Chapter 5 - Molecule-graphene and molecule-carbon surface binding energies from molecular mechanics

Abstract

Force field calculations using MM2 and MM3 parameters have been used to model molecular interactions with graphene, multilayer graphene, carbon nanotubes, and surface-modified graphene structures. The physical adsorption of molecules on carbon surfaces has many practical applications, and predictions of the molecule-surface binding energies are a critical aspect of such a system's behavior. Experimental molecule-surface binding energy ( E *) values have been correlated with or predicted from computed molecule-surface binding energy (Δ E ) values for several systems presented here. MM3 molecular mechanics gave good results for the binding energies of molecules adsorbed on carbon nanotubes (CNTs) with comparisons to experimental values. Additional comparisons were made with DFT calculated values and DFT with dispersion correction values. MM2 with a simple adjustment gave good results for correlating E * and Δ E values for 118 molecules adsorbed on multilayer graphene (graphite) and provided a way to predict the binding energy for molecules on a graphene surface. One additional application of force field calculations was the design of a linker molecule to hold two CNTs in a non-preferred perpendicular orientation. A second application was the development of a graphene bilayer hydroxylated pore to enhance the adsorption of 22 explosive molecules where the modified layer might function as part of a molecular sensor.