Improvement of optical properties of ZnO/ PVA nanocomposites

The polymer nanocomposites (PVA-ZnO) were prepared by adding different concentrations nanoparticles with weight ratios (0, 1, 3, 5, 7 wt %) in a polyvinyl alcohol mixture using the casting method for studying their optical characteristics. The results of transmittance and absorbance spectra were recorded in the wavelength range (190-1100) nm. The effect of the weight ratio of the ZnO nanoparticles on the optical parameters (transmittance, absorption coefficient) of polymer composite (ZnO-PVA) has been studied, The practical results showed that transmittance of polymer composites films (ZnO-PVA) decreases with the increase of the weight ratio of (ZnO) NPs, while the absorption coefficient increases with increasing the weight ratio of the (ZnO) NPs. The results also revealed that electronic transitions are indirect, and that the energy gap decreases with increasing the weight ratio of the (ZnO) NPs, while Urbach's energy increases with the increase of the weight ratio of nano (ZnO). The Fourier transform infrared spectrum showed the presence of (Zn-O) group in the (PVA-ZnO) nanocomposites.