High Concentration Few-layer Graphene Sheets Obtained by Liquid Phase Exfoliation of Graphite in Ionic Liquid

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 was charachterized by Raman spectroscopy, atomic force miscroscopy and field emission electron microscopy. From the UV-Vis characterization, a graphene concentration as high as 2.543 mg/ml was obtained, which is the highest value reported so far in any solvent.