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Li J, Zhu C, Zhao W, Gao Y, Bai J, Jiang J, Zeng XC. Formation of a two-dimensional helical square tube ice in hydrophobic nanoslit using the TIP5P water model. J Chem Phys 2024; 160:164716. [PMID: 38661200 DOI: 10.1063/5.0205343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 04/09/2024] [Indexed: 04/26/2024] Open
Abstract
In extreme and nanoconfinement conditions, the tetrahedral arrangement of water molecules is challenged, resulting in a rich and new phase behavior unseen in bulk phases. The unique phase behavior of water confined in hydrophobic nanoslits has been previously observed, such as the formation of a variety of two-dimensional (2D) ices below the freezing temperature. The primary identified 2D ice phase, termed square tube ice (STI), represents a unique arrangement of water molecules in 2D ice, which can be viewed as an array of 1D ice nanotubes stacked in the direction parallel to the confinement plane. In this study, we report the molecular dynamics (MD) simulations evidence of a novel 2D ice phase, namely, helical square tube ice (H-STI). H-STI is characterized by the stacking of helical ice nanotubes in the direction parallel to the confinement plane. Its structural specificity is evident in the presence of helical square ice nanotubes, a configuration unseen in both STI and single-walled ice nanotubes. A detailed analysis of the hydrogen bonding strength showed that H-STI is a 2D ice phase diverging from the Bernal-Fowler-Pauling ice rules by forming only two strong hydrogen bonds between adjacent molecules along its helical ice chain. This arrangement of strong hydrogen bonds along ice nanotube and weak bonds between the ice nanotube shows a similarity to quasi-one-dimensional van der Waals materials. Ab initio molecular dynamics simulations (over a 30 ps) were employed to further verify H-STI's stability at 1 GPa and temperature up to 200 K.
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Affiliation(s)
- Jiaxian Li
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - Chongqin Zhu
- College of Chemistry, Key Laboratory of Theoretical and Computational Photochemistry of Ministry of Education, Beijing Normal University, Beijing 100190, People's Republic of China
| | - Wenhui Zhao
- Department of Physics, School of Physical Science and Technology, Ningbo University, 818 Fenghua Road, Ningbo 315211, People's Republic of China
| | - Yurui Gao
- Laboratory of Theoretical and Computational Nanoscience, National Center for Nanoscience and Technology, Beijing 100190, People's Republic of China
| | - Jaeil Bai
- Department of Physics, University of Nebraska-Omaha, Omaha, Nebraska 68182, USA
| | - Jian Jiang
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
- Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong 999077, People's Republic of China
- Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518057, People's Republic of China
| | - Xiao Cheng Zeng
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
- Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong 999077, People's Republic of China
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2
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Agosta L, Arismendi-Arrieta D, Dzugutov M, Hermansson K. Origin of the Hydrophobic Behaviour of Hydrophilic CeO 2. Angew Chem Int Ed Engl 2023; 62:e202303910. [PMID: 37011105 DOI: 10.1002/anie.202303910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/02/2023] [Accepted: 04/03/2023] [Indexed: 04/05/2023]
Abstract
The nature of the hydrophobicity found in rare-earth oxides is intriguing. The CeO2 (100) surface, despite its strongly hydrophilic nature, exhibits hydrophobic behaviour when immersed in water. In order to understand this puzzling and counter-intuitive effect we performed a detailed analysis of the confined water structure and dynamics. We report here an ab-initio molecular dynamics simulation (AIMD) study which demonstrates that the first adsorbed water layer, in immediate contact with the hydroxylated CeO2 surface, generates a hydrophobic interface with respect to the rest of the liquid water. The hydrophobicity is manifested in several ways: a considerable diffusion enhancement of the confined liquid water as compared with bulk water at the same thermodynamic condition, a weak adhesion energy and few H-bonds above the hydrophobic water layer, which may also sustain a water droplet. These findings introduce a new concept in water/rare-earth oxide interfaces: hydrophobicity mediated by specific water patterns on a hydrophilic surface.
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Affiliation(s)
- Lorenzo Agosta
- Department of Chemistry-Ångström, Uppsala University, 751 21, Uppsala, Sweden
| | | | - Mikhail Dzugutov
- Department of Chemistry-Ångström, Uppsala University, 751 21, Uppsala, Sweden
| | - Kersti Hermansson
- Department of Chemistry-Ångström, Uppsala University, 751 21, Uppsala, Sweden
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3
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Deng L, Qiu H, Wang B, Guo Z. Adjustable high-speed and directional diffusion of water nanodroplets confined by graphene sheets. Phys Chem Chem Phys 2023; 25:4266-4275. [PMID: 36688339 DOI: 10.1039/d2cp03421b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Diffusion of confined water is important in nanofluidic and other water transport systems. In this study, the diffusion of water nanodroplets confined by graphene sheets is investigated based on molecular dynamics simulations. We find that the confined water nanodroplets can achieve a high-speed and directional motion. The impact of the size of water nanodroplets and distance of graphene sheets on diffusion is studied. The results show that the diffusion of confined water nanodroplets is adjustable and the speed is about 3 orders of magnitude faster than that of the self-diffusing water molecules in liquid water. Subsequently, the most suitable morphology of confined nanodroplets for rapid movement is found. We also find that the direction of diffusion of confined water nanodroplets is affected by the thermal vibrations of carbon atoms. Finally, the interaction energy and friction coefficient between confined nanodroplets and graphene sheets are analyzed to give an insight into the fast and directional diffusion behaviors of water nanodroplets. Our results reveal that a variation in the structure of interfacial water molecules with the distance of graphene sheets is the key to the rapid movement of confined water nanodroplets. The phenomena reported here can enrich the knowledge of molecular mechanisms for nanoconfined water systems, and may stimulate more ideas for the rapid removal of confined water.
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Affiliation(s)
- Lijun Deng
- School of Science, Harbin Institute of Technology, ShenZhen, 518055, China.
| | - Hai Qiu
- School of Mechanical Engineering, Jiangsu University of Science and Technology, ZhenJiang, 212003, China
| | - Ben Wang
- School of Science, Harbin Institute of Technology, ShenZhen, 518055, China.
| | - Zaoyang Guo
- School of Science, Harbin Institute of Technology, ShenZhen, 518055, China.
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4
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Fardis M, Karagianni M, Gkoura L, Papavassiliou G. Self-Diffusion in Confined Water: A Comparison between the Dynamics of Supercooled Water in Hydrophobic Carbon Nanotubes and Hydrophilic Porous Silica. Int J Mol Sci 2022; 23:ijms232214432. [PMID: 36430907 PMCID: PMC9697084 DOI: 10.3390/ijms232214432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 11/15/2022] [Accepted: 11/17/2022] [Indexed: 11/22/2022] Open
Abstract
Confined liquids are model systems for the study of the metastable supercooled state, especially for bulk water, in which the onset of crystallization below 230 K hinders the application of experimental techniques. Nevertheless, in addition to suppressing crystallization, confinement at the nanoscale drastically alters the properties of water. Evidently, the behavior of confined water depends critically on the nature of the confining environment and the interactions of confined water molecules with the confining matrix. A comparative study of the dynamics of water under hydrophobic and hydrophilic confinement could therefore help to clarify the underlying interactions. As we demonstrate in this work using a few representative results from the relevant literature, the accurate assessment of the translational mobility of water molecules, especially in the supercooled state, can unmistakably distinguish between the hydrophilic and hydrophobic nature of the confining environments. Among the numerous experimental methods currently available, we selected nuclear magnetic resonance (NMR) in a field gradient, which directly measures the macroscopic translational self-diffusion coefficient, and quasi-elastic neutron scattering (QENS), which can determine the microscopic translational dynamics of the water molecules. Dielectric relaxation, which probes the re-orientational degrees of freedom, are also discussed.
