Effect of annealed ZnS nanoparticles on the structural and optical properties of PVA polymer nanocomposite

PVA/ZnS nano-composites were prepared by both thermolysis and casting procedures. The influence of annealing temperature of ZnS nano filler on the structure properties of composite films was studied by x-ray diffraction and Fourier transform infrared (FTIR) techniques. X-ray analysis revealed that ZnS can be obtained by changing the annealing temperature up to 500 °C, above this temperature ZnS converted into ZnO. Moreover, the crystallite size of ZnS increased from 4 to 10 nm as the annealing temperature rose from 300 to 500 °C. The effect of crystallite size of nano filler on extinction coefficient, refractive index, band gap, dielectric constant, single-oscillator and the dispersion energies was studied in details using UV–vis. spectrophotometer technique. The photoluminescence technique (PL) showed that, PVA/annealed ZnS nano-composite films exhibited five sub-emissions spectra for ZnS annealed at 300 °C and 400 °C while the sample contained ZnS annealed at 500 °C displayed two sub-emissions. PL intensity enhanced with increasing the crystallite size of ZnS nano particles.