Effect of Zn–Fe2O3 nanomaterials on the phase separated morphologies of polyvinylidene fluoride piezoelectric nanogenerators

Abstract

Self-powered devices based on piezoelectric nanogenerators (PENGs) are becoming crucial in the upcoming smart societies as they can integrate multifunctional applications, especially sensing, energy storage, etc. In this work, we explore the piezoelectric voltage generation happening in polyvinylidene fluoride (PVDF) nanocomposites developed by phase separation. The simple method adopted for the nanocomposite synthesis rules out the high voltage required for the normal electrospun PENGs and adds to their cost-effectiveness. Zinc-doped iron oxide (Zn–Fe₂O₃) nanomaterials influence the piezoelectric properties by enhancing the crystallinity and structural properties of the polymer. The phase separation process causes structural rearrangements within the PVDF by inducing the directional alignment of –CH₂– and –CF₂-chains and is the major reason for electroactive phase enhancement. Layers of Zn–Fe₂O₃ were uniformly distributed in the phase-separated PVDF without being negatively influenced by the solvent-non-solvent interactions during phase separation. At 3 wt%, the Zn–Fe₂O₃ induced an open circuit voltage of 0.41 volts, about 12 times greater than that of the neat PVDF film. Nanoparticles affected the thermal degradation and crystallinity of the polymer composites most effectively, and the dielectric properties of the PVDF/Zn–Fe₂O₃ composite microfilms were also pronounced. The proposed simple and cost-effective approach to flexible microfilm fabrication suggests significant applications in wearable electronics.