Synthesis, Structural and Optical Characterization of MgO Nanocrystalline Embedded in PVA Matrix

Nano-magnesium oxide (MgO) was prepared by wet chemical method using magnesium chloride and sodium hydroxide as precursors and soluble gelatin as stabilizing agent in this paper. The synthesized nano MgO was characterized by XRD, SEM, and FTIR. The results showed that the size of nano-MgO was about 20.62 nm. Polyvinyl alcohol (PVA) polymer based nanocomposites, with different concentrations of MgO (1, 2, 3, 4 wt%), have been prepared using solvent casting technique. The results of SEM revealed that the MgO nanoparticles are uniformly distributed in PVA polymer matrix. FTIR analysis evidently saw the interaction between MgO with hydroxyl group of PVA through hydrogen bonding. The influences of MgO nanoparticle on the optical characterisation of PVA have been considered using UV-Vis-NIR spectroscopy. Energy band gap and tail of localized state of PVA/MgO nanocomposites have been calculated by using Tauc and Urbach relations, respectively. The band gap of the nanocomposites samples decreases as MgO wt% increases. Wemple-DiDomenico single-oscillator model has been applied to analyze the dispersion of the refractive index of the films, and the dispersion parameters are calculated to obtain the information about disorder degree.