PVC–Silica Sol-gel Hybrids: Effect of Interphase Bonding by Aminopropyltrimethoxysilane on Thermal and Mechanical Properties

A novel optical model of the experimental transmission spectra of nanocomposite PVC-PS hybrid thin films doped with silica nanoparticles

We propose a novel derived optical model fitted to the experimental transmittance of PVC-PS hybrid thin films doped with Silica nanoparticles. The films are synthesized using a simple dip-coating method. The model has successfully interpreted the experimental spectral behaviour of transmittance of amorphous semiconductors and dielectric thin films. Interestingly, our model reproduces the optical parameters of the investigated thin films in good agreement with those predicted by Tauc plot. The great advantage of the proposed model over other models lies in its ability to explain the correlations between the film thickness and the optical bandgap. Furthermore, we investigate the structural, physical, and optical properties of PVC-PS- SiO₂ thin films, in relevance to the silica percentage content. XRD measurements show that the as-prepared polymeric thin films are amorphous. In addition, SEM micrographs indicate that silica nanoparticles are well dispersed on the surface of the PVC-PS thin films with an average diameter of 100-400 nm. The effect of annealing parameters is also investigated to optimize the projected water contact angle of PVC-PS- SiO₂ thin films. At annealing temperature of 2000°C, films become hydrophobic. The transmittance T% of the PVC-PS thin films is found to be about 83% in the visible region. The T% enhances to 90% upon adding silica NPs into PVC-PS polymeric thin films. Obtaining coatings with high transmittance is of crucial importance for several optoelectronic and photonic applications.