Synthesis of dark brown single-walled carbon nanotubes and their characterization by HSQC-NMR

Abstract

We report here a simple and effective approach to the covalent attachment of single-walled carbon nanotubes (SWCNTs) and azo compounds. The functionalized SWCNTs prepared (through a radical mechanism) have been used for a diazonium coupling reaction. The results showed that the chemical method used has improved the processability and solubility of the carbon nanotubes. The dark brown SWCNTs obtained which can produce a yellow colour in organic solvents were characterized by different spectroscopic analyses. Heteronuclear single quantum coherence spectra (13C-1H HSQC) have been used to detect the carbon nanotube allylic protons. The morphology of the main product has been shown by scanning electron microscopy (SEM). Dark brown SWCNTs have been prepared through a covalent attachment of diazo compound to the surfaces of functionalized single-walled carbon nanotubes. The structure of the products have been assigned by HSQC-NMR spectroscopy.