Effect of Cu surface and graphene on the conformation of n-octadecane: a molecular dynamics study

In order to study the micro behavior of alkanes and their interaction with carbon nanomaterials and metal nanomaterials in composite phase change materials (CPCM), in this paper, Cu surface and amorphous n-octadecane composite system (system A) and Cu surface, as well as graphene/n-octadecane composite system (system B), were constructed. The micro behavior of alkanes on the Cu surface was studied by molecular dynamics (MD) simulation. The MD results show that the alkane molecules are arranged in a relatively orderly crystalline form on the Cu surface because of the interface interaction and make the thermal conductivity of the alkane molecules in the composite system improved. Moreover, by comparing the self-diffusion coefficient of n-octadecane in these two systems, it is found that the phase transition temperature of n-octadecane in system A is about 300 K, while the phase transition temperature of n-octadecane/graphene composite system in system B is enhanced to 320 K.