  The behavior of nanostructures under high strain-rate conditions has been
object of interest in recent years. For instance, recent experimental
investigations showed that at high velocity impacts carbon nanotubes can unzip
resulting into graphene nanoribbons. Carbon nanoscrolls (CNS) are among the
structures whose high impact behavior has not yet been investigated. CNS are
graphene membranes rolled up into papyrus-like structures. Their unique
open-ended topology leads to properties not found in close-ended structures,
such as nanotubes. Here we report a fully atomistic reactive molecular dynamics
study on the behavior of CNS colliding at high velocities against solid
targets. Our results show that the velocity and scroll axis orientation are key
parameters to determine the resulting formed nanostructures after impact. The
relative orientation of the scroll open ends and the substrate is also very
important. We observed that for appropriate velocities and orientations, the
nanoscrolls can experience large structural deformations and large-scale
fractures. We have also observed unscrolling (scrolls going back to planar or
quasi-planar graphene membranes), unzip resulting into nanoribbons, and
significant reconstructions from breaking and/or formation of new chemical
bonds. Another interesting result was that if the CNS impact the substrate with
their open ends, for certain velocities, fused scroll walls were observed.
