Impact of Cobalt Tungstate Loading on the Structural, Optical and Dielectric Performance of Polyvinyl Chloride/Polyethylene Glycol Polymer Composite

This work conducts to examine the influence of cobalt tungstate (CoWO 4 ) nanoparticle incorporation on the structural, optical, fluorescence, and dielectric features of polyvinyl chloride/polyethylene glycol (PVC/PEG) blended polymer. Blended polymer containing CoWO 4 at concentrations of 0, 5, 10, 20 and 30 wt% were produced and assessed via the X-ray diffraction (XRD), scanning electron microscopy, UV–vis diffused spectroscopy and dielectric impedance analysis. The XRD validated the effective integration of monoclinic CoWO 4 filler into the blended polymer matrix. Optical investigations demonstrated a notable increase in UV absorption, a substantial decrease in visible transmittance, and a marked redshift in the absorption edge with higher CoWO 4 content. The optical band gap consistently diminished to (3.71, 2.89) eV (direct) and (3.69, 2.1) eV (indirect) at 30 wt% loading. The refractive index, extinction coefficient, optical conductivity, and nonlinear optical susceptibility exhibited significant enhancement, signifying strengthened light–matter interactions. Dielectric investigations revealed enhanced dielectric constants and energy storage capacities, with the best performance noted for particular filler loadings. AC conductivity escalated with frequency, reaching a maximum at 20 wt% CoWO 4 . Electric modulus and impedance spectroscopy indicated non-Debye relaxation behavior and enhanced ionic conductivity. The findings delineate distinct structure–property connections, underscoring the promise of CoWO 4 -loaded PVC/PEG composites for utilize in flexible optoelectronics, advanced energy storage devices, optical limiters, and adjustable photonic systems.