tetrahedral entropy of aqueous solvation shells. J Chem Phys 2020; 153:154505. [PMID: 33092370 DOI: 10.1063/5.0022580] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Small rigid ions perturb the water structure around them significantly. At constant viscosity, alkali cations (Li+, Na+, and so on) exhibit an anomalous non-monotonic dependence of diffusivity on ion-size, in stark violation of the Stokes-Einstein expression. Although this is a well-known problem, we find that an entropic view of the problem can be developed, which provides valuable insight. The local entropy experienced by the solute ion is relevant here, which leads to the connection with local viscosity, discussed earlier by many. Due to the strong interactions with ions, the translational and rotational entropy of solvation water decreases sharply; however, an opposite effect comes from the disruption of the tetrahedral network structure of water near the charges. We compute the tetrahedral order of water molecules (qtet) around the ion and suitably defined tetrahedral entropy [S(qtet)] that is a contribution to the excess entropy of the system. Our results reveal that although the structural properties of the second shell become nearly identical to the bulk, S(qtet) of the second shell is found to play an important role in giving rise to the non-monotonic ion-size dependence. The detailed study of the static and dynamic fluctuations in qtet and the number of hydration water molecules provides interesting insights into correlation between the structure and dynamics; the smallest static fluctuation of qtet for the first hydration shell water molecules of Li+ is indicative of the iceberg picture. The study of fluctuation properties of qtet and the coordination number also reveals the role of the second hydration layer and could explain the anomalous behavior of the Rb+ ion.
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Affiliation(s)
- Puja Banerjee
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
| | - Biman Bagchi
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012, India
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17
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Abal JPK, Bordin JR, Barbosa MC. Salt parameterization can drastically affect the results from classical atomistic simulations of water desalination by MoS 2 nanopores. Phys Chem Chem Phys 2020; 22:11053-11061. [PMID: 32373906 DOI: 10.1039/d0cp00484g] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Water scarcity is a reality in our world, and scenarios predicted by leading scientists in this area indicate that it will worsen in the next decades. However, new technologies based on low-cost seawater desalination can prevent the worst scenarios, providing fresh water for humanity. With this goal, membranes based on nanoporous materials have been suggested in recent years. One of the materials suggested is MoS2, and classical Molecular Dynamics (MD) simulation is one of the most powerful tools to explore these nanomaterials. However, distinct force fields employed in MD simulations are parameterized based on distinct experimental quantities. In this paper, we compare two models of salt that were built based on distinct properties of water-salt mixtures. One model fits the hydration free energy and lattice properties, and the second fits the crystal density and the density and the dielectric constant of water and salt mixtures. To compare the models, MD simulations for salty water flow through nanopores of two sizes were used - one pore big enough to accommodate hydrated ions, and one smaller in which the ion has to dehydrate to enter - and two rigid water models from the TIP4P family - TIP4P/2005 and TIP4P/ε. Our results indicate that the water permeability and salt rejection by the membrane are more influenced by the salt model than by the water model, especially for the narrow pore. In fact, completely distinct mechanisms were observed, and they are related to the characteristics employed in the ion model parameterization. The results show that not only can the water model influence the outcomes, but the ion model plays a crucial role when the pore is small enough.
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Affiliation(s)
- João P K Abal
- Institute of Physics, Federal University of Rio Grande do Sul, 91501-970, Porto Alegre, Brazil.