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5
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Ma N, Zhao X, Liang X, Zhu W, Sun Y, Zhao W, Zeng XC. Continuous and First-Order Liquid–Solid Phase Transitions in Two-Dimensional Water. J Phys Chem B 2022; 126:8892-8899. [DOI: 10.1021/acs.jpcb.2c05618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nan Ma
- Department of Physics, Ningbo University, Ningbo, Zhejiang 315211, China
| | - Xiaorong Zhao
- Department of Physics, Ningbo University, Ningbo, Zhejiang 315211, China
| | - Xiaoying Liang
- Department of Physics, Ningbo University, Ningbo, Zhejiang 315211, China
| | - Weiduo Zhu
- Department of Physics, Hefei University of Technology, Hefei, Anhui 230009, China
| | - Yunxiang Sun
- Department of Physics, Ningbo University, Ningbo, Zhejiang 315211, China
| | - Wenhui Zhao
- Department of Physics, Ningbo University, Ningbo, Zhejiang 315211, China
| | - Xiao Cheng Zeng
- Department of Materials Science & Engineering, City University of Hong Kong, Kowloon 999077, Hong Kong, China
- Department of Chemistry, University of Nebraska─Lincoln, Lincoln, Nebraska 68588, United States
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Tinti A, Camisasca G, Giacomello A. Structure and dynamics of water confined in cylindrical nanopores with varying hydrophobicity. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2021; 379:20200403. [PMID: 34455842 PMCID: PMC8403978 DOI: 10.1098/rsta.2020.0403] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 05/18/2021] [Indexed: 06/11/2023]
Abstract
We report a detailed study of the main structural and dynamical features of water confined in model Lennard-Jones nanopores with tunable hydrophobicity and finite length ([Formula: see text] Å). The generic model of cylindrical confinement used is able to reproduce the wetting features of a large class of technologically and biologically relevant systems spanning from crystalline nanoporous materials, to mesoporous silica and ion channels. The aim of this work is to discuss the influence of parameters such as wall hydrophobicity, temperature, and pore size on the structural and dynamical features of confined water. Our simulation campaign confirmed the existence of a core domain in which water displays bulk-like structural features even in extreme ([Formula: see text] Å) confinement, while dynamical properties were shown to depend non-trivially on the size and hydrophobicity of the pores. This article is part of the theme issue 'Progress in mesoscale methods for fluid dynamics simulation'.
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Affiliation(s)
- Antonio Tinti
- Dipartimento di Ingegneria Meccanica e Aerospaziale, Sapienza Università di Roma, Rome, Italy
| | - Gaia Camisasca
- Dipartimento di Matematica e Fisica, Università Roma Tre, Rome, Italy
| | - Alberto Giacomello
- Dipartimento di Ingegneria Meccanica e Aerospaziale, Sapienza Università di Roma, Rome, Italy
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Majumdar J, Moid M, Dasgupta C, Maiti PK. Dielectric Profile and Electromelting of a Monolayer of Water Confined in Graphene Slit Pore. J Phys Chem B 2021; 125:6670-6680. [PMID: 34107687 DOI: 10.1021/acs.jpcb.1c02266] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A monolayer of water confined between two parallel graphene sheets exists in many different phases and exhibits fascinating dielectric properties that have been studied in experiments. In this work, we use molecular dynamics simulations to study how the dielectric properties of a confined monolayer of water is affected by its structure. We consider six of the popular nonpolarizable water models-SPC/E, SPC/Fw, TIP3P, TIP3P_M (modified), TIP4P-2005, and TIP4P-2005f-and find that the in-plane structure of the water molecules at ambient temperature and pressure is strongly dependent on the water model: all the 3-point water models considered here show square ice formation, whereas no such structural ordering is observed for the 4-point water models. This allows us to investigate the role of the in-plane structure of the water monolayer on its dielectric profile. Our simulations show an anomalous perpendicular dielectric constant compared to the bulk, and the models that do not exhibit ice formation show very different dielectric response along the channel width compared to models that exhibit square ice formation. We also demonstrate the occurrence of electromelting of the in-plane ordered water under the application of a perpendicular electric field and find that the critical field for electromelting strongly depends on the water model. Together, we have shown the dependence of confined water properties on the different water structures that it may take when sandwiched between bilayer graphene. These remarkable properties of confined water can be exploited in various nanofluidic devices, artificial ion channels, and molecular sieving.
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Affiliation(s)
- Jeet Majumdar
- Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India
| | - Mohd Moid
- Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India
| | - Chandan Dasgupta
- Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India.,International Centre for Theoretical Sciences, Bangalore 560089, India
| | - Prabal K Maiti
- Centre for Condensed Matter Theory, Department of Physics, Indian Institute of Science, Bangalore 560012, India
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8
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Mohammed S, Asgar H, Benmore CJ, Gadikota G. Structure of ice confined in silica nanopores. Phys Chem Chem Phys 2021; 23:12706-12717. [PMID: 34037014 DOI: 10.1039/d1cp00686j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Observed anomalous thermodynamic properties of confined water such as deviations in the melting point and freezing point motivate the determination of the structure of confined water as a function of pore size and temperature. In this study, we investigate the dynamic evolution of the structure of confined ice in SBA-15 porous materials with pore diameters of 4 nm, 6 nm, and 8 nm at temperatures ranging from 183 K to 300 K using in operando Wide-Angle X-Ray Scattering (WAXS) measurements, X-Ray Partial Distribution Function (PDF) measurements, and classical Molecular Dynamics (MD) simulations. Formation of hexagonal ice structures is noted in all the three pore sizes. In silica nanopores with diameters of 4 nm, cubic ice formation is noted in addition to hexagonal ice. Longer lasting hydrogen bonds and longer residence times of the water molecules in the first coordination shell contribute to observed crystalline organization of ice in confinement. Self-diffusion coefficients of confined liquid water, predicted from classical MD simulations, are four orders of magnitude higher compared to ice formed in confinement. These experimental and simulation results provide comprehensive insights underlying the organization of confined water and ice in silica nanopores and the underlying physico-chemical interactions that contribute to the observed structures.
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Affiliation(s)
- Sohaib Mohammed
- School of Civil and Environmental Engineering, Cornell University, Ithaca, New York 14853, USA.
| | - Hassnain Asgar
- School of Civil and Environmental Engineering, Cornell University, Ithaca, New York 14853, USA.
| | - Chris J Benmore
- Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA
| | - Greeshma Gadikota
- School of Civil and Environmental Engineering, Cornell University, Ithaca, New York 14853, USA.
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9
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Both AK, Gao Y, Zeng XC, Cheung CL. Gas hydrates in confined space of nanoporous materials: new frontier in gas storage technology. NANOSCALE 2021; 13:7447-7470. [PMID: 33876814 DOI: 10.1039/d1nr00751c] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Gas hydrates (clathrate hydrates, clathrates, or hydrates) are crystalline inclusion compounds composed of water and gas molecules. Methane hydrates, the most well-known gas hydrates, are considered a menace in flow assurance. However, they have also been hailed as an alternative energy resource because of their high methane storage capacity. Since the formation of gas hydrates generally requires extreme conditions, developing porous material hosts to synthesize gas hydrates with less-demanding constraints is a topic of great interest to the materials and energy science communities. Though reports of modeling and experimental analysis of bulk gas hydrates are plentiful in the literature, reliable phase data for gas hydrates within confined spaces of nanoporous media have been sporadic. This review examines recent studies of both experiments and theoretical modeling of gas hydrates within four categories of nanoporous material hosts that include porous carbons, metal-organic frameworks, graphene nanoslits, and carbon nanotubes. We identify challenges associated with these porous systems and discuss the prospects of gas hydrates in confined space for potential applications.
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Affiliation(s)
- Avinash Kumar Both
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA.
| | - Yurui Gao
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA.
| | - Xiao Cheng Zeng
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA.
| | - Chin Li Cheung
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA.
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10
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Goswami A, Singh JK. A hybrid topological and shape-matching approach for structure analysis. J Chem Phys 2021; 154:154502. [DOI: 10.1063/5.0046419] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Affiliation(s)
- Amrita Goswami
- Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India
| | - Jayant K. Singh
- Department of Chemical Engineering, Indian Institute of Technology Kanpur, Kanpur 208016, India
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11
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Contrasting thermally-induced structural and microstructural evolution of alumino-silicates with tubular and planar arrangements: Case study of halloysite and kaolinite. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2020.126106] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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12
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Cobeña-Reyes J, Sahimi M. Rheology of water in small nanotubes. Phys Rev E 2020; 102:023106. [PMID: 32942370 DOI: 10.1103/physreve.102.023106] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2020] [Accepted: 07/20/2020] [Indexed: 11/07/2022]
Abstract
The properties of water in confinement are very different from those under bulk conditions. In some cases the melting point of ice may be shifted and one may find either ice, icelike water, or a state in which freezing is completely inhibited. Understanding the dynamics and rheology of water in confined media, such as small nanotubes, is of fundamental importance to the biological properties of micro-organisms at low temperatures, to the development of new devices for preserving DNA samples, and for other biological materials and fluids, lubrication, and development of nanostructured materials. We study rheology and dynamics of water in small nanotubes using extensive equilibrium and nonequilibrium molecular dynamics simulations. The results demonstrate that in strong confinement in nanotubes at temperatures significantly below and above bulk freezing temperature water behaves as a shear-thinning fluid at shear rates smaller than the inverse of the relaxation time in the confined medium. In addition, our results indicate the presence of regions in which the local density of water varies significantly over the same range of temperature in the nanotube. These findings may also have important implications for the design of nanofluidic systems.
