| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
Materials vs Minerals: Bridging the Gap between Materials Science and Earth and Planetary Science
|
| Presentation Title |
Chemical Pathways for Formation of Carbon Nanostructures from Graphite: Implications for Circumstellar and Solar-system Carbon |
| Author(s) |
Abhishek Kumar Thakur, Krishna Muralidharan, Thomas J Zega, Lucy M Ziurys |
| On-Site Speaker (Planned) |
Abhishek Kumar Thakur |
| Abstract Scope |
Using classical and ab-initio molecular dynamics, we investigate the effects of thermal and mechanical-shock stimuli on graphite. Specifically, for graphite, thermal effects lead to curling of edges of the individual sheets, ultimately leading to the formation of tubular structures at sheet edges. Further, depending on thickness of the graphitic system, we see the formation of both single wall and multiwall tubular structures, which then rearrange to form configurations that resemble single wall and multiwall carbon-nanotubes. The impact of mechanical shock stimulus is similar to thermal effects in terms of formation of tubular structures; however, we also see ejection of carbon fragments. Finally, using unsupervised machine learning, we analyze the trajectories of MD simulations and estimate the activation barriers and kinetics of formation of nanotubes and spherical fullerene molecules. This work has fundamental implications for analyzing meteoritic and planetary materials as well as for interpretation of currently unidentified diffuse interstellar bands. |