Fracture and negative Poisson’s ratio of novel spanned-fullerenes nanotube networks under tension

Abstract

Carbon-based nanomaterials have attracted significant attention due to their unique physical properties. In this study, various multi-dimensional graphitic architectures are constructed by spanning fullerenes with carbon nanotube (CNT) super-bonds. The mechanical properties of these novel architectures are systematically investigated by full atomistic simulations. The stress and strain of 1D nano-bamboo structures upon the onset of instability are almost constant, about 1/5 and 1/2, respectively, of those of a perfect CNT. The deformation and fracture behavior of 2D and 3D periodic graphitic nanostructures are largely dictated by the inter-fullerene distance and loading orientation. Surprising negative Poisson’s ratio observed in 2D and 3D networks is revealed to originate as a result of curvature-flattening or rigid mechanical model. The magnitude of Poisson’s ratio is strongly dependent on the level of strain, CNT length as well as temperature. The insight on the deformation mechanism of these periodic graphitic nanostructures will facilitate the integration of low-dimensional materials towards high-dimensional organized structures to realize targeted multi-functional properties.