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18
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Effects of hexamethylenetetramine (HMTA) on the aqueous solution structure, dynamics and ion solvation scenario: A concentration and temperature dependent study with potential HMTA models. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.111820] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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19
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Guo Z, Wang T, Wei H, Long Y, Yang C, Wang D, Lang J, Huang K, Hussain N, Song C, Guan B, Ge B, Zhang Q, Wu H. Ice as Solid Electrolyte To Conduct Various Kinds of Ions. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201907832] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Zeliang Guo
- State Key Lab of New Ceramics and Fine ProcessingSchool of Materials Science and EngineeringTsinghua University Beijing 100084 China
| | - Tianshuai Wang
- School of Materials Science and EngineeringBeihang University Beijing 100191 China
| | - Hehe Wei
- State Key Lab of New Ceramics and Fine ProcessingSchool of Materials Science and EngineeringTsinghua University Beijing 100084 China
| | - Yuanzheng Long
- State Key Lab of New Ceramics and Fine ProcessingSchool of Materials Science and EngineeringTsinghua University Beijing 100084 China
| | - Cheng Yang
- State Key Lab of New Ceramics and Fine ProcessingSchool of Materials Science and EngineeringTsinghua University Beijing 100084 China
| | - Dong Wang
- State Key Lab of New Ceramics and Fine ProcessingSchool of Materials Science and EngineeringTsinghua University Beijing 100084 China
| | - Jialiang Lang
- State Key Lab of New Ceramics and Fine ProcessingSchool of Materials Science and EngineeringTsinghua University Beijing 100084 China
| | - Kai Huang
- State Key Lab of New Ceramics and Fine ProcessingSchool of Materials Science and EngineeringTsinghua University Beijing 100084 China
| | - Naveed Hussain
- State Key Lab of New Ceramics and Fine ProcessingSchool of Materials Science and EngineeringTsinghua University Beijing 100084 China
| | - Chenxi Song
- State Key Lab of New Ceramics and Fine ProcessingSchool of Materials Science and EngineeringTsinghua University Beijing 100084 China
| | - Bo Guan
- Institute of ChemistryChinese Academy of Sciences 100190 Beijing China
| | - Binghui Ge
- Beijing National Laboratory for Condensed Matter PhysicsInstitute of PhysicsChinese Academy of Sciences 100190 Beijing China
| | - Qianfan Zhang
- School of Materials Science and EngineeringBeihang University Beijing 100191 China
| | - Hui Wu
- State Key Lab of New Ceramics and Fine ProcessingSchool of Materials Science and EngineeringTsinghua University Beijing 100084 China
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20
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Guo Z, Wang T, Wei H, Long Y, Yang C, Wang D, Lang J, Huang K, Hussain N, Song C, Guan B, Ge B, Zhang Q, Wu H. Ice as Solid Electrolyte To Conduct Various Kinds of Ions. Angew Chem Int Ed Engl 2019; 58:12569-12573. [PMID: 31267652 DOI: 10.1002/anie.201907832] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Indexed: 12/21/2022]
Abstract
Water, considered as a universal solvent to dissolve salts, has been extensively studied as liquid electrolyte in electrochemical devices. The water/ice phase transition at around 0 °C presents a common phenomenon in nature, however, the chemical and electrochemical behaviors of ice have rarely been studied. Herein, we discovered that the ice phase provides efficient ionic transport channels and therefore can be applied as generalized solid-state ionic conductor. Solid state ionic conducting ices (ICIs) of Li+ , Na+ , Mg2+ , Al3+ , K+ , Mn2+ , Fe2+ , Co2+ , Ni2+ , Cu2+ , and Zn2+ , frozen from corresponding sulphate solutions, exhibit ionic conductivities ranging from ≈10-7 S cm-1 (Zn2+ ) to ≈10-3 S cm-1 (Li+ ) at temperatures spanning from -20 °C to -5 °C. The discovery of ICIs opens new insight to design and fabrication of solid-state electrolytes that are simple, inexpensive, and versatile.
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Affiliation(s)
- Zeliang Guo
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Tianshuai Wang
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Hehe Wei
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Yuanzheng Long
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Cheng Yang
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Dong Wang
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Jialiang Lang
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Kai Huang
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Naveed Hussain
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Chenxi Song
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
| | - Bo Guan
- Institute of Chemistry, Chinese Academy of Sciences, 100190, Beijing, China
| | - Binghui Ge
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, 100190, Beijing, China
| | - Qianfan Zhang
- School of Materials Science and Engineering, Beihang University, Beijing, 100191, China
| | - Hui Wu
- State Key Lab of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China
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21
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Su Z, Chen J, Zhao Y, Su J. How ions block the single-file water transport through a carbon nanotube. Phys Chem Chem Phys 2019; 21:11298-11305. [PMID: 31106311 DOI: 10.1039/c9cp01714c] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Understanding the blockage of ions for water transport through nanochannels is crucial for the design of desalination nanofluidic devices. In this work, we systematically clarify how ions block the single-file water transport through a (6,6) carbon nanotube (CNT) by using molecular dynamics simulations. We consider various pressure differences and salt concentrations. With the increase of pressure difference, the water flux shows a linear growth that coincides with the Hagen-Poiseuille equation. Interestingly, the dependence of the CNT-ion interaction on the salt concentration results in a distinct ion blockage effect that ultimately leads to water flux bifurcation. The water translocation time shows a power law decay with pressure, depending on the salt concentration. Furthermore, with the increase of salt concentration, the water flux shows a linear decay with a larger slope for higher pressure, while the water translocation time shows an opposite behavior. Therefore, the ions can not only block the water entering but also slow down the water motion inside the CNT. Notably, the probability of cations and anions appearing at the CNT entrance is quite similar, suggesting a similar blockage effect; however, anions show deeper interactions with the CNT because of their larger size. We finally find a unique linear relation between the water flux and occupancy divided by the translocation time. Our results provide insightful information on the ion blockage effect for the single-file water transport, and are thus helpful for the design of novel filtration membranes.
