Chemical oxidation of single wall carbon nanotubes (SWNTs), produced with the HiPco method, is studied by resonance Raman scattering. The analysis of the radial breathing mode makes it possible to assign the observed bands to metallic and semiconducting SWNTs and to suggest the chiral indices of SWNTs contributing to the spectra. On this basis we observe that the most important parameter which determines the attack of the nanotubes is their diameter: Small diameter tubes, due to the stress induced by the curvature, are first attacked and destroyed. Some reactivity is also observed for larger diameter metallic nanotubes, which, however, are not easily destroyed

No abstract

No abstract

No abstract

Poly(ethylene glycol) (PEG) was grafted to shortened single-walled carbon nanotubes (shSWNTs) obtained from original SWNTs after acid oxidative cutting and etching processes. PEGsh-SWNTs, prepared by treating the sh-SWNTs with SOCl 2 followed by amidation with PEGmonoamine (molecular weight = 2000), are moderately soluble in tetrahydrofuran, chlorinated hydrocarbons (ca. 1 mg/ml), sparingly soluble in water, acetone CH 3 OH and insoluble in non polar solvents such as toluene, hexanes or carbon disulfide. Non linear transmission measurements on solutions of PEG-sh-SWNTs in CHCl 3 showed a better optical limiting performance relative to that recorded for original SWNTs suspended in the same solvent.