Enhancement of electrical conductivity and band gap of epoxy/MWCNT/GNP/glass fibers hybrid materials

Polymer composites containing carbon nanoparticles have attracted considerable attention because of their special functional characteristics. Characterization of optical and dielectric characteristics was done. To comprehend the impact of nanofillers, dielectric characteristics, UV–Vis spectroscopy, XRD, and Fourier transform spectroscopy were employed. The role of carbon fillers on metrics, such as band gap energy, absorption coefficient, and dielectric characteristics of nanocomposites was examined to differentiate between the effects of nanofillers. The AC conductivity is explained following the classical percolation theory. The percolation threshold is discovered to be 1 wt.% of a hybrid system of nanofillers consisting of graphene nanoplatelets (GNPs) and multi-walled carbon nanotubes (MWCNTs). The presence of carbon nanofillers significantly enhances the electrical conductivity of the nanocomposites. The optical band gap energy of nanocomposites was obtained from the Tauc method. The study establishes the relationship between band gap energy and AC conductivity using Tauc's relation and Jonscher's power law. The results show that the band gap energy of composites decreases with the addition of hybrid nanofillers, with values observed at 2.65 eV and 2.95 eV, while without fillers of 3.1 eV and 3.05 eV attributed to increased localized states within the bandgap. Composites with nanofillers show an AC conductivity of 1.86 S/m at 1 wt% of nanofillers, compared to 1.52 × 10−6 S/m and 1.09 × 10−6 S/m for composites without nanofillers. The UV–Vis spectra reveal a significant blue shift in the absorption peak when the weight percentage of carbon nanoparticles is increased. The findings of this study point toward the possibilities of the development of novel nanocomposites with enhanced performance for electronics and energy storage.