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Affiliation(s)
- Zhenglong Su
- Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.
| | - Jingyi Chen
- School of Material Science and Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, China
| | - Yunzhen Zhao
- Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.
| | - Jiaye Su
- Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, China.
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22
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Harada M, Okada T, Nakamura K, Saito S, Shibukawa M. Facilitated Dehydration of Rb
+
Ions in Cation‐Exchange Resin when Surrounded by Cs
+
Ions: A Marked Phenomenon in Superheated Water. ChemistrySelect 2019. [DOI: 10.1002/slct.201900388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Makoto Harada
- Department of ChemistryTokyo Institute of Technology, Meguro-ku Tokyo 152–8551 Japan
| | - Tetsuo Okada
- Department of ChemistryTokyo Institute of Technology, Meguro-ku Tokyo 152–8551 Japan
| | - Keisuke Nakamura
- Graduate School of Science and TechnologySaitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 Japan
| | - Shingo Saito
- Graduate School of Science and TechnologySaitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 Japan
| | - Masami Shibukawa
- Graduate School of Science and TechnologySaitama University, 255 Shimo-Okubo, Sakura-ku, Saitama 338-8570 Japan
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23
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24
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Chand A, Chettiyankandy P, Chowdhuri S. Behaviour of cis- and trans-N-methylformamide in liquid mixture: Dynamical properties at varying pressure and temperature, and ion solvation scenario. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.08.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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25
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Abstract
The design of a water pump, which has huge potential for applications in nanotechnology and daily life, is the dream of many scientists. In this paper, we successfully design a nanometer water pump by using molecular dynamics simulations. Ions of either sodium or chlorine in a narrow channel will generate electric current under electric fields, which then drives the water through a wider channel, similar to recent experimental setups. Considerable water flux is achieved within small field strengths that are accessible by experimentation. Of particular interest, is that for sodium the water flux increases almost linearly with field strengths; while for chlorine there exists a critical field strength, the water flux exhibits a plateau before the critical value and increases linearly after it. This result follows the behavior of ion velocity, which is related to friction behavior. We also estimate the power and energy consumption for such a pump, and compare it to the macroscopic mechanical pumps. A further comparison suggests that different ions will have different pumping abilities. This study not only provides new, significant results with possible connection to existing research, but has tremendous potential application in the design of nanofluidic devices.
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Affiliation(s)
- Jiaye Su
- Department of Applied Physics, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, People's Republic of China
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26
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Kumar P, Bharadwaj MD, Yashonath S. Effect of interionic interactions on the structure and dynamics of ionic solvation shells in aqueous electrolyte solutions. RSC Adv 2016. [DOI: 10.1039/c6ra26819f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Molecular dynamics (MD) simulations to explore the structure and dynamics of the ionic solvation shell of alkali ions and halide ions in aqueous solution.
