Key points are not available for this paper at this time.
Stable high-concentration suspensions (up to 0.95 mg mL(-1)) of non-oxidized few layer graphene (FLG), five or less sheets, with micrometre-long edges were obtained via direct exfoliation of natural graphite flakes in ionic liquids, such as 1-butyl-3-methyl-imidazolium bis(trifluoro-methane-sulfonyl)imide (Bmim-Tf(2)N), by tip ultrasonication.
Wang et al. (Fri,) studied this question.