Molecular dynamics simulation of interactions on graphene/polypyrrole nanocomposites interface

Graphene receives world-wide attention due to its unique two-dimensional structure and exceptional electrical and mechanical properties. The graphene/polypyrrole (Gr/PPy) nanocomposites, have been synthesized via dispersing the graphene into polymers, which can be widely used in microwave absorption, supercapacitors and electronic devices. Molecular dynamics simulations are carried out to investigate the microscopic mechanism of interactions on Gr/PPy nanocomposites interface. The interaction configurations, intermolecular interaction energy and pair correlation functions between graphene and PPy are computed. The curves of temperature, energy evolution and interaction energy analysis indicate that Gr/PPy system reaches equilibrium in a relatively short time, and it is a thermodynamic equilibrium system. The interaction configurations show that there is an attractive interaction between the graphene and PPy. Pair correlation functions reveal that there are van der Waals interactions and hydrogen bond between the graphene and PPy, which are strong short-range non-bonded interactions. The strong interactions mainly arise from the sp² hybridized π-conjugated structure of graphene and PPy, which engenders π-π interaction.