Influence of nanocomposite (1-x)CdS/xCuS on optical characteristics of PVA/CMC/PEG blended polymer; effect of ratio (x)

Abstract

PVA/CMC/PEG blended polymers loaded with (1-x)CdS/xCuS nanocomposites (x = 0, 0.3, 0.5, 0.7, 1) were formed applying the thermolysis and casting techniques. Rietveld analysis of synchrotron x-ray diffraction data measured for (1-x)CdS/xCuS manifested a single hexagonal phase CuS (x = 1.0) and biphasic structure, hexagonal and cubic, for CdS (x = 0.0); composite samples (x = 0.3, 0.5, and 0.7) exhibited the three phases with varied percentages. Average crystallite size for all nanofillers ranged 4–12 nm. The surface morphology and chemical compositions of the different blends were investigated using SEM and EDS techniques. The effect of loading PVA/CMC/PEG blends with multi phases CdS–CuS nanocomposite on the optical linear and nonlinear behaviors was explored using diffused reflectance technique. The direct and indirect optical band gaps (Eg) values determined for PVA/CMC/PEG are 5.62 and 5.18 eV, respectively, which reduced to (4.2, 4.5, 4.47, 4.56, 3.89) and (3.43, 3.9, 3.74, 3.98, 3.18) eV upon loading with (1-x)CdS-xCuS for x = 0, 0.3, 0.5, 0.7, and 1, respectively. The refractive index of all loaded blends increased non monotonically with (x) reached its highest value for λ ≥ 500 nm upon loading with x = 0.0 (CdS). The fluorescence (FL) intensity of the blended polymers nearly quenched upon loading with CuS (x = 1.0) and greatly enhanced for x = 0.5.