C-13 NMR evidence for dynamics of nanotubes in ropes - art. no. 100302

We report on C-13 nuclear magnetic resonance from 10 up to 350 K on single wall carbon nanotubes. The magic angle spinning NMR spectrum shows one isot ropic line at 126 ppm and the static spectrum a powder pattern typical for a curved graphene sheet. The T dependence of the spin-lattice relaxation ra te T-1(-1) reveals an unusual phenomenon which could be explained by therma lly activated small amplitude motion (SAM) of the nanotubes. If above 170 K , diffusion of twistons might be responsible for the local SAM of the C-13 sites, below this transition temperature frozen in twistons could appear wi th an orientational order of the nanotubes in the ropes.