Structural, optical, and dielectric characteristics of copper oxide nanoparticles loaded CMC/PEO matrix

Polymer nanocomposite films were prepared using the casting method through filling a polymer mixture of carboxymethyl cellulose (CMC) and polyethylene oxide (PEO) (70:30 wt%) by different weight ratios (0.0, 0.3, 0.8, 2, 4, and 6 wt%) of copper oxide nanoparticles (CuO NPs) prepared by sol–gel method. Significant structural and morphological changes of the prepared mixture were noticed upon the increase of CuO NPs content, which in turn led to shift the absorption edge toward the lower frequencies and thus decreased the energy gap value. The electrical and dielectric properties of the polymeric mixture were improved after being filled with CuO NPs reaching their optimum at 2 wt%. For further AC conductivity (σ_ac) studies, the temperature dependence of the σ_ac and dielectric parameters for the optimum concentration CMC/PEO-CuO NPs (2 wt%) were investigated throughout a wide range of frequencies (0.1Hz–10 MHz). The calculation of the activation energy (E_a) and relaxation time (τ) suggests that these nanocomposite films are promising for solid-state supercapacitors.