Molecular dynamics simulations of the aggregation behaviour of overlapped graphene sheets in linear aliphatic hydrocarbons

Abstract

Molecular dynamics simulations were used to investigate the aggregation of two partially overlapped graphene sheets in hexane, dodecane and eicosane. When partially overlapped graphene sheets are adjacent to one another, they will expel the adsorbed layers of the solvent molecules on the graphene surface, and the amount of overlap will increase. When the overlapped regions of the graphene sheets are separated by solvent molecules, they cannot expel the adsorption layers between them, and so the sheets remain separated. The driving force for aggregation is the van der Waals interaction between the two graphene sheets, while the van der Waals interaction between the graphene sheets and the solvent molecules inhibits graphene aggregation. The diffusion rate of the hydrocarbon molecules with shorter chain lengths is higher. Thus, they diffuse faster during graphene aggregation, which leads to a higher rate of graphene overlapping in the shorter hydrocarbons. This work provides useful insights into graphene aggregation in linear hydrocarbon solvents of varying lengths at the nanoscale.