Theoretical study of the formation of polydopamine on regular graphene as a precursor of composite materials

Abstract

Composite materials based on graphene have excellent properties due to their high electrical and thermal conductivity, which make them interesting for applications in areas such as electronics, energy and medicine. Polydopamine (PDA) can be obtained through the self-polymerization of dopamine (DA), forming, under appropriate conditions, a coating that prevents the agglomeration of the reduced graphene oxide sheets. These coatings exhibit several properties such as the formation of strong bonds, easy implementation on different substrate surfaces, excellent biocompatibility and versatile post-functionalization accessibility. Some studies would indicate that 5,6-dihydroxyindole (DHI) acts as an initiator in the formation of the PDA coating. In this work, the adsorption of DHI and PDA dimers on the graphene surface is studied using a theoretical model. The calculations were carried out within the framework of Density Functional Theory (DFT) and considering periodic models. The behavior of these systems was comparatively examined, and the adhesiveness was evaluated.