Tailoring the electrical properties of cerium oxide-supported carboxymethyl cellulose composites for electronics and...

A composite of carboxymethyl cellulose (CMC) and cerium oxide (CeO₂) nanoparticles was synthesized using the solution cast method with CeO₂ concentrations of 5 %, 10 %, and 15 %. Surface topography, dispersion, and elemental composition were analyzed via SEM and EDX, while impedance spectroscopy was performed at temperatures of 298-373 K over a frequency range of 50 Hz-1.2 MHz. The study revealed that temperature and CeO₂ concentration significantly influence the composite properties. D.C. conductance increased with temperature and CeO₂ content, rising from 2.8 × 10^-9 S for pure CMC to 58.2 × 10^-9 S at 15 % CeO₂. Activation energy decreased from 220.05 meV (pure CMC) to 69.54 meV (15 % CeO₂). At 10 % CeO₂, the conduction mechanism was identified as non-overlapping small polaron due to homogenous dispersion. Higher CeO₂ concentrations led to nanoparticle aggregation, affecting the dielectric constant and increasing interface-induced polarization. Dielectric loss anomalies and modulus spectra changes at high CeO₂ content were linked to disrupted CMC molecular structure. Ionic conduction dominated below 348 K. Computational studies (DFT and MD simulations) confirmed increased binding energy between components, from 420.3 eV (5 % CeO₂) to 1226.3 eV (15 % CeO₂), highlighting temperature and concentration effects on interactions.