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Affiliation(s)
- Parveen Kumar
- Center for Study of Science, Technology and Policy
- Bangalore-560094
- India
| | | | - S. Yashonath
- Solid Sate and Structural Chemistry Unit
- Indian Institute of Science
- Bangalore-560012
- India
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27
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Di Tommaso D, Ruiz-Agudo E, de Leeuw NH, Putnis A, Putnis CV. Modelling the effects of salt solutions on the hydration of calcium ions. Phys Chem Chem Phys 2015; 16:7772-85. [PMID: 24643252 DOI: 10.1039/c3cp54923b] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Classical molecular dynamics simulations of several aqueous alkali halide salt solutions have been used to determine the effect of electrolytes on the structure of water and the hydration properties of calcium ions. Compared with the simulations of Ca(2+) ions in pure liquid water, the frequency of water exchange in the first hydration shell of calcium, which is a fundamental process in controlling the reactivity of calcium(ii) aqua-ions, is drastically reduced in the presence of other electrolytes in solution. The strong stabilization of the hydration shell of Ca(2+) occurs not only when the halide anions are directly coordinated to calcium, but also when the alkali and halide ions are placed at or outside the second coordination shell of Ca(2+), suggesting that the reactivity of the first solvation shell of the calcium ion can be influenced by the specific affinity of other ions in solution for the water molecules coordinated to Ca(2+). Analysis of the hydrogen-bonded structure of water in the vicinity of the calcium ion shows that the average number of hydrogen bonds per water molecules, which is 1.8 in pure liquid water, decreases as the concentration of alkali-halide salts in solution increases, and that the temporal fluctuations of hydrogen bonds are significantly larger than those obtained for Ca(2+) in pure liquid water. This effect has been explained in terms of the dynamics of reorganization of the O-H···X(-) (X = F, Cl and Br) hydrogen bond. This work shows the importance of solution composition in determining the hydrogen-bonding network and ligand-exchange dynamics around metal ions, both in solution and at the mineral-water interfaces, which in turn has implications for interactions occurring at the mineral-water interface, ultimately controlling the mobilization of ions in the environment as well as in industrial processes.
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Affiliation(s)
- 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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28
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Bouazizi S, Nasr S. Concentration effects on aqueous lithium chloride solutions. Molecular dynamics simulations and x-ray scattering studies. J Mol Liq 2014. [DOI: 10.1016/j.molliq.2014.04.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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29
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Su J, Yang K, Guo H. Translocation of a nanoparticle through a fluidic channel: the role of grafted polymers. NANOTECHNOLOGY 2014; 25:185703. [PMID: 24736046 DOI: 10.1088/0957-4484/25/18/185703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The surface properties of nanoparticles (NPs) are key factors for their design and use in biomedicine; however, our understanding of the effect of surface properties on the translocation of NPs through membranes is still rather poor. Herein, we have used molecular dynamics simulations to study the translocation of a polymer-grafted NP through a fluidic channel. We change the length, number, amount of charge and the charge position of grafted polymers. With the increase of polymer length, the NP flux decreases as a whole due to the increase of NP size, where the -NP translocation fails at the smallest polymer length, because of the strong binding of Na(+). Surprisingly, the NP flux exhibits a maximum with the increase of the polymer number or charge amount, which is co-determined by the NP net charge and size. Owing to the NP-membrane adsorption and NP-ion binding, the NP flux decreases with the decrease of charge position. We also analyze the transport of counterions, which depends on both the NP-ion binding and NP dynamics. Finally, we investigate the effect of electric fields for a given NP type. Our results reveal the important role of grafted polymers in the NP translocation and may have implications in the design of highly efficient NP delivery.
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Affiliation(s)
- Jiaye Su
- Beijing National Laboratory for Molecular Sciences, Joint Laboratory of Polymer Sciences and Materials, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China
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30
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31
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Turchenkov DA, Boronovsky SE, Nartsissov YR. Model of ion diffusion in synaptic cleft based on stochastical integration of langevin equation at dielectric friction approximation. Biophysics (Nagoya-shi) 2013. [DOI: 10.1134/s0006350913060195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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32
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Su J, Guo H. Translocation of a Charged Nanoparticle Through a Fluidic Nanochannel: The Interplay of Nanoparticle and Ions. J Phys Chem B 2013; 117:11772-9. [DOI: 10.1021/jp406951s] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Jiaye Su
- Beijing National Laboratory
for Molecular
Sciences, Joint Laboratory of Polymer Sciences and Materials, State
Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Hongxia Guo
- Beijing National Laboratory
for Molecular
Sciences, Joint Laboratory of Polymer Sciences and Materials, State
Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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33
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Kumar P, Varanasi SR, Yashonath S. Relation Between the Diffusivity, Viscosity, and Ionic Radius of LiCl in Water, Methanol, and Ethylene Glycol: A Molecular Dynamics Simulation. J Phys Chem B 2013; 117:8196-208. [DOI: 10.1021/jp4036919] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Parveen Kumar
