Stability differences and conversion mechanism between nanotubes and scrolls

Using total energy and structure optimization calculations, we investigate the relative stability and the conversion mechanism between multiwall carbon nanotubes and graphitic scrolls. We suggest that axial segments of a nanotube and a scroll may coexist within the same tubular nanostructure, separated by a dislocation region. A scroll may convert to the more stable nanotube by concerted bond-rearrangement rather than bond breaking. We postulate the zipperlike conversion to proceed very efficiently due to the unusually low associated activation barrier.