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Affiliation(s)
- Jose Cobeña-Reyes
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-1211, USA
| | - M Sahimi
- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, California 90089-1211, USA
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13
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Ghorbanfekr H, Behler J, Peeters FM. Insights into Water Permeation through hBN Nanocapillaries by Ab Initio Machine Learning Molecular Dynamics Simulations. J Phys Chem Lett 2020; 11:7363-7370. [PMID: 32787306 DOI: 10.1021/acs.jpclett.0c01739] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Water permeation between stacked layers of hBN sheets forming 2D nanochannels is investigated using large-scale ab initio-quality molecular dynamics simulations. A high-dimensional neural network potential trained on density-functional theory calculations is employed. We simulate water in van der Waals nanocapillaries and study the impact of nanometric confinement on the structure and dynamics of water using both equilibrium and nonequilibrium methods. At an interlayer distance of 10.2 Å confinement induces a first-order phase transition resulting in a well-defined AA-stacked bilayer of hexagonal ice. In contrast, for h < 9 Å, the 2D water monolayer consists of a mixture of different locally ordered patterns of squares, pentagons, and hexagons. We found a significant change in the transport properties of confined water, particularly for monolayer water where the water-solid friction coefficient decreases to half and the diffusion coefficient increases by a factor of 4 as compared to bulk water. Accordingly, the slip-velocity is found to increase under confinement and we found that the overall permeation is dominated by monolayer water adjacent to the hBN membranes at extreme confinements. We conclude that monolayer water in addition to bilayer ice has a major contribution to water transport through 2D nanochannels.
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Affiliation(s)
- Hossein Ghorbanfekr
- Data Science Hub, Flemish Institute for Technological Research (VITO), Boeretang 200, 2400 Mol, Belgium
- Departement Fysica, Universiteit Antwerpen,, Groenenborgerlaan 171, Antwerpen B-2020, Belgium
| | - Jörg Behler
- Institut für Physikalische Chemie, Theoretische Chemie, Universität Göttingen, Tammannstrasse 6, 37077 Göttingen, Germany
| | - François M Peeters
- Departement Fysica, Universiteit Antwerpen,, Groenenborgerlaan 171, Antwerpen B-2020, Belgium
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14
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Tran TH, Phan GTT, Luc HT, Nguyen PT, Hoang H. Molecular dynamics simulations on aqueous solution confined in charged nanochannels: asymmetric effect of surface charge. MOLECULAR SIMULATION 2020. [DOI: 10.1080/08927022.2020.1773459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- Thi Ha Tran
- Laboratory of Advanced Materials Chemistry, Advanced Institute of Materials Science, Ton Duc Thang University, Ho Chi Minh City, Vietnam
- Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - Giang T. T. Phan
- Institute of Fundamental and Applied Sciences, Duy Tan University, Vietnam
- Faculty of Natural Sciences, Duy Tan University, Danang, Vietnam
| | - Han Tuong Luc
- Institute of Fundamental and Applied Sciences, Duy Tan University, Vietnam
- Faculty of Natural Sciences, Duy Tan University, Danang, Vietnam
| | - Phuoc The Nguyen
- Faculty of Natural Sciences, Duy Tan University, Danang, Vietnam
| | - Hai Hoang
- Institute of Fundamental and Applied Sciences, Duy Tan University, Vietnam
- Faculty of Natural Sciences, Duy Tan University, Danang, Vietnam
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15
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Water in confinement of epoxy layer and hydroxylated (001) γ-alumina: An atomistic simulation view. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.112976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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16
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Li F, Korotkin IA, Karabasov SA. Rheology of Water Flows Confined between Multilayer Graphene Walls. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:5633-5646. [PMID: 32370511 DOI: 10.1021/acs.langmuir.0c01049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Water confined by hydrophilic materials shows unique transport properties compared to bulk water, thereby offering new opportunities for the development of nanofluidic devices. Recent experimental and numerical studies showed that nanoconfined water undergoes liquid- to solid-phase-like transitions depending on the degree of confinement. In the case of water confined by graphene layers, the van der Waals forces are known to deform the graphene layers, whose bending leads to further nonuniform confinement effects. Despite the extensive studies of nanoconfined water under equilibrium conditions, the interplay between the confinement and rheological water properties, such as viscosity, slip length, and normal stress differences under shear flow conditions, is poorly understood. The current investigation uses a validated all-atom nonequilibrium molecular dynamics model to simultaneously analyze the continuum transport and atomistic structural properties of water in a slit between two moving graphene walls under Couette flow conditions. A range of different slit widths and velocity strain rates are considered. It is shown that under subnanometer confinement, water loses the rotational symmetry of a Newtonian fluid. Under such conditions, water transforms into ice, where the atomistic structure is completely insensitive to the applied shear force and behaves like a frozen slab sliding between the graphene walls. This leads to the shear viscosity increase, although it is not as dramatic as the normal force increase that contributes to the increased friction force reported in previous experimental studies. On the other end of the spectrum, for flows at large velocity strain rates in moderate to large slits between the graphene walls, water is in the liquid state and reveals shear thinning behavior. In this case, water exhibits a constant slip length on the wall, which is typical of liquids in the vicinity of hydrophobic surfaces.
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Affiliation(s)
- F Li
- The School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, E1 4NS London, United Kingdom
| | - I A Korotkin
- The School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, E1 4NS London, United Kingdom
- Mathematical Sciences, University of Southampton, University Road, SO17 1BJ Southampton, United Kingdom
| | - S A Karabasov
- The School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, E1 4NS London, United Kingdom
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17
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Xiang Z, Tang C, Chang C, Liu G. A primary model of THz and far-infrared signal generation and conduction in neuron systems based on the hypothesis of the ordered phase of water molecules on the neuron surface I: signal characteristics. Sci Bull (Beijing) 2020; 65:308-317. [PMID: 36659096 DOI: 10.1016/j.scib.2019.12.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 09/25/2019] [Accepted: 11/08/2019] [Indexed: 01/21/2023]
Abstract
In this paper, we use the theory of quantum optics and electrodynamics to study the electromagnetic field problem in the nervous system based on the assumption of an ordered arrangement of water molecules on the neuronal surface. Using the Lagrangian of the water molecule-field ion, the dynamic equations for neural signal generation and transmission are derived. Perturbation theory and the numerical method are used to solve the dynamic equations, and the characteristics of high-frequency signals (the dispersion relation, the time domain of the field, the frequency domain waveform, etc.) are discussed. This model predicts some intrinsic vibration modes of electromagnetic radiation on the neuronal surface. The frequency range of these vibration modes is in the THz and far-infrared ranges.
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Affiliation(s)
- Zuoxian Xiang
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China; Innovation Laboratory of Terahertz Biophysics, National Innovation Institute of Defense Technology, Beijing 100071, China
| | - Chuanxiang Tang
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
| | - Chao Chang
- Innovation Laboratory of Terahertz Biophysics, National Innovation Institute of Defense Technology, Beijing 100071, China.
| | - Guozhi Liu
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China.
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18
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Asgar H, Semeykina V, Hunt M, Mohammed S, Kuzmenko I, Zharov I, Gadikota G. Thermally-Induced morphological evolution of spherical silica nanoparticles using in-operando X-ray scattering measurements. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2019.124260] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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19
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Goswami A, Singh JK. A general topological network criterion for exploring the structure of icy nanoribbons and monolayers. Phys Chem Chem Phys 2020; 22:3800-3808. [DOI: 10.1039/c9cp04902a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We develop intuitive metrics for quantifying complex nucleating systems under confinement.
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Affiliation(s)
- Amrita Goswami
- Department of Chemical Engineering
- Indian Institute of Technology Kanpur
- India
| | - Jayant K. Singh
- Department of Chemical Engineering
- Indian Institute of Technology Kanpur
- India
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20
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Ghosh K, Krishnamurthy CV. Frenkel line crossover of confined supercritical fluids. Sci Rep 2019; 9:14872. [PMID: 31619694 PMCID: PMC6795815 DOI: 10.1038/s41598-019-49574-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Accepted: 08/28/2019] [Indexed: 11/09/2022] Open
Abstract
We investigate the temperature evolution of dynamics and structure of partially confined Lennard Jones (LJ) fluids in supercritical phase along an isobaric line in the P-T phase diagram using molecular dynamics simulations. We compare the Frenkel line (FL) crossover features of partially confined LJ fluids to that of the bulk LJ fluids in supercritical phase. Five different spacings have been chosen in this study and the FL crossover characteristics have been monitored for each of these spacings for temperatures ranging from 240 K to 1500 K keeping the pressure fixed at 5000 bar. We characterize the FL crossover using density of states (DoS) function and find that partially confined supercritical fluids (SCF) exhibit a progressive shift of FL crossover point to higher temperatures for smaller spacings. While the DoS perpendicular to the walls shows persistent oscillatory modes, the parallel component exhibits a smooth crossover from an oscillatory to non-oscillatory characteristics representative of FL crossover. We find that the vanishing of peaks in DoS parallel to the walls indicates that the SCF no longer supports shear mode excitations and could serve as an identifier of the FL crossover for confined systems just as is done for the bulk. Layer heights of density profiles, self-diffusivity and the peak heights of radial distribution function parallel to the walls also feature the FL crossover consistent with the DoS criteria. Surprisingly, self-diffusivity undergoes an Arrhenius to super-Arrhenius crossover at low temperatures for smaller spacings as a result of enhanced structural order evidenced via pair-excess entropy. This feature, typical of glass-forming liquids and binary supercooled liquids, is found to develop from the glass-like characteristic slowdown and strong caging in confined supercritical fluid, evidenced via mean squared displacement and velocity autocorrelation function respectively, over intermediate timescales.
