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Li H, Xu Z, Ma M. Temperature-dependent slip length for water and electrolyte solution. J Colloid Interface Sci 2023; 636:512-517. [PMID: 36652826 DOI: 10.1016/j.jcis.2023.01.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 01/01/2023] [Accepted: 01/08/2023] [Indexed: 01/12/2023]
Abstract
HYPOTHESIS The temperature dependence of boundary slip at liquid-solid interface is critical both for the fundamental theory and applications of fluid mechanics on micro and nanoscale, such as sustainable cooling of electronic devices. However, there is a controversy on the temperature dependence of boundary slip which lacks experimental evidence, we aim to resolve it by hypothesizing that the temperature dependent slip length depends on the variation in the interfacial energy barrier. EXPERIMENTS Here, we measured ls - T relation of water and NaCl solution on self-assembled FDTS (Perfluorodecyltrichlorosilane) surface using colloidal probe AFM. The transition of ls - T monotonicity is found. For water and 0.1 M NaCl solution, ls is negatively correlated with T, while for 1 M NaCl solution, ls is positively correlated with T. FINDINGS Together with molecular dynamics simulations, such observation is quantitatively explained with an analytical model based on rate theory, where the ls - T monotonicity depends on the difference between liquid-solid interfacial energy barrier and liquid internal energy barrier. Our results provide not only solid experimental evidence for the boundary slip being a rate process, but also a basis for the thermal-hydrodynamic design of microfluidic and nanofluidic devices.
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Affiliation(s)
- Han Li
- Department of Mechanical Engineering, State Key Laboratory of Tribology in Advanced Equipment (SKLT), Tsinghua University, Beijing 100084, China; Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
| | - Zhi Xu
- Department of Mechanical Engineering, State Key Laboratory of Tribology in Advanced Equipment (SKLT), Tsinghua University, Beijing 100084, China; Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
| | - Ming Ma
- Department of Mechanical Engineering, State Key Laboratory of Tribology in Advanced Equipment (SKLT), Tsinghua University, Beijing 100084, China; Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China.
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2
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Xu Z, Li H, Ma M. Accurate estimation of dynamical quantities for nonequilibrium nanoscale systems. Phys Rev E 2023; 107:014124. [PMID: 36797886 DOI: 10.1103/physreve.107.014124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 12/09/2022] [Indexed: 06/18/2023]
Abstract
Fluctuations of dynamical quantities are fundamental and inevitable. For the booming research in nanotechnology, huge relative fluctuation comes with the reduction of system size, leading to large uncertainty for the estimates of dynamical quantities. Thus, increasing statistical efficiency, i.e., reducing the number of samples required to achieve a given accuracy, is of great significance for accurate estimation. Here we propose a theory as a fundamental solution for such problem by constructing auxiliary path for each real path. The states on auxiliary paths constitute canonical ensemble and share the same macroscopic properties (NVT) with the initial states of the real path. By implementing the theory in molecular dynamics simulations, we obtain a nanoscale Couette flow field with an accuracy of 0.2μm/s with relative standard error <0.1. The required number of samples is reduced by 12 orders compared to conventional method. The predicted thermolubric behavior of water sliding on a self-assembled surface is directly validated by experiment under the same velocity. This theory only assumes the system is initially in thermal equilibrium, then driven from that equilibrium by an external perturbation. It could serve as a general approach for extracting the accurate estimate of dynamical quantities from large fluctuations to provide insights on atomic level under experimental conditions, and benefit the studies on mass transport through (biological) nanochannels and fluid film lubrication of nanometer thickness.
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Affiliation(s)
- Zhi Xu
- Department of Mechanical Engineering, State Key Laboratory of Tribology in Advanced Equipment (SKLT), Tsinghua University, Beijing 100084, China and Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
| | - Han Li
- Department of Mechanical Engineering, State Key Laboratory of Tribology in Advanced Equipment (SKLT), Tsinghua University, Beijing 100084, China and Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
| | - Ming Ma
- Department of Mechanical Engineering, State Key Laboratory of Tribology in Advanced Equipment (SKLT), Tsinghua University, Beijing 100084, China and Center for Nano and Micro Mechanics, Tsinghua University, Beijing 100084, China
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3
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Drecun O, Striolo A, Bernardini C, Sarwar M. Hydration Structures on γ-Alumina Surfaces With and Without Electrolytes Probed by Atomistic Molecular Dynamics Simulations. J Phys Chem B 2022; 126:9105-9122. [PMID: 36321420 PMCID: PMC9661474 DOI: 10.1021/acs.jpcb.2c06491] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A wide range of systems, both engineered and natural, feature aqueous electrolyte solutions at interfaces. In this study, the structure and dynamics of water at the two prevalent crystallographic terminations of gamma-alumina, [110] and [100], and the influence of salts─sodium chloride, ammonium acetate, barium acetate, and barium nitrate on such properties─were investigated using equilibrium molecular dynamics simulations. The resulting interfacial phenomena were quantified from simulation trajectories via atomic density profiles, angle probability distributions, residence times, 2-D density distributions within the hydration layers, and hydrogen bond density profiles. Analysis and interpretation of the results are supported by simulation snapshots. Taken together, our results show stronger interaction and closer association of water with the [110] surface, compared to [100], while ion-induced disruption of interfacial water structure was more prevalent at the [100] surface. For the latter, a stronger association of cations is observed, namely sodium and ammonium, and ion adsorption appears determined by their size. The differences in surface-water interactions between the two terminations are linked to their respective surface features and distributions of surface groups, with atomistic-scale roughness of the [110] surface promoting closer association of interfacial water. The results highlight the fundamental role of surface characteristics in determining surface-water interactions, and the resulting effects on ion-surface and ion-water interactions. Since the two terminations of gamma-alumina considered represent interfaces of significance to numerous industrial applications, the results provide insights relevant for catalyst preparation and adsorption-based water treatment, among other applications.
