eng Science and Education Publishing Physics and Materials Chemistry 2372-7101 2015-11-13 3 2 18 24 10.12691/pmc-3-2-1 PMC2015321 article Omed Gh. Abdullah omed.abdullah@univsul.edu.iq 1 Yahya A.K. Salman 2 Salwan A. Saleem 2 Department of Physics, Faculty of Science and Science Education, School of Science, University of Sulaimani, Kurdistan Region, Iraq Department of Physics, College of Science, University of Mosul, Iraq Polymer based nanocomposite films of polyvinyl alcohol (PVA) doped with mercury sulfide (HgS) were prepared via in-situ chemical reduction and the solution cast methods, with different HgS concentrations, in order to study the effect of HgS content on optical properties of PVA. The nanocomposites films were characterized using FTIR, XRD, and SEM. The UV-Visible absorption spectra in the wavelength range (190-1100) nm were analyzed in terms of absorption formula for non-crystalline materials. The band gap and the fundamental optical constants of the prepared samples have been investigated and showed a clear dependence on the HgS concentration. The observed value of band gap for pure polyvinyl alcohol is about 6.27 eV and decreases to a value 4.88 eV for the film of 0.04M HgS content. The refractive index and consequently the related dispersion parameters of PVA and PVA/HgS nanocomposite versus HgS content have been determined and explained using Wemple-DiDomenico single oscillator model. http://pubs.sciepub.com/pmc/3/2/1/pmc-3-2-1.pdf polymer nanocomposite mercury sulfide optical band gap complex dielectric constant