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Affiliation(s)
- Kanka Ghosh
- Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India.
| | - C V Krishnamurthy
- Department of Physics, Indian Institute of Technology Madras, Chennai, 600036, India
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21
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Li S, Schmidt B. Replica exchange MD simulations of two-dimensional water in graphene nanocapillaries: rhombic versus square structures, proton ordering, and phase transitions. Phys Chem Chem Phys 2019; 21:17640-17654. [PMID: 31364628 DOI: 10.1039/c9cp00849g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The hydrogen bond patterns, proton ordering, and phase transitions of monolayer ice in two-dimensional hydrophobic confinement are fundamentally different from those found for bulk ice. To investigate the behavior of quasi-2D ice, we perform molecular dynamics simulations of water confined between fixed graphene plates at a distance of 0.65 nm. While experimental results are still limited and theoretical investigations are often based on a single, often empirically based force field model, this work presents a systematic study modeling the water-graphene interaction by effective Lennard-Jones potentials previously derived from high-level ab initio CCSD(T) calculations of water adsorbed on graphene [Phys. Chem. Chem. Phys., 2013, 15, 4995]. For the water-water interaction different water force fields, i.e. SPCE, TIP3P, TIP4P, TIP4P/ICE, and TIP5P, are used. The water occupancy of the graphene capillary at a pressure of 1000 MPa is determined to be between 13.5 and 13.9 water molecules per square nanometer, depending on the choice of the water force field. Based on these densities, we explore the structure and dynamics of quasi-2D water for temperatures ranging from 200 K to about 600 K for each of the five force fields. To ensure complete sampling of the configurational space and to overcome the barriers separating metastable structures, these simulations are based on the replica exchange molecular dynamics technique. We report different tetragonal hydrogen bond patterns, which are classified as nearly square or as rhombic. While many of these arrangements are essentially flat, in some cases puckered arrangements are found, too. Also the proton ordering of the quasi-2D water structures is considered, allowing us to identify them as ferroelectric, ferrielectric or antiferroelectric. For temperatures between 200 K and 400 K we find several second-order phase transitions from one ice structure to another, changing in many cases both the arrangements of the oxygen atoms and the proton ordering. For temperatures between 400 K and 600 K there are melting-like transitions from a monolayer of ice to a monolayer of liquid water. These first-order phase transitions have a latent heat between 3.4 and 4.0 kJ mol-1. Both the values of the transition temperatures and of the latent heats display considerable model dependence for the five different water models investigated here.
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Affiliation(s)
- Shujuan Li
- Institute for Mathematics, Freie Universität Berlin, Arnimallee 6, D-14195 Berlin, Germany.
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22
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23
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Zaragoza A, Gonzalez MA, Joly L, López-Montero I, Canales MA, Benavides AL, Valeriani C. Molecular dynamics study of nanoconfined TIP4P/2005 water: how confinement and temperature affect diffusion and viscosity. Phys Chem Chem Phys 2019; 21:13653-13667. [PMID: 31190039 DOI: 10.1039/c9cp02485a] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In the past few decades great effort has been devoted to the study of water confined in hydrophobic geometries at the nanoscale (tubes and slit pores) due to the multiple technological applications of such systems, ranging from drug delivery to water desalination devices. To our knowledge, neither numerical/theoretical nor experimental approaches have so far reached a consensual understanding of structural and transport properties of water under these conditions. In this work, we present molecular dynamics simulations of TIP4P/2005 water under different nanoconfinements (slit pores or nanotubes, with two degrees of hydrophobicity) within a wide temperature range. It has been found that water is more structured near the less hydrophobic walls, independently of the confining geometries. Meanwhile, we observe an enhanced diffusion coefficient of water in both hydrophobic nanotubes. Finally, we propose a confined Stokes-Einstein relation to obtain the viscosity from diffusivity, whose result strongly differs from the Green-Kubo expression that has been used in previous works. While viscosity computed with the Green-Kubo formula (applied for anisotropic and confined systems) strongly differs from that of the bulk, viscosity computed with the confined Stokes-Einstein relation is not so much affected by the confinement, independently of its geometry. We discuss the shortcomings of both approaches, which could explain this discrepancy.
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Affiliation(s)
- A Zaragoza
- Departamento de Estructura de la Materia, Facultad de Ciencias Físicas, Física Térmica y Electrónica, Universidad Complutense de Madrid, 28040 Madrid, Spain. and Depto. Ingeniería Física, División de Ciencias e Ingenierías, Universidad de Guanajuato, 37150 León, Mexico
| | - M A Gonzalez
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - L Joly
- Univ. Lyon, Université Claude Bernard Lyon 1, CNRS, Institut Lumière Matière, F-69622 Villeurbanne, France
| | - I López-Montero
- Departamento de Química Física, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain and Instituto de Investigación Hospital Doce de Octubre (i+12), Avenida de Córdoba s/n, 28041 Madrid, Spain
| | - M A Canales
- Departamento de Química Orgánica I, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - A L Benavides
- Depto. Ingeniería Física, División de Ciencias e Ingenierías, Universidad de Guanajuato, 37150 León, Mexico
| | - C Valeriani
- Departamento de Estructura de la Materia, Facultad de Ciencias Físicas, Física Térmica y Electrónica, Universidad Complutense de Madrid, 28040 Madrid, Spain.
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24
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Salvati Manni L, Assenza S, Duss M, Vallooran JJ, Juranyi F, Jurt S, Zerbe O, Landau EM, Mezzenga R. Soft biomimetic nanoconfinement promotes amorphous water over ice. NATURE NANOTECHNOLOGY 2019; 14:609-615. [PMID: 30962546 DOI: 10.1038/s41565-019-0415-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Accepted: 02/26/2019] [Indexed: 06/09/2023]
Abstract
Water is a ubiquitous liquid with unique physicochemical properties, whose nature has shaped our planet and life as we know it. Water in restricted geometries has different properties than in bulk. Confinement can prevent low-temperature crystallization of the molecules into a hexagonal structure and thus create a state of amorphous water. To understand the survival of life at subzero temperatures, it is essential to elucidate this behaviour in the presence of nanoconfining lipidic membranes. Here we introduce a family of synthetic lipids with designed cyclopropyl modifications in the hydrophobic chains that exhibit unique liquid-crystalline behaviour at low temperature, which enables the maintenance of amorphous water down to ~10 K due to nanoconfinement. The combination of experiments and molecular dynamics simulations unveils a complex lipid-water phase diagram in which bicontinuous cubic and lamellar liquid crystalline phases that contain subzero liquid, glassy or ice water emerge as a competition between the two components, each pushing towards its thermodynamically favoured state.
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Affiliation(s)
- Livia Salvati Manni
- Department of Chemistry, University of Zürich, Zürich, Switzerland
- Department of Health Sciences & Technology, ETH Zürich, Zürich, Switzerland
| | - Salvatore Assenza
- Department of Health Sciences & Technology, ETH Zürich, Zürich, Switzerland
| | - Michael Duss
- Department of Chemistry, University of Zürich, Zürich, Switzerland
| | - Jijo J Vallooran
- Department of Chemistry, University of Zürich, Zürich, Switzerland
- Department of Health Sciences & Technology, ETH Zürich, Zürich, Switzerland
| | - Fanni Juranyi
- Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institut, Villigen, Switzerland
| | - Simon Jurt
- Department of Chemistry, University of Zürich, Zürich, Switzerland
| | - Oliver Zerbe
- Department of Chemistry, University of Zürich, Zürich, Switzerland
| | - Ehud M Landau
- Department of Chemistry, University of Zürich, Zürich, Switzerland.
| | - Raffaele Mezzenga
- Department of Health Sciences & Technology, ETH Zürich, Zürich, Switzerland.
