Abstract

Sidewall functionalization by chemical agents can improve the dispersion of carbon nanotubes (CNTs), but the improvement is at the expense of their properties and structure. An environmentally friendly dispersant, cyclodextrins (CD), was revealed as a preferable alternative to functionalize CNTs without changing their pristine structure and properties. In this study, multi-walled carbon nanotubes (MWCNTs) were functionalized using beta-CD (β-CD). Different concentrations of β-CD served as the dispersants, and different non aqueous media (ethanol, acetic acid, and water) were studied to achieve required degree of functionalization for MWCNTs. The functionalized MWCNTs were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, dynamic light scattering, thermo gravimetric analysis, and X-ray diffraction. The analytical results indicated the degree of functionalization increases with increasing β-CD ratios. However, a lower degree of functionalization was shown by using a higher solvent polarity of non aqueous media. The functionalized MWCNTs were shown to have open-ended and defect free walls.

Keywords: β-cyclodextin, characterization, concentration ratio, functionalization, multi-walled carbon nanotubes, non aqueous media