Concluding Remarks

Understanding the dynamics of particles at fluid-fluid interfaces has attracted considerable research interest over the past several decades as fluid interfaces create an environment where monolayer thin films can be assembled through a ‘bottom-up’ approach. For example, fluid-fluid interfaces have been used to manufacture highly transparent and electrically conductive thin films of graphene flakes as it has been shown that graphene flakes are thermodynamically favorable at the interface between two immiscible fluids. However, the dynamics of film formation and the interactions between graphene flakes are currently not understood. Furthermore, it has proven difficult to isolate and experimentally probe the dynamics of pristine monolayer graphene flakes at fluid-fluid interfaces. This study aims to address this gap by using computational simulations, which have been shown to reliably estimate real-world experimental scenarios. Molecular dynamics simulations were employed to investigate the lateral interactions and stacking dynamics of mono- and few-layer graphene flakes at a vapor-water interface. Adaptive biasing force (ABF) simulations were used to render potential of mean force profiles and identify different stacking pathways. Additionally, distance versus time profiles were generated for two interacting monolayer flakes and the results were fit according to a power law relation to understand how the interaction pair potential scaled with center-to-center separation distance. Ultimately, this study offers a new perspective into the investigation of interactions between interfacially-bound particles.