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Zheng L, Liu S, Ji F, Tong L, Xu S. Structural Causes of Brittleness Changes in Aluminosilicate Glasses with Different Cooling Rates. MATERIALS (BASEL, SWITZERLAND) 2024; 17:1595. [PMID: 38612109 PMCID: PMC11012692 DOI: 10.3390/ma17071595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2024] [Revised: 03/18/2024] [Accepted: 03/27/2024] [Indexed: 04/14/2024]
Abstract
Numerous sources have already demonstrated that varying annealing rates can result in distinct toughness and brittleness in glass. To determine the underlying mechanisms driving this phenomenon, molecular dynamic (MD) simulations were employed to investigate the microstructure of aluminosilicate glasses under different cooling rates, and then uniaxial stretching was performed on them under controlled conditions. Results indicated that compared with short-range structure, cooling rate has a greater influence on the medium-range structure in glass, and it remarkably affects the volume of voids. Both factors play a crucial role in determining the brittleness of the glass. The former adjusts network connectivity to influence force transmission by manipulating the levels of bridging oxygen (BO) and non-bridging oxygen (NBO), and the latter accomplishes the objective of influencing brittleness by modifying the environmental conditions that affect the changes in BO and NBO content. The variation in the void environment results in differences in the strategies of the changes in BO and NBO content during glass stress. These findings stem from the excellent response of BO and NBO to the characteristic points of stress-strain curves during stretching. This paper holds importance in understanding the reasons behind the effect of cooling rates on glass brittleness and in enhancing our understanding of the ductile/brittle transition (DTB) in glass.
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Affiliation(s)
- Liqiang Zheng
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China; (L.Z.); (L.T.)
| | - Shimin Liu
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China; (L.Z.); (L.T.)
| | - Fushun Ji
- Hebei Building Materials Vocational and Technical College, Qinhuangdao 066004, China;
| | - Lianjie Tong
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China; (L.Z.); (L.T.)
| | - Shiqing Xu
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, China; (L.Z.); (L.T.)
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2
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Suzuki T, Hamada Y, Shimizu M, Urata S, Shimotsuma Y, Miura K. Atomistic mechanism of structural and volume relaxation below glass transition temperature in a soda-lime silicate glass revealed by Raman spectroscopy and its DFT calculations. J Chem Phys 2024; 160:034501. [PMID: 38226825 DOI: 10.1063/5.0181160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Accepted: 12/22/2023] [Indexed: 01/17/2024] Open
Abstract
To elucidate the atomistic origin of volume relaxation in soda-lime silicate glass annealed below the glass transition temperature (Tg), the experimental and calculated Raman spectra were compared. By decomposing the calculated Raman spectra into specific groups of atoms, the Raman peaks at 800, 950, 1050, 1100, and 1150 cm-1 were attributed to oxygen and silicon in Si-O-Si, non-bridging oxygen in the Q2 unit, bridging oxygen in low-angle Si-O-Si, non-bridging oxygen in the Q4 unit, and bridging oxygen in high-angle Si-O-Si, respectively. Based on these attributions, we found that by decreasing the fictive temperature by annealing below Tg - 70 K, a homogenization reaction Q2 + Q4 → 2Q3 and an increase in average Si-O-Si angle occurred simultaneously. By molecular dynamics simulation, we clarified how the experimentally demonstrated increase in average Si-O-Si angle contributes to volume shrinkage; increasing Si-O-Si angles can expand the space inside the rings, and Na can be inserted into the ring center.
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Affiliation(s)
- Taisuke Suzuki
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Yuya Hamada
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
- AGC, Inc., Yokohama, Kanagawa 230-0045, Japan
| | - Masahiro Shimizu
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | | | - Yasuhiko Shimotsuma
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Kiyotaka Miura
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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3
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Bertani M, Charpentier T, Faglioni F, Pedone A. Accurate and Transferable Machine Learning Potential for Molecular Dynamics Simulation of Sodium Silicate Glasses. J Chem Theory Comput 2024. [PMID: 38217496 DOI: 10.1021/acs.jctc.3c01115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2024]
Abstract
An accurate and transferable machine learning (ML) potential for the simulation of binary sodium silicate glasses over a wide range of compositions (from 0 to 50% Na2O) was developed. The potential energy surface is approximated by the sum of atomic energy contributions mapped by a neural network algorithm from the local geometry comprising information on atomic distances and angles with neighboring atoms using the DeePMD code [Wang, H. Comput. Phys. Commun. 2018, 228, 178-184]. Our model was trained on a large data set of total energies and atomic forces computed at the density functional theory level on structures extracted from classical molecular dynamics (MD) simulations performed at several temperatures from 300 to 3000 K. This allows for the generation of a robust and transferable ML potential applicable over the full compositional range of glass formability at different temperatures that outperforms the empirical potentials available in the literature in reproducing structures and properties such as bond angle distribution, total distribution functions, and vibrational density of state. The generality of the approach enables the future training of a potential with other or more elements allowing for simulations of structures, properties, and behavior of ternary and multicomponent oxide glasses with nearly ab initio accuracy at a fraction of the computational cost.
