The Benefits of the ZnO/Clay Composite Formation as a Promising Antifungal Coating for Paint Applications

Abstract

The presence of mold is a serious problem in different environments as industrial, agricultural, hospital and household, especially for human health. Large quantities of mold spores can potentially cause allergic reactions and respiratory problems. Therefore, it is essential to keep buildings free of fungi without harming human health and the environment. Here, we pose a composite of modified bentonite clay and ZnO nanoparticles as an alternative antifungal preservative. The new composite is obtained by an easy and eco-friendly method based on a dry nanodispersion, without altering the properties of each material. The antifungal test reveals a robust response against fungi thanks to the ZnO nanoparticles’ contribution. Our results reveal that the antifungal activity of ZnO/clay composite is governed by both a uniform distribution and an adequate concentration of the ZnO nanoparticles onto the clay surface. Specifically, we find that for concentration below 10 wt.% of the ZnO nanoparticles, the nanoparticles are well dispersed onto clay giving rise to an excellent antifungal response. By contrast, when the concentration of ZnO increases, the formation of ZnO agglomerates onto the clay surface is favored. This effect provokes that antifungal behavior changes towards a more moderate improvement. Finally, we have demonstrated that this composite can be used as a promising paint preservative for antifungal applications.