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Sahu P, Ali SM. Uniqueness of Nanoscale Confinement for Fast Water Transport: Effect of Nanotube Diameter and Hydrophobicity. J Phys Chem B 2024; 128:222-243. [PMID: 38149848 DOI: 10.1021/acs.jpcb.3c05979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
Inspired by the enhanced water permeability of carbon nanotubes (CNTs), molecular dynamics simulations were performed to investigate the transport behavior through nanotubes made of boron nitride (BNNT), silicon carbide (SiC), and silicon nitride (SiN) alongside carbon nanotubes (which have different hydrophobic attributes) considering their implication for reverse osmosis (RO) membranes under different practical environments. According to our findings, not only do CNTs but also other kinds of nanotubes exhibit transition anomalies with increasing diameter. Utilizing the robust two-phase thermodynamic (2PT) methods, the current examinations shed light on thermodynamic origin of favorable water filling of these nanotubes. The results show that regardless of the nanotube material, the filling of water inside small nanopores (d < 10 Å) as well as within pores of diameter larger than 15 Å will always be favored by the entropy of filling. However, the entropic preference for filling nanotubes with a diameter of 10-15 Å depends on the constituent material. In particular, the enhancement in total entropy of confined water was mainly due to the increased rotational freedom of confined water molecules. The thermodynamic origin of water transport was correlated with the structural and fluidic behavior of water inside these nanotubes. The observed data for density, flow, structure correlation functions, water-water coordination, tetrahedral order parameter, hydrogen bonds, and density of states functions quantitatively support the observed entropy behavior. Of critical importance is that the present study demonstrates the effectiveness of RO filtration using nanotubes of boron nitride rather than carbon. Furthermore, it was found that one should avoid the use of silicon nanotubes unless filtration needs to be performed under harsh environments where nanotube of other materials cannot survive. Specifically, the results show that both the structural and dynamic properties of water confined in BNNTs are similar to those of CNT's, and for SiNT it is similar as SiC. Our results show that besides the nanotube material, the chirality index of the nanotube also plays a significant role in determining the structure, dynamics and thermodynamics of confined water molecules.
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Affiliation(s)
- Pooja Sahu
- Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Mumbai 400094, India
| | - Sk Musharaf Ali
- Bhabha Atomic Research Centre, Mumbai 400085, India
- Homi Bhabha National Institute, Mumbai 400094, India
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2
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Duivenvoorden JR, Caporaletti F, Woutersen S, Keune K, Hermans JJ. Nanoconfined Water Clusters in Zinc White Oil Paint. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2023; 127:19269-19277. [PMID: 37791101 PMCID: PMC10544026 DOI: 10.1021/acs.jpcc.3c04720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 08/31/2023] [Indexed: 10/05/2023]
Abstract
Pigments in oil paint are bound by a complex oil polymer network that is prone to water-related chemical degradation. We use cryo-Fourier-transform infrared spectroscopy and differential scanning calorimetry to study how water distributes inside zinc white oil paint. By measuring water freezing and melting transitions, we show that water-saturated zinc white oil paint contains both liquid-like clustered water and nonclustered water. A comparison of titanium white paint and nonpigmented model systems indicates that water clustering happens near the pigment-polymer interface. The cluster size was estimated in the nanometer range based on the ice melting and freezing temperatures and on the position of the O-D vibration band. As liquid-like water can play a crucial role in the dissolution and transport of ions and molecules, understanding the factors that favor this phenomenon is essential for establishing safe conditions for the conservation of painted works of art.
