Graphene Oxide (GO), an oxidized form of graphene, a carbon allotrope, has many applications including the formation of conductive films for use in flexible electronics and chemical sensors, nanofiltration membranes, and even as a replacement for tin-oxide in batteries. One of the pressing issues with carbon allotropes in general and GO in particular, however, is that they cannot form freestanding films on their own; instead they rely on a secondary reactant to help aid in the synthesis of such films. To synthesize such nanocomposite substrates, cyclic voltammetry is a very commonly used technique, where an electrolyte containing a monomer to be electropolymerized is used along with the nanoparticles. Electropolymerized substrates consisting of GO and polypyrrole (Ppy), an organic polymer created by polymerizing pyrrole, have drawn much attention owing to their applications in solid state supercapacitors, biosensing, tissue engineering, and artificial muscle studies. It has been proven theoretically and experimentally that Ppy and GO do interact and exhibit improvement in conductivity and thermal stability compared to pure Ppy and GO, but there is still very little information on the interactions at the molecular level between GO and pyrrole monomers especially during the synthesis of such nanocomposites.

This work deals with the study of interactions at the interface of GO and pyrrole in order to better understand the evolution of Ppy over the surface of GO during the formation of these films. The system is modeled using Visual Molecular Dynamics (VMD) and all–atom simulations are carried out using Nanoscale Molecular Dynamics (NAMD) at ten different temperatures based on the peak currents and scan–rate through the Randles–Sevcik equation. Each simulation is carried out for 100 nanoseconds, thereby looking into a total of one microsecond-long window of interactions between GO and 50 pyrrole monomers as the polypyrrole film is evolved over the surface of GO. Stability of the GO/ Ppy nanocomposite is quantified through RMSD (Root Mean Square Deviation), conformational energies and center of mass deviations. Interaction energies are calculated to understand the role of non – bonding interactions such as Van der Waals and electrostatics between the monomers and between monomers and GO. It is anticipated that pyrrole monomers form dimers in the bulk of the solution, trimers when near the surface of GO, and tetramers when adsorbed on the surface of the GO. Based on these results, a potential mechanism is proposed on the way monomers interact with the nanoparticles during electropolymerization and the role of such interactions in synthesizing carbon–based freestanding films.