Role of ZnO nanoparticles on the structural, optical and dielectric properties of PVP/PC blend

Abstract

Polymer nanocomposite films based on poly (vinyl pyrrolidone) (PVP) and polycarbonate (PC) blend (60/40 wt%) doped different concentrations (≤0.6 wt%.) of zinc oxide (ZnO) nanopowder are prepared and characterized using various techniques. The change of the structure of the films are characterized using X-ray diffraction, Fourier transform infrared (FTIR) and UV–Vis spectroscopy. The semicrystalline nature of the structure of these nanocomposites have been observed from X-ray spectra and its effect after addition of ZnO. The main characteristic of IR bands of PVP and PC are observed. The intensity of some bands has significantly reduced with the stretch of the broad band at 2887 cm−1 confirms that the ZnO interacts with the functional groups in PVP/PC blend. The ultraviolet–visible (UV–vis) spectra is studied. The values of the optical energy band gap (Eg) are decreased attributed to the changes of the structure in the nanocomposites that occur after the addition of ZnO. The values of ε' and ε'' gradually decrease with increase of the frequency and they reached to constant values at higher frequencies attributed to the polarization. The variation of modulus parameters M' and M'' against Log (f) are studied. The lower values of the modulus parameters M' and M'' are the indication of transport of the ions and it is the approach towards the relaxation at high frequency. The plot of Z″ as a function of Z′ shows a semicircle which indicates the presence of heterogeneous or broad relaxation processes. The decrease of tan δ since hopping frequency of charge carriers don't follow the change of applied field.