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Affiliation(s)
- Marco Bertani
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Modena 41125, Italy
| | | | - Francesco Faglioni
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Modena 41125, Italy
| | - Alfonso Pedone
- Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Modena 41125, Italy
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4
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Antony AC, Goyal S, Park H, Banerjee J, Smith NJ, Agnello G, Manley RG. Passivation of Mid-Gap Electronic States at Calcium Aluminosilicate Glass Surfaces upon Water Exposure: An Ab Initio Study. J Phys Chem B 2022; 126:7709-7719. [PMID: 36149757 DOI: 10.1021/acs.jpcb.2c02550] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
When a clean glass surface is exposed to humid air, a thin water layer forms on the hydrophilic surface. Using ab initio molecular dynamics, we simulate the changes in the electronic structure of a CaO-Al2O3-SiO2 glass model upon vacuum fracture and subsequent exposure to H2O. When the glass is fractured, dangling bonds form, which lower the band gap of the surface by ∼1.8 eV compared to the bulk value due to mid-gap surface states. When H2O adsorbs onto the vacuum-fractured surface, the band gap increases to a value closer to that of the bulk band gap. Using two different hydroxylation methods, we find that the calculated band gap of the glass surface depends on the hydroxylation state. Surfaces with ∼4.5 OH/nm2 have smaller band gaps due to unfilled surface states, and surfaces with ∼2.5 OH/nm2 have larger band gaps with no apparent unfilled surface states. The resulting changes in the electronic structure, quantified by electron affinity and work function values, are hypothesized to play an important role in the electrostatic charge transfer based on the principles of surface state theory, which posit that the density of electronic surface states determines the amount of electronic charge transfer to or from material surfaces.
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Affiliation(s)
- Andrew C Antony
- Corning Incorporated, Sullivan Park Research Center, Corning, New York 14831, United States
| | - Sushmit Goyal
- Corning Incorporated, Sullivan Park Research Center, Corning, New York 14831, United States
| | - Hyunhang Park
- Corning Technology Center Korea, Asan, Chungcheongnam-do 31454, South Korea
| | - Joy Banerjee
- Corning Research and Development Corporation, Sullivan Park Research Center, Corning, New York 14831, United States
| | - Nicholas J Smith
- Corning Research and Development Corporation, Sullivan Park Research Center, Corning, New York 14831, United States
| | - Gabriel Agnello
- Corning Research and Development Corporation, Sullivan Park Research Center, Corning, New York 14831, United States
| | - Robert G Manley
- Corning Research and Development Corporation, Sullivan Park Research Center, Corning, New York 14831, United States
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5
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Wang Z, Yu L, Wen G, Liu F, Wang F, Barati M. A combined computational-experimental study on the effect of Na2O on the fluoride volatilization in molten slags. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.117499] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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6
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Bisbrouck N, Micoulaut M, Delaye JM, Bertani M, Charpentier T, Gin S, Angeli F. Influence of Magnesium on the Structure of Complex Multicomponent Silicates: Insights from Molecular Simulations and Neutron Scattering Experiments. J Phys Chem B 2021; 125:11761-11776. [PMID: 34664506 DOI: 10.1021/acs.jpcb.1c06990] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A series of multicomponent glasses containing up to five oxides are studied using classical molecular dynamics simulations and neutron scattering experiments. The focus is on the role of magnesium in determining the structural properties of these glasses and the possible mixed effect during a sodium/magnesium substitution. Calculated structure functions (pair correlation function and structure factor) rather accurately reproduce their experimental counterpart, and we show that more fine structural features are qualitatively reproduced well, despite some discrepancies in the preferential spatial distribution between sodium and magnesium to aluminum and boron, as well as the nonbridging oxygen, distribution. The simulated systems offer a solid basis to support previous experimental findings on the composition-structure relationship, allowing for further analysis and property calculation. It is confirmed that the substitution of sodium by magnesium leads to the decrease of four-fold boron and a modification of the alkali coordinations with a significant change of the network structure. Specifically, magnesium coordination extracted from numerical simulations highlights a potential dissociation from penta- to tetra- and hexahedral units with increasing MgO contents along the glass series, which could not be resolved experimentally.
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Affiliation(s)
- N Bisbrouck
- CEA, DES, ISEC, DE2D, Université de Montpellier, Marcoule, 30207 Bagnols-sur-Cèze Cedex, France
| | - M Micoulaut
- Sorbonne Université, Laboratoire de Physique Théorique de la Matière Condensée, CNRS UMR 7600, 4 Place Jussieu, 75252 Paris Cedex 05, France
| | - J-M Delaye
- CEA, DES, ISEC, DE2D, Université de Montpellier, Marcoule, 30207 Bagnols-sur-Cèze Cedex, France
| | - M Bertani
- Université Paris-Saclay, CEA, CNRS, NIMBE, 91191 Gif-sur-Yvette, France.,Department of Chemical and Geological Sciences, University of Modena and Reggio Emilia, Via G. Campi 103, 41125 Modena, Italy
| | - T Charpentier
- Université Paris-Saclay, CEA, CNRS, NIMBE, 91191 Gif-sur-Yvette, France
| | - S Gin
- CEA, DES, ISEC, DE2D, Université de Montpellier, Marcoule, 30207 Bagnols-sur-Cèze Cedex, France
| | - F Angeli
- CEA, DES, ISEC, DE2D, Université de Montpellier, Marcoule, 30207 Bagnols-sur-Cèze Cedex, France
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7
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Naji M, El Kssiri O, Ory S, Canizarès A, Filali M, Simon P, Faik A, Vaills Y. Insight into the structure-elastic property relationship of calcium silicate glasses: a multi-length scale approach. Phys Chem Chem Phys 2021; 23:17973-17983. [PMID: 34382044 DOI: 10.1039/d1cp02398e] [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
Based on a combination of molecular dynamics simulations, and Raman and Brillouin light scattering spectroscopies, we investigate the structure and elastic properties relationship in an archetypical calcium silicate glass system. From molecular dynamics and Raman spectroscopy, we show that the atomic structure at the short and intermediate length scales is made up of long polymerized silicate chains, which adjusts itself by closing the Si-O-Si angles and leaving more space to [CaO]n edge shared polyhedra to strengthen the glass. Using Brillouin spectroscopy, we observe an increase of elastic constants of the glass with the calcium content, as the cohesion of the glass structure is enhanced through an increase of the binding between the cross-linked calcium-silicate frameworks. This result, albeit being simple in its nature, illustrates for the first time the implication of the calcium framework in the elastic behavior of the glass and will contribute substantially to the understanding of the composition-structure-property relationships in multi-component industrial glasses.
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Affiliation(s)
- Mohamed Naji
- LPAIS Laboratory, University of Sidi Mohamed Ben Abdellah, B. P. 1796 Fès-Atlas, 30003, Morocco.
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8
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Shimizu M, Murota T, Urata S, Takato Y, Hamada Y, Koike A, Shimotsuma Y, Fujita K, Miura K. Structural origin of thermal shrinkage in soda-lime silicate glass below the glass transition temperature: A theoretical investigation by microsecond timescale molecular dynamics simulations. J Chem Phys 2021; 155:044501. [PMID: 34340397 DOI: 10.1063/5.0056464] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Microscopic dynamical features in the relaxation of glass structures are one of the most important unsolved problems in condensed matter physics. Although the structural relaxation processes in the vicinity of glass transition temperature are phenomenologically expressed by the Kohlrausch-Williams-Watts function and the relaxation time can be successfully interpreted by Adam-Gibbs theory and/or Narayanaswamy's model, the atomic rearrangement, which is the origin of the volume change, and its driving force have not been elucidated. Using the microsecond time-scale molecular dynamics simulations, this study provides insights to quantitatively determine the origin of the thermal shrinkage below Tg in a soda-lime silicate glass. We found that during annealing below Tg, Na ions penetrate into the six-membered silicate rings, which remedies the acute O-O-O angles of the energetically unstable rings. The ring structure change makes the space to possess the cation inside the rings, but the ring volume is eventually reduced, which results in thermal shrinkage of the soda-lime silica glass. In conclusion, the dynamical structural relaxation due to the cation displacement evokes the overall volume relaxation at low temperature in the glassy material.
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Affiliation(s)
- Masahiro Shimizu
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Teppei Murota
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | | | | | - Yuya Hamada
- AGC, Inc., Yokohama, Kanagawa 221-8755, Japan
| | - Akio Koike
- AGC, Inc., Yokohama, Kanagawa 221-8755, Japan
| | - Yasuhiko Shimotsuma
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Koji Fujita
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
| | - Kiyotaka Miura
- Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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9
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Venugopal V, Sahoo S, Zaki M, Agarwal M, Gosvami NN, Krishnan NMA. Looking through glass: Knowledge discovery from materials science literature using natural language processing. PATTERNS (NEW YORK, N.Y.) 2021; 2:100290. [PMID: 34286304 PMCID: PMC8276010 DOI: 10.1016/j.patter.2021.100290] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 05/10/2021] [Accepted: 05/24/2021] [Indexed: 02/06/2023]
Abstract
Most of the knowledge in materials science literature is in the form of unstructured data such as text and images. Here, we present a framework employing natural language processing, which automates text and image comprehension and precision knowledge extraction from inorganic glasses' literature. The abstracts are automatically categorized using latent Dirichlet allocation (LDA) to classify and search semantically linked publications. Similarly, a comprehensive summary of images and plots is presented using the caption cluster plot (CCP), providing direct access to images buried in the papers. Finally, we combine the LDA and CCP with chemical elements to present an elemental map, a topical and image-wise distribution of elements occurring in the literature. Overall, the framework presented here can be a generic and powerful tool to extract and disseminate material-specific information on composition-structure-processing-property dataspaces, allowing insights into fundamental problems relevant to the materials science community and accelerated materials discovery.
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Affiliation(s)
- Vineeth Venugopal
- Department of Civil Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
- Corresponding author
| | - Sourav Sahoo
- Department of Materials Science and Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Mohd Zaki
- Department of Civil Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Manish Agarwal
- Computer Services Center, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Nitya Nand Gosvami
- Department of Materials Science and Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - N. M. Anoop Krishnan
- Department of Civil Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
- Department of Materials Science and Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
- Corresponding author
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10
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Zhou Q, Shi Y, Deng B, Neuefeind J, Bauchy M. Experimental method to quantify the ring size distribution in silicate glasses and simulation validation thereof. SCIENCE ADVANCES 2021; 7:7/28/eabh1761. [PMID: 34233881 PMCID: PMC8262800 DOI: 10.1126/sciadv.abh1761] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Accepted: 05/25/2021] [Indexed: 06/13/2023]
Abstract
Silicate glasses have no long-range order and exhibit a short-range order that is often fairly similar to that of their crystalline counterparts. Hence, the out-of-equilibrium nature of glasses is largely encoded in their medium-range order. However, the ring size distribution-the key feature of silicate glasses' medium-range structure-remains invisible to conventional experiments and, hence, is largely unknown. Here, by combining neutron diffraction experiments and force-enhanced atomic refinement simulations for two archetypical silicate glasses, we show that rings of different sizes exhibit a distinct contribution to the first sharp diffraction peak in the structure factor. On the basis of these results, we demonstrate that the ring size distribution of silicate glasses can be determined solely from neutron diffraction patterns, by analyzing the shape of the first sharp diffraction peak. This method makes it possible to uncover the nature of silicate glasses' medium-range order.