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Affiliation(s)
- Olivera Drecun
- Department
of Chemical Engineering, University College
London, London WC1E 7JE, United Kingdom
| | - Alberto Striolo
- Department
of Chemical Engineering, University College
London, London WC1E 7JE, United Kingdom,School
of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, Oklahoma 73019, United States,
| | - Cecilia Bernardini
- Johnson
Matthey Technology Centre, Sonning Common, Reading RG4 9NH, United Kingdom
| | - Misbah Sarwar
- Johnson
Matthey Technology Centre, Sonning Common, Reading RG4 9NH, United Kingdom
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4
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Zhao Y, Li W, Zhan S, Jin Z. Breakthrough pressure of oil displacement by water through the ultra-narrow kerogen pore throat from the Young-Laplace equation and molecular dynamic simulations. Phys Chem Chem Phys 2022; 24:17195-17209. [PMID: 35792334 DOI: 10.1039/d2cp01643e] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
As one common unconventional reservoir, shale plays a pivotal role to compensate the depletion of conventional oil resources. There are numerous nanoscale pores and ultra-narrow pore throats (sub 2 nm) in shale media. To displace oil through ultra-narrow pore throats by water, one needs to overcome excessively-high capillary pressure. Understanding the water-oil two-phase displacement process through pore throats is critical to numerical simulation on tight/shale oil exploitation and ultimate oil recovery estimation. In this work, we use molecular dynamics simulations to investigate oil (represented by n-octane) displacement by water through a ~2 nm kerogen (represented by Type II-C kerogen) pore throat. Besides, the applicability of the Young-Laplace equation to the ultra-narrow kerogen pore throat has been assessed. We find that although the Type II-C kerogen is generally oil-wet, water has an excellent displacement efficiency without the oil film on the substrate, thanks to the hydrogen bonding formed between water and heteroatoms (such as O, N, and S) on the kerogen surface. Unlike previous studies, the capillary pressure obtained from the widely used Young-Laplace equation shows a good agreement with the breakthrough pressure obtained from MD simulations for the ∼2 nm kerogen pore throat. Our work indicates that explicitly considering intermolecular interactions as well as atomistic and molecular level characteristics is imperative to study the two-phase displacement process through ultra-narrow pore throats.
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Affiliation(s)
- Yinuo Zhao
- School of Mining and Petroleum Engineering, Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
| | - Wenhui Li
- School of Mining and Petroleum Engineering, Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
| | - Shiyuan Zhan
- College of Energy, Chengdu University of Technology, Chengdu 610059, China.,State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, China
| | - Zhehui Jin
- School of Mining and Petroleum Engineering, Department of Civil and Environmental Engineering, University of Alberta, Edmonton, AB T6G 1H9, Canada.
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5
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Li J, Cao W, Li J, Ma M. Fluorination to enhance superlubricity performance between self-assembled monolayer and graphite in water. J Colloid Interface Sci 2021; 596:44-53. [PMID: 33826969 DOI: 10.1016/j.jcis.2021.03.133] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 03/22/2021] [Accepted: 03/23/2021] [Indexed: 11/26/2022]
Abstract
HYPOTHESIS Achievement of superlubricity is an effective method to reduce friction and wear, which has a prominent influence on the operational efficiency and lifetime of a device. However, some burning issues still remain to be solved for the practical applications of superlubricity, such as the poor load-bearing capacity, especially in liquid superlubricity. Therefore, exploring an effective method to enhance the superlubricity performance is essential to accelerate the application of superlubricity. EXPERIMENTS The friction properties between two different self-assembled monolayers (SAMs)-a perfluorocarbon SAM and a hydrocarbon SAM-and graphite in water were explored and compared by atomic force microscopy (AFM). FINDINGS Enhanced superlubricity performance due to the fluorination was observed. Specifically, we observed an approximately 85% reduction of the friction coefficient after fluorination, and superlubricity was achieved with extremely low friction coefficient of 0.0003. Moreover, 2.4-fold greater load-bearing capacity of the superlubricity was obtained after fluorination. The molecular origin of the superlubricity enhancement by fluorination was revealed by molecular dynamics (MD) simulations, indicating that the greater load-bearing capacity of the perfluorocarbon SAM was ascribed to the enhanced interaction between the water and SAM by fluorination to form a more robust layered water structure confined in the contact zone, which played a pivotal role in the superlubricity.
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Affiliation(s)
- Jianfeng Li
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Wei Cao
- Department of Physical Chemistry, School of Chemistry, The Raymond and Beverly Sackler Faculty of Exact Sciences and The Sackler Center for Computational Molecular and Materials Science, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Jinjin Li
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China.
| | - Ming Ma
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China.
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6
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Senanayake HS, Greathouse JA, Ilgen AG, Thompson WH. Simulations of the IR and Raman spectra of water confined in amorphous silica slit pores. J Chem Phys 2021; 154:104503. [PMID: 33722003 DOI: 10.1063/5.0040739] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Water in nano-scale confining environments is a key element in many biological, material, and geological systems. The structure and dynamics of the liquid can be dramatically modified under these conditions. Probing these changes can be challenging, but vibrational spectroscopy has emerged as a powerful tool for investigating their behavior. A critical, evolving component of this approach is a detailed understanding of the connection between spectroscopic features and molecular-level details. In this paper, this issue is addressed by using molecular dynamics simulations to simulate the linear infrared (IR) and Raman spectra for isotopically dilute HOD in D2O confined in hydroxylated amorphous silica slit pores. The effect of slit-pore width and hydroxyl density on the silica surface on the vibrational spectra is also investigated. The primary effect of confinement is a blueshift in the frequency of OH groups donating a hydrogen bond to the silica surface. This appears as a slight shift in the total (measurable) spectra but is clearly seen in the distance-based IR and Raman spectra. Analysis indicates that these changes upon confinement are associated with the weaker hydrogen-bond accepting properties of silica oxygens compared to water molecules.
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Affiliation(s)
| | - Jeffery A Greathouse
- Geochemistry Department, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - Anastasia G Ilgen
- Geochemistry Department, Sandia National Laboratories, Albuquerque, New Mexico 87185, USA
| | - Ward H Thompson
- Department of Chemistry, University of Kansas, Lawrence, Kansas 66045, USA
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7
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Moncayo-Riascos I, Hoyos BA. Fluorocarbon versus hydrocarbon organosilicon surfactants for wettability alteration: A molecular dynamics approach. J IND ENG CHEM 2020. [DOI: 10.1016/j.jiec.2020.04.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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8
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PDADMAC/PSS Oligoelectrolyte Multilayers: Internal Structure and Hydration Properties at Early Growth Stages from Atomistic Simulations. Molecules 2020; 25:molecules25081848. [PMID: 32316422 PMCID: PMC7222011 DOI: 10.3390/molecules25081848] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/06/2020] [Accepted: 04/14/2020] [Indexed: 11/17/2022] Open
Abstract
We analyze the internal structure and hydration properties of poly(diallyl dimethyl ammonium chloride)/poly(styrene sulfonate sodium salt) oligoelectrolyte multilayers at early stages of their layer-by-layer growth process. Our study is based on large-scale molecular dynamics simulations with atomistic resolution that we presented recently [Sánchez et al., Soft Matter2019, 15, 9437], in which we produced the first four deposition cycles of a multilayer obtained by alternate exposure of a flat silica substrate to aqueous electrolyte solutions of such polymers at 0.1M of NaCl. In contrast to any previous work, here we perform a local structural analysis that allows us to determine the dependence of the multilayer properties on the distance to the substrate. We prove that the large accumulation of water and ions next to the substrate observed in previous overall measurements actually decreases the degree of intrinsic charge compensation, but this remains as the main mechanism within the interface region. We show that the range of influence of the substrate reaches approximately 3 nm, whereas the structure of the outer region is rather independent from the position. This detailed characterization is essential for the development of accurate mesoscale models able to reach length and time scales of technological interest.
