Effect of aluminium ferrite nanofillers on carboxy methyl cellulose /poly(vinyl alcohol) biopolymer films: improved structural, electrical, optical, and dielectric properties

This study investigated the effect of aluminum ferrite (AlFe₂O₄ ) nanofillers on the structural, optical, and dielectric characteristics of a polymer blend composed of sodium carboxymethyl cellulose (NaCMC) and poly(vinyl alcohol) (PVA). Hybrid AlFe₂O₄ nanofillers were synthesized using a co-precipitation method. The synthesized nanofillers were incorporated into the NaCMC/PVA blend at various nanoparticle concentrations (1, 2, 3, 4, and 5 wt%). using the solution-casting method. The effects of the nanofiller loading on the characteristic vibrational bands of the polymer blend were examined using Fourier transform infrared (FTIR) spectroscopy. XRD analysis was employed to assess changes in the crystallinity of the polymer nanocomposite films. The compositions and component percentages of the various polymer nanocomposite films were confirmed by Energy Dispersive X-ray (EDS) analysis, and the surface morphologies of the blends were examined using scanning electron microscopy (SEM).The optical properties of the polymer nanocomposite films were analyzed using a UV-visible spectrometer, revealing a decrease in the direct bandgap from 5.76 eV to 5.50 eV and the indirect bandgap from 5.13 eV to 4.74 eV. TGA studies indicated a increase in the thermal stability of the nanocomposite films, whereas DSC analysis showed a decline in the glass transition temperature with increasing amounts of AlFe₂O₄ nanoparticles. Impedance spectroscopy was used to determine the electrical conductivities of the nanocomposites. The electrical and dielectric properties of the prepared samples were examined to determine their viability for electrical applications. These findings indicate that the sample containing 3 wt. % of nanoparticles exhibited high direct current (dc) conductivity. The dielectric loss ( \(\epsilon^{\prime\prime}\) ) and dielectric constant ( \(\epsilon^{\prime}\) ) displayed significant values at low frequencies, whereas reduced values were recorded at high frequencies. Additionally, the \(\text{M}^{\prime}\) and \(\text{M}^{\prime\prime}\) values decreased with increasing AlFe₂O₄ nanofiller content within the polymer matrix. Additionally, the loss tangent ( \(\tan\delta\) ) was estimated as a function of frequency for the samples at room temperature. These findings are expected to create various opportunities for the use of AlFe₂O₄ nanoparticle-doped NaCMC/PVA nanocomposites in energy storage applications.