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560012 India
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34
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Affiliation(s)
- Liang Hao
- Beijing National
Laboratory for Molecular Sciences,
Joint Laboratory of Polymer Sciences and Materials, State Key Laboratory
of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jiaye Su
- Beijing National
Laboratory for Molecular Sciences,
Joint Laboratory of Polymer Sciences and Materials, State Key Laboratory
of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Hongxia Guo
- Beijing National
Laboratory for Molecular Sciences,
Joint Laboratory of Polymer Sciences and Materials, State Key Laboratory
of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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35
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Pressure effects on the dynamics of ions and solvent molecules in liquid methanol under ambient and cold conditions: Importance of solvent's H-bonding network. J Mol Liq 2013. [DOI: 10.1016/j.molliq.2013.01.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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36
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Shevkunov SV. Computer simulation of dissociative equilibrium in aqueous NaCl electrolyte with account for polarization and ion recharging. Model of interactions. RUSS J ELECTROCHEM+ 2013. [DOI: 10.1134/s1023193513030129] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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37
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Shevkunov SV. Computer simulation of dissociative equilibrium in aqueous NaCl electrolyte with account for polarization and ion recharging. Ionization mechanism. RUSS J ELECTROCHEM+ 2013. [DOI: 10.1134/s1023193513030130] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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38
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Zhang Q, Zhang X, Zhao DX. Ion disturbance and clustering in the NaCl water solutions. J Mol Model 2012; 19:661-72. [DOI: 10.1007/s00894-012-1581-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Accepted: 08/22/2012] [Indexed: 10/27/2022]
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39
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Pattanayak SK, Chowdhuri S. A molecular dynamics simulations study on the behavior of liquid N-methylacetamide in presence of NaCl: Structure, dynamics and H-bond properties. J Mol Liq 2012. [DOI: 10.1016/j.molliq.2012.05.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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40
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PATTANAYAK SUBRATKUMAR, CHOWDHURI SNEHASIS. SIZE DEPENDENCE OF SOLVATION STRUCTURE AND DYNAMICS OF IONS IN LIQUID N-METHYLACETAMIDE: A MOLECULAR DYNAMICS SIMULATION STUDY. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2012. [DOI: 10.1142/s0219633612500241] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The solvation structure and dynamics of alkali metal (Li+, Na+, K+, Rb+, Cs+) and halide (F-, Cl-, Br-, I-) ions in liquid N -methylacetamide (NMA) are calculated at two different temperatures T = 313 K and 453 K, by using classical molecular dynamics simulations. We have also considered [Formula: see text] and some larger cations such as I +, Me 4 N +, and Et4N+ in this study to investigate the size dependence solvation structure and dynamics of ions in liquid NMA. With the increase of ion size, the self-diffusion coefficients of cations are found to increase and the maximum is observed at Me4N+ , whereas for halide ions the increase of diffusion coefficient with ion size continues up to I- and no maximum is observed. However, the relative increase of the diffusion coefficients of larger ion compared to those of Li+ and F+ are found to be significantly higher at low temperature. Results are very good in agreement with experimental observation.
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Affiliation(s)
| | - SNEHASIS CHOWDHURI
- School of Basic Sciences, Indian Institute of Technology, Bhubaneswar 751013, India
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41
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Chakraborty D, Chandra A. Voids and necks in liquid ammonia and their roles in diffusion of ions of varying size. J Comput Chem 2012; 33:843-52. [DOI: 10.1002/jcc.22910] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 10/30/2011] [Accepted: 11/20/2011] [Indexed: 11/05/2022]
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42
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Su J, de la Cruz MO, Guo H. Solubility and transport of cationic and anionic patterned nanoparticles. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2012; 85:011504. [PMID: 22400574 DOI: 10.1103/physreve.85.011504] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 01/05/2012] [Indexed: 05/31/2023]
Abstract
We analyze bulk diffusion and transport through hydrophobic nanochannels of nanoparticles (NPs) with different hydrophobic-hydrophilic patterns achieved by coating a fraction of the NP sites with positive or negative charges via explicit solvent molecular dynamics simulations. Ten different charge pattern types including Janus charged-hydrophobic NPs are studied. The cationic NPs are more affected by the patterns and have higher diffusion constants and fluxes than their anionic NPs counterparts. The NP-water interaction dependence on surface pattern and field strength explains these observations. The NP-water Coulomb interaction of anionic NPs in the bulk, which are much stronger than the hydrophobic NP-water interactions, are stronger for NPs with higher localized charge, and stronger than in the cationic NPs counterparts. The diffusion and transport of anionic NPs such as proteins and protein charge ladders with the same total charge but different surface charge patterns are slowest for the highest localized charge pattern, which also adsorb strongest onto surfaces. Our model demonstrates the separation (by reverse osmosis, capillary electrophoresis, or chromatography) of cationic NPs, including proteins with equal net charge but different surface charge distributions.
