Effect of ZnO nanoparticle and KI functionalized ZnO nanoparticle on structural, dielectric and thermal properties of poly(vinylidene fluoride)

Poly (vinylidene fluoride) (PVDF) and nanocomposite samples were prepared by the solution-grown method. The surface morphology of PVDF-ZnO nanocomposite was characterized by SEM (scanning electron microscopy). The dispersion of nanoparticle in PVDF matrix was clearly viewed by SEM spectra. The interaction between the nanoparticle and PVDF was studied by XRD (X-ray diffraction) and FTIR (Fourier transform infrared spectroscopy) spectra. The intensity of IR spectra decreases after the addition of KI (Potassium iodide) functionalized ZnO nanoparticle, which is evidence of atomic interaction. XRD spectra confirm the presence of crystalline and amorphous regions. The variation of dielectric properties including dielectric permittivity and dielectric loss were studied for different frequencies and temperature. Dielectric study showed that the incorporation of ZnO nanoparticle in PVDF matrix resulted the increase in dielectric permittivity due to increase in β phase content. The decrease in dielectric permittivity and dielectric loss with increase in frequency confirms the presence of dipoles or interfaces. Dielectric permittivity increases with temperature because the molecular chain segmental motions at room temperature, which are practically frozen. The differential scanning calorimetry (DSC) results show significant endothermic peaks of PVDF and PVDF nanocomposite corresponding to the glass transition temperature and melting temperature.