  Carbon nitride-based nanostructures have attracted special attention (from
theory and experiments) due to their remarkable electromechanical properties.
In this work we have investigated the mechanical properties of some
graphene-like carbon nitride membranes through fully atomistic reactive
molecular dynamics simulations. We have analyzed three different structures of
these CN families, the so-called graphene-based g-CN, triazine-based g-C3N4 and
heptazine-based g-C3N4. The stretching dynamics of these membranes was studied
for deformations along their two main axes and at three different temperatures:
10K, 300K and 600K. We show that g-CN membranes have the lowest ultimate
fracture strain value, followed by heptazine-based and triazine-based ones,
respectively. This behavior can be explained in terms of their differences in
terms of density values, topologies and types of chemical bonds. The dependency
of the fracture patterns on the stretching directions is also discussed.
