Solid-State NMR Study of Nanodiamonds Produced by the Detonation Technique

Nanodiamonds obtained by the detonation method have been investigated by means of solid-state magnetic nuclear resonance (NMR) and electron paramagnetic resonance. 13 C and 1 H magic angle spinning (MAS) NMR and 13 C MAS NMR with 1 H to 13 C cross-polarization allow the determination of surface-hydrogenated groups (CH, CH 2, and COH) and the quasi-absence of an sp 2 carbon fullerene-like shell on the diamond surface to be underlined. The 1 H and 13 C spin−lattice relaxation time ( T 1 ) and second moment measurements are presented as a function of the temperature. Relaxation is shown to be mainly caused by paramagnetic centers in the case of 13 C nuclei, whereas the presence of a molecular motion with an activation energy of 11.15 kJ·mol −1 is involved for 1 H nuclei.