Monodisperse chemically modified graphene obtained by density gradient ultracentrifugal rate separation.

A simple density gradient ultracentrifuge separation method has been developed for sorting chemically modified graphene (CMG) by sheet size and surface chemistry in just a few minutes. By optimizing the parameters, including the density gradient and centrifugation time, CMG sheets with specific size ranges and optical properties can be targeted selectively. UV-vis absorbance and photoluminescence spectra revealed the properties of separated CMG samples are highly dependent on their sheet size and degree of oxidation. A possible mechanism for the separation is discussed.