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Affiliation(s)
- Jiaye Su
- Beijing National Laboratory for Molecular Sciences, Chinese Academy of Sciences, Beijing 100190, China
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Pattanayak SK, Chowdhuri S. Effect of Water on Solvation Structure and Dynamics of Ions in the Peptide Bond Environment: Importance of Hydrogen Bonding and Dynamics of the Solvents. J Phys Chem B 2011; 115:13241-52. [DOI: 10.1021/jp206027e] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Snehasis Chowdhuri
- School of Basic Sciences, Indian Institute of Technology, Bhubaneswar 751013, India
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44
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Chakraborty D, Chandra A. Diffusion of ions in supercritical water: Dependence on ion size and solvent density and roles of voids and necks. J Mol Liq 2011. [DOI: 10.1016/j.molliq.2011.05.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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45
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Understanding the role of ion interactions in soluble salt flotation with alkylammonium and alkylsulfate collectors. Adv Colloid Interface Sci 2011; 163:1-22. [PMID: 21353193 DOI: 10.1016/j.cis.2011.01.003] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2010] [Revised: 01/06/2011] [Accepted: 01/10/2011] [Indexed: 11/22/2022]
Abstract
There is anecdotal evidence for the significant effects of salt ions on the flotation separation of minerals using process water of high salt content. Examples include flotation of soluble salt minerals such as potash, trona and borax in brine solutions using alkylammonium and alkylsulfate collectors such as dodecylamine hydrochloride and sodium dodecylsulfate. Although some of the effects are expected, some do not seem to be encompassed by classical theories of colloid science. Several experimental and modeling techniques for determining solution viscosity, surface tension, bubble-particle attachment time, contact angle, and molecular dynamics simulation have been used to provide further information on air-solution and solid-solution interfacial phenomena, especially with respect to the interfacial water structure due to the presence of dissolved ions. In addition atomic force microscopy, and sum frequency generation vibrational spectroscopy have been used to provide further information on surface states. These studies indicate that the ion specificity effect is the most significant factor influencing flotation in brine solutions.
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46
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Corradini D, Gallo P, Rovere M. Structure and thermodynamics of supercooled aqueous solutions: Ionic solutes compared with water in a hydrophobic environment. J Mol Liq 2011. [DOI: 10.1016/j.molliq.2010.03.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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47
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Gallo P, Corradini D, Rovere M. Ion hydration and structural properties of water in aqueous solutions at normal and supercooled conditions: a test of the structure making and breaking concept. Phys Chem Chem Phys 2011; 13:19814-22. [DOI: 10.1039/c1cp22166c] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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48
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Corradini D, Gallo P, Rovere M. Molecular dynamics studies on the thermodynamics of supercooled sodium chloride aqueous solution at different concentrations. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:284104. [PMID: 21399276 DOI: 10.1088/0953-8984/22/28/284104] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In this paper we compare recent results obtained by means of molecular dynamics computer simulations on the thermodynamics of TIP4P bulk water and on solutions of sodium chloride in TIP4P water. The concentrations studied are c = 0.67, 1.36 and 2.10 mol kg( - 1). The results are checked against change of water-salt potential and size effects. The systems are studied in a wide range of temperatures, going from ambient temperature to the supercooled region. Analysis of simulated state points, performed on the isochores and on the isotherm plane, allowed the determination of the limit of mechanical stability and of the temperature of maximum density lines. While the presence of ions in the system does not affect the limit of mechanical stability with respect to the bulk, it causes the temperature of the maximum density line to shift to lower pressure and temperature upon increasing concentration. The occurrence of minima in the trend of potential energy as a function of density and the inflections in the low temperature isotherms suggest the presence of liquid-liquid coexistence for bulk water and for the sodium chloride solutions at all concentrations studied.
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Affiliation(s)
- D Corradini
- Dipartimento di Fisica, Università Roma Tre, Via della Vasca Navale 84, I-00146 Roma, Italy
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49
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Shevkunov SV. Nonpair interactions in Na+(H2O) n clusters under thermal fluctuation conditions. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2009. [DOI: 10.1134/s0036024409060181] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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50
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Corradini D, Gallo P, Rovere M. Effect of concentration on the thermodynamics of sodium chloride aqueous solutions in the supercooled regime. J Chem Phys 2009; 130:154511. [DOI: 10.1063/1.3119634] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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