Effect of graphene on solid–liquid coexistence in Cu nanodroplets

Abstract

The microstructure determines the macro properties, so the chemical and physical properties of nanoparticles can be tuned by changing their structures. A molecular dynamics simulation for the rapid solidification of Cu nanodroplets on the graphene sheet is conducted to investigate the effect of substrate on nanoparticles. The phase transition, structure evolution, and crystallinity are quantified by the potential energy, the largest standard cluster analysis, and Bond-orientation order parameters. It is found that the solidification is inhomogeneous and stepwise crystallization. Interestingly, originating from the graphene wettability, different solid–liquid coexistence states are obtained that may have the potential to modify the chemical and physical reactions on nanoparticles. The temperature of this solid–liquid coexistence state depends strongly on the structural evolution of crystallization and thus can be regulated by the wetting properties of the graphene substrate. These results significantly extend the fundamental understanding of heterogeneous nucleation in nanodroplets, providing important insights for designing and fabricating composite materials with multifunctional properties.