Functionalization of SWCNTs with amine derivatives and comparative solubilization studies

Abstract

Single-walled carbon nanotubes (SWCNTs) were functionalized by means of a series of aromatic and heterocyclic amines (4-anisidine, 5-aminobenzene-1,3-dicarboxylic acid (5-aminoisophthalic acid), 1,3-dimethyl-5-aminobenzene-1,3-dicarboxylate, dimethyl 5-aminoisophthalate, 4-aminopyridine, 2-aminothiazole, 4-sulfanilamide) by two methods: acidic treatment and molten urea-assisted synthesis. The reactions products were characterized by scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, and thermogravimetric analysis. The dispersion ability of several solvents (acetone, water, dimethylformamide, ethanol, toluene, and ethylene glycol) to “dissolve” the functionalized SWCNTs was determined for each product. The dispersion ability of the used solvents with respect to the functionalized SWCNTs was found to be considerably dependent on the nature of the solvent (in particular, its polarity), the organic compound used as the functionalizing agent, and, in a lesser account, on the functionalization method followed.