Utilising the hydrodynamics of thin liquid films flowing over a spinning disc to produce graphene*

We explore the use of thin liquid films flowing over a spinning disc to produce graphene, a two-dimensional nanomaterial which has remarkable mechanical, electrical, thermal and optical properties. This process produces atomically thin graphene nanosheets through shear-driven exfoliation of a graphite precursor dispersed in N-Methyl-2-pyrrolidone solvent. The thin liquid films are subjected to large centrifugal forces, leading to the formation of large amplitude waves that generate a high-shear environment which can induce this exfoliation process. The aim of the study is to examine how the hydrodynamics of the flow affects graphene exfoliation. The wave regimes have been investigated experimentally using high-speed imagery, and through direct numerical simulations that implement a volume-of-fluid approach. The preliminary results suggest that the wave regime and shear rate, governed primarily by the rotational speed and flowrate of the liquid on the disc, has a direct impact on the material obtained and production yield.