Nano-silica mediated poly(vinyl alcohol) films with tailored opto-structural properties

The present investigation dealt with the fabrication and opto-structural characterization of silica nanoparticles (SNPs) incorporated polyvinyl alcohol (PVA)-based nanocomposite films. The said films were prepared via the solution casting approach followed by characterization using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), x-ray diffraction (XRD) and water contact angle (WCA) analyses. Moreover, the optical parameters including direct/indirect bandgaps, absorption coefficient and the Urbach energy of the test films were determined using UV visible spectroscopy. The SEM results indicated the spherical morphology of the as-prepared SNPs and their regular distribution of them in the PVA-based composite film. The WCA of the pristine PVA film increased from 50.2 to 94.4o for the resultant nanocomposite film. This indicated that the prepared nanocomposite films exhibited surface non-wetting, which could be ascribed to their enhanced crystallinity due to certain physicochemical and structural rearrangements. The results of mechanical properties demonstrated that the tensile strength increased and elongation at the break decreased by adding the SNPs in the PVA matrix. The overall direct, indirect and optical bandgap values significantly decreased on 1 (%, w/w) loading of SNPs in the nanocomposite film. The prepared nanocomposite films might be useful in fabricating optoelectronic devices workable even in mild humid environments.

Automated summary

This study focused on the production and characterization of silica nanoparticles (SNPs) incorporated polyvinyl alcohol (PVA)-based nanocomposite films. SEM, FTIR, XRD, and WCA were used for characterization, while UV visible spectroscopy was utilized for determining the optical parameters. The results showed that the prepared nanocomposite films exhibited surface non-wetting and enhanced mechanical properties, making them potentially useful for optoelectronic devices even in humid environments.