Water-Soluble Multiwalled Carbon Nanotubes Functionalized with Sulfonated Polyaniline

Abstract

Multiwalled carbon nanotubes (MWNTs) functionalized with a water-soluble conducting polymer, sulfonated\npolyaniline (SPAN), were prepared by in situ polymerization of aniline followed by sulfonation with\nchlorosulfonic acid in an inert solvent and by hydrolysis in water. Electron microscopy, laser Raman\nspectroscopy, X-ray photoelectron spectroscopy, and UV−vis absorption spectroscopy were employed to\ncharacterize the morphology and chemical structure of the resulting product. The results show that the quinonoid\nstructure of SPAN preferentially interacts with the nanotubes and is stabilized by strong π−π interaction\nbetween two components. The structure of MWNTs was not perturbed by the incorporation of SPAN, since\nthe π−π interaction between MWNTs and SPAN is much weaker in comparison to that of the carbon covalent\nbond. The SPAN functionalized MWNTs are highly dispersible in water, thus opening new possibilities for\ntheir prospective technological applications.