Interfacial adhesion behavior between conductive polymers and functionalized graphene via molecular dynamic simulation

Abstract

The interaction mechanism between typical conductive polymers and chemically functionalized graphene layers was investigated via molecular dynamics (MD) simulation. The designed adjoining systems consist of typical conductive polymers, such as polythiophene (PTh), polypyrrole (PPy) and functionalized graphene. Various functional groups including amine (NH2), carboxyl (COOH), hydroxyl (OH), and methyl (CH3) were distributed uniformly throughout the intrinsic graphene upper surface to achieve graphene functionalized structures. The simulation calculation results show that the interfacial interaction energy between the conductive polymers and the graphene oxide was more than that between the conductive polymer and the intrinsic graphene. Moreover, the electronegativity of functional groups and surface roughness of functionalized graphene play predominant roles in the interaction energy between the conductive polymers and the functionalized modified graphene layer, which functional groups with greater chemical electronegativity led to further enhancement in interfacial adhesion behavior. The interface interaction energy was decreased as the surface numerical density of functional group, except for the graphene oxided with the non-polar methyl groups. In addition, the highest interfacial interaction energy was observed at the interfacial region of PPy and carboxylated functionalized graphene as a result of forming hydrogen bonding interaction. The density profiles were studied to characterize interfacial properties of polymers due to the active and powerful interfacial adhesion behavior between modified graphene and conductive polymers. The results can be applied to develop and manufacture more high performance reinforced nanocomposites for next generation microelectronic packaging and solar cell applications.