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Affiliation(s)
- Jorien R. Duivenvoorden
- Van
‘t Hoff Institute for Molecular Sciences, University of Amsterdam Science Park 904, 1098 XH Amsterdam, The Netherlands
- Conservation
& Science, Rijksmuseum Hobbemastraat 22, 1071 ZC Amsterdam, The Netherlands
| | - Federico Caporaletti
- Laboratory
of Polymer and Soft Matter Dynamics, Experimental Soft Matter and
Thermal Physics, Université Libre
de Bruxelles Avenue, Franklin Roosevelt 50, 1050 Brussels, Belgium
| | - Sander Woutersen
- Van
‘t Hoff Institute for Molecular Sciences, University of Amsterdam Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Katrien Keune
- Van
‘t Hoff Institute for Molecular Sciences, University of Amsterdam Science Park 904, 1098 XH Amsterdam, The Netherlands
- Conservation
& Science, Rijksmuseum Hobbemastraat 22, 1071 ZC Amsterdam, The Netherlands
| | - Joen J. Hermans
- Van
‘t Hoff Institute for Molecular Sciences, University of Amsterdam Science Park 904, 1098 XH Amsterdam, The Netherlands
- Conservation
& Science, Rijksmuseum Hobbemastraat 22, 1071 ZC Amsterdam, The Netherlands
- Conservation
& Restoration, Amsterdam School of Heritage, Memory and Material
Culture, University of Amsterdam Turfdraagsterpad 15-17, 1012 XT Amsterdam, The Netherlands
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3
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Light, Water, and Melatonin: The Synergistic Regulation of Phase Separation in Dementia. Int J Mol Sci 2023; 24:ijms24065835. [PMID: 36982909 PMCID: PMC10054283 DOI: 10.3390/ijms24065835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 03/17/2023] [Indexed: 03/22/2023] Open
Abstract
The swift rise in acceptance of molecular principles defining phase separation by a broad array of scientific disciplines is shadowed by increasing discoveries linking phase separation to pathological aggregations associated with numerous neurodegenerative disorders, including Alzheimer’s disease, that contribute to dementia. Phase separation is powered by multivalent macromolecular interactions. Importantly, the release of water molecules from protein hydration shells into bulk creates entropic gains that promote phase separation and the subsequent generation of insoluble cytotoxic aggregates that drive healthy brain cells into diseased states. Higher viscosity in interfacial waters and limited hydration in interiors of biomolecular condensates facilitate phase separation. Light, water, and melatonin constitute an ancient synergy that ensures adequate protein hydration to prevent aberrant phase separation. The 670 nm visible red wavelength found in sunlight and employed in photobiomodulation reduces interfacial and mitochondrial matrix viscosity to enhance ATP production via increasing ATP synthase motor efficiency. Melatonin is a potent antioxidant that lowers viscosity to increase ATP by scavenging excess reactive oxygen species and free radicals. Reduced viscosity by light and melatonin elevates the availability of free water molecules that allow melatonin to adopt favorable conformations that enhance intrinsic features, including binding interactions with adenosine that reinforces the adenosine moiety effect of ATP responsible for preventing water removal that causes hydrophobic collapse and aggregation in phase separation. Precise recalibration of interspecies melatonin dosages that account for differences in metabolic rates and bioavailability will ensure the efficacious reinstatement of the once-powerful ancient synergy between light, water, and melatonin in a modern world.
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Guo R, Yin Y, Gao T, Lin S, Zhao L. Non-Newtonian shear viscosity of confined water in forsterite nanoslits: insights from molecular dynamics simulations. MOLECULAR SIMULATION 2022. [DOI: 10.1080/08927022.2022.2074480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Rui Guo
- National Engineering Research Center of Turbo-Generator Vibration, School of Energy and Environment, Southeast University, Nanjing, People’s Republic of China
| | - Yuming Yin
- National Engineering Research Center of Turbo-Generator Vibration, School of Energy and Environment, Southeast University, Nanjing, People’s Republic of China
| | - Teng Gao
- National Engineering Research Center of Turbo-Generator Vibration, School of Energy and Environment, Southeast University, Nanjing, People’s Republic of China
| | - Shangchao Lin
- Institute of Engineering Thermophysics, School of Mechanical and Power Engineering, Shanghai Jiao Tong University, Shanghai, People’s Republic of China
| | - Lingling Zhao
- National Engineering Research Center of Turbo-Generator Vibration, School of Energy and Environment, Southeast University, Nanjing, People’s Republic of China
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5
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Feng D, Chen Z, Wu K, Li J, Dong X, Peng Y, Jia X, Li X, Wang D. A comprehensive review on the flow behaviour in shale gas reservoirs: Multi‐scale, multi‐phase, and multi‐physics. CAN J CHEM ENG 2022. [DOI: 10.1002/cjce.24439] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Dong Feng