- Department of Materials, ETH Zürich, Zürich, Switzerland.
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25
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Oprzeska-Zingrebe EA, Smiatek J. Aqueous Mixtures of Urea and Trimethylamine-N-oxide: Evidence for Kosmotropic or Chaotropic Behavior? J Phys Chem B 2019; 123:4415-4424. [PMID: 31046272 DOI: 10.1021/acs.jpcb.9b02598] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Trimethylamine-N-oxide (TMAO) and urea are commonly produced in many extremophilic microorganisms that live in harsh environments. In view of high temperature, high pressure, or high salt content, TMAO is known as a protein structure stabilizer, whereas urea destabilizes protein structures even under ambient conditions. Despite clear evidence, destabilizers are often regarded as chaotropes, meaning water-structure breakers, whereas kosmotropes as water-structure makers are classified as stabilizers. Using atomistic molecular dynamics simulations, we study aqueous mixtures of TMAO and urea in various biologically relevant concentrations to gain insight into the molecular details of their mutual cross-interactions and their influence on water dynamics and structure. Our results for binary and ternary solutions in combination with different mixing ratios show that both co-solutes strengthen the water network in terms of dynamic and structural aspects. Slight differences in the water binding behavior between both species result in only negligible compensation effects. The outcomes of our simulations thus question the validity and the ill-considered use of attributes like kosmotropic or chaotropic substances for stabilizers and destabilizers.
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Affiliation(s)
| | - Jens Smiatek
- Institute for Computational Physics , University of Stuttgart , D-70569 Stuttgart , Germany.,Helmholtz-Institute Münster: Ionics in Energy Storage (HIMS-IEK 12) , Forschungszentrum Jülich GmbH , D-48149 Münster , Germany
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26
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Cao B, Xu E, Li T. Anomalous Stability of Two-Dimensional Ice Confined in Hydrophobic Nanopores. ACS NANO 2019; 13:4712-4719. [PMID: 30892864 DOI: 10.1021/acsnano.9b01014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The freezing of water mostly proceeds via heterogeneous ice nucleation, a process in which an effective nucleation medium not only expedites ice crystallization but also may effectively direct the polymorph selection of ice. Here, we show that water confined within a hydrophobic slit nanopore exhibits a freezing behavior strongly distinguished from its bulk counterpart. Such a difference is reflected by a strong, non-monotonic pore-size dependence of freezing temperature but, more surprisingly, by an unexpected stacking ordering of crystallized two-dimensional ice containing just a few ice layers. In particular, confined trilayer ice is found to exclusively crystallize into a well-ordered, hexagonal stacking sequence despite the fact that nanopore exerts no explicit constraint on stacking order. The absence of cubic stacking sequence is found to be originated from the intrinsically lower thermodynamic stability of cubic ice over hexagonal ice at the interface, which contrasts sharply the nearly degenerated stability of bulk hexagonal and cubic ices. Detailed examination clearly reveals that the divergence is attributed to the inherent difference between the two ice polymorphs in their surface phonon modes, which is further found to generically occur at both hydrophobic and hydrophilic surfaces.
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Affiliation(s)
- Boxiao Cao
- Department of Civil and Environmental Engineering , George Washington University , Washington , D.C. 20052 , United States
| | - Enshi Xu
- Department of Civil and Environmental Engineering , George Washington University , Washington , D.C. 20052 , United States
| | - Tianshu Li
- Department of Civil and Environmental Engineering , George Washington University , Washington , D.C. 20052 , United States
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27
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Yun Y, Khaliullin RZ, Jung Y. Low-Dimensional Confined Ice Has the Electronic Signature of Liquid Water. J Phys Chem Lett 2019; 10:2008-2016. [PMID: 30946585 DOI: 10.1021/acs.jpclett.9b00921] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Water confined in nanomaterials demonstrates anomalous behavior. Recent experiments and simulations have established that room-temperature water inside carbon nanotubes and between graphene layers behaves as solid ice: its molecules form four hydrogen bonds in a highly organized network with long-range order and exhibit low mobility. Here, we applied a first-principle energy decomposition analysis to reveal that the strength and patterns of donor-acceptor interactions between molecules in these low-dimensional ice structures resemble those in bulk liquid water rather than those in hexagonal ice. A correlation analysis shows that this phenomenon originates from a variety of hydrogen-bond distortions, different in 1D and 2D ice, from the tetrahedral configuration due to constraints imposed by nanomaterials. We discuss the implications of the reported interplay between the electronic and geometric structure of hydrogen bonds in "room-temperature ice" for computer modeling of confined water using traditional force fields.
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Affiliation(s)
| | - Rustam Z Khaliullin
- Department of Chemistry , McGill University , 801 Sherbrooke Street West , Montreal , QC H3A 0B8 , Canada
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28
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Mosaddeghi H, Alavi S, Kowsari MH, Najafi B, Az'hari S, Afshar Y. Molecular dynamics simulations of nano-confined methanol and methanol-water mixtures between infinite graphite plates: Structure and dynamics. J Chem Phys 2019; 150:144510. [PMID: 30981262 DOI: 10.1063/1.5088030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Molecular dynamics simulations are used to investigate microscopic structures and dynamics of methanol and methanol-water binary mixture films confined between hydrophobic infinite parallel graphite plate slits with widths, H, in the range of 7-20 Å at 300 K. The initial geometric densities of the liquids were chosen to be the same as bulk methanol at the same temperature. For the two narrowest slit widths, two smaller initial densities were also considered. For the nano-confined system with H = 7 Å and high pressure, a solid-like hexagonal arrangement of methanol molecules arranged perpendicular to the plates is observed which reflects the closest packing of the molecules and partially mirrors the structure of the underlying graphite structure. At lower pressures and for larger slit widths, in the contact layer, the methanol molecules prefer having the C-O bond oriented parallel to the walls. Layered structures of methanol parallel to the wall were observed, with contact layers and additional numbers of central layers depending on the particular slit width. For methanol-water mixtures, simulations of solutions with different composition were performed between infinite graphite slits with H = 10 and 20 Å at 300 K. For the nanoslit with H = 10 Å, in the solution mixtures, three layers of molecules form, but for all mole fractions of methanol, methanol molecules are excluded from the central fluid layer. In the nanopore with H = 20 Å, more than three fluid layers are formed and methanol concentrations are enhanced near the confining plates walls compared to the average solution stoichiometry. The self-diffusion coefficients of methanol and water molecules in the solution show strong dependence on the solution concentration. The solution mole fractions with minimal diffusivity are the same in confined and non-confined bulk methanol-water mixtures.
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Affiliation(s)
- Hamid Mosaddeghi
- Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Saman Alavi
- Department of Chemistry and Biomolecular Sciences, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Mohammad H Kowsari
- Department of Chemistry and Center for Research in Climate Change and Global Warming (CRCC), Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran
| | - Bijan Najafi
- Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Sara Az'hari
- Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Yaser Afshar
- Department of Aerospace Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
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29
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Roy P, Ghosh B, Chatterjee P, Sengupta N. Cosolvent Impurities in SWCNT Nanochannel Confinement: Length Dependence of Water Dynamics Investigated with Atomistic Simulations. J Chem Inf Model 2019; 59:2026-2034. [PMID: 30908024 DOI: 10.1021/acs.jcim.8b00889] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The advent of nanotechnology has seen a growing interest in the nature of fluid flow and transport under nanoconfinement. The present study leverages fully atomistic molecular dynamics (MD) simulations to study the effect of nanochannel length and intrusion of molecules of the organic solvent, hexafluoro-2-propanol (HFIP), on the dynamical characteristics of water within it. Favorable interactions of HFIP with the nanochannels comprised of single-walled carbon nanotubes traps them over time scales greater than 100 ns, and confinement confers small but distinguishable spatial redistribution between neighboring HFIP pairs. Water molecules within the nanochannels show clear signatures of dynamical slowdown relative to bulk water even for pure systems. The presence of HFIP causes further rotational and translational slowdown in waters when the nanochannel dimension falls below a critical length of 30 Å. The enhanced slowdown in the presence of HFIP is quantified from characteristic relaxation parameters and diffusion coefficients in the absence and presence of HFIP. It is finally seen that the net flow of water between the ends of the nanochannel shows a decreasing dependence with nanochannel length only when the number of HFIP molecules is small. These results lend insights into devising ways of modulating solvent properties within nanochannels with cosolvent impurities.
