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Molecular dynamics simulations have been performed to study the initial roll guided structural transition of graphene. The flat graphene is thermodynamic metastable and small disturbance can strike its balance and lead to fold. An initial roll at one end causes the graphene layer to transform into double-fold, multi-fold and scroll spontaneously, depending on the size of the initial roll. This unique phenomenon results from the combined action of the van der Waals interaction and the π-π stacking effect. The potential energy of the final structures decreases with the increase of compact level. This study provides crucial simulation input to help guide to designing the required graphene-based nanostructures. The flat graphene is thermodynamic metastable and an initial roll at one end can cause the graphene layer to transform into double-fold, multi-fold and scroll spontaneously, depending on the size of the initial roll. The suggested mechanism is that the vdW force among graphene layers induced by the initial roll provides sufficient attractive force to overcome the energy barrier, the π-π stacking effect between graphene layers cause the structure of graphene to transform spontaneously and stabilizes two parallel graphene walls to achieve the lowest energy AB stacking. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulation is used to observe the traveling behavior of a water cluster released from the interior of single-walled carbon nanotube (SWCNT) to a graphite sheet. The simulation results reveal that there is a need for the water cluster overcoming the energy barrier of the binding energy between the water cluster and the SWCNT to escape from the tube. The water cluster undergoes a three-dimensional motion when released from the SWCNT, due to the effect of the thermal velocity. When encountering the graphite sheet in the forward direction, the x axis impact velocity has much effect on the delivery of the water cluster. The fact that the water cluster is bounced back reduces the possibility of being captured by the graphite sheet, resulting in a decrease in the delivery efficiency of the water cluster. The presence of the electric charges can help the graphite sheet to effectively trap the water cluster. These results have implications for the design and fabrication of novel drug delivery devices. [ABSTRACT FROM AUTHOR]

Similar to the water wave on a pond caused by dropping a pebble, the formation of ripples is shown in a single layer graphene (SLG) when it is stroked by a C60 molecule, no matter whether the graphene is plane or corrugated. The controllable ripple in SLG is investigated by molecular dynamics simulations. Noticeable diffraction and interference of the ripples are observed. This study indicates that the ripple propagation in graphene can be used to detect defects. [ABSTRACT FROM AUTHOR]

Molecular dynamics simulations are performed to examine the heterogeneous solidification of silicon on foreign graphite sheets (GSs). It clearly indicates that silicon atoms are concentrated to form hierarchical nanostructures composed of equidistant nanolayers. Graphite plate induces strong ordered liquid silicon layers near the surfaces of GSs. This study suggests ordered liquid layers should be the early form of the solid crystal, which determine the subsequent nucleation. The confined nanospace between two GSs favors the solidification and results in the decrease in the distance between layers. GSs make silicon atoms solidify into an hcp crystal rather than fcc structure. [ABSTRACT FROM AUTHOR]

The growth of silicon atoms at the heterogeneous surface of carbon nanotubes (CNTs) is studied by means of molecular dynamics simulations. The results indicate that silicon atoms are concentrated to form an “annual ring” structure around CNTs. The structures of CNTs have strong correlation with the stacking sequence of silicon atoms. Heredity effect can be clearly observed during the heterogeneous nucleation. The uniform internal potential field around CNTs results in the formation of annual ring structures. [ABSTRACT FROM AUTHOR]