Theoretical Study of Graphene as a Diffusion Barrier in Metal-Based Nanoenergetic Films

Graphene has emerged as a promising component for nanoenergetic composites, yet its capability to suppress interfacial diffusion under near-room-temperature fabrication and storage conditions remains insufficiently understood. In this work, first-principles calculations combined with ab initio molecular dynamics (AIMD) simulations were employed to systematically investigate the adsorption, diffusion, and penetration behaviors of representative metal fuels (Al, Mg, and Ti) on graphene. Static adsorption calculations reveal distinct interaction strengths, with Ti exhibiting chemisorption, Al weak chemisorption, and Mg physisorption. AIMD simulations demonstrate that Al adatoms remain adsorbed while diffusing freely in-plane, Mg undergoes spontaneous desorption, and Ti remains strongly localized at hollow sites due to a significantly higher diffusion barrier. Penetration studies show that all three metals face prohibitively high energy barriers when traversing graphene, confirming its effectiveness as a diffusion barrier under near-ambient conditions. Electronic structure analyses indicate that the strong Ti adsorption originates from d-π hybridization and interfacial charge redistribution, whereas Al adsorption involves mixed ionic-covalent interactions, and Mg adsorption is dominated by weak polarization effects. These findings establish a clear structure-property relationship governing interfacial stability and demonstrate that graphene can effectively suppress premature interdiffusion in nanoenergetic multilayer films, particularly in Ti-based systems.