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Affiliation(s)
- Priti Roy
- Department of Biological Sciences , Indian Institute of Science Education and Research Kolkata , Mohanpur 741 246 , India
| | - Brataraj Ghosh
- Department of Biological Sciences , Indian Institute of Science Education and Research Kolkata , Mohanpur 741 246 , India
| | - Prathit Chatterjee
- Advanced Polymer Lab in association with Polymer Research Centre , IISER Kolkata, ADO ADDITIVES MFG PVT. LTD. , 201/A, Nadibhag 2nd Lane , Madhyamgram, Kolkata 700 128 , India
| | - Neelanjana Sengupta
- Department of Biological Sciences , Indian Institute of Science Education and Research Kolkata , Mohanpur 741 246 , India.,Centre for Advanced Functional Materials (CAFM) , Indian Institute of Science Education and Research Kolkata , Mohanpur 741 246 , India
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30
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Cai X, Xie WJ, Yang Y, Long Z, Zhang J, Qiao Z, Yang L, Gao YQ. Structure of water confined between two parallel graphene plates. J Chem Phys 2019; 150:124703. [DOI: 10.1063/1.5080788] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Affiliation(s)
- Xiaoxia Cai
- Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
| | - Wen Jun Xie
- Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
| | - Ying Yang
- Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
| | - Zhuoran Long
- Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
| | - Jun Zhang
- Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
| | - Zhuoran Qiao
- Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
| | - Lijiang Yang
- Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
| | - Yi Qin Gao
- Institute of Theoretical and Computational Chemistry, College of Chemistry and Molecular Engineering, Beijing National Laboratory for Molecular Sciences, Peking University, Beijing 100871, China
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31
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Ghosh K, Krishnamurthy CV. Soft-wall induced structure and dynamics of partially confined supercritical fluids. J Chem Phys 2019; 150:111102. [PMID: 30901989 DOI: 10.1063/1.5092121] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The interplay between the structure and dynamics of partially confined Lennard Jones (LJ) fluids, deep into the supercritical phase, is studied over a wide range of densities in the context of the Frenkel line (FL), which separates rigid liquidlike and non-rigid gaslike regimes in the phase diagram of the supercritical fluids. Extensive molecular dynamics simulations carried out at the two ends of the FL (P = 5000 bars, T = 300 K, and T = 1500 K) reveal intriguing features in supercritical fluids as a function of stiffness of the partially confining atomistic walls. The liquidlike regime of a LJ fluid (P = 5000 bars, T = 300 K), mimicking argon, partially confined between walls separated by 10 Å along the z-axis, and otherwise unconstrained, reveals amorphous and liquidlike structural signatures in the radial distribution function parallel to the walls and enhanced self-diffusion as the wall stiffness is decreased. In sharp contrast, in the gas-like regime (P = 5000 bars, T = 1500 K), soft walls lead to increasing structural order hindering self-diffusion. Furthermore, the correlations between the structure and self-diffusion are found to be well captured by excess entropy. The rich behaviour shown by supercritical fluids under partial confinement, even with simple interatomic potentials, is found to be fairly independent of hydrophilicity and hydrophobicity. The study identifies persisting sub-diffusive features over intermediate time scales, emerging from the strong interplay between density and confinement, to dictate the evolution and stabilization of structures. It is anticipated that these results may help gain a better understanding of the behaviour of partially confined complex fluids found in nature.
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Affiliation(s)
- Kanka Ghosh
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
| | - C V Krishnamurthy
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
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32
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Pršlja P, Lomba E, Gómez-Álvarez P, Urbič T, Noya EG. Adsorption of water, methanol, and their mixtures in slit graphite pores. J Chem Phys 2019; 150:024705. [PMID: 30646695 PMCID: PMC6910600 DOI: 10.1063/1.5078603] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 12/19/2018] [Indexed: 11/15/2022] Open
Abstract
The behavior of water, methanol, and water-methanol mixtures confined in narrow slit graphite pores as a function of pore size was investigated by Monte Carlo, hybrid Monte Carlo, and Molecular Dynamics simulations. Interactions were described using TIP4P/2005 for water, OPLS/2016 for methanol, and cross interactions fitted to excess water/methanol properties over the whole range of concentrations, which provide a rather accurate description of water-methanol mixtures. As expected for hydrophobic pores, whereas pure methanol is adsorbed already from the gas phase, pure water only enters the pore at pressures well beyond bulk saturation for all pore sizes considered. When adsorbed from a mixture, however, water adsorbs at much lower pressures due to the formation of hydrogen bonds with previously adsorbed methanol molecules. For all studied compositions and pore sizes, methanol adsorbs preferentially over water at liquid-vapor equilibrium conditions. In pure components, both water and methanol are microscopically structured in layers, the number of layers increasing with pore size. This is also the case in adsorbed mixtures, in which methanol has a higher affinity for the walls. This becomes more evident as the pore widens. Diffusion of pure water is higher than that of pure methanol for all pore sizes due to the larger size of the methyl group. In mixtures, both components present similar diffusivities at all pore sizes, which is explained in terms of the coupling of molecular movements due to strong hydrogen bonding between methanol and water molecules. This is particularly evident in very narrow pores, in which pure methanol diffusion is completely impeded on the time scale of our simulations, but the presence of a small amount of water molecules facilitates alcohol diffusion following a single-file mechanism. Additionally, our results indicate that pure water diffusivities display a non-monotonous dependence of pore size, due to effects of confinement (proximity to a fluid-solid-fluid transition induced by confinement as reported in previous work) and the dynamic anomalies of water.
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Affiliation(s)
- Paulina Pršlja
- Institute of Physical Chemistry "Rocasolano," Serrano 119, E-28006 Madrid, Spain
| | - Enrique Lomba
- Institute of Physical Chemistry "Rocasolano," Serrano 119, E-28006 Madrid, Spain
| | - Paula Gómez-Álvarez
- Institute of Physical Chemistry "Rocasolano," Serrano 119, E-28006 Madrid, Spain
| | - Tomaz Urbič
- Faculty of Chemistry and Chemical technology, University of Ljubljana, Ljubljana, Slovenia
| | - Eva G Noya
- Institute of Physical Chemistry "Rocasolano," Serrano 119, E-28006 Madrid, Spain
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33
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Wu M, Wei W, Liu X, Liu K, Li S. Structure and dynamic properties of stretched water in graphene nanochannels by molecular dynamics simulation: effects of stretching extent. Phys Chem Chem Phys 2019; 21:19163-19171. [DOI: 10.1039/c9cp03981c] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Water confined in nanochannels can be stretched with the variation of external pressure, leading to the more disordered microstructure and higher diffusion coefficient than bulk water.
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Affiliation(s)
- Mingbing Wu
- State Key Laboratory of Coal Combustion
- School of Energy and Power Engineering
- Huazhong University of Science and Technology
- Wuhan 430074
- China
| | - Wei Wei
- State Key Laboratory of Coal Combustion
- School of Energy and Power Engineering
- Huazhong University of Science and Technology
- Wuhan 430074
- China
| | - Xiaowei Liu
- State Key Laboratory of Coal Combustion
- School of Energy and Power Engineering
- Huazhong University of Science and Technology
- Wuhan 430074
- China
| | - Kang Liu
- MOE Key Laboratory of Hydrodynamic Transients
- School of Power and Mechanical Engineering
- Wuhan University
- Wuhan
- P. R. China
| | - Song Li
- State Key Laboratory of Coal Combustion
- School of Energy and Power Engineering
- Huazhong University of Science and Technology
- Wuhan 430074
- China
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Bai J, Francisco JS, Zeng XC. Two-dimensional dry ices with rich polymorphic and polyamorphic phase behavior. Proc Natl Acad Sci U S A 2018; 115:10263-10268. [PMID: 30249649 PMCID: PMC6187129 DOI: 10.1073/pnas.1809198115] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Both carbon dioxide (CO2) and water (H2O) are triatomic molecules that are ubiquitous in nature, and both are among the five most abundant gases in the Earth's atmosphere. At low temperature and ambient pressure, both CO2 and H2O form molecular crystals--dry ice I and ice I h Because water possesses distinctive hydrogen bonds, it exhibits intricate and highly pressure-dependent phase behavior, including at least 17 crystalline ice phases and three amorphous ice phases. In contrast, due to its weak van der Waals intermolecular interactions, CO2 exhibits fewer crystalline phases except at extremely high pressures, where nonmolecular ordered structures arise. Herein, we show the molecular dynamics simulation results of numerous 2D polymorphs of CO2 molecules in slit nanopores. Unlike bulk polymorphs of CO2, 2D CO2 polymorphs exhibit myriad crystalline and amorphous structures, showing remarkable polymorphism and polyamorphism. We also show that depending on the thermodynamic path, 2D solid-to-solid phase transitions can give rise to previously unreported structures, e.g., wave-like amorphous CO2 structures. Our simulation also suggests intriguing structural connections between 2D and 3D dry ice phases (e.g., Cmca and PA-3) and offers insights into CO2 polyamorphic transitions through intermediate liquid or amorphous phases.
