Molecular Dynamics Simulations of Folding of Supported Graphene

The controlled folding of graphene structures driven by molecular interactions with water nanodroplets is analyzed taking into account interactions with supported substrates such as silicon dioxide (SiO2), hexamethyldisilazane (HMDS), and isopropyl alcohol (IPA) on SiO2. The interaction between unsupported graphene and a water nanodroplet is strong enough to induce folding on graphene nanostructures. However, when the graphene is supported on SiO2, the attraction between graphene and the substrate prevents graphene from folding but if the substrate is a hydrophobic surface such as HMDS or a solvent such as IPA, the interaction between graphene and the substrate is weak, and depending on the geometry of the graphene structure, folding is possible. The selection of an acceptable substrate and graphene geometry opens the possibility of a controlled fabrication of graphene-based capsules, scrolls, sandwiches, and rings able to carry a payload.