Atomistic simulations of Epoxy/Water/Aluminum systems using the ReaxFF method

The molecular dynamics (MD) method can be a reliable tool for studying of organic coating/metallic substrate systems, however its accuracy is limited to the force field governing the dynamics of systems. These systems can be divided into three parts: (i) organic phase, (ii) substrate, (iii) interface between the organic phase and substrate. In this work, three recent ReaxFF descriptions were selected. A set of complex experimental data and density functional calculations was selected as the reference point. The density and structural analysis of a wide range of crystalline organic compounds were studied. The density, structural analysis, and self-diffusion constant of water at room temperature were obtained. The glass transition temperature of three different cross-linked epoxy were obtained and compared with the reported experimental results. The interaction energies of different configurations of epoxy and water over an alumina substrate were studied. Additionally, the reaction of water with aluminum was studied. The accuracy of these ReaxFF descriptions in reproducing the reference data was assessed. The results show there is a single ReaxFF description for accurate simulation of C/H/N/O/Al systems, which enables atomistic simulations of complex epoxy coatings/aluminum substrates systems.