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.