Preparation and Characterization of Multiwall Carbon Nanotube (MWCNT) Reinforced Chitosan Nanocomposites: Effect of Gamma Radiation

Abstract

Nanocomposites of biodegradable chitosan and multiwalled carbon nanotubes (MWCNTs) were prepared using two kinds of MWCNTs, i.e., pristine multiwalled carbon nanotubes (p-MWCNTs) and carboxyl-functionalized multiwalled carbon nanotubes (f-MWCNTs). The nanocomposites were subjected to gamma irradiation (60Co) at different intensities (1–50 kGy), and the variation of different physicomechanical properties has been extensively studied. Various techniques such as Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), optical microscopy (OM), thermogravimetric analysis (TGA), differential scanning colorimetry (DSC), and universal testing machine (UTM) were used to investigate the physicochemical, morphological, and thermomechanical properties of the nanocomposites. FTIR spectra and OM confirmed that oxygen-containing functional groups were present on the surface of the tubes that helped better dispersion of f-MWCNTs in chitosan solution. The experimental results demonstrated that the tensile strength (TS) and modulus (TM) of nanocomposites were increased by 57 and 48 %, respectively, through the addition of 1 % MWCNTs with the chitosan matrix; however, no significant changes of TS and TM are observed for more MWCNTs (above 1 %) in the composites. Considering the effect of irradiation doses, it was observed that low irradiation doses (up to 10 kGy) significantly increases thermal stability and tensile properties of the nanocomposite compared with the nonirradiated samples.