Coalescence of single-walled carbon nanotubes

The coalescence of single-walled nanotubes is studied in situ under electro n irradiation at high temperature in a transmission electron microscope. Th e merging process is investigated at the atomic level, using tight-binding molecular dynamics and Monte Carte simulations. Vacancies induce coalescenc e via a zipper-like mechanism, imposing a continuous reorganization of atom s on individual tube Lattices along adjacent tubes. Other topological defec ts induce the polymerization of tubes. Coalescence seems to be restricted t o tubes with the same chirality, explaining the low frequency of occurrence of this event.