Structural and optical properties of PVP/PEO blends doped with CNTs

Carbon nanotubes (CNTs) have garnered substantial interest as nanofillers for improving the properties of polymer composites due to their exceptional mechanical, electrical, and thermal characteristics. As nanofillers, carbon nanotubes can be incorporated into various materials to enhance their performance and functionality. In the present work, polymer blends of polyvinylpyrrolidone (PVP)/polyethylene oxide (PEO) doped with different concentrations of carbon nanotubes (CNTS 1%, 3%, and 5%) were fabricated by solution casting technique. X-ray diffraction studies reveal that the prepared polymer blend nanocomposites exhibit the semicrystalline nature. The intensity of the XRD peaks obtained for PVP/PEO blend at 19.3 is found to be reduced with an increase of CNTs concentration from 1 to 5%. The DSC thermograms show the glass transition temperatures (Tg) of PVP/PEO films doped with different concentrations of CNTs appeared in the region between 51-60 degrees C. The decrease in the degree of crystallinity for PVP/PEO doped with CNTs is noticed. The surface morphology and chemical composition of pure and CNTs doped PVP/PEO blends were examined by FESEM with EDS. The direct and indirect optical bandgap values for pure PVP/PEO blend are found to be 4.90 eV and 4.66 eV. With the increase of concentration of CNTs from 1 to 5%, the direct band gap ranges from 4.30 to 3.40 eV, while the indirect band gap decreases from 4.20 to 3.67 eV. The obtained results confirm that PVP/PEO doped with CNTs had promising applications in the optoelectronic and photonic devices.