In Situ Polymerization on Graphene Surfaces

Graphene has exceptional mechanical, electrical, and electronic properties, and these could be utilized by forming composites with polymers. This article aims to investigate the formation of chemical bonds at the graphene polymer interface by first functionalizing the graphene and then growing polymer on the surface by in situ polymerization reaction. The density functional theory was used to reveal the mechanism of free radical addition polymerization reaction of ethylene with graphene. The results showed that graphene can be functionalized with an oxy radical, and the resulting radical can initiate the polymerization reaction so that chemically bonded polymer chains can grow on graphene. The reaction with a second graphene sheet can terminate the growing chain and at the same time generate a radical center on the second graphene sheet for another polymer chain to grow. The polymer chains can function as spacers to prevent restacking of graphene sheets. The results demonstrated that the intact structure of graphene is conserved to some extent through the controlled formation of ripples on graphene sheet, thereby forming covalent bonds more easily at the crests of the ripples.