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Affiliation(s)
- Jaeil Bai
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588
| | - Joseph S Francisco
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588;
| | - Xiao Cheng Zeng
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588;
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, 100029 Beijing, China
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35
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Engstler J, Giovambattista N. Temperature Effects on Water-Mediated Interactions at the Nanoscale. J Phys Chem B 2018; 122:8908-8920. [PMID: 30178667 DOI: 10.1021/acs.jpcb.8b05430] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We perform molecular dynamics simulations to study the effects of temperature on the water-mediated interactions between nanoscale apolar solutes. Specifically, we calculate the potential of mean force (PMF) between two graphene plates immersed in water at 240 ≤ T ≤ 400 K and P = 0.1 MPa. These are thermodynamic conditions relevant to cooling- and heating-induced protein denaturation. It is found that both cooling and heating tend to suppress the attraction, and ultimate collapse, of the graphene plates. However, the underlying role played by water upon heating and cooling is different. Isobaric heating reduces the strength and range of the interactions between the plates. Instead, isobaric cooling stabilizes the plates separations that can accommodate an integer number of water layers between the graphene plates. In particular, the energy barriers separating these plate separations increase linearly with 1/ T. We also explore the sensitivity of the plates PMF to the water model employed. In the case of the TIP4P/2005 model, water confined between the plates crystallizes into a defective bilayer ice at low temperatures, whereas in the case of the SPC/E model, water remains in the liquid state at same thermodynamic conditions. The effects of varying water-graphene interactions on the plates PMF are also studied.
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Affiliation(s)
- Justin Engstler
- Department of Physics , Brooklyn College of the City University of New York , Brooklyn , New York 11210 , United States
| | - Nicolas Giovambattista
- Department of Physics , Brooklyn College of the City University of New York , Brooklyn , New York 11210 , United States.,Ph.D. Programs in Chemistry and Physics , The Graduate Center of the City University of New York , New York , New York 10016 , United States
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36
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Tsimpanogiannis IN, Moultos OA, Franco LFM, Spera MBDM, Erdős M, Economou IG. Self-diffusion coefficient of bulk and confined water: a critical review of classical molecular simulation studies. MOLECULAR SIMULATION 2018. [DOI: 10.1080/08927022.2018.1511903] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Ioannis N. Tsimpanogiannis
- Environmental Research Laboratory, National Center for Scientific Research “Demokritos”, Aghia Paraskevi Attikis, Greece
- Institute of Nanoscience and Nanotechnology, National Center for Scientific Research “Demokritos”, Aghia Paraskevi Attikis, Greece
| | - Othonas A. Moultos
- Engineering Thermodynamics, Process & Energy Department, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Delft, The Netherlands
| | - Luís F. M. Franco
- School of Chemical Engineering, University of Campinas, Campinas, Brazil
| | | | - Máté Erdős
- Engineering Thermodynamics, Process & Energy Department, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Delft, The Netherlands
| | - Ioannis G. Economou
- Institute of Nanoscience and Nanotechnology, National Center for Scientific Research “Demokritos”, Aghia Paraskevi Attikis, Greece
- Chemical Engineering Program, Texas A&M University at Qatar, Doha, Qatar
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37
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38
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Qiu H, Xue M, Shen C, Guo W. Anomalous cation diffusion in salt-doped confined bilayer ice. NANOSCALE 2018; 10:8962-8968. [PMID: 29682648 DOI: 10.1039/c8nr01301b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The diffusive dynamics of aqueous electrolyte solutions in nanoconfined spaces has attracted considerable attention due to their potential applications in desalination, biosensors and supercapacitors. Here we show by molecular dynamics simulations that lithium and sodium ions diffuse at a rate at least an order of magnitude higher than that of water molecules when the ions are trapped in an ice bilayer confined between two parallel plates. This novel picture is in sharp contrast to the prevailing view that the diffusion rate of ions is comparable to or even lower than that of water in both bulk and confined solutions. The predicted high ion mobility stems from frequent lateral hopping of ions along the coordination sites inside the hydrogen-bonding network connecting the two water layers of the ice bilayer. This anomalous diffusion should provide new insights into the physics of confined aqueous electrolytes.
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Affiliation(s)
- Hu Qiu
- State Key Laboratory of Mechanics and Control of Mechanical Structures and Key Laboratory for Intelligent Nano Materials and Devices of MOE, Institute of Nano Science, Nanjing University of Aeronautics and Astronautics, Nanjing, 210016, China.
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39
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Fomin YD, Gaiduk EA, Tsiok EN, Ryzhov VN. The phase diagram and melting scenarios of two-dimensional Hertzian spheres. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1464676] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Yu. D. Fomin
- Institute for High Pressure Physics RAS, Moscow, Russia
| | - E. A. Gaiduk
- Institute for High Pressure Physics RAS, Moscow, Russia
| | - E. N. Tsiok
- Institute for High Pressure Physics RAS, Moscow, Russia
| | - V. N. Ryzhov
- Institute for High Pressure Physics RAS, Moscow, Russia
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40
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Abstract
The behavior of water confined at the nanoscale plays a fundamental role in biological processes and technological applications, including protein folding, translocation of water across membranes, and filtration and desalination. Remarkably, nanoscale confinement drastically alters the properties of water. Using molecular dynamics simulations, we determine the phase diagram of water confined by graphene sheets in slab geometry, at T = 300 K and for a wide range of pressures. We find that, depending on the confining dimension D and density σ, water can exist in liquid and vapor phases, or crystallize into monolayer and bilayer square ices, as observed in experiments. Interestingly, depending on D and σ, the crystal-liquid transformation can be a first-order phase transition, or smooth, reminiscent of a supercritical liquid-gas transformation. We also focus on the limit of stability of the liquid relative to the vapor and obtain the cavitation pressure perpendicular to the graphene sheets. Perpendicular cavitation pressure varies non-monotonically with increasing D and exhibits a maximum at D ≈ 0.90 nm (equivalent to three water layers). The effect of nanoconfinement on the cavitation pressure can have an impact on water transport in technological and biological systems. Our study emphasizes the rich and apparently unpredictable behavior of nanoconfined water, which is complex even for graphene.
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41
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Ternes P, Salcedo E, Barbosa MC. Relation between boundary slip mechanisms and waterlike fluid behavior. Phys Rev E 2018; 97:033104. [PMID: 29776176 DOI: 10.1103/physreve.97.033104] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Indexed: 06/08/2023]
Abstract
The slip of a fluid layer in contact with a solid confining surface is investigated for different temperatures and densities using molecular dynamic simulations. We show that for an anomalous waterlike fluid the slip goes as follows: for low levels of shear, defect slip appears and is related to the particle exchange between the fluid layers; at high levels of shear, global slip occurs and is related to the homogeneous distribution of the fluid in the confining surfaces. The oscillations in the transition velocity from defect to global slip are shown to be associated with changes in the layering distribution in the anomalous fluid.
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Affiliation(s)
- Patricia Ternes
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, 91501-970 Porto Alegre, RS, Brazil
| | - Evy Salcedo
- Coordenadoria Especial de Física, Química e Matemática, Universidade Federal de Santa Catarina, Rua Pedro João Pereira 150, 88905-120 Araranguá, SC, Brazil
| | - Marcia C Barbosa
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, 91501-970 Porto Alegre, RS, Brazil
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42
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Ghosh K, Krishnamurthy CV. Structural behavior of supercritical fluids under confinement. Phys Rev E 2018; 97:012131. [PMID: 29448330 DOI: 10.1103/physreve.97.012131] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2017] [Indexed: 11/07/2022]
Abstract
The existence of the Frenkel line in the supercritical regime of a Lennard-Jones (LJ) fluid shown through molecular dynamics (MD) simulations initially and later corroborated by experiments on argon opens up possibilities of understanding the structure and dynamics of supercritical fluids in general and of the Frenkel line in particular. The location of the Frenkel line, which demarcates two distinct physical states, liquidlike and gaslike within the supercritical regime, has been established through MD simulations of the velocity autocorrelation (VACF) and radial distribution function (RDF). We, in this article, explore the changes in the structural features of supercritical LJ fluid under partial confinement using atomistic walls. The study is carried out across the Frenkel line through a series of MD simulations considering a set of thermodynamics states in the supercritical regime (P=5000 bar, 240K≤T≤1500K) of argon well above the critical point. Confinement is partial, with atomistic walls located normal to z and extending to "infinity" along the x and y directions. In the "liquidlike" regime of the supercritical phase, particles are found to be distributed in distinct layers along the z axis with layer spacing less than one atomic diameter and the lateral RDF showing amorphous-like structure for specific spacings (packing frustration) and non-amorphous-like structure for other spacings. Increasing the rigidity of the atomistic walls is found to lead to stronger layering and increased structural order. For confinement with reflective walls, layers are found to form with one atomic diameter spacing and the lateral RDF showing close-packed structure for the smaller confinements. Translational order parameter and excess entropy assessment confirms the ordering taking place for atomistic wall and reflective wall confinements. In the "gaslike" regime of the supercritical phase, particle distribution along the spacing and the lateral RDF exhibit features not significantly different from that due to normal gas regime. The heterogeneity across the Frenkel line, found to be present both in bulk and confined systems, might cause the breakdown of the universal scaling between structure and dynamics of fluids necessitating the determination of a unique relationship between them.
