Waterborne hygienic coatings based on self-crosslinking acrylic latex with embedded inorganic nanoparticles: a comparison of nanostructured ZnO and MgO as antibacterial additives

Abstract

This paper deals with a facile fabrication of environmentally friendly hygienic coatings based on acrylic latex comