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Wang WB, Li W, Ohta R, Kambara M. Cluster-Assisted Mesoplasma Chemical Vapor Deposition for Fast Epitaxial Growth of SiGe/Si Heterostructures: A Molecular Dynamics Simulation Study. MATERIALS (BASEL, SWITZERLAND) 2024; 17:2448. [PMID: 38793514 PMCID: PMC11123204 DOI: 10.3390/ma17102448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/15/2024] [Accepted: 05/16/2024] [Indexed: 05/26/2024]
Abstract
Co-condensation of mixed SiGe nanoclusters and impingement of SiGe nanoclusters on a Si substrate were applied using molecular dynamics (MD) simulation in this study to mimic the fast epitaxial growth of SiGe/Si heterostructures under mesoplasma chemical vapor deposition (CVD) conditions. The condensation dynamics and properties of the SiGe nanoclusters during the simulations were investigated first, and then the impingement of transient SiGe nanoclusters on both Si smooth and trench substrate surfaces under varying conditions was studied theoretically. The results show that the mixed nanoclusters as precursors demonstrate potential for enhancing epitaxial SiGe film growth at a high growth rate, owing to their loosely bound atomic structures and high mobility on the substrate surface. By varying cluster sizes and substrate temperatures, this study also reveals that smaller clusters and higher substrate temperatures contribute to faster structural ordering and smoother surface morphologies. Furthermore, the formed layers display a consistent SiGe composition, closely aligning with nominal values, and the cluster-assisted deposition method achieves the epitaxial bridging of heterostructures during cluster impingement, highlighting its additional distinctive characteristics. The implications of this work make it clear that the mechanism of fast alloyed epitaxial film growth by cluster-assisted mesoplasma CVD is critical for extending it as a versatile platform for synthesizing various epitaxial films.
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Affiliation(s)
- Wen-bo Wang
- School of Materials Science and Engineering, Dongguan University of Technology, Dongguan 523808, China;
- School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China
| | - Wenfang Li
- School of Materials Science and Engineering, Dongguan University of Technology, Dongguan 523808, China;
| | - Ryoshi Ohta
- Department of Materials Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo, Tokyo 113-8656, Japan
| | - Makoto Kambara
- Department of Materials Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo, Tokyo 113-8656, Japan
- Department of Materials and Manufacturing Science, Osaka University, 2-1, Yamadaoka, Suita 565-0871, Japan
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Jiang H, Shao J, Zhu Y, Yu J, Cheng W, Yang H, Zhang X, Chen H. Production mechanism of high-quality carbon black from high-temperature pyrolysis of waste tire. JOURNAL OF HAZARDOUS MATERIALS 2023; 443:130350. [PMID: 36444061 DOI: 10.1016/j.jhazmat.2022.130350] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 10/09/2022] [Accepted: 11/06/2022] [Indexed: 06/16/2023]
Abstract
High-temperature pyrolysis of waste tires is a promising method to produce high-quality carbon black. In this study, carbon black formation characteristics were investigated during tire pyrolysis at 1000-1300 °C with residence times of < 1 s, 1-2 s, and 2-4 s. It is shown that with temperature increasing from 1000 °C to 1300 °C carbon black yield was increased from 10% to 27% with residence times of 2-4 s. Carbon black exhibited a core-shell nanostructure over 1100 °C and the graphitization degree was promoted with the temperature and residence time. While the mean particle diameter decreased with the temperature to 69 nm at 1300 °C and further increased by residence time. The molecular-level evolution from tire to initial carbon black was further revealed by reactive force field molecular dynamics simulations. Light oil, gas, and radicals were transformed to initial cyclic molecules and long carbon chains via carbon-addition-hydrogen-migration, H-abstraction-C2H2-addition, and radical-chain reactions, subsequently forming PAHs. The coupling of PAHs aliphatic side chains formed large graphene layers that gradually bent to fullerene-like cores and generated incipient carbon black. The process mechanism from volatiles evolution to carbon black was proposed, which may be helpful for obtaining high-quality carbon black from high-temperature pyrolysis of waste tires.
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Affiliation(s)
- Hao Jiang
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science & Technology, Wuhan 430074, Hubei, China; Department of New Energy Science and Engineering, School of Energy and Power Engineering, Huazhong University of Science & Technology, Wuhan 430074, Hubei, China.
| | - Jing'ai Shao
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science & Technology, Wuhan 430074, Hubei, China; Department of New Energy Science and Engineering, School of Energy and Power Engineering, Huazhong University of Science & Technology, Wuhan 430074, Hubei, China.
| | - Youjian Zhu
- School of Energy and Power Engineering, Zhengzhou University of Light Industry, Zhengzhou 450002, Henan, China.
| | - Jie Yu
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science & Technology, Wuhan 430074, Hubei, China.
| | - Wei Cheng
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science & Technology, Wuhan 430074, Hubei, China.
| | - Haiping Yang
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science & Technology, Wuhan 430074, Hubei, China.
| | - Xiong Zhang
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science & Technology, Wuhan 430074, Hubei, China.
| | - Hanping Chen
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science & Technology, Wuhan 430074, Hubei, China; Department of New Energy Science and Engineering, School of Energy and Power Engineering, Huazhong University of Science & Technology, Wuhan 430074, Hubei, China.
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Yin F, Yang L, Hou W, Yuan Y, Yu H. Study of dielectric properties of meta-aramid fibers by molecular dynamics methods using modified OPLSAA force field. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.125331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Gao Y, Clares AP, Manogharan G, van Duin ACT. A Reactive Molecular Dynamics Study of Bi-modal Particle Size Distribution in Binder-Jetting Additive Manufacturing using Stainless-Steel Powders. Phys Chem Chem Phys 2022; 24:11603-11615. [DOI: 10.1039/d2cp00630h] [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
In order to improve a final part’s density and achieve desired mechanical properties, binder-jetting additive manufacturing usually requires lengthy post-processing steps such as curing, sintering, and infiltration. The role of...
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Chen C, Jiang X. Molecular dynamics simulation of soot formation during diesel combustion with oxygenated fuel addition. Phys Chem Chem Phys 2020; 22:20829-20836. [PMID: 32914155 DOI: 10.1039/d0cp01917h] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This study investigates the soot formation process of diesel combustion using molecular dynamics simulations with reactive force fields by examining the effects of five oxygenated additives on diesel soot reduction. The newly improved ReaxFF CHO2016 parameters are employed due to their feasibility in modelling the kinetics of large hydrocarbon fuels and describing the chemistry of carbon condensed phases. The detailed pathways of soot formation examined include the thermal decomposition of fuels, the formation of aromatic rings, the mechanism of nucleation, and the mass growth of nascent soot. The morphological developments of the soot formation are obtained, together with quantities indicating the physical and chemical properties, such as mass, size, C : H ratio and aliphatic-to-aromatic C : H ratio. The role of aliphatic-substituted aromatics in nascent soot coalescence and the appearance of aliphatic side chains in soot structures are identified. The concentrations of C-atoms in nascent soot particles contributed from oxygenates blended with diesel are quantified and visualized for the first time. The effects of the molecular structure of the oxygenated additives, i.e. the existence of esters, alcohols, carbonyl groups and ethers, on soot precursor mitigation are elucidated by evaluating the early formation of CO and CO2 quantitatively during the thermal decomposition.
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Affiliation(s)
- Cheng Chen
- School of Engineering & Materials Science, Queen Mary University of London, London E1 4NS, UK.
| | - Xi Jiang
- School of Engineering & Materials Science, Queen Mary University of London, London E1 4NS, UK.
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