Preparation, Structure, and Surface Characterization Effects on the Dielectric Properties of Flexible CA/CeO 2 Nanocomposite Films for Electronic Applications

In this work, flexible cellulose acetate/cerium oxide (CA/CeO2) polymer nanocomposite films were successfully fabricated using the solution casting technique. The CA/CeO2 nanocomposites were characterized using SEM, TEM, XRD, and Raman spectroscopy. Raman analysis indicated interfacial interactions between the polymer matrix and nanofillers. XRD patterns confirmed the successful formation of the nanocomposite structure. SEM observations demonstrated uniform dispersion of CeO2 nanoparticles and enhanced interfacial compatibility, which play a critical role in improving dielectric performance. TEM analysis further verified the homogeneous distribution of CeO2 nanoparticles within the CA matrix, with particle sizes ranging from 13 to 30 nm. Dielectric measurements performed over a frequency range of 0.1 Hz to 7 MHz showed a significant enhancement in dielectric properties with increasing CeO2 content. The dielectric constant increased from 2.13 for pristine CA to 3.82 for the CA/CeO2-3 composite, accompanied by an increase in energy density from 9.44 × 10−7 J/m3 to 1.69 × 10−6 J/m3. Moreover, the dielectric relaxation time (τᵣ) decreased from 8.5 × 10−5 s to 2.8 × 10−5 s, indicating faster polarization dynamics. These results demonstrate that CeO2 nanofillers effectively enhance the dielectric response of CA-based nanocomposites, highlighting their suitability for flexible electronic applications.