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Affiliation(s)
- Qi Zhou
- Science and Technology Division, Corning Incorporated, Corning, NY 14831, USA
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, USA
| | - Ying Shi
- Science and Technology Division, Corning Incorporated, Corning, NY 14831, USA.
| | - Binghui Deng
- Science and Technology Division, Corning Incorporated, Corning, NY 14831, USA
| | - Jörg Neuefeind
- Neutron Scattering Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Mathieu Bauchy
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095, USA
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11
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Chai W, Zhang L, Li W, Zhang M, Huang J, Zhang W. Preparation of Plastics- and Foaming Agent-Free and Porous Bamboo Charcoal based Composites Using Sodium Silicate as Adhesives. MATERIALS 2021; 14:ma14102468. [PMID: 34064560 PMCID: PMC8151041 DOI: 10.3390/ma14102468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/29/2021] [Accepted: 05/06/2021] [Indexed: 11/16/2022]
Abstract
Plastics and foaming agents are often used to prepare large-size and low-density bamboo charcoal (BC) based composites. In this study, a plastic-free and foaming agent-free BC based composite was prepared by substituting sodium silicate (SS) for plastics. The effect of both the BC particle sizes and the usage amount of SS on the mechanical and adsorptive properties of the BC/SS composites were investigated. The experimental results show that when the BC particle size is 270 μm and the mass ratio of BC to SS is equal to 10:5, the BC/SS composite has the optimal foaming effect and best comprehensive properties. In addition, the foaming pores of the composite are caused by water vapor, which has difficulty escaping the BC because of the blockage of SS during the hot pressing process. In the BC/SS composite (10:5), the static bending intensity and the compressive strength reach respectively 6.13 MPa and 5.5 MPa, and the average pore size and porosity are 557.85 nm and 52.03%, respectively. In addition, its formaldehyde adsorptionrate reaches 21.6%. In view of good mechanical properties, formaldehyde adsorption, and environmentally friendly performance, the BC/SS composite has a great potential as a core layer of interior building materials.
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Affiliation(s)
- Weisheng Chai
- School of Engineering, Zhejiang A&F University, Hangzhou 311300, China; (W.C.); (L.Z.); (W.L.); (M.Z.)
| | - Liang Zhang
- School of Engineering, Zhejiang A&F University, Hangzhou 311300, China; (W.C.); (L.Z.); (W.L.); (M.Z.)
| | - Wenzhu Li
- School of Engineering, Zhejiang A&F University, Hangzhou 311300, China; (W.C.); (L.Z.); (W.L.); (M.Z.)
| | - Min Zhang
- School of Engineering, Zhejiang A&F University, Hangzhou 311300, China; (W.C.); (L.Z.); (W.L.); (M.Z.)
- Research Institute for Sustainable Humanosphere, Kyoto 606-8501, Japan
| | - Jingda Huang
- School of Engineering, Zhejiang A&F University, Hangzhou 311300, China; (W.C.); (L.Z.); (W.L.); (M.Z.)
- Correspondence: (J.H.); (W.Z.)
| | - Wenbiao Zhang
- School of Engineering, Zhejiang A&F University, Hangzhou 311300, China; (W.C.); (L.Z.); (W.L.); (M.Z.)
- Correspondence: (J.H.); (W.Z.)
