hereby incorporated by reference provides a procedure for preparation of fishbone fibrils substantially free of a pyrolytic overcoat these carbon nanotubes are also useful in the practice of the invention see also u s pat no 5 165 909 to tennent hereby incorporated by reference oxidized nanofibers are used to form rigid porous assemblages u s pat no 5 965 470 hereby incorporated by reference describes processes for oxidizing the surface of carbon nanotubes that include contacting the nanotubes with an oxidizing agent that includes sulfuric acid h 2 so 4 and potassium chlorate kclo 3 under reaction conditions e g time temperature and pressure sufficient to oxidize the surface of the fibril the nanotubes oxidized according to the processes of mccarthy et al are non uniformly oxidized that is the carbon atoms are substituted with a mixture of carboxyl aldehyde ketone phenolic and other carbonyl groups nanotubes have also been oxidized non uniformly by treatment with nitric acid international application wo95 07316 discloses the formation of oxidized fibrils containing a mixture of functional groups in published work mccarthy and bening polymer preprints acs div of polymer chem 30 1 420 1990 prepared derivatives of oxidized nanotubes in order to demonstrate that the surface comprised a variety of oxidized groups the compounds they prepared phenylhydrazones haloaromaticesters thallous salts etc were selected because of their analytical utility being for example brightly colored or exhibiting some other strong and easily identified and differentiated signal nanotubes may be oxidized using hydrogen peroxide chlorate nitric acid and other suitable reagents see for example u.