Investigation of structure and optical characteristics of irradiated PVP/CMC nanocomposite films based on ZnS/SnO2 nanofillers

Abstract

PVP/CMC/50%ZnS-50%SnO₂ blends were formed by solid state reaction, sol-gel methods and casting technique. The structure and the crystallite size of the nanofillers (ZnS and SnO₂) were examined using x-ray diffraction technique (XRD). The effect of laser irradiation energies compared to the proportions of loaded nanofillers on the films internal structure and morphology was studied using XRD. The high miscibility among blends has been confirmed through Fourier transform infrared spectroscopy (FTIR). The energy dispersive x-ray spectroscopy (EDS) analysis proved the presence of the nanocomposite polymer blends constituent atoms. The blends surface morphology has been investigated through scanning electron microscope (SEM). The dual effect of both different laser energies and oxygen atoms content simultaneously, on the linear and nonlinear optical parameters of nanocomposite films were explored as well. Results showed that, the laser irradiation energy process has the highest enhancement on the optical properties. The optical band gap (E_g) values were reduced from 4.8 eV (in the case of unirradiated blend) to 3.5 eV (for blends irradiated with 150 mJ/cm²) for allowed direct transitions, but for allowed indirect transitions E_g decreased from 3.3 eV (for unirradiated) to 2.2 eV (for irradiated with 150 mJ/cm²).

Highlights

• A comparative discussion upon the effect of excess oxygen atoms has been represented.
• A dominant effect for the laser exposure compared to both the particle size and excess oxygen atoms.
• The variations of the nanocomposite films structural and optical features were promising.