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12
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Thermal conductivity prediction and structure-property relationship of CaO-SiO2-Al2O3 ternary system: A combination of molecular dynamics simulations and machine learning. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.114697] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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13
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Sahu P, Ali SM, Shenoy KT, Mohan S, Arvind A, Sugilal G, Kaushik CP. Molecular dynamics simulations of simplified sodium borosilicate glasses: the effect of composition on structure and dynamics. Phys Chem Chem Phys 2021; 23:14898-14912. [PMID: 34223588 DOI: 10.1039/d1cp00207d] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The fusion of valuable material properties has led to the acceptance of sodium borosilicate (NBS) glasses for nuclear waste immobilization. Although popular, the mechanisms associated with these properties are still only partially discovered and need further exploration. Bearing this in mind, the combination of experiments, molecular dynamics (MD) simulations and the Dell, Yuan and Bray model have been used to understand the role of composition variation for structural and physical aspects of vitrified borosilicate glasses. Experiments have been conducted to evaluate the macroscopic glass parameters of density (ρ), glass transition temperature (Tg) and thermal expansion coefficient (TEC). Experimentally observed trends for ρ, Tg and TEC with composition have been found in good agreement with the MD results. MD studies also provide a microscopic understanding of the glass structure and phenomena associated with the change in the glass composition. A detailed view of local structure and medium-range connectivity for the borosilicate glasses has been explored. Owing to a large B4 population, the results showed the abundant presence of BO4-BO4 connections, we hereby omit the generally accepted "B[4] avoidance rule" for glass. The relative propensity for connecting SiO4/BO3/BO4 structural motifs is in line with the predictions made by the Dell, Yuan and Bray model. Furthermore, the effects of composition on the mechanical integrity of NBS glasses, including the elastic nature, plastic distortion, yielding, breaking stress, and brittle fracture, have been explored by MD simulations. In addition, the glass dynamics have been evaluated by diffusion coefficient and the results suggest that Na+ is likely to be more mobile in the case of NBS1 as compared to NBS2 and NBS3 due to significant disruption in the glass network introduced by a larger amount of Na2O network modifier. Also, the diffusivity was reduced with increasing B2O3 due to the altered role of Na+ ions from network modifiers to charge compensators. The combined study of experiments, MD simulations and the Dell, Yuan and Bray model establish the correlation between the microscopic structure and macroscopic properties of NBS glasses with varied composition, which might be of great scientific use for future glasses in various applications including nuclear waste immobilization.
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Affiliation(s)
- Pooja Sahu
- Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India. and Homi Bhabha National Institute, Mumbai, Maharashtra, India
| | - Sk Musharaf Ali
- Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India. and Homi Bhabha National Institute, Mumbai, Maharashtra, India
| | - K T Shenoy
- Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.
| | - Sadhana Mohan
- Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India.
| | - A Arvind
- Nuclear Recycle Group, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
| | - G Sugilal
- Homi Bhabha National Institute, Mumbai, Maharashtra, India and Nuclear Recycle Group, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
| | - C P Kaushik
- Homi Bhabha National Institute, Mumbai, Maharashtra, India and Nuclear Recycle Group, Bhabha Atomic Research Centre, Mumbai, Maharashtra, India
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14
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Lyngdoh GA, Kumar R, Krishnan NMA, Das S. Dynamics of confined water and its interplay with alkali cations in sodium aluminosilicate hydrate gel: insights from reactive force field molecular dynamics. Phys Chem Chem Phys 2020; 22:23707-23724. [PMID: 33057524 DOI: 10.1039/d0cp04646a] [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
This paper presents the dynamics of confined water and its interplay with alkali cations in disordered sodium aluminosilicate hydrate (N-A-S-H) gel using reactive force field molecular dynamics. N-A-S-H gel is the primary binding phase in geopolymers formed via alkaline activation of fly ash. Despite attractive mechanical properties, geopolymers suffer from durability issues, particularly the alkali leaching problem which has motivated this study. Here, the dynamics of confined water and the mobility of alkali cations in N-A-S-H is evaluated by obtaining the evolution of mean squared displacements and Van Hove correlation function. To evaluate the influence of the composition of N-A-S-H on the water dynamics and diffusion of alkali cations, atomistic structures of N-A-S-H with Si/Al ratio ranging from 1 to 3 are constructed. It is observed that the diffusion of confined water and sodium is significantly influenced by the Si/Al ratio. The confined water molecules in N-A-S-H exhibit a multistage dynamic behavior where they can be classified as mobile and immobile water molecules. While the mobility of water molecules gets progressively restricted with an increase in Si/Al ratio, the diffusion coefficient of sodium also decreases as the Si/Al ratio increases. The diffusion coefficient of water molecules in the N-A-S-H structure exhibits a lower value than those of the calcium-silicate-hydrate (C-S-H) structure. This is mainly due to the random disordered structure of N-A-S-H as compared to the layered C-S-H structure. To further evaluate the influence of water content in N-A-S-H, atomistic structures of N-A-S-H with water contents ranging from 5-20% are constructed. Qn distribution of the structures indicates significant depolymerization of N-A-S-H structure with increasing water content. Increased conversion of Si-O-Na network to Si-O-H and Na-OH components with an increase in water content helps explain the alkali-leaching issue in fly ash-based geopolymers observed macroscopically. Overall, the results in this study can be used as a starting point towards multiscale simulation-based design and development of durable geopolymers.
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Affiliation(s)
- Gideon A Lyngdoh
- Department of Civil and Environmental Engineering, University of Rhode Island, Kingston, RI, USA.
| | - Rajesh Kumar
- Department of Civil Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
| | - N M Anoop Krishnan
- Department of Civil Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India. and Department of Materials Science and Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| | - Sumanta Das
- Department of Civil and Environmental Engineering, University of Rhode Island, Kingston, RI, USA.
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15
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Sørensen SS, Biscio CAN, Bauchy M, Fajstrup L, Smedskjaer MM. Revealing hidden medium-range order in amorphous materials using topological data analysis. SCIENCE ADVANCES 2020; 6:eabc2320. [PMID: 32917687 PMCID: PMC11206462 DOI: 10.1126/sciadv.abc2320] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Accepted: 07/22/2020] [Indexed: 06/11/2023]
Abstract
Despite the numerous technological applications of amorphous materials, such as glasses, the understanding of their medium-range order (MRO) structure-and particularly the origin of the first sharp diffraction peak (FSDP) in the structure factor-remains elusive. Here, we use persistent homology, an emergent type of topological data analysis, to understand MRO structure in sodium silicate glasses. To enable this analysis, we introduce a self-consistent categorization of rings with rigorous geometrical definitions of the structural entities. Furthermore, we enable quantitative comparison of the persistence diagrams by computing the cumulative sum of all points weighted by their lifetime. On the basis of these analysis methods, we show that the approach can be used to deconvolute the contributions of various MRO features to the FSDP. More generally, the developed methodology can be applied to analyze and categorize molecular dynamics data and understand MRO structure in any class of amorphous solids.
