  The study of the mechanical properties of nanostructured systems has gained
importance in theoretical and experimental research in recent years. Carbon
nanotubes (CNTs) are one of the strongest nanomaterials found in nature, with
Young's Modulus (YM) in the order 1.25 TPa. One interesting question is about
the possibility of generating new nanostructures with 1D symmetry and with
similar and/or superior CNT properties. In this work, we present a study on the
dynamical, structural, mechanical properties, fracture patterns and YM values
for one class of these structures, the so-called pentagraphene nanotubes
(PGNTs). These tubes are formed rolling up pentagraphene membranes (which are
quasi-bidimensional structures formed by densely compacted pentagons of carbon
atoms in sp3 and sp2 hybridized states) in the same form that CNTs are formed
from rolling up graphene membranes. We carried out fully atomistic molecular
dynamics simulations using the ReaxFF force field. We have considered
zigzag-like and armchair-like PGNTs of different diameters. Our results show
that PGNTs present YM ~ 800 GPa with distinct elastic behavior in relation to
CNTs, mainly associated with mechanical failure, chirality dependent fracture
patterns and extensive structural reconstructions.
