Graphene oxides for homogeneous dispersion of carbon nanotubes.

Graphene oxides (GOs) in terms of both structure and property are essentially polyelectrolytes in a two-dimensional sheet configuration. As is well-established in the literature, polyelectrolytes are, in general, good dispersion agents for single-walled carbon nanotubes (SWNTs), which are otherwise in bundles because of strong van der Waals interactions. We report here a study in which GOs were used to disperse SWNTs, both as-purified and separated semiconducting SWNTs, for solution-like homogeneous suspensions. As a demonstration for their potentials, the optically transparent dispersions were used in a more accurate determination of the absorptivities for the band-gap transitions in semiconducting SWNTs. Results on exploration of the use of the GO-dispersed SWNTs in the development of unique carbon nanocomposite materials are also presented and discussed.