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Affiliation(s)
- Søren S Sørensen
- Department of Chemistry and Bioscience, Aalborg University, DK-9220 Aalborg, Denmark
| | | | - Mathieu Bauchy
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Lisbeth Fajstrup
- Department of Mathematical Sciences, Aalborg University, DK-9220 Aalborg, Denmark
| | - Morten M Smedskjaer
- Department of Chemistry and Bioscience, Aalborg University, DK-9220 Aalborg, Denmark.
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16
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Atila A, Ouaskit S, Hasnaoui A. Ionic self-diffusion and the glass transition anomaly in aluminosilicates. Phys Chem Chem Phys 2020; 22:17205-17212. [PMID: 32677636 DOI: 10.1039/d0cp02910f] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The glass transition temperature (Tg) is the temperature after which a supercooled liquid undergoes a dynamical arrest. Usually, glass network modifiers (e.g., Na2O) affect the behavior of Tg. However, in aluminosilicate glasses, the effect of different modifiers on Tg is still unclear and shows an anomalous behavior. Here, based on molecular dynamics simulations, we show that Tg decreases with increasing charge balancing cation field strength (FS) in the aluminosilicate glasses, which is an anomalous behavior as compared to other oxide glasses. The results show that the origins of this anomaly come from the dynamics of the supercooled liquid above Tg, which in turn is correlated to pair excess entropy. Our results deepen our understanding of the effect of different modifiers on the properties of the aluminosilicate glasses.
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Affiliation(s)
- Achraf Atila
- Friedrich-Alexander-Universität Erlangen-Nürnberg, Materials Science and Engineering, Institute I, Martensstr. 5, Erlangen 91058, Germany.
| | - Said Ouaskit
- Laboratoire de Physique de la Matière Condensée, Faculté des Sciences Ben M'sik, University Hassan II of Casablanca, B.P 7955, Av Driss El Harti, Sidi Othmane, Casablanca, Morocco
| | - Abdellatif Hasnaoui
- LS3M, Faculté Polydisciplinaire Khouribga, Sultan Moulay Slimane University of Beni Mellal, B.P 145, 25000 Khouribga, Morocco
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17
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Zhao C, Zhou W, Zhou Q, Zhang Y, Liu H, Sant G, Liu X, Guo L, Bauchy M. Precipitation of calcium-alumino-silicate-hydrate gels: The role of the internal stress. J Chem Phys 2020; 153:014501. [PMID: 32640807 DOI: 10.1063/5.0010476] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Concrete gains its strength from the precipitation of a calcium-alumino-silicate-hydrate (C-A-S-H) colloidal gel, which acts as its binding phase. However, despite concrete's ubiquity in the building environment, the atomic-scale mechanism of C-A-S-H precipitation is still unclear. Here, we use reactive molecular dynamics simulations to model the early-age precipitation of a C-A-S-H gel. We find that, upon gelation, silicate and aluminate precursors condensate and polymerize to form an aluminosilicate gel network. Notably, we demonstrate that the gelation reaction is driven by the existence of a mismatch of atomic-level internal stress between Si and Al polytopes, which are initially experiencing some local tension and compression, respectively. The polymerization of Si and Al polytopes enables the release of these competitive stresses.
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Affiliation(s)
- Cheng Zhao
- State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China
| | - Wei Zhou
- State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China
| | - Qi Zhou
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
| | - Yao Zhang
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
| | - Han Liu
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
| | - Gaurav Sant
- Laboratory for the Chemistry of Construction Materials (LC), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
| | - Xinghong Liu
- State Key Laboratory of Water Resources and Hydropower Engineering Science, Wuhan University, Wuhan 430072, China
| | - Lijie Guo
- National Centre for International Research on Green Metal Mining, BGRIMM Technology Group, Beijing 100160, China
| | - Mathieu Bauchy
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
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18
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Schweinhart B, Rodney D, Mason JK. Statistical topology of bond networks with applications to silica. Phys Rev E 2020; 101:052312. [PMID: 32575235 DOI: 10.1103/physreve.101.052312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2019] [Accepted: 03/09/2020] [Indexed: 11/07/2022]
Abstract
Whereas knowledge of a crystalline material's unit cell is fundamental to understanding the material's properties and behavior, there are no obvious analogs to unit cells for disordered materials despite the frequent existence of considerable medium-range order. This article views a material's structure as a collection of local atomic environments that are sampled from some underlying probability distribution of such environments, with the advantage of offering a unified description of both ordered and disordered materials. Crystalline materials can then be regarded as special cases where the underlying probability distribution is highly concentrated around the traditional unit cell. The H_{1} barcode is proposed as a descriptor of local atomic environments suitable for disordered bond networks and is applied with three other descriptors to molecular dynamics simulations of silica glasses. Each descriptor reliably distinguishes the structure of glasses produced at different cooling rates, with the H_{1} barcode and coordination profile providing the best separation. The approach is generally applicable to any system that can be represented as a sparse graph.
