Structural, thermal, and linear optical properties of SiO2 nanoparticles dispersed in polyvinyl alcohol nanocomposite films

In the present work, polyvinyl alcohol (PVA) films were prepared for polymer optoelectronic applications, in which the SiO2 nanoparticles were incorporated through a sonication technique followed by a solution casting method. The structure of PVA/SiO2 films was evaluated using the experimental results attained by X‐ray diffraction (XRD), Fourier transform infrared (FTIR), and scanning electron microscope (SEM) examinations. A thermal stability study of the nanocomposite films was performed. UV‐vis spectra were used to investigate the optical properties of PVA/SiO2 nanocomposite films. The XRD results confirmed the semicrystalline nature of the PVA. The SEM results ascertained the homogeneity of the SiO2 nanoparticles in the polymer matrix. From the study, a simultaneous increase of SiO2 nanoparticle content decreased the direct optical band gap and Urbach energy; however, the refractive index and extinction coefficient were increased. The acquired nanocomposite films could be utilized in polymer optoelectronic applications. Change of the refractive index and direct band gap of the polyvinyl alcohol films with the change of the SiO2 nanoparticle concentration in the polymer matrix.