The study of structural and optical properties of PVA:PbO2 based solid polymer nanocomposites

In this work the structural and optical properties of PVA:PbO2 based solid polymer nanocomposites was investigated. The XRD results indicated the existence of both alpha and beta phases of PbO2 distributed along the PVA matrix. The crystallite size of PbO2 particles was found to be in the nanoscale range (ae19 nm). A pronounced red shift in the absorption spectra and decreased energy gap of the nanocomposite films were observed upon the addition of various fractions of PbO2. These indicated an enhancement in the intermolecular interaction between the PVA host and PbO2 dopant. The plot of refractive index versus dopant fraction was successfully fitted to an empirical equation and a parabolic correlation was found between them, by which a homogeneous distribution of the PbO2 nanoparticles has been confirmed. The proposed Wemple-DiDomenico model in describing the optical band gap was seen to be inconsistent, implying that the PVA:PbO2 nanocomposite films does not obey this model. Consequently, a detailed elaboration on the optical and structural behaviours of the PVA:PbO2 system was given.