Graphene can be prepared in liquid-phase. This allows upscaling the production, in order
to obtain a much higher amount of graphene. The easiest method would be
to disperse the graphite in an organic solvent with nearly the same surface energy as
graphite [4]. Thereby, the energy barrier is reduced, which has to be overcome in order to detach a graphene layer from the crystal. The solution is then sonicated in an ultrasound bath for several hundreds hours or a voltage is applied [5]. After the dispersion, the solution has to be centrifuged in order to dispose of the thicker flakes. The quality of the obtained graphene flakes is very high in accordance with the micromechanical exfoliation. Its size however is still very small, neither is the controllability given. On the other hand, the complexity is very low, and as mentioned above this method allows preparing large amounts of
graphene.