Modeling the Liquid Phase Exfoliation of Graphene

Abstract

Graphene is a revolutionary nanomaterial with wide ranging applications from nanoscale electronics to high strength alloys. Liquid phase exfoliation from graphite is a feasible, large scale method for the production of graphene. A good understanding of the solvent stabilization of graphene is necessary to fine-tune the experimental procedures. In this work, our approach is to elucidate the energy barrier separating graphite and single-layer graphene. Accurate simulation methods, including quantum-mechanical contributions, are used to model the graphene exfoliation process. A plot of shift distance vs. energy shows that completely stacked bilayer graphene is more stable than the fully separated sheets. Hence, the exfoliation of graphene from bulk graphite is an activated process (i.e. a driving force is necessary for the reaction to happen). The results of several different simulations methods are compared. After the energy barrier separating the graphene sheets is calculated, it would be possible to estimate the kinetics of the reaction.