Molecular dynamics simulations on the orientation of n-alkanes with different lengths on graphene

The orientation of molecules on surface is very important in the design of nanomaterials. Molecular dynamics simulation was used to study the mechanism of n-alkane molecules orientation on graphene surface. The chain length effects the orientation of n-alkanes on graphene surface. Short n-alkanes are perpendicular to the graphene surface and the long n-alkanes are laid parallel to the surface. The two kinds of orientation processes are shown directly and are considered as a three-step process (adsorption, orientation, and growth). The critical temperatures of the orientation of n-alkanes on graphene surface increases with chain length increasing. In addition, the simulation results show the interactions of n-alkane-n-alkane and n-alkane-graphene playing a key role in the orientation of n-alkanes on graphene surface.