- State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum (Beijing) Beijing P. R. China
| | - Zhangxin Chen
- State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum (Beijing) Beijing P. R. China
- Department of Chemical and Petroleum Engineering University of Calgary Calgary Canada
| | - Keliu Wu
- State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum (Beijing) Beijing P. R. China
| | - Jing Li
- State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum (Beijing) Beijing P. R. China
| | - Xiaohu Dong
- State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum (Beijing) Beijing P. R. China
| | - Yan Peng
- State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum (Beijing) Beijing P. R. China
| | - Xinfeng Jia
- State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum (Beijing) Beijing P. R. China
| | - Xiangfang Li
- State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum (Beijing) Beijing P. R. China
| | - Dinghan Wang
- State Key Laboratory of Petroleum Resources and Prospecting China University of Petroleum (Beijing) Beijing P. R. China
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6
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Neffati R, Judeinstein P, Rault J. Supercooled nano-droplets of water confined in hydrophobic rubber. Phys Chem Chem Phys 2021; 23:25347-25355. [PMID: 34750601 DOI: 10.1039/d1cp03774a] [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
Hydrophobic elastomers are capable of absorbing a small amount of water that forms droplets around hydrophilic sites. These systems allow the study of confinement effects by a hydrophobic environment on the dynamics and thermodynamic behaviour of water molecules. The freezing-melting properties and the dynamics of water inside nano-droplets in butyl rubber are affected, as revealed by differential scanning calorimetry (DSC) and deuterium nuclear magnetic resonance (2H-NMR). Upon cooling down, all water crystalizes with a bimodal droplet population (da = 3.4 nm and db = 4.4 nm) in a temperature range associated with the droplet size distribution. However, the melting temperature is not shifted according to the Gibbs-Thomson equation. The relative decrease of the 2H-NMR longitudinal magnetization is not a single exponential and, by inverse Laplace transformation, it was deduced to be bimodal in agreement with the DSC measurements (T1,a ∼ 10 ms and T1,b ∼ 200 ms). The deduced correlation time of molecular reorientation is longer than that of bulk water and the behaviour with temperature follows the Vogel-Fulcher-Tammann (VFT) equations with a changing fragility as the droplet size is reduced when reducing hydration.
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Affiliation(s)
- R Neffati
- Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha, Saudi Arabia. .,Laboratoire de Physique de la Matière Condensée, Département de Physique, Faculté des Sciences de Tunis, Université Tunis El Manar, Campus Universitaire, 1060 Tunis, Tunisia
| | - P Judeinstein
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France.,Université Paris-Saclay, CNRS, CEA, Laboratoire Léon Brillouin, 91191, Gif-sur-Yvette, France
| | - J Rault
- Université Paris-Saclay, CNRS, Laboratoire de Physique des Solides, 91405, Orsay, France
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7
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Nazari M, Davoodabadi A, Huang D, Luo T, Ghasemi H. Transport Phenomena in Nano/Molecular Confinements. ACS NANO 2020; 14:16348-16391. [PMID: 33253531 DOI: 10.1021/acsnano.0c07372] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The transport of fluid and ions in nano/molecular confinements is the governing physics of a myriad of embodiments in nature and technology including human physiology, plants, energy modules, water collection and treatment systems, chemical processes, materials synthesis, and medicine. At nano/molecular scales, the confinement dimension approaches the molecular size and the transport characteristics deviates significantly from that at macro/micro scales. A thorough understanding of physics of transport at these scales and associated fluid properties is undoubtedly critical for future technologies. This compressive review provides an elaborate picture on the promising future applications of nano/molecular transport, highlights experimental and simulation metrologies to probe and comprehend this transport phenomenon, discusses the physics of fluid transport, tunable flow by orders of magnitude, and gating mechanisms at these scales, and lists the advancement in the fabrication methodologies to turn these transport concepts into reality. Properties such as chain-like liquid transport, confined gas transport, surface charge-driven ion transport, physical/chemical ion gates, and ion diodes will provide avenues to devise technologies with enhanced performance inaccessible through macro/micro systems. This review aims to provide a consolidated body of knowledge to accelerate innovation and breakthrough in the above fields.