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Affiliation(s)
- Kanka Ghosh
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
| | - C V Krishnamurthy
- Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India
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43
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Zubeltzu J, Artacho E. Simulations of water nano-confined between corrugated planes. J Chem Phys 2017; 147:194509. [PMID: 29166107 DOI: 10.1063/1.5011468] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Water confined to nanoscale widths in two dimensions between ideal planar walls has been the subject of ample study, aiming at understanding the intrinsic response of water to confinement, avoiding the consideration of the chemistry of actual confining materials. In this work, we study the response of such nanoconfined water to the imposition of a periodicity in the confinement by means of computer simulations, both using empirical potentials and from first-principles. For that we propose a periodic confining potential emulating the atomistic oscillation of the confining walls, which allows varying the lattice parameter and amplitude of the oscillation. We do it for a triangular lattice, with several values of the lattice parameter: one which is ideal for commensuration with layers of Ih ice and other values that would correspond to more realistic substrates. For the former, the phase diagram shows an overall rise of the melting temperature. The liquid maintains a bi-layer triangular structure, however, despite the fact that it is not favoured by the external periodicity. The first-principles liquid is significantly affected by the modulation in its layering and stacking even at relatively small amplitudes of the confinement modulation. Beyond some critical modulation amplitude, the hexatic phase present in flat confinement is replaced by a trilayer crystalline phase unlike any of the phases encountered for flat confinement. For more realistic lattice parameters, the liquid does not display higher tendency to freeze, but it clearly shows inhomogeneous behaviour as the strength of the rugosity increases. In spite of this expected inhomogeneity, the structural and dynamical response of the liquid is surprisingly insensitive to the external modulation. Although the first-principles calculations give a more triangular liquid than the one observed with empirical potentials (TIP4P/2005), both agree remarkably well for the main conclusions of the study.
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Affiliation(s)
- Jon Zubeltzu
- CIC nanoGUNE, 20018 Donostia-San Sebastián, Spain
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44
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Ferrara CG, Grigera TS. Dynamics and structural behavior of water in large confinement with planar amorphous walls. J Chem Phys 2017; 147:024705. [PMID: 28711040 DOI: 10.1063/1.4991834] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We study the structure and dynamics of liquid water confined between planar amorphous walls using molecular dynamics (MD) simulations. We report MD results for systems of more than 23 000 SPC/E water molecules confined between two hydrophilic or hydrophobic walls, separated by distances of about 15 nm. We find that the walls induce ordering of the liquid and slow down the dynamics, affecting the properties of the confined water up to distances of about 8 nm at 275 K. We quantify this influence by computing dynamic and static penetration lengths and studying their temperature dependence. Our results indicate that in the temperature range considered, hydrophobic walls perturb static properties over larger lengths compared to hydrophilic walls. We also find opposite temperature trends in the dynamic penetration lengths, with hydrophobic walls increasing their range of influence on increasing the temperature.
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Affiliation(s)
- C Gastón Ferrara
- Universidad Nacional Arturo Jauretche, Florencio Varela, Argentina
| | - Tomás S Grigera
- Instituto de Física de Líquidos y Sistemas Biológicos (IFLYSIB), CONICET and Facultad de Ciencias Exactas, Universidad Nacional de La Plata, Calle 59 No. 789, B1900BTE La Plata, Argentina
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45
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Allahyarov E, Löwen H, Taylor PL. Simulation Study of Ion Diffusion in Charged Nanopores with Anchored Terminal Groups. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.04.158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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46
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Gavazzoni C, Giovambattista N, Netz PA, Barbosa MC. Structure and mobility of water confined in AlPO 4-54 nanotubes. J Chem Phys 2017. [PMID: 28641422 DOI: 10.1063/1.4985626] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We performed molecular dynamics simulations of water confined within AlPO4-54 nanotubes. AlPO4-54 is an artificial material made of AlO4 and of PO4 in tetrahedra arranged in a periodic structure forming pores of approximately 1.3 nm in diameter. This makes AlPO4-54 an excellent candidate for practical applications, such as for water filtration and desalination. In this work, the structural and dynamical properties of the confined water are analyzed for various temperatures and water loadings. We find that the water structure is controlled by the heterogeneity of the nanopore surface with the water molecules located preferentially next to the surface of oxygens of AlPO4-54; consequently, at very low densities, water forms helicoidal structures in string-like arrangements.
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Affiliation(s)
- Cristina Gavazzoni
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970 Porto Alegre, Rio Grande do Sul, Brazil
| | - Nicolas Giovambattista
- Brooklyn College, City University of New York, 365 Fifth Avenue, New York, New York 10016, USA
| | - Paulo A Netz
- Instituto de Química, Universidade Federal do Rio Grande do Sul, CEP 91501-970 Porto Alegre, Rio Grande do Sul, Brazil
| | - Marcia C Barbosa
- Instituto de Física, Universidade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-970 Porto Alegre, Rio Grande do Sul, Brazil
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47
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Abstract
Van der Waals (vdW) interaction between two-dimensional crystals (2D) can trap substances in high pressurized (of order 1 GPa) on nanobubbles. Increasing the adhesion between the 2D crystals further enhances the pressure and can lead to a phase transition of the trapped material. We found that the shape of the nanobubble can depend critically on the properties of the trapped substance. In the absence of any residual strain in the top 2D crystal, flat nanobubbles can be formed by trapped long hydrocarbons (that is, hexadecane). For large nanobubbles with radius 130 nm, our atomic force microscopy measurements show nanobubbles filled with hydrocarbons (water) have a cylindrical symmetry (asymmetric) shape which is in good agreement with our molecular dynamics simulations. This study provides insights into the effects of the specific material and the vdW pressure on the microscopic details of graphene bubbles. Graphene nanobubbles can act as enclosures for holding small volumes of substances. Here the authors find a correlation between bubble shape and the encapsulated material providing a potential method for determining the graphene bubble content by its deformation.
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48
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Motevaselian MH, Aluru NR. An EQT-based cDFT approach for thermodynamic properties of confined fluid mixtures. J Chem Phys 2017; 146:154102. [DOI: 10.1063/1.4979896] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- M. H. Motevaselian
- Department of Mechanical Science and Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - N. R. Aluru
- Department of Mechanical Science and Engineering, Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
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50
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B Krott L, Gavazzoni C, Bordin JR. Anomalous diffusion and diffusion anomaly in confined Janus dumbbells. J Chem Phys 2016; 145:244906. [PMID: 28049334 DOI: 10.1063/1.4972578] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Self-assembly and dynamical properties of Janus nanoparticles have been studied by molecular dynamic simulations. The nanoparticles are modeled as dimers and they are confined between two flat parallel plates to simulate a thin film. One monomer from the dumbbells interacts by a standard Lennard-Jones potential and the other by a two-length scales shoulder potential, typically used for anomalous fluids. Here, we study the effects of removing the Brownian effects, typical from colloidal systems immersed in aqueous solution, and consider a molecular system, without the drag force and the random collisions from the Brownian motion. Self-assembly and diffusion anomaly are preserved in relation to the Brownian system. Additionally, a superdiffusive regime associated to a collective reorientation in a highly structured phase is observed. Diffusion anomaly and anomalous diffusion are explained in the two length scale framework.
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Affiliation(s)
- Leandro B Krott
- Centro Araranguá, Universidade Federal de Santa Catarina, Rua Pedro João Pereira, 150, CEP 88905-120 Araranguá, SC, Brazil
| | - Cristina Gavazzoni
- Instituto de Física, Univeridade Federal do Rio Grande do Sul, Caixa Postal 15051, CEP 91501-570 Porto Alegre, RS, Brazil
| | - José Rafael Bordin
- Campus Caçapava do Sul, Universidade Federal do Pampa, Av. Pedro Anunciação, 111, CEP 96570-000 Caçapava do Sul, RS, Brazil
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