Optical and electrical properties of copper alumina nanoparticles reinforced chlorinated polyethylene composites for optoelectronic devices

The incorporation of transition metal oxide fillers into the polymer matrix through solution mixing polymerization imparts enhanced electrical and thermal properties. The present work focused on the optical properties, crystallinity, thermal stability, temperature-dependent conductivity, dielectric constant and modulus of chlorinated polyethylene/copper alumina (CPE/Cu–Al₂O₃) nanocomposites. Optical absorption measured using an ultraviolet–visible (UV–visible) spectrometer shows enhanced intensity and a blue shift for CPE/Cu–Al₂O₃ nanocomposites. The bandgap energy of CPE/Cu–Al₂O₃ nanocomposites was lower than pure CPE and minimum bandgap energy was recorded for a 7 wt% composites. The X-ray diffraction demonstrates that Cu–Al₂O₃ nanoparticles were uniformly introduced into the CPE matrix. Thermogravimetric analysis (TGA) manifests improved thermal stability of nanocomposites. Dielectric properties decrease with frequency, whereas AC conductivity increases with frequency, and both AC conductivity and dielectric properties increase with temperature. The maximum AC conductivity and dielectric constant were obtained for 7 wt % nanofiller loaded sample. For all systems, the activation energy for electrical conductivity decreases with rising temperatures. The experimental dielectric constant values of CPE nanocomposites were correlated with different theoretical models. The Bruggeman model was in good agreement with the experimental permittivity. The impedance experiments showed a decreasing trend with temperature, indicating the semiconducting nature of prepared nanocomposites.