Tailoring the Electrical and Thermal Response of PVA Nanofibers Through Metal Oxide Incorporation via Electrospinning

Abstract

This study investigates the structural, thermal, and electrical properties of polyvinyl alcohol (PVA) nanofibers doped with a ZnO–CoO binary oxide, synthesized via a controlled electrospinning process at an applied voltage of 16 kV and a flow rate of 0.8 mL/h. FESEM analysis revealed a systematic morphological transition from smooth, uniform fibers to a bead-on-string structure as the dopant concentration increased from 1 wt% to 5 wt%. Moreover, quantitative analysis revealed fine fiber morphologies, with the minimum diameters reaching 17 nm, 23 nm, and 26 nm of different concentration ratios, respectively. X-ray diffraction (XRD) analysis confirmed the amorphous nature of both the pristine and doped nanofibers. The absence of metallic crystalline peaks suggests that the dopants were uniformly distributed throughout the polymer matrix, which is consistent with established literature. Fourier Transform Infrared (FTIR) spectra demonstrated an increasing shift in the vibrations of the hydroxyl (–OH) functional groups, signifying strengthened intermolecular interactions. Thermal analysis via TGA/DSC indicated that while low-level doping (1 wt%) enhances thermal stability, higher dopant concentrations result in a reduction of the characteristic degradation temperatures. Electrical characterization revealed that the conductivity follows an Arrhenius-type behavior, in which the activation energy ( ) was significantly reduced with increasing dopant concentration. The lowest  value of 0.031 eV was attained for the composite containing 4 wt% of the ZnO–CoO hybrid. These results suggest that the charge transport mechanism is thermally activated and that the incorporation of metal oxide dopants effectively lowers the energy barrier for carrier hopping. Consequently, the synthesized hybrid nanofibers demonstrate a high degree of tailoring capability for tunable electronic applications