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Affiliation(s)
- Masoumeh Nazari
- Department of Mechanical Engineering, University of Houston, 4726 Calhoun Road, Houston, Texas 77204, United States
| | - Ali Davoodabadi
- Department of Mechanical Engineering, University of Houston, 4726 Calhoun Road, Houston, Texas 77204, United States
| | - Dezhao Huang
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Tengfei Luo
- Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Hadi Ghasemi
- Department of Mechanical Engineering, University of Houston, 4726 Calhoun Road, Houston, Texas 77204, United States
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8
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Shaat M, Javed U, Faroughi S. Wettability and confinement size effects on stability of water conveying nanotubes. Sci Rep 2020; 10:17167. [PMID: 33051583 PMCID: PMC7555514 DOI: 10.1038/s41598-020-74398-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Accepted: 09/25/2020] [Indexed: 12/02/2022] Open
Abstract
This study investigates the wettability and confinement size effects on vibration and stability of water conveying nanotubes. We present an accurate assessment of nanotube stability by considering the exact mechanics of the fluid that is confined in the nanotube. Information on the stability of nanotubes in relation to the fluid viscosity, the driving force of the fluid flow, the surface wettability of the nanotube, and the nanotube size is missing in the literature. For the first time, we explore the surface wettability dependence of the nanotube natural frequencies and stability. By means of hybrid continuum-molecular mechanics (HCMM), we determined water viscosity variations inside the nanotube. Nanotubes with different surface wettability varying from super-hydrophobic to super-hydrophilic nanotubes were studied. We demonstrated a multiphase structure of nanoconfined water in nanotubes. Water was seen as vapor at the interface with the nanotube, ice shell in the middle, and liquid water in the nanotube core. The average velocity of water flow in the nanotube was obtained strongly depend on the surface wettability and the confinement size. In addition, we report the natural frequencies of the nanotube as functions of the applied pressure and the nanotube size. Mode divergence and flutter instabilities were observed, and the activation of these instabilities strongly depended on the nanotube surface wettability and size. This work gives important insights into understanding the stability of nanotubes conveying fluids depending on the operating pressures and the wettability and size of confinement. We revealed that hydrophilic nanotubes are generally more stable than hydrophobic nanotubes when conveying fluids.
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Affiliation(s)
- M Shaat
- Mechanical Engineering Department, Abu Dhabi University, P.O.BOX 1790, Al Ain, United Arab Emirates.
| | - U Javed
- Department of Engineering, American University of Iraq Sulaimani (AUIS), Sulaimania, 46001, Iraq
| | - S Faroughi
- Faculty of Mechanical Engineering, Urmia University of Technology, Urmia, Iran
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9
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Lynch C, Rao S, Sansom MSP. Water in Nanopores and Biological Channels: A Molecular Simulation Perspective. Chem Rev 2020; 120:10298-10335. [PMID: 32841020 PMCID: PMC7517714 DOI: 10.1021/acs.chemrev.9b00830] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Indexed: 12/18/2022]
Abstract
This Review explores the dynamic behavior of water within nanopores and biological channels in lipid bilayer membranes. We focus on molecular simulation studies, alongside selected structural and other experimental investigations. Structures of biological nanopores and channels are reviewed, emphasizing those high-resolution crystal structures, which reveal water molecules within the transmembrane pores, which can be used to aid the interpretation of simulation studies. Different levels of molecular simulations of water within nanopores are described, with a focus on molecular dynamics (MD). In particular, models of water for MD simulations are discussed in detail to provide an evaluation of their use in simulations of water in nanopores. Simulation studies of the behavior of water in idealized models of nanopores have revealed aspects of the organization and dynamics of nanoconfined water, including wetting/dewetting in narrow hydrophobic nanopores. A survey of simulation studies in a range of nonbiological nanopores is presented, including carbon nanotubes, synthetic nanopores, model peptide nanopores, track-etched nanopores in polymer membranes, and hydroxylated and functionalized nanoporous silica. These reveal a complex relationship between pore size/geometry, the nature of the pore lining, and rates of water transport. Wider nanopores with hydrophobic linings favor water flow whereas narrower hydrophobic pores may show dewetting. Simulation studies over the past decade of the behavior of water in a range of biological nanopores are described, including porins and β-barrel protein nanopores, aquaporins and related polar solute pores, and a number of different classes of ion channels. Water is shown to play a key role in proton transport in biological channels and in hydrophobic gating of ion channels. An overall picture emerges, whereby the behavior of water in a nanopore may be predicted as a function of its hydrophobicity and radius. This informs our understanding of the functions of diverse channel structures and will aid the design of novel nanopores. Thus, our current level of understanding allows for the design of a nanopore which promotes wetting over dewetting or vice versa. However, to design a novel nanopore, which enables fast, selective, and gated flow of water de novo would remain challenging, suggesting a need for further detailed simulations alongside experimental evaluation of more complex nanopore systems.
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Affiliation(s)
- Charlotte
I. Lynch
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, U.K.
| | - Shanlin Rao
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, U.K.
| | - Mark S. P. Sansom
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford, OX1 3QU, U.K.