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9
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Smirnov KS. Structure and sum-frequency generation spectra of water on uncharged Q 4 silica surfaces: a molecular dynamics study. Phys Chem Chem Phys 2020; 22:2033-2045. [PMID: 31904065 DOI: 10.1039/c9cp05765j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The structural characteristics and sum-frequency generation (SFG) spectra of water near neutral Q4 silica surfaces were investigated by molecular dynamics simulations. The interactions of water molecules with atoms of the solid were described by different potential models, in particular by the CLAYFF [Cygan et al., J. Phys. Chem. B, 2004, 108, 1255] and INTERFACE [Heinz et al. Langmuir, 2013, 29, 1754] force fields. The calculations of the contact angle of water have shown that the silica surface modeled with CLAYFF behaves as macroscopically hydrophilic, in contrast to the surface described with the INTERFACE model. The hydrophilicity of CLAYFF stems from too attractive electrostatic surface-water interactions. Regardless of the surface's affinity for water, the aqueous phase has a layered structure in the direction perpendicular to the surface with density fluctuations decaying within a distance of 10 Å from the surface. The orientational ordering of H2O molecules was found to be more short-range than the density fluctuations, especially for the hydrophobic surfaces. Modeling the SFG spectra has shown that the spectra of all studied hydrophobic silica-water interfaces are similar and have features in common with the spectrum of the water-vapor interface. The spectra fairly agree with experimental results obtained for the silica-water interface at low pH conditions [Myalitsin et al., J. Phys. Chem. C, 2016, 120, 9357]. The spectral response for the hydrophobic interface was computed to primarily arise from the topmost molecules of the first layer of interfacial water. In contrast, the SFG signal from the hydrophilic silica-water interface is accumulated over a greater distance extending for several water layers due to more long-range perturbation of the structure by the surface.
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Affiliation(s)
- Konstantin S Smirnov
- Univ. Lille, CNRS, UMR 8516 - LASIR - Laboratoire de Spectrochimie Infrarouge et Raman, F-59000 Lille, France.
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10
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M R, Ayappa KG. Influence of surface hydrophilicity and hydration on the rotational relaxation of supercooled water on graphene oxide surfaces. Phys Chem Chem Phys 2020; 22:16080-16095. [DOI: 10.1039/d0cp01515f] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The presence of a bulk water film influences the dynamical transitions of supercooled water on graphene oxide surfaces.
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Affiliation(s)
- Rajasekaran M
- Department of Chemical Engineering
- Indian Institute of Science
- Bangalore
- India
| | - K. Ganapathy Ayappa
- Department of Chemical Engineering
- Indian Institute of Science
- Bangalore
- India
- Centre for Biosystems Science and Engineering
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11
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Sánchez PA, Vögele M, Smiatek J, Qiao B, Sega M, Holm C. Atomistic simulation of PDADMAC/PSS oligoelectrolyte multilayers: overall comparison of tri- and tetra-layer systems. SOFT MATTER 2019; 15:9437-9451. [PMID: 31720676 DOI: 10.1039/c9sm02010a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
By employing large-scale molecular dynamics simulations of atomistically resolved oligoelectrolytes in aqueous solutions, we study in detail the first four layer-by-layer deposition cycles of an oligoelectrolyte multilayer made of poly(diallyl dimethyl ammonium chloride)/poly(styrene sulfonate sodium salt) (PDADMAC/PSS). The multilayers are grown on a silica substrate in 0.1 M NaCl electrolyte solutions and the swollen structures are then subsequently exposed to varying added salt concentration. We investigated the microscopic properties of the films, analyzing in detail the differences between three- and four-layer systems. Our simulations provide insights into the early stages of growth of a multilayer, which are particularly challenging for experimental observations. We found rather strong complexation of the oligoelectrolytes, with fuzzy layering of the film structure. The main charge compensation mechanism is for all cases intrinsic, whereas extrinsic compensation is relatively enhanced for the layer of the last deposition cycle. In addition, we quantified other fundamental observables of these systems, such as the film thickness, water uptake, and overcharge fractions for each deposition layer.
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Affiliation(s)
- Pedro A Sánchez
- Ural Federal University, 51 Lenin av., Ekaterinburg, 620000, Russian Federation. and Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf e.V., Dresden, Germany
| | - Martin Vögele
- Department of Computer Science, Stanford University, Stanford, California, USA
| | - Jens Smiatek
- Institut für Computerphysik, Universität Stuttgart, 70569 Stuttgart, Germany
| | - Baofu Qiao
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois, USA
| | - Marcello Sega
- Forschungszentrum Jülich, Helmholtz Institute Erlangen-Nuremberg, Nuremberg, Germany
| | - Christian Holm
- Institut für Computerphysik, Universität Stuttgart, 70569 Stuttgart, Germany
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12
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Apostolopoulou M, Santos MS, Hamza M, Bui T, Economou IG, Stamatakis M, Striolo A. Quantifying Pore Width Effects on Diffusivity via a Novel 3D Stochastic Approach with Input from Atomistic Molecular Dynamics Simulations. J Chem Theory Comput 2019; 15:6907-6922. [PMID: 31603675 DOI: 10.1021/acs.jctc.9b00776] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The increased production of unconventional hydrocarbons emphasizes the need to understand the transport of fluids through narrow pores. Although it is well-known that confinement affects fluids structure and transport, it is not yet possible to quantitatively predict properties such as diffusivity as a function of pore width in the range of 1-50 nm. Such pores are commonly found not only in shale rocks but also in a wide range of engineering materials, including catalysts. We propose here a novel and computationally efficient methodology to obtain accurate diffusion coefficient predictions as a function of pore width for pores carved out of common materials, such as silica, alumina, magnesium oxide, calcite, and muscovite. We implement atomistic molecular dynamics (MD) simulations to quantify fluid structure and transport within 5 nm-wide pores, with particular focus on the diffusion coefficient within different pore regions. We then use these data as input to a bespoke stochastic kinetic Monte Carlo (KMC) model, developed to predict fluid transport in mesopores. The KMC model is used to extrapolate the fluid diffusivity for pores of increasing width. We validate the approach against atomistic MD simulation results obtained for wider pores. When applied to supercritical methane in slit-shaped pores, our methodology yields data within 10% of the atomistic simulation results, with significant savings in computational time. The proposed methodology, which combines the advantages of MD and KMC simulations, is used to generate a digital library for the diffusivity of gases as a function of pore chemistry and pore width and could be relevant for a number of applications, from the prediction of hydrocarbon transport in shale rocks to the optimization of catalysts, when surface-fluid interactions impact transport.