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Affiliation(s)
- B Schweinhart
- Department of Mathematics, Ohio State University, Columbus, Ohio 43210, USA
| | - D Rodney
- Institut Lumière Matière, University of Lyon, Villeurbanne, Lyon F-69622, France
| | - J K Mason
- Department of Materials Science and Engineering, University of California, Davis, California 95616, USA
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19
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Bauchy M, Mauro JC, Smedskjaer MM. Bauchy et al. Reply. PHYSICAL REVIEW LETTERS 2020; 124:199602. [PMID: 32469581 DOI: 10.1103/physrevlett.124.199602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 04/22/2020] [Indexed: 06/11/2023]
Affiliation(s)
- Mathieu Bauchy
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
| | - John C Mauro
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Morten M Smedskjaer
- Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark
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20
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Wang Z, Du T, Anoop Krishnan NM, Smedskjaer MM, Bauchy M. On the equivalence of vapor-deposited and melt-quenched glasses. J Chem Phys 2020; 152:164504. [DOI: 10.1063/5.0006590] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Zhe Wang
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
| | - Tao Du
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
- School of Civil Engineering, Harbin Institute of Technology, 150090 Harbin, China
| | - N. M. Anoop Krishnan
- Department of Civil Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
- Department of Materials Science and Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Morten M. Smedskjaer
- Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark
| | - Mathieu Bauchy
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
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21
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Urata S. An efficient computational procedure to obtain a more stable glass structure. J Chem Phys 2019; 151:224502. [DOI: 10.1063/1.5133413] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Affiliation(s)
- Shingo Urata
- Innovative Technology Laboratories, AGC Inc., 1150 Hazawa-cho Kanagawa-ku, Yokohama 221-8755, Kanagawa, Japan
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22
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Ravinder R, Garg P, Krishnan NMA. Glass Transition and Crystallization in Hexagonal Boron Nitride: Crucial Role of Orientational Order. ADVANCED THEORY AND SIMULATIONS 2019. [DOI: 10.1002/adts.201900174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- R. Ravinder
- Department of Civil EngineeringIndian Institute of Technology Delhi Hauz Khas New Delhi 110016 India
| | - Prateet Garg
- Department of Civil EngineeringIndian Institute of Technology Delhi Hauz Khas New Delhi 110016 India
| | - N. M. Anoop Krishnan
- Department of Civil EngineeringIndian Institute of Technology Delhi Hauz Khas New Delhi 110016 India
- Department of Materials Science and EngineeringIndian Institute of Technology Delhi Hauz Khas New Delhi 110016 India
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23
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Lyngdoh GA, Kumar R, Krishnan NMA, Das S. Realistic atomic structure of fly ash-based geopolymer gels: Insights from molecular dynamics simulations. J Chem Phys 2019. [DOI: 10.1063/1.5121519] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Affiliation(s)
- Gideon A. Lyngdoh
- Department of Civil and Environmental Engineering, University of Rhode Island, Kingston, Rhode Island 02881, USA
| | - Rajesh Kumar
- Department of Civil Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - N. M. Anoop Krishnan
- Department of Civil Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
- Department of Materials Science and Engineering, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Sumanta Das
- Department of Civil and Environmental Engineering, University of Rhode Island, Kingston, Rhode Island 02881, USA
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24
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Predicting the Young's Modulus of Silicate Glasses using High-Throughput Molecular Dynamics Simulations and Machine Learning. Sci Rep 2019; 9:8739. [PMID: 31217500 PMCID: PMC6584533 DOI: 10.1038/s41598-019-45344-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 06/04/2019] [Indexed: 11/16/2022] Open
Abstract
The application of machine learning to predict materials’ properties usually requires a large number of consistent data for training. However, experimental datasets of high quality are not always available or self-consistent. Here, as an alternative route, we combine machine learning with high-throughput molecular dynamics simulations to predict the Young’s modulus of silicate glasses. We demonstrate that this combined approach offers good and reliable predictions over the entire compositional domain. By comparing the performances of select machine learning algorithms, we discuss the nature of the balance between accuracy, simplicity, and interpretability in machine learning.
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25
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Mahadevan TS, Sun W, Du J. Development of Water Reactive Potentials for Sodium Silicate Glasses. J Phys Chem B 2019; 123:4452-4461. [DOI: 10.1021/acs.jpcb.9b02216] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Thiruvilla S. Mahadevan
- Department of Materials Science and Engineering, University of North Texas, Denton, Texas 76203, United States
| | - Wei Sun
- Department of Materials Science and Engineering, University of North Texas, Denton, Texas 76203, United States
| | - Jincheng Du
- Department of Materials Science and Engineering, University of North Texas, Denton, Texas 76203, United States
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26
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Evidence of a two-dimensional glass transition in graphene: Insights from molecular simulations. Sci Rep 2019; 9:4517. [PMID: 30872750 PMCID: PMC6418284 DOI: 10.1038/s41598-019-41231-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Accepted: 03/05/2019] [Indexed: 11/23/2022] Open
Abstract
Liquids exhibit a sudden increase in viscosity when cooled fast enough, avoiding thermodynamically predicted route of crystallization. This phenomenon, known as glass transition, leads to the formation of non-periodic structures known as glasses. Extensive studies have been conducted on model materials to understand glass transition in two dimensions. However, despite the synthesis of disordered/amorphous single-atom thick structures of carbon, little attention has been given to glass transition in realistic two-dimensional materials such as graphene. Herein, using molecular dynamics simulation, we demonstrate the existence of glass transition in graphene leading to a realistic two-dimensional glassy structure, namely glassy graphene. We show that the resulting glassy structure exhibits excellent agreement with experimentally realized disordered graphene. Interestingly, this glassy graphene exhibits a wrinkled but stable structure, with reduced thermal vibration in comparison to its crystalline counterpart. We suggest that the topological disorder induced by glass transition governs the unique properties of this structure.