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10
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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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11
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Sam A, Hartkamp R, Kumar Kannam S, Babu JS, Sathian SP, Daivis PJ, Todd BD. Fast transport of water in carbon nanotubes: a review of current accomplishments and challenges. MOLECULAR SIMULATION 2020. [DOI: 10.1080/08927022.2020.1782401] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- Alan Sam
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
| | - Remco Hartkamp
- Process and Energy Department, Delft University of Technology, Delft, The Netherlands
| | - Sridhar Kumar Kannam
- Faculty of Science, Engineering and Technology, Swinburne University of Technology, Melbourne, Australia
| | - Jeetu S. Babu
- Department of Mechanical Engineering, Amrita Vishwa Vidyapeetham, Amritapuri, India
| | - Sarith P. Sathian
- Department of Applied Mechanics, Indian Institute of Technology Madras, Chennai, India
| | - Peter J. Daivis
- School of Applied Sciences, RMIT University, Melbourne, Australia
| | - B. D. Todd
- Department of Mathematics, Swinburne University of Technology, Melbourne, Australia
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12
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Chan Y, Lee SL, Chen W, Zheng L, Shi Y, Ren Y. Newtonian flow inside carbon nanotube with permeable boundary taking into account van der Waals forces. Sci Rep 2019; 9:12121. [PMID: 31431670 PMCID: PMC6702207 DOI: 10.1038/s41598-019-48614-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 08/08/2019] [Indexed: 11/09/2022] Open
Abstract
Here, water flow inside large radii semi-infinite carbon nanotubes is investigated. Permeable wall taking into account the molecular interactions between water and a nanotube, and the slip boundary condition will be considered. Furthermore, interactions among molecules are approximated by the continuum approximation. Incompressible and Newtonian fluid is assumed, and the Navier-Stokes equations, after certain assumptions, transformations and derivations, can be reduced into two first integral equations. In conjunction with the asymptotic expansion technique, we are able to derive the radial and axial velocities analytically, capturing the effect of the water leakage, where both mild and exceptionally large leakages will be considered. The radial velocity obeys the prescribed boundary condition at the (im)permeable wall. Through the mean of the radial forces, the sufficiently large leakages will enhance the radial velocity at the center of the tube. On the other hand, unlike the classical laminar flow, the axial velocity attains its maximum at the wall due to the coupling effect with the radial forces as water is being pushed into the proximity of the inner wall. In addition, the axial velocity and the flux with the consideration of the suck-in forces, induced by the tubes’ entry turn out to be one order higher than that without the suck-in forces. All the aforementioned considerations might partially resolve the mysteriously high water penetration through nanotubes. Axial velocity also drops with the tube’s length when the water leakage is permitted and the suck-in forces will ease the decline rate of the axial velocity. The present mathematical framework can be directly employed into the water flow inside other porous nano-materials, where large water leakage is permitted and therefore are of huge practical impact on ultra-filtration and environmental protection.
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Affiliation(s)
- Yue Chan
- Institute for Advanced Study, Shenzhen University, Nanshan District Shenzhen, Guangdong, 518060, China.
| | - Shern-Long Lee
- Institute for Advanced Study, Shenzhen University, Nanshan District Shenzhen, Guangdong, 518060, China.
| | - Wenjian Chen
- Institute for Advanced Study, Shenzhen University, Nanshan District Shenzhen, Guangdong, 518060, China
| | - Lian Zheng
- Department of Mechanical, Materials and Manufacturing Engineering, Faculty of Science and Engineering, The University of Nottingham Ningbo China, 199 Taikang East Road, Ningbo, China
| | - Yong Shi
- Department of Mechanical, Materials and Manufacturing Engineering, Faculty of Science and Engineering, The University of Nottingham Ningbo China, 199 Taikang East Road, Ningbo, China
| | - Yong Ren
- Department of Mechanical, Materials and Manufacturing Engineering, Faculty of Science and Engineering, The University of Nottingham Ningbo China, 199 Taikang East Road, Ningbo, China.
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Sahu P, Ali SM. Breakdown of continuum model for water transport and desalination through ultrathin graphene nanopores: insights from molecular dynamics simulations. Phys Chem Chem Phys 2019; 21:21389-21406. [DOI: 10.1039/c9cp04364k] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In the quest for identifying a graphene membrane for efficient water desalination, molecular dynamics simulations were performed for the pressure-driven flow of salty water across a multilayer graphene membrane.
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Affiliation(s)
- Pooja Sahu
- Bhabha Atomic Research Center
- Mumbai 400085
- India
- Homi Bhabha National Institute
- Mumbai 400094
| | - Sk. Musharaf Ali
- Bhabha Atomic Research Center
- Mumbai 400085
- India
- Homi Bhabha National Institute
- Mumbai 400094
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