A new VECMA paper has been accepted for publication in Physical Chemistry Chemical Physics, on Micromechanical Exfoliation of Graphene on the Atomistic Scale.
Graphene is known for being the strongest material in the world, lightweight and with extraordinary electrical, thermal and optical properties. Unsurprisingly, it offers many benefits for commercial application.
There are various methods for producing graphene from the readily available raw material graphite, including the famous adhesive tape method developed by Nobel Prize winner Andre Geim, where individual graphene sheets are exfoliated. However little has been known until now about how this process works on atomic scale.
We show for the first time the exfoliation of graphene with sticky tape with atomic precision, using the technique molecular dynamics. This is made possible by using a recently developed molecular dynamics forcefield, GraFF, to represent graphene’s unusual dispersion interactions. We see clearly graphene peeling away from a graphite stack, much like lifting the top card from a deck of playing cards.
We find that depending on the adhesive used the outcome of this exfoliation process can vary widely, potentially making a far more efficient way to produce graphene from graphite. Under the correct conditions, one could produce graphene with only 4 exfoliations rather than 11 if the experiment is carried out naively. Exfoliating graphene, rather than simply producing more graphite, depends strongly on the viscosity of the polymer present in the adhesive used. Armed with this new chemical insight we discuss the experimental methods that could improve graphene production.
The paper will soon be available from Physical Chemistry Chemical Physics.