Twisting graphene nanoribbons into carbon nanotubes

Growth of carbon nanotubes via twisted graphene nanoribbons

Carbon nanotubes have long been described as rolled-up graphene sheets. It is only fairly recently observed that longitudinal cleavage of carbon nanotubes, using chemical, catalytical and electrical approaches, unzips them into thin graphene strips of various widths, the so-called graphene nanoribbons. In contrast, rolling up these flimsy ribbons into tubes in a real experiment has not been pos...

Size, structure, and helical twist of graphene nanoribbons controlled by confinement in carbon nanotubes.

Carbon nanotubes (CNTs) act as efficient nanoreactors, templating the assembly of sulfur-terminated graphene nanoribbons (S-GNRs) with different sizes, structures, and conformations. Spontaneous formation of nanoribbons from small sulfur-containing molecules is efficiently triggered by heat treatment or by an 80 keV electron beam. S-GNRs form readily in CNTs with internal diameters between 1 an...

Synthesis of carbon nanotubes by rolling up patterned graphene nanoribbons using selective atomic adsorption.

We demonstrate a new method (U.S. Patent Appl., serial no. 60/908039) for synthesizing carbon nanotubes (CNTs), using first-principles and classical molecular dynamics simulations. The single-walled nanotubes (SWNTs) are formed by folding graphene nanoribbons patterned on graphite films through adsorption of atoms of varying coverage, which introduces an external stress to drive the folding pro...

Defect- and dopant-controlled carbon nanotubes fabricated by self-assembly of graphene nanoribbons

Formation of a carbon nanoribbon by spontaneous collapse of a carbon nanotube grown from a γ-Fe nanoparticle via an origami mechanism.

We report a simple method of fabricating graphite nanoribbons by utilizing a self-collapsing mechanism of multi-walled carbon nanotubes during their growth. In the growth process, a nanotube is expelled from a γ-Fe seed nanoparticle, and then collapses spontaneously forming a nanoribbon. Our microscopic analysis of the structures and crystal orientations of γ-Fe nanoparticles and graphite nanor...