(706d) Study on the Interfacial Interaction between Carbon Nanotubes and Catalyst: The Effects on the Tube Diameter

Single-walled carbon nanotubes (SWCNTs) are seamless cylinders of graphene that have been at the forefront of nanotechnology research for the past two decades. While mass-produced SWCNT powders are adequate for some applications, many emerging applications require stricter control over SWCNT properties and architectures, necessitating targeted growth, i.e. tailoring the physical properties of the SWCNTs (diameter, orientation/architecture, etc.).

This work attempts to prove the key role of the graphene properties and the metal - catalyst interaction in the relation between catalyst size and nanotube diameter. We work on the assumption that the curvature energy is one of the most influential factors in the graphene film formation and a crucial constraint to determine the stable diameter of the nanotube during the growth. The calculation of interlayer binding energies using density functional theory (DFT) and pseudopotential functions has been valuable to find the transition diameter between fullerene and tube. Additionally, we propose a new model that links statistical mechanics theory with the possible strain energy states and allows the calculation of the expected or most probable diameter. This is just the first step to bring light to the yet undiscovered reigning principle for the nanotube’s diameter stability during nucleation.