Sidewall functionalization of single-walled carbon nanotubes with hydroxyl group-terminated moieties

Single-walled carbon nanotubes functionalized with the OH group-terminated moieties (hydroxyl nanotubes) have been prepared by fluorine displacement reactions of fluoronanotubes with a series of diols and glycerol in the presence of alkali, LiOH, NaOH, or KOH or with amino alcohols in the presence of Py as a catalyst. The hydroxyl nanotubes were characterized by optical spectroscopy (Raman, ATR-FTIR, UV-vis-NIR), electron microscopy (TEM), atomic force microscopy (AFM), and thermal degradation (TGA and VTP-MS) materials characterization methods. The degree of sidewall functionalization in the prepared SWNT derivatives was estimated to be in the range of 1 in 15 to 25 carbons, depending on derivatization method and alcohol reagent used. The hydroxyl nanotubes form stable suspension solutions in polar solvents, such as water, ethanol, and dimethylformamide, which facilitate their improved processing in copolymers and ceramics nanofabrication and provide for compatibility with biomaterials.