Temperature- and Frequency-Tunable Dielectrics: A PVA/PEG Composite with Hybrid CuCo ₂ O ₄ /PANI/MWCNT Fillers

We examined the effects of temperature on the dielectric attributes of polyvinyl alcohol (PVA)/polyethylene glycol (PEG)/CuCo ₂ O ₄ /polyaniline (PANI)/x wt% multi-walled carbon nanotube (MWCNT) blended samples for use in energy storage applications. Composite polymers of PVA/PEG/CuCo ₂ O ₄ /PANI/x wt% MWCNTs were synthesized utilizing hydrothermal and casting approaches. The structure and morphology of the fabricated blend were explored. The impact of fillers, frequency, and temperature on the dielectric features of diverse blends was inspected. Peak values for real and imaginary portions of the dielectric constant were attained at distinct filler loadings: x = 0.02 wt% and x = 0.04 wt%, respectively. At 293 K and 1 kHz, doped sample with 0.02 wt% MWCNTs has a dielectric constant of 48.88 while a sample with x = 0.04 wt% MWCNTs has a dielectric loss of 1.86. Values of dielectric constant, energy density, and AC conductivity were enhanced as temperature increased. At 353 K and 1 kHz, sample with x = 0.02 wt% has a dielectric constant of 112.06 while the undoped sample has an energy density of 63.64 × 10 ^–3 J m ⁻³ . The effect of fillers on the different electric transport mechanism was determined. All samples adhere to the correlated barrier hopping mechanism. Nyquist plots were utilized to evaluate the influence of different fillers on the bulk resistance of the host blended sample.