Insertion of atoms and fullerenes into layers of graphene structures
In this paper, we use a continuum approach together with the Lennard-Jones potential to determine the potential energy for an atom and a C60 fullerene interacting with a single-layer graphene sheet. We also consider the interactions involving double-layer graphene structures. In order to explore the possibility of using double-layer graphene structures as a nano-carrier for targeted drug delivery, we investigate the molecular insertion of a carbon atom and a C60 molecule into the space between the graphene layers. We find that an atom and the outer surface of the fullerene prefer to be approximately 3.4 and 2.95 ˚A away from a single-layer graphene, which is consistent with the literature. Further, we find that the minimum distances between the two layers of the graphene structure for an atom and a C60 molecule to be accepted into the interspace are 6.2 and 12.2 ˚A, respectively. However, we find that when the distances between the layers equal to 6.8 and 13 ˚A for the atom and the C60 molecule, respectively, the total interaction energy is minimum and therefore the system is most stable. When the inter-layer distance is greater than 6.8 and 13 ˚A for the atom and the fullerene C60, even though the atom and the fullerene C60 will be accepted into the inter-layer spacing, the system is not stable as the energy is higher. Knowledge of the size of the inter-layer spacing may be particularly useful for the design of the double-layer graphene structures for drug delivery applications.