i think the carbon nano-tubes just dispersible by sonication 

You can actually digest the CNTs using strong acid combination (as well as the activated carbon and most probably the resin too).

I studied about MWCNTs treatment: http://onlinelibrary.wiley.com/doi/10.1002/open.201500096/full

However that makes them mixed in the solvent. What kind of characterization do you need?

I want to do NMR for resin