Interplay of Wetting and Elasticity in the Nucleation of Carbon Nanotubes

We use molecular dynamics and simple thermodynamic arguments to model the interaction between catalyst nanoparticles and carbon nanotube caps, and we illustrate how the competition between cap strain energy and adhesion plays a role in the lifting of these caps from the catalyst surface prior to tub...

Full description

Bibliographic Details
Main Authors: Schebarchov, Dmitri, Hendy, Shaun C., Ertekin, Seyda, Grossman, Jeffrey C.
Other Authors: Massachusetts Institute of Technology. Department of Materials Science and Engineering
Format: Article
Language:en_US
Published: American Physical Society (APS) 2012
Online Access:http://hdl.handle.net/1721.1/69065
https://orcid.org/0000-0003-1281-2359
https://orcid.org/0000-0001-6541-1650
Description
Summary:We use molecular dynamics and simple thermodynamic arguments to model the interaction between catalyst nanoparticles and carbon nanotube caps, and we illustrate how the competition between cap strain energy and adhesion plays a role in the lifting of these caps from the catalyst surface prior to tube elongation. Given a particular cap structure, we show that there is a lower bound on the catalyst size from which the cap can lift. This lower bound depends on the cap’s spontaneous curvature and bending rigidity, as well as the catalyst binding strength, and it explains the mismatch between single-walled carbon nanotube and catalyst diameters observed in prior experiments. These findings offer new insight into the nucleation of carbon nanotubes, and they may lead to the design of catalysts that can better control nanotube structure.