In the present work, the use of a commercial ionic liquid as a convenient solvent medium for graphite exfoliation in mild and easy conditions without any chemical modification is presented. To confirm the presence of few layer graphene, its dispersion, which exhibits Tyndall effect, was characterized by Raman and UV spectroscopies, and atomic force and field emission electron microscopies. It is noteworthy that, by gravimetric analysis, a graphene concentration as high as 5.33 mg ml À1 was determined, which is the highest value reported so far in any solvent.

We describe a facile and scalable surface treatment for the functionalization of the graphene sheets (GSs). The approach consists of a surface plasma treatment of GSs by first covalently attaching fluorine and then exposing the obtained fluorinated graphene sheets (F-GSs) to a polymerization initiator such as butylamine at room temperature. Infrared and x-ray photoelectron spectroscopy have been used to demonstrate that both the fluorination of the GSs and the subsequent attachment of the amino groups to the GSs thorough the elimination of the fluorine atoms have been obtained. The successful dispersion of graphene nanosheets in organic solvents is extremely useful for their use as additives in polymer-based composites and other functional applications.

We describe a facile method to use soluble chemically derived graphene sheets (GSs), which has a oneatom thickness and a two-dimensional structure, as transparent electrode for the preparation of polymer solar cells. Chemically functionalized GSs were obtained by first covalently attaching fluorine and then exposing the obtained fluorinated graphene sheets to an aliphatic amine at room temperature. Scanning electron microscopy, atomic force microscopy and UV-Vis analyses confirmed the obtaining of transparent graphene sheets with an average thickness of 0.7-0.9 nm. A proof-of-concept application in a polymer solar cell is demonstrated. The functionalized graphene, which is cheap and easily prepared, is expected to be a competitive candidate as hole acceptor material in polymer photovoltaic applications.