Preparation and Characterization of Oxidized Multi-Walled Carbon Nanotubes and Glycine Functionalized Multi-Walled Carbon Nanotubes

In this work, oxidized multi-walled carbon nanotubes (MWCNTs) and glycine functionalized MWCNTs were synthesized and characterized using ultraviolet-visible (UV-Vis), fourier transform infrared (FT-IR), electron paramagnetic resonance (EPR), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques.. UV-Vis spectroscopic study shows a characteristic peak at 276 nm for oxidized MWCNTs, and the red shift was observed for glycine-functionalized MWCNTs at 296 nm. The appearance of another peak at around similar to 350 nm is attributed to the formation of glycine-functionalized MWCNTs. FT-IR spectral study confirms that glycine molecules have bonded to MWCNTs. EPR study reveals that the line shape is a Gaussian line shape and the electron spin concentration decreases with increasing concentration of glycine, which indicates that the unpaired electrons undergo a reduction process in the glycine-functionalized MWCNTs. The g-value indicates that the systems are isotropic in nature. The surface morphology of the samples was observed from SEM images. The EDX analysis shows the high purity of both oxidized and glycine-functionalized MWCNTs.