title: Tearing graphene sheets from adhesive substrates produces tapered nanoribbons.
abstract: Graphene is a truly two-dimensional atomic crystal with exceptional electronic and mechanical properties. Whereas conventional bulk and thin-film materials have been studied extensively, the key mechanical properties of graphene, such as tearing and cracking, remain unknown, partly due to its two-dimensional nature and ultimate single-atom-layer thickness, which result in the breakdown of conventional material models. By combining first-principles ReaxFF molecular dynamics and experimental studies, a bottom-up investigation of the tearing of graphene sheets from adhesive substrates is reported, including the discovery of the formation of tapered graphene nanoribbons. Through a careful analysis of the underlying molecular rupture mechanisms, it is shown that the resulting nanoribbon geometry is controlled by both the graphene-substrate adhesion energy and by the number of torn graphene layers. By considering graphene as a model material for a broader class of two-dimensional atomic crystals, these results provide fundamental insights into the tearing and cracking mechanisms of highly confined nanomaterials.
authors.affiliation: Laboratory for Atomistic and Molecular Mechanics, Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
authors.forename: Dipanjan
authors.initials: D
authors.lastname: Sen
authors.forename: Kostya S
authors.initials: KS
authors.lastname: Novoselov
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Reis
authors.forename: Markus J
authors.initials: MJ
authors.lastname: Buehler
mesh_terms: D006108:Graphite / Q000737:chemistry; D056004:Molecular Dynamics Simulation; D049329:Nanostructures / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D013499:Surface Properties
chemical_list: D006108:Graphite