Tri-layer graphene films produced by mechanochemical exfoliation of graphite

We report a method for the production of transparent thin films composed in majority (59%) by tri-layer graphene, in which both the synthesis and processing are combined in one single step. Starting from graphite, two mechanical exfoliation processes are performed, followed by chemical/thermal exfoliation in a water/oil two phase system, which yields few layer graphene flakes spontaneously self-assembled at the water/oil interface as a thin film that is easily transferred to an arbitrary substrate.