Shortened single-walled nanotubes functionalized with poly(ethylene glycol): preparation and properties

Poly(ethylene glycol) (PEG) was grafted to shortened single-walled carbon nanotubes (sh-SWNTs) obtained from original SWNTs after acid oxidative cutting and etching processes. PEG-sh-SWNTs, prepared by treating the sh-SWNTs with SOCl2 followed by amidation with PEG-monoamine (molecular weight = 2000), are moderately soluble in tetrahydrofuran, chlorinated hydrocarbons (ca. 1 mg/ml), sparingly soluble in water, acetone CH3OH and insoluble in non polar solvents such as toluene, hexanes or carbon disulfide. Non linear transmission measurements on solutions of PEG-sh-SWNTs in CHCl3 showed a better optical limiting performance relative to that recorded for original SWNTs suspended in the same solvent