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Affiliation(s)
- Maria Apostolopoulou
- Department of Chemical Engineering , University College London , Torrington Place , London WC1E 7JE , United Kingdom
| | - Mirella S Santos
- Chemical Engineering Program , Texas A&M University at Qatar , P.O. Box 23874, Doha , Qatar
| | - Muhammad Hamza
- Chemical Engineering Program , Texas A&M University at Qatar , P.O. Box 23874, Doha , Qatar
| | - Tai Bui
- Department of Chemical Engineering , University College London , Torrington Place , London WC1E 7JE , United Kingdom
| | - Ioannis G Economou
- Chemical Engineering Program , Texas A&M University at Qatar , P.O. Box 23874, Doha , Qatar
| | - Michail Stamatakis
- Department of Chemical Engineering , University College London , Torrington Place , London WC1E 7JE , United Kingdom
| | - Alberto Striolo
- Department of Chemical Engineering , University College London , Torrington Place , London WC1E 7JE , United Kingdom
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13
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Li J, Cao W, Wang Z, Ma M, Luo J. Origin of hydration lubrication of zwitterions on graphene. NANOSCALE 2018; 10:16887-16894. [PMID: 30175359 DOI: 10.1039/c8nr05724a] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Formation of a hydration layer on charge sites can support normal pressure, and meanwhile it retains excellent fluidity to provide efficient boundary lubrication; however, it is limited to the sliding system between two similarly charged surfaces. In the present study, we report extremely low friction as the zwitterions in a lipid bilayer slide on the topmost graphene layer of graphite across pure water, with the friction coefficient falling to the level of 0.001, which provides direct evidence that hydration lubrication is effective even between such dissimilar surfaces. The origin of hydration lubrication on graphene was studied by atomic force microscopy and molecular dynamics simulation simultaneously. It reveals that a subnanometer hydration layer is confined between zwitterions and graphene, which remains as a liquid phase under normal pressure. The shear occurs between water molecules and graphene because of the extremely low shear strength of the water/graphene interface, which contributes to extremely low friction. Our finding demonstrates that the formation of a hydration layer is possible to lubricate layered materials efficiently, which has potential implications for designing efficient boundary lubrication with layered materials.
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Affiliation(s)
- Jinjin Li
- State Key Laboratory of Tribology, Tsinghua University, Beijing, 100084, China.
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14
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Shevkunov S, Singh JK. Bicanonical ensemble Monte Carlo simulation of water condensation in the field of crystal lattice defects. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.05.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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15
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Wang W, Dong W, Jiang D, Ning Z. Water molecules migration at the oil-paper interface during heating: a large-scale distributed computing study. MOLECULAR SIMULATION 2018. [DOI: 10.1080/08927022.2018.1475738] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Wei Wang
- Beijing Key Laboratory of High Voltage & Electromagnetic Compatibility, North China Electric Power University , Beijing, China
| | - Wenyan Dong
- Beijing Key Laboratory of High Voltage & Electromagnetic Compatibility, North China Electric Power University , Beijing, China
| | - Da Jiang
- Beijing Key Laboratory of High Voltage & Electromagnetic Compatibility, North China Electric Power University , Beijing, China
| | - Zhongzheng Ning
- Beijing Key Laboratory of High Voltage & Electromagnetic Compatibility, North China Electric Power University , Beijing, China
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16
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Ho TA, Greathouse JA, Lee AS, Criscenti LJ. Enhanced Ion Adsorption on Mineral Nanoparticles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:5926-5934. [PMID: 29746135 DOI: 10.1021/acs.langmuir.8b00680] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Classical molecular dynamics simulation was used to study the adsorption of Na+, Ca2+, Ba2+, and Cl- ions on gibbsite edge (1 0 0), basal (0 0 1), and nanoparticle (NP) surfaces. The gibbsite NP consists of both basal and edge surfaces. Simulation results indicate that Na+ and Cl- ions adsorb on both (1 0 0) and (0 0 1) surfaces as inner-sphere species (i.e., no water molecules between an ion and the surface). Outer-sphere Cl- ions (i.e., one water molecule between an ion and the surface) were also found on these surfaces. On the (1 0 0) edge, Ca2+ ions adsorb as inner-sphere and outer-sphere complexes, whereas on the (0 0 1) surface, outer-sphere Ca2+ ions are the dominant species. Ba2+ ions were found as inner-sphere and outer-sphere complexes on both surfaces. Calculated ion surface coverages indicate that, for all ions, surface coverages are always higher on the basal surface compared to those on the edge surface. More importantly, surface coverages for cations on the gibbsite NP are always higher than those calculated for the (1 0 0) and (0 0 1) surfaces. This enhanced ion adsorption behavior for the NP is due to the significant number of inner-sphere cations found at NP corners. Outer-sphere cations do not contribute to the enhanced surface coverage. In addition, there is no ion adsorption enhancement observed for the Cl- ion. Our work provides a molecular-scale understanding of the relative significance of ion adsorption onto gibbsite basal versus edge surfaces and demonstrates the corner effect on ion adsorption on NPs.
