| Autor: |
Nieman R; Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA., Spezia R; Laboratoire de Chimie Théorique, Sorbonne Université, UMR 7616 CNRS, 4 Place Jussieu, 75005 Paris, France., Jayee B; Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA., Minton TK; Ann and H. J. Smead Department of Aerospace Engineering Sciences, University of Colorado, Boulder, Colorado 80303, USA., Hase WL; Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, USA., Guo H; Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA. |
| Abstrakt: |
Atomic nitrogen is formed in the high-temperature shock layer of hypersonic vehicles and contributes to the ablation of their thermal protection systems (TPSs). To gain atomic-level understanding of the ablation of carbon-based TPS, collisions of hyperthermal atomic nitrogen on representative carbon surfaces have recently be investigated using molecular beams. In this work, we report direct dynamics simulations of atomic-nitrogen [N( 4 S)] collisions with pristine, defected, and oxidized graphene. Apart from non-reactive scattering of nitrogen atoms, various forms of nitridation of graphene were observed in our simulations. Furthermore, a number of gaseous molecules, including the experimentally observed CN molecule, have been found to desorb as a result of N-atom bombardment. These results provide a foundation for understanding the molecular beam experiment and for modeling the ablation of carbon-based TPSs and for future improvement of their properties. |
