What do you mean exactly by "carbon nanometers"? And if you are asking for solubility, there are several papers about soluble carbon nanotubes...
But changing a matter physical condition, is totally another thing. You have to loosen the molecular attractions, which might be possible but I think the outcome will be really unstable and needs super controlled condition to achieve...
Sonication of carbon nanoparticles can be a temporary solution only. To obtain really stable nano-fluids, chemical surface modification is required to provide a covalent bonding between carbon nanoparticles and matrix molecules. Each medium, as well as each type of nanoparticles requires special surface modification.