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Affiliation(s)
- Tuan A Ho
- Geochemistry Department , Sandia National Laboratories , Albuquerque , New Mexico 87185 , United States
| | - Jeffery A Greathouse
- Geochemistry Department , Sandia National Laboratories , Albuquerque , New Mexico 87185 , United States
| | - Andrew S Lee
- Geochemistry Department , Sandia National Laboratories , Albuquerque , New Mexico 87185 , United States
| | - Louise J Criscenti
- Geochemistry Department , Sandia National Laboratories , Albuquerque , New Mexico 87185 , United States
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17
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Le TT, Striolo A. Propane-Water Mixtures Confined within Cylindrical Silica Nanopores: Structural and Dynamical Properties Probed by Molecular Dynamics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:11310-11320. [PMID: 28910531 PMCID: PMC5657426 DOI: 10.1021/acs.langmuir.7b03093] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 09/11/2017] [Indexed: 06/07/2023]
Abstract
Despite the multiple length and time scales over which fluid-mineral interactions occur, interfacial phenomena control the exchange of matter and impact the nature of multiphase flow, as well as the reactivity of C-O-H fluids in geologic systems. In general, the properties of confined fluids, and their influence on porous geologic phenomena are much less well understood compared to those of bulk fluids. We used equilibrium molecular dynamics simulations to study fluid systems composed of propane and water, at different compositions, confined within cylindrical pores of diameter ∼16 Å carved out of amorphous silica. The simulations are conducted within a single cylindrical pore. In the simulated system all the dangling silicon and oxygen atoms were saturated with hydroxyl groups and hydrogen atoms, respectively, yielding a total surface density of 3.8 -OH/nm2. Simulations were performed at 300 K, at different bulk propane pressures, and varying the composition of the system. The structure of the confined fluids was quantified in terms of the molecular distribution of the various molecules within the pore as well as their orientation. This allowed us to quantify the hydrogen bond network and to observe the segregation of propane near the pore center. Transport properties were quantified in terms of the mean square displacement in the direction parallel to the pore axis, which allows us to extract self-diffusion coefficients. The diffusivity of propane in the cylindrical pore was found to depend on pressure, as well as on the amount of water present. It was found that the propane self-diffusion coefficient decreases with increasing water loading because of the formation of water bridges across the silica pores, at sufficiently high water content, which hinder propane transport. The rotational diffusion, the lifespan of hydrogen bonds, and the residence time of water molecules at contact with the silica substrate were quantified from the simulated trajectories using the appropriate autocorrelation functions. The simulations contribute to a better understanding of the molecular phenomena relevant to the behavior of fluids in the subsurface.
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Affiliation(s)
- Tran Thi
Bao Le
- Department of Chemical Engineering, University College London, London WC1E 6BT United Kingdom
| | - Alberto Striolo
- Department of Chemical Engineering, University College London, London WC1E 6BT United Kingdom
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Shevkunov SV. Water-vapor clustering on the surface of β-AgI crystal in the field of defects with a disordered structure. COLLOID JOURNAL 2017. [DOI: 10.1134/s1061933x1705012x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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19
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Le T, Striolo A, Turner CH, Cole DR. Confinement Effects on Carbon Dioxide Methanation: A Novel Mechanism for Abiotic Methane Formation. Sci Rep 2017; 7:9021. [PMID: 28827636 PMCID: PMC5566444 DOI: 10.1038/s41598-017-09445-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 07/26/2017] [Indexed: 11/08/2022] Open
Abstract
An important scientific debate focuses on the possibility of abiotic synthesis of hydrocarbons during oceanic crust-seawater interactions. While on-site measurements near hydrothermal vents support this possibility, laboratory studies have provided data that are in some cases contradictory. At conditions relevant for sub-surface environments it has been shown that classic thermodynamics favour the production of CO2 from CH4, while abiotic methane synthesis would require the opposite. However, confinement effects are known to alter reaction equilibria. This report shows that indeed thermodynamic equilibrium can be shifted towards methane production, suggesting that thermal hydrocarbon synthesis near hydrothermal vents and deeper in the magma-hydrothermal system is possible. We report reactive ensemble Monte Carlo simulations for the CO2 methanation reaction. We compare the predicted equilibrium composition in the bulk gaseous phase to that expected in the presence of confinement. In the bulk phase we obtain excellent agreement with classic thermodynamic expectations. When the reactants can exchange between bulk and a confined phase our results show strong dependency of the reaction equilibrium conversions, [Formula: see text], on nanopore size, nanopore chemistry, and nanopore morphology. Some physical conditions that could shift significantly the equilibrium composition of the reactive system with respect to bulk observations are discussed.
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Affiliation(s)
- Thu Le
- Department of Chemical Engineering, University College London, London, WC1E 6BT, United Kingdom
| | - Alberto Striolo
- Department of Chemical Engineering, University College London, London, WC1E 6BT, United Kingdom
| | - C Heath Turner
- Department of Chemical and Biological Engineering, University of Alabama, Tuscaloosa, AL, 35487, United States
| | - David R Cole
- School of Earth Sciences, The Ohio State University, Columbus, Ohio, 43210, United States.
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20
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Nie X, Chen J, Sheng N, Zeng L, Yang H, Wang C. Effect of water molecules on nanoscale wetting behaviour of molecular ethanol on hydroxylated SiO2 substrate. MOLECULAR SIMULATION 2017. [DOI: 10.1080/08927022.2017.1353692] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Xuechuan Nie
- Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jige Chen
- Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China
| | - Nan Sheng
- Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China
| | - Li Zeng
- College of Physics and Electronic Engineering, Guangxi Teachers Education University, Nanning, China
| | - Haijun Yang
- Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China
| | - Chunlei Wang
- Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China
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Rimsza JM, Jones RE, Criscenti LJ. Surface Structure and Stability of Partially Hydroxylated Silica Surfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:3882-3891. [PMID: 28375622 DOI: 10.1021/acs.langmuir.7b00041] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Surface energies of silicates influence crack propagation during brittle fracture and decrease with surface relaxation caused by annealing and hydroxylation. Molecular-level simulations are particularly suited for the investigation of surface processes. In this work, classical MD simulations of silica surfaces are performed with two force fields (ClayFF and ReaxFF) to investigate the effect of force field reactivity on surface structure and energy as a function of surface hydroxylation. An unhydroxylated fracture surface energy of 5.1 J/m2 is calculated with the ClayFF force field, and 2.0 J/m2 is calculated for the ReaxFF force field. The ClayFF surface energies are consistent with the experimental results from double cantilever beam fracture tests (4.5 J/m2), whereas ReaxFF underestimated these surface energies. Surface relaxation via annealing and hydroxylation was performed by creating a low-energy equilibrium surface. Annealing condensed neighboring siloxane bonds increased the surface connectivity, and decreased the surface energies by 0.2 J/m2 for ClayFF and 0.8 J/m2 for ReaxFF. Posthydroxylation surface energies decreased further to 4.6 J/m2 with the ClayFF force field and to 0.2 J/m2 with the ReaxFF force field. Experimental equilibrium surface energies are ∼0.35 J/m2, consistent with the ReaxFF force field. Although neither force field was capable of replicating both the fracture and equilibrium surface energies reported from experiment, each was consistent with one of these conditions. Therefore, future computational investigations that rely on accurate surface energy values should consider the surface state of the system and select the appropriate force field.
