Effect of Fe nanoparticles on the structure and optical properties of polyvinyl alcohol nanocomposite films.

Polyvinyl alcohol (PVA) nanocomposite films embedded with iron (Fe) nanoparticles were prepared via the solution cast technique. The effect of Fe nanoparticles on the structural and optical properties of PVA nanocomposite films were investigated using X-ray diffraction, a scanning electron microscope, and UV–Vis spectroscopy. The size of the Fe nanoparticles was calculated using the Debye–Scherrer equation, and it was found that there was an increase in nanoparticle size after dispersion in the polymer matrix due to aggregation. Optical parameters such as optical band gap, Urbach energy, refractive index and extinction coefficient were investigated. The transmittance of a pure PVA film decreases from 82% to 18% after 3 wt% Fe nanoparticle dispersion in a polymer matrix. The direct optical band gap was found to decrease whereas Urbach energy was found to increase with the increase in Fe nanoparticle concentration. In addition, the refractive index and extinction coefficient of polymer nanocomposite films were found to increase compared to those made of pure PVA. Also, the optical dielectric and optical conductivity were observed to increase with an increase in Fe nanoparticle concentration. • The structure and linear optical properties of pure PVA and PVA filled with Fe nanoparticles were studied. • The introduction of a little amount of Fe nanoparticles tuning the refractive index of the PVA matrix. • The optical conductivity increases with increasing the concentration of Fe nanoparticles. [ABSTRACT FROM AUTHOR]