Highly transparent nanocomposite films from water-based poly(2-ethyl-2-oxazoline)/TiO2 dispersions

Abstract

Aqueous dispersions containing TiO₂ nanoparticles and hydrophilic poly(2-ethyl-2-oxazoline) allow the preparation of highly transparent nanocomposites containing up to 44 wt% of TiO₂. Transmission Electron Microscopy (TEM) images indicate that the nanoparticles are homogeneously distributed in the polymeric matrix with no significant agglomeration. Nanocomposite films remain highly transparent to visible light, absorb the ultraviolet (UV) radiation, and their refractive indices can be regulated in the range from 1.52 to 1.65 by the content of TiO₂ nanoparticles. While specular gloss measurements reveal an increase of the root-mean-square (RMS) surface roughness with TiO₂ content, distinctness-of-image gloss measurements demonstrate that it does not negatively affect the image information carried by the underlying layer.