A Self-Cleaning UV-Cured Organic Coating with ZnO-Ag Hybrid Nanoparticles

This study aims to explore how ZnO-Ag hybrid nanoparticles (HNPs) can provide the self-cleaning behavior to UV-curable acrylate urethane (UVACU) coating. To our best knowledge, this is the first work reporting the self-cleaning organic nanocoating under visible light irradiation for both indoor and outdoor applications. Self-cleaning tests of dirty UVACU coatings have been examined with artificial dirty (AD) mixture or methylene blue (MB) under visible light and UV irradiation. It was shown that cross-linked UVACU/ZnO-Ag nanocomposite coatings have significantly removed MB from the coating surface after 12 h of exposure to light radiation, while for AD, after 112 h of exposure to light radiation, nearly 70% of AD still attaches to the surface of neat coating. In the presence of HNPs, only about 35% of AD remained on the surface of nanocomposite coating. This finding indicates that ZnO-Ag HNPs provide the self-cleaning property to UVACU coating. This self-cleaning can take place via: (i) photocatalytic effect of the HNPs loses the adhesion of MB on the surface of UVACU/ZnO-Ag coating; (ii) photodegradation can also degrade MB, then reduce the binding between these dust particles themselves, and (iii) photocatalytic photocatalytic degradation induced by HNPs on UVACU coating itself.