Effect of R-TiO2 and ZnO nanoparticles on the UV-shielding efficiency of water-borne acrylic coating

In this study, the high UV-shielding nanocomposite coatings based on pure acrylic emulsion and R-TiO2/or ZnO nanoparticles were successfully prepared. The effect of the nanoparticles on the photostability and UV shielding efficiency has been studied by using a UV/condensation weathering chamber equipped with UVB-313 fluorescent lamps. The obtained results showed that the coatings with the 2 wt% R-TiO2/or ZnO nanoparticles and a thickness of 45 μm have the highest UV-shielding and photostability. These coatings could shield more than 98% (for R-TiO2) and 85% (for ZnO) of UV radiations in wavelength range from 230 to 380 nm. After 60 cycles of UV/CON exposure, color of coating samples protected by the R-TiO2 and ZnO nanocomposite coatings change insignificantly, their adhesion only decreased slightly, from their initial values of 2.5 and 2.4 to the values of 2.3 and 2.1 N/mm2, respectively. These nanocomposite coatings have possibly a promising potential for UV shielding applications.