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27
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Wang M, Smedskjaer MM, Mauro JC, Bauchy M. Modifier clustering and avoidance principle in borosilicate glasses: A molecular dynamics study. J Chem Phys 2019; 150:044502. [PMID: 30709277 DOI: 10.1063/1.5051746] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Oxide glasses are typically described as having a random, disordered skeleton of network-forming polyhedra that are depolymerized by network-modifying cations. However, the existence of local heterogeneity or clustering within the network-forming and network-modifying species remains unclear. Here, based on molecular dynamics simulations, we investigate the atomic structure of a series of borosilicate glasses. We show that the network-modifying cations exhibit some level of clustering that depends on composition-in agreement with Greaves' modified random network model. In addition, we demonstrate the existence of some mutual avoidance among network-forming atoms, which echoes the Loewenstein avoidance principle typically observed in aluminosilicate phases. Importantly, we demonstrate that the degree of heterogeneity in the spatial distribution of the network modifiers is controlled by the level of ordering in the interconnectivity of the network formers. Specifically, the mutual avoidance of network formers is found to decrease the propensity for modifier clustering.
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Affiliation(s)
- Mengyi Wang
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
| | - Morten M Smedskjaer
- Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark
| | - John C Mauro
- Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Mathieu Bauchy
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
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28
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Yang K, Kachmar A, Wang B, Krishnan NMA, Balonis M, Sant G, Bauchy M. New insights into the atomic structure of amorphous TiO 2 using tight-binding molecular dynamics. J Chem Phys 2018; 149:094501. [PMID: 30195301 DOI: 10.1063/1.5042783] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Amorphous TiO2 (a-TiO2) could offer an attractive alternative to conventional crystalline TiO2 phases for photocatalytic applications. However, the atomic structure of a-TiO2 remains poorly understood with respect to that of its crystalline counterparts. Here, we conduct some classical molecular dynamics simulations of a-TiO2 based on a selection of empirical potentials. We show that, on account of its ability to dynamically assign the charge of each atom based on its local environment, the second-moment tight-binding charge equilibration potential yields an unprecedented agreement with available experimental data. Based on these simulations, we investigate the degree of order and disorder in a-TiO2. Overall, the results suggest that a-TiO2 features a large flexibility in its local topology, which may explain the high sensitivity of its structure to the synthesis method being used.
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Affiliation(s)
- Kai Yang
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), University of California, Los Angeles, California 90095-1593, USA
| | - Ali Kachmar
- Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar
| | - Bu Wang
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), University of California, Los Angeles, California 90095-1593, USA
| | - N M Anoop Krishnan
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), University of California, Los Angeles, California 90095-1593, USA
| | - Magdalena Balonis
- Department of Materials Science and Engineering, University of California, Los Angeles, California 90095-1593, USA
| | - Gaurav Sant
- Department of Materials Science and Engineering, University of California, Los Angeles, California 90095-1593, USA
| | - Mathieu Bauchy
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), University of California, Los Angeles, California 90095-1593, USA
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29
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Sundararaman S, Huang L, Ispas S, Kob W. New optimization scheme to obtain interaction potentials for oxide glasses. J Chem Phys 2018; 148:194504. [DOI: 10.1063/1.5023707] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- Siddharth Sundararaman
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
- Laboratoire Charles Coulomb (L2C), University of Montpellier, CNRS, Montpellier, France
| | - Liping Huang
- Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, USA
| | - Simona Ispas
- Laboratoire Charles Coulomb (L2C), University of Montpellier, CNRS, Montpellier, France
| | - Walter Kob
- Laboratoire Charles Coulomb (L2C), University of Montpellier, CNRS, Montpellier, France
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30
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Yu Y, Krishnan NMA, Smedskjaer MM, Sant G, Bauchy M. The hydrophilic-to-hydrophobic transition in glassy silica is driven by the atomic topology of its surface. J Chem Phys 2018; 148:074503. [DOI: 10.1063/1.5010934] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Yingtian Yu
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
| | - N. M. Anoop Krishnan
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
| | - Morten M. Smedskjaer
- Department of Chemistry and Bioscience, Aalborg University, 9220 Aalborg, Denmark
| | - Gaurav Sant
- Laboratory for the Chemistry of Construction Materials (LC2), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
- California Nanosystems Institute (CNSI), University of California, Los Angeles, California 90095, USA
| | - Mathieu Bauchy
- Physics of AmoRphous and Inorganic Solids Laboratory (PARISlab), Department of Civil and Environmental Engineering, University of California, Los Angeles, California 90095, USA
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