Using a 2-step purification/oxidation procedure, an investigation was made of the effect of basic treatments and solvent washing upon the functionalization and final properties of single-walled carbon nanotubes. It was demonstrated, using a number of spectroscopic techniques that, in the absence of NaOH treatment, a COOH functionality was introduced directly onto single-walled carbon nanotubes and not only onto carbonaceous material present in the sample. Covalent functionalization of the oxidized materials was also investigated by attachment of a fluorescent probe. Whether treated with base or solvent washes, the resultant materials were nearly identical with respect to both their appearance and properties. It was demonstrated that, using either of these purification/oxidation strategies, functionalized materials could be produced that exhibited distinctive optical/electronic properties, as demonstrated by sustained structured spectroscopic absorption and emission features.

Critical Investigation of Defect Site Functionalization on Single-Walled Carbon Nanotubes. E.Del Canto, K.Flavin, D.Movia, C.Navio, C.Bittencourt, S.Giordani: Chemistry of Materials, 2011, 23[1], 67-74