Exploring reactivity and product formation in N(4S) collisions with pristine and defected graphene with direct dynamics simulations

Abstract

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(4S)] 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.

Document Details

Document Type
Pub Defense Publication
Publication Date
Nov 10, 2020
Source ID
10.1063/5.0028253

Entities

People

  • Bhumika Jayee
  • Hua Guo
  • Reed Nieman
  • Riccardo Spezia
  • Timothy K. Minton
  • William L Hase

Organizations

  • Air Force Office of Scientific Research
  • Robert A. Welch Foundation
  • Sorbonne University
  • Texas Tech University
  • University of Colorado
  • University of New Mexico

Tags

Fields of Study

  • Physics

Readers

  • Computational Fluid Dynamics (CFD)
  • Molecular Photonics/Laser Physics
  • Nanocomposite Materials Science

Technology Areas

  • Hypersonics
  • Hypersonics - Hypersonic Flight
  • Microelectronics