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Affiliation(s)
- J M Rimsza
- Geochemistry Department, Sandia National Laboratories , Albuquerque, New Mexico 87185, United States
| | - R E Jones
- Science-Based Material Modeling Department, Sandia National Laboratories , Livermore, California 94551, United States
| | - L J Criscenti
- Geochemistry Department, Sandia National Laboratories , Albuquerque, New Mexico 87185, United States
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Gautam S, Le T, Striolo A, Cole D. Molecular dynamics simulations of propane in slit shaped silica nano-pores: direct comparison with quasielastic neutron scattering experiments. Phys Chem Chem Phys 2017; 19:32320-32332. [DOI: 10.1039/c7cp05715f] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
MD simulations reveal the origin of anomalous pressure dependence of propane diffusion in silica mesopores.
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Affiliation(s)
- Siddharth Gautam
- School of Earth Sciences
- The Ohio State University
- Columbus 43210
- USA
| | - Thu Le
- Department of Chemical Engineering
- University College London
- London WC1E 6BT
- UK
| | - Alberto Striolo
- Department of Chemical Engineering
- University College London
- London WC1E 6BT
- UK
| | - David Cole
- School of Earth Sciences
- The Ohio State University
- Columbus 43210
- USA
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23
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Affiliation(s)
- Alberto Striolo
- Department of Chemical Engineering, University College London, London, UK
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24
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Zheng J, Zhang J, Tan L, Li D, Huang L, Wang Q, Liu Y. Effects of Aspect Ratio on Water Immersion into Deep Silica Nanoholes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:8759-8766. [PMID: 27506253 DOI: 10.1021/acs.langmuir.6b01575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Understanding the influence of aspect ratio on water immersion into silica nanoholes is of significant importance to the etching process of semiconductor fabrication and other water immersion-related physical and biological processes. In this work, the processes of water immersion into silica nanoholes with different height/width aspect ratios (ϕ = 0.87, 1.92, 2.97, 4.01, 5.06) and different numbers of water molecules (N = 9986, 19972, 29958, 39944) were studied by molecular dynamics simulations. A comprehensive analysis has been conducted about the detailed process of water immersion and the influence of aspect ratios on water immersion rates. Five distinguishable stages were identified for the immersion process with all studied models. The results reveal that water can easily immerse into the silica nanoholes with larger ϕ and smaller N. The calculation also suggests that aspect ratios have a greater effect on water immersion rates for larger N numbers. The mechanism of the water immersion process is discussed in this work. We also propose a mathematical model to correlate the complete water immersion process for different aspect ratios.
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Affiliation(s)
- Jing Zheng
- Department of Chemistry and Soft Matter Research Center, Zhejiang University , Hangzhou 310027, People's Republic of China
| | - Junqiao Zhang
- Department of Chemistry and Soft Matter Research Center, Zhejiang University , Hangzhou 310027, People's Republic of China
| | - Lu Tan
- Department of Chemistry and Soft Matter Research Center, Zhejiang University , Hangzhou 310027, People's Republic of China
| | - Debing Li
- Department of Chemistry and Soft Matter Research Center, Zhejiang University , Hangzhou 310027, People's Republic of China
| | - Liangliang Huang
- School of Chemical, Biological & Materials Engineering, University of Oklahoma , Norman, Oklahoma 73019, United States
| | - Qi Wang
- Department of Chemistry and Soft Matter Research Center, Zhejiang University , Hangzhou 310027, People's Republic of China
| | - Yingchun Liu
- Department of Chemistry and Soft Matter Research Center, Zhejiang University , Hangzhou 310027, People's Republic of China
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Phan A, Cole DR, Weiß RG, Dzubiella J, Striolo A. Confined Water Determines Transport Properties of Guest Molecules in Narrow Pores. ACS NANO 2016; 10:7646-7656. [PMID: 27490280 DOI: 10.1021/acsnano.6b02942] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We computed the transport of methane through 1 nm wide slit-shaped pores carved out of solid substrates. Models for silica, magnesium oxide, and alumina were used as solid substrates. The pores were filled with water. The results show that the methane permeability through the hydrated pores is strongly dependent on the solid substrate. Detailed analysis of the simulated systems reveals that local properties of confined water, including its structure, and more importantly, evolution of solvation free energy and hydrogen bond structure are responsible for the pronounced differences observed. The simulations are extended to multicomponent systems representative of natural gas, containing methane, ethane, and H2S. The results show that all pores considered have high affinity for H2S, moderate affinity for methane, and low affinity for ethane. The H2S/methane transport selectivity through the hydrated alumina pore is comparable, or superior, to that reported for existing commercial membranes. A multiscale approach was then implemented to demonstrate that a Smoluchowski one-dimensional model is able to reproduce the molecular-level results for short pores when appropriate values for the local self-diffusion coefficients are used as input parameters. We propose that the model can be extended to predict methane transport through uniform hydrated pores of macroscopic length. When verified by experiments, our simulation results could have important implications in applications such as natural gas sweetening and predictions of methane migration through hydraulically fractured shale formations.
