About this Abstract |
Meeting |
MS&T23: Materials Science & Technology
|
Symposium
|
Thermodynamics of Materials in Extreme Environments
|
Presentation Title |
Formation of Carbon Nanotubes from Multilayered Graphene in Astrophysical Settings |
Author(s) |
Abhishek Kumar Thakur, Krishna Muralidharan, Abu Asaduzzaman, Thomas J. Zega, Lucy M. Ziurys |
On-Site Speaker (Planned) |
Abhishek Kumar Thakur |
Abstract Scope |
Current understanding of how structures like carbon nanotubes (CNTs) can be synthesized and incorporated into diffuse clouds is very limited. Using density functional theory (DFT), we demonstrate, a new mechanism for in situ synthesis of single-walled CNTs from few-layer thick graphite grains, which have been previously detected in astrophysical settings. Specifically, by calculating the enthalpy of formation and the corresponding activation barriers, we show that in finite-sized graphite grains, the atoms at and near the sheet-edges can be sufficiently perturbed due to thermal and/or mechanical impulses, followed by curling up of these sheets in the form of CNTs. Further, the DFT calculations demonstrate that the identified mechanism preferentially leads to the formation of armchair nanotubes (n, n). These valuable insights provide further guidance towards a targeted examination of spectroscopic signatures of armchair nanotubes in astrophysical settings. |