ABSTRACT
Being the building block of graphite, graphene may not appear like a "new" material. Graphite is the most common and thermodynamically stable form of carbon. Its structure has been well-documented and consists of an ordered stacking of numerous graphene layers on top of each other. Until now, the fabrication of defect-free high-quality graphene in large areas, which is critical for nanoelectronic devices, is still a big challenge. Mechanical exfoliation is a convenient method to extract thin carbon layers from bulk graphite through cleavage/peeling. Nanomanipulation is possible by using atomic force microscope and scanning tunneling microscope. Recently, a new method of mechanochemical preparation was reported, which yielded edge-functionalized graphene from graphite. In contrast to the dry exfoliation of graphite, exfoliation with the assistance of ultrasonication in a liquid phase has also been investigated using various solutions, including organic, aqueous, as well as ionic liquids.