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Affiliation(s)
- Anh Phan
- Department of Chemical Engineering, University College London , London WC1E 7JE, U.K
| | - David R Cole
- School of Earth Sciences, The Ohio State University , Columbus, Ohio 43210, United States
| | - R Gregor Weiß
- Institut für Physik, Humboldt-Universität zu Berlin , Newtonstrasse 15, D-12489 Berlin, Germany
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin , Hahn-Meitner Platz 1, D-14109 Berlin, Germany
| | - Joachim Dzubiella
- Institut für Physik, Humboldt-Universität zu Berlin , Newtonstrasse 15, D-12489 Berlin, Germany
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin , Hahn-Meitner Platz 1, D-14109 Berlin, Germany
| | - Alberto Striolo
- Department of Chemical Engineering, University College London , London WC1E 7JE, U.K
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26
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Chen C, Zhang N, Li W, Song Y. Hydrogen bonds at silica–CO2 saturated water interface under geologic sequestration conditions. Mol Phys 2016. [DOI: 10.1080/00268976.2016.1203466] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Cong Chen
- Department of Energy and Power Engineering, Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian, P. R. China
| | - Ning Zhang
- Department of Petroleum and Chemical Engineering, Dalian University of Technology, Panjin, P. R. China
| | - Weizhong Li
- Department of Energy and Power Engineering, Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian, P. R. China
| | - Yongchen Song
- Department of Energy and Power Engineering, Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of Education, Dalian University of Technology, Dalian, P. R. China
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27
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Fomin YD, Ryzhov VN, Tsiok EN. The behaviour of water and sodium chloride solution confined into asbestos nanotube. Mol Phys 2016. [DOI: 10.1080/00268976.2016.1196833] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Yu. D. Fomin
- Laboratory of Phase Transitions in Strongly Correlated and Disordered Systems, Institute for High Pressure Physics, Russian Academy of Sciences, Troitsk, Moscow, Russia
- Department of Condensed Matter under Extreme Conditions, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - V. N. Ryzhov
- Laboratory of Phase Transitions in Strongly Correlated and Disordered Systems, Institute for High Pressure Physics, Russian Academy of Sciences, Troitsk, Moscow, Russia
- Department of Condensed Matter under Extreme Conditions, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia
| | - E. N. Tsiok
- Laboratory of Phase Transitions in Strongly Correlated and Disordered Systems, Institute for High Pressure Physics, Russian Academy of Sciences, Troitsk, Moscow, Russia
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28
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Savoy ES, Escobedo FA. Molecular simulation of the effects of humidity and of interfacial Si- and B-hydroxyls on the adhesion energy between glass plates. J Colloid Interface Sci 2016; 465:233-41. [DOI: 10.1016/j.jcis.2015.11.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 11/11/2015] [Indexed: 10/22/2022]
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Phan A, Cole DR, Striolo A. Factors governing the behaviour of aqueous methane in narrow pores. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:rsta.2015.0019. [PMID: 26712646 DOI: 10.1098/rsta.2015.0019] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/12/2015] [Indexed: 06/05/2023]
Abstract
All-atom equilibrium molecular dynamics simulations were employed to investigate the behaviour of aqueous methane confined in 1-nm-wide pores obtained from different materials. Models for silica, alumina and magnesium oxide were used to construct the slit-shaped pores. The results show that methane solubility in confined water strongly depends on the confining material, with silica yielding the highest solubility in the systems considered here. The molecular structure of confined water differs within the three pores, and density fluctuations reveal that the silica pore is effectively less 'hydrophilic' than the other two pores considered. Comparing the water fluctuation autocorrelation function with local diffusion coefficients of methane across the hydrated pores we observed a direct proportional coupling between methane and water dynamics. These simulation results help to understand the behaviour of gas in water confined within narrow subsurface formations, with possible implications for fluid transport.
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Affiliation(s)
- Anh Phan
- Department of Chemical Engineering, University College London, Torrington Place, London WC1 E7JE, UK
| | - David R Cole
- School of Earth Sciences, The Ohio State University, Columbus, OH 43210, USA
| | - Alberto Striolo
- Department of Chemical Engineering, University College London, Torrington Place, London WC1 E7JE, UK
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30
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Sega M, Sbragaglia M, Biferale L, Succi S. The importance of chemical potential in the determination of water slip in nanochannels. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2015; 38:127. [PMID: 26614498 DOI: 10.1140/epje/i2015-15127-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2015] [Accepted: 10/30/2015] [Indexed: 06/05/2023]
Abstract
We investigate the slip properties of water confined in graphite-like nanochannels by non-equilibrium molecular dynamics simulations, with the aim of identifying and analyze separately the influence of different physical quantities on the slip length. In a system under confinement but connected to a reservoir of fluid, the chemical potential is the natural control parameter: we show that two nanochannels characterized by the same macroscopic contact angle--but a different microscopic surface potential--do not exhibit the same slip length unless the chemical potential of water in the two channels is matched. Some methodological issues related to the preparation of samples for the comparative analysis in confined geometries are also discussed.
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Affiliation(s)
- M Sega
- Institute of Computational Physics, University of Vienna, Sensengasse 8/9, 1090, Vienna, Austria.
| | - M Sbragaglia
- Department of Physics and INFN, University of "Tor Vergata", Via della Ricerca Scientifica 1, 00133, Rome, Italy
| | - L Biferale
- Department of Physics and INFN, University of "Tor Vergata", Via della Ricerca Scientifica 1, 00133, Rome, Italy
| | - S Succi
- Istituto per le Applicazioni del Calcolo CNR, Via dei Taurini 19, 00185, Rome, Italy
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31
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Tummala NR, Liu S, Argyris D, Striolo A. Interfacial water properties in the presence of surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:2084-2094. [PMID: 25631335 DOI: 10.1021/la504388r] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Water, because of its fundamental role in biology, geology, and many industrial applications and its anomalous behavior compared to that of simple fluids, continues to fascinate and attract extensive scientific interest. Building on previous studies of water in contact with different surfaces, in this study, we report results obtained from molecular dynamics simulations of water near hydrophilic and hydrophobic interfaces in the presence of nonionic and ionic amphiphilic molecules, hexaethylene glycol monododecyl ether (C12E6) and sodium dodecyl sulfate (SDS). We elucidate how these surfactants affect the packing (i.e., density profiles) and orientation of interfacial water. The results highlight the interplay of both surfactant charges and the substrate charge distribution predominantly with respect to the orientation of water molecules, up to distances longer than those expected based on simulation results on flat solid surfaces. We also quantify the dynamics of interfacial water molecules by computing the residence probability for water in contact with various substrates. We compare our results to those previously obtained for interfacial water on silica and graphite and also with experimental sum-frequency vibrational spectroscopy results at the air-water interface in the presence of surfactants. Our analysis could be useful for a better understanding of interfacial water not only near solid substrates but also near self-assembled/aggregated molecules at a variety of interfaces.
