Cui, Z, Zhao, J, He, L et al. (3 more authors) (2020) A reactive molecular dynamics study of hyperthermal atomic oxygen erosion mechanisms for graphene sheets. Physics of Fluids, 32 (11). 112110. ISSN 1070-6631
Abstract
Carbon-based composite materials are widely used in the aerospace field due to their light weight and excellent physical/chemical properties. The mechanisms of the erosion process, e.g., surface catalysis and ablation, during the impact of oxygen atoms, however, remain unclear. In this study, the surface catalysis and ablation behavior during the erosion process of hyperthermal atomic oxygens were achieved through the molecular dynamics method with the reactive force field potential. The concomitant impacts of energy flux density of energetic oxygen atoms, the presence of multiple layers beneath the graphene sheet, and the morphology of graphite surfaces, i.e., graphite basal plane, armchair (AC) edge surface, and zigzag edge surface, respectively, were discussed. The results show that the adsorption of oxygen atoms dominates at the beginning by generating O2 molecules, suggesting the importance of surface catalytic for any ablation study. A unique “layer-by-layer” ablation phenomenon by hyperthermal atomic oxygen is observed for multi-layered graphite slab, and the ablation rate reduces as the number of graphene layers increases. The morphology/structure of the surface shows significant effects on the ablation rate, with AC surfaces showing the largest etching rate and the basal one showing the lowest. The low binding energies of the AC edge are responsible for the difficulty in the formation of stable functional group structures to resist the etching of high-enthalpy oxygen atoms. Such revelation of the detailed surface catalysis and ablation mechanism at the atomistic scale provides insight into design of future materials for the augmentation of the thermal protection effect.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 Author(s). This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in Cui, Z, Zhao, J, He, L et al. (3 more authors) (2020) A reactive molecular dynamics study of hyperthermal atomic oxygen erosion mechanisms for graphene sheets. Physics of Fluids, 32 (11). 112110 and may be found at https://doi.org/10.1063/5.0030749. Uploaded in accordance with the publisher's self-archiving policy. |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemical & Process Engineering (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 18 Dec 2020 14:46 |
Last Modified: | 18 Dec 2020 14:46 |
Status: | Published |
Publisher: | AIP Publishing |
Identification Number: | 10.1063/5.0030749 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:169111 |