| 초록 |
In this work, we study the functionalization of small-diameter single-walled carbon nanotubes (SWNTs) via air oxidation, in a manner similar to that employed for functionalization of other carbon surfaces. The Raman spectroscopy, XPS, TEM, SEM, and TG/DTG techniques are used to study the characteristics of SWNTs after oxidation. As a result, the oxidation of SWNTs (O-SWNTs) produces oxygenated functional groups, e.g., carboxylic acid, ester, and quinone moieties. The electrical resistance of the O-SWNTs depends on the degree of oxidation and is about 100-200 times higher than that of pristine SWNTs, owing to the deformation of the π-conjugation structure along the tube. The O-SWNTs are easily dispersed in dimethylformamide (DMF) and show enhanced solubility in other polar solvents, such as water and ethanol. The O-SWNT suspensions consist of individual and shortened tubes due to the separation of nanotube bundles and the shortening that results from oxidation. Consequently, the air oxidation can lead to afford heavily functionalized on nanotubes that do not re-rope and remain them as individuals in organic solvents giving enormous increases in solubility. |