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Affiliation(s)
- Naga Rajesh Tummala
- School of Chemistry and Biochemistry, Georgia Institute of Technology , 901 Atlantic Drive, Atlanta, Georgia 30318, United States
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Shevkunov SV. Structure of water in microscopic fractures of a silver iodide crystal. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2014. [DOI: 10.1134/s003602441402023x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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33
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Kumar V, Errington JR. Application of the interface potential approach to calculate the wetting properties of a water model system. MOLECULAR SIMULATION 2013. [DOI: 10.1080/08927022.2013.817672] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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34
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Wright LB, Freeman CL, Walsh TR. Benzene adsorption at the aqueous (0 1 1) α-quartz interface: is surface flexibility important? MOLECULAR SIMULATION 2013. [DOI: 10.1080/08927022.2013.796589] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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35
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Phan A, Cole DR, Striolo A. Liquid Ethanol Simulated on Crystalline Alpha Alumina. J Phys Chem B 2013; 117:3829-40. [DOI: 10.1021/jp312238d] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Anh Phan
- School of Chemical, Biological,
and Materials Engineering, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - David R. Cole
- School of Earth Sciences, The Ohio State University, Columbus, Ohio 43210, United
States
| | - Alberto Striolo
- School of Chemical, Biological,
and Materials Engineering, University of Oklahoma, Norman, Oklahoma 73019, United States
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36
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Vanzo D, Bratko D, Luzar A. Wettability of pristine and alkyl-functionalized graphane. J Chem Phys 2012; 137:034707. [DOI: 10.1063/1.4732520] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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37
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Qiao BF, Sega M, Holm C. Properties of water in the interfacial region of a polyelectrolyte bilayer adsorbed onto a substrate studied by computer simulations. Phys Chem Chem Phys 2012; 14:11425-32. [PMID: 22801605 DOI: 10.1039/c2cp41115f] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
We study the static and dynamic properties of water near a poly(styrene sulfonate)/poly(diallyldimethylammonium) (PSS/PDADMA) bilayer adsorbed onto a substrate by atomistic molecular dynamics simulations. Qualitative changes in the dynamics of water in the proximity of the adsorbed bilayer are observed - such as in the lateral diffusion, residence time and hydrogen-bonding lifetime - as compared with water in the presence of the bare substrate. Static properties of water are similarly influenced, and a high polarization of water molecules is found to be present surprisingly far from the adsorbed bilayer.
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Affiliation(s)
- Bao-Fu Qiao
- Institute for Computational Physics, Universität Stuttgart, Pfaffenwaldring 27, 70569 Stuttgart, Germany
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38
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Ho TA, Argyris D, Cole DR, Striolo A. Aqueous NaCl and CsCl solutions confined in crystalline slit-shaped silica nanopores of varying degree of protonation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:1256-1266. [PMID: 22148873 DOI: 10.1021/la2036086] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
All-atom molecular dynamics simulations were conducted to study the dynamics of aqueous electrolyte solutions confined in slit-shaped silica nanopores of various degrees of protonation. Five degrees of protonation were prepared by randomly removing surface hydrogen atoms from fully protonated crystalline silica surfaces. Aqueous electrolyte solutions containing NaCl or CsCl salt were simulated at ambient conditions. In all cases, the ionic concentration was 1 M. The results were quantified in terms of atomic density distributions within the pores, and the self-diffusion coefficient along the direction parallel to the pore surface. We found evidence for ion-specific properties that depend on ion-surface, water-ion, and only in some cases ion-ion correlations. The degree of protonation strongly affects the structure, distribution, and the dynamic behavior of confined water and electrolytes. Cl(-) ions adsorb on the surface at large degrees of protonation, and their behavior does not depend significantly on the cation type (either Na(+) or Cs(+) ions are present in the systems considered). The cations show significant ion-specific behavior. Na(+) ions occupy different positions within the pore as the degree of protonation changes, while Cs(+) ions mainly remain near the pore center at all conditions considered. For a given degree of protonation, the planar self-diffusion coefficient of Cs(+) is always greater than that of Na(+) ions. The results are useful for better understanding transport under confinement, including brine behavior in the subsurface, with important applications such as environmental remediation.
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Affiliation(s)
- Tuan A Ho
- School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, Oklahoma 73019, USA
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39
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Tummala NR, Shi L, Striolo A. Molecular dynamics simulations of surfactants at the silica–water interface: Anionic vs nonionic headgroups. J Colloid Interface Sci 2011; 362:135-43. [DOI: 10.1016/j.jcis.2011.06.033] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Revised: 06/11/2011] [Accepted: 06/13/2011] [Indexed: 11/17/2022]
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40
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Skelton AA, Wesolowski DJ, Cummings PT. Investigating the quartz (1010)/water interface using classical and ab initio molecular dynamics. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:8700-8709. [PMID: 21648451 DOI: 10.1021/la2005826] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Two different terminations of the (1010) surface of quartz (α and β) interacting with water are simulated by classical (CMD) (using two different force fields) and ab initio molecular dynamics (AIMD) and compared with previously published X-ray reflectivity (XR) experiments. Radial distribution functions between hydroxyl and water show good agreement between AIMD and CMD using the ClayFF force field for both terminations. The Lopes et al. (Lopes, P. E. M.; Murashov, V.; Tazi, M.; Demchuk, E.; MacKerell, A. D. J. Phys. Chem. B2006, 110, 2782-2792) force field (LFF), however, underestimates the extent of hydroxyl-water hydrogen bonding. The β termination is found to contain hydroxyl-hydroxyl hydrogen bonds; the quartz surface hydroxyl hydrogens and oxygens that hydrogen bond with each other exhibit greatly reduced hydrogen bonding to water. Conversely, the hydroxyl hydrogen and oxygens that are not hydrogen bonded to other surface hydroxyls but are connected to those that are show a considerable amount of hydrogen bonding to water. The electron density distribution of an annealed surface of quartz (1010) obtained by XR is in qualitative agreement with electron densities calculated by CMD and AIMD. In all simulation methods, the interfacial water peak appears farther from the surface than observed by XR. Agreement among AIMD, LFF, and XR is observed for the relaxation of the near-surface atoms; however, ClayFF shows a larger discrepancy. Overall, results show that for both terminations of (1010), LFF treats the near-surface structure more accurately whereas ClayFF treats the interfacial water structure more accurately. It is shown that the number of hydroxyl and water hydrogen bonds to the bridging Si-O-Si oxygens connecting the surface silica groups to the rest of the crystal is much greater for the α than the β termination. It is suggested that this may play a role in the greater resistance to dissolution of the β termination than that of the α termination.
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Affiliation(s)
- A A Skelton
- Department of Chemical Engineering, Vanderbilt University, Nashville, Tennessee, United States.
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Affiliation(s)
- Alberto Striolo
- School of Chemical, Biological and Materials Engineering, University of Oklahoma, Norman, OK 73019, U.S.A
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Qiao B, Sega M, Holm C. An atomistic study of a poly(styrene sulfonate)/poly(diallyldimethylammonium) bilayer: the role of surface properties and charge reversal. Phys Chem Chem Phys 2011; 13:16336-42. [DOI: 10.1039/c1cp21777a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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