Influence of Cr₂O₃ nanoparticles on the structural, optical, thermal and electrical properties of PEO/CMC nanocomposites

Abstract

In the present paper, different concentrations of chromium oxide (Cr₂O₃) nanoparticles (≤ 0.6 wt%) were incorporated within PEO/CMC polymer blend to produce nanocomposite films using the casting technique. X-ray diffraction was performed on PEO/CMC-Cr₂O₃ nanocomposites. The main X-ray peaks of Cr₂O₃ were observed and defined as cubic structure and orthorhombic shape. The average particle size was calculated by Scherer’s equation in the range between 50 and 60 nm. A decrease of some IR bands after the addition of Cr₂O₃ nanoparticles was found, which was attributed to the interactions between PEO/CMC and Cr₂O₃. The effect of Cr₂O₃ nanoparticles on optical properties such as absorbance and optical energy gap (E_g) was characterized using UV–Vis spectroscopy. The E_g was reduced after the addition of Cr₂O₃ nanoparticles. The AC conductivity (σ_ac), dielectric constant (ε′), dielectric loss (${\varepsilon }^{{^{\prime}}{^{\prime}}}$) and the dielectric modulus (${\text{M}}^{{^{\prime}}}\text{and }{\text{M}}^{{^{\prime}}{^{\prime}}}$) were calculated at the frequency range of 0.1 Hz -7 GHz. The increase in direct conductivity (σdc) indicates the resulting free charge density or charge mobility. The calculated values of both ε′ and ${\varepsilon }^{{^{\prime}}{^{\prime}}}$ were decreased with increasing the frequency. The addition of Cr₂O₃ nanoparticles causes the formation of a charge-transfer complex. The Cole–Cole plot between (${\text{M}}^{{^{\prime}}}\text{ and }{\text{M}}^{{^{\prime}}{^{\prime}}}$) shows a semi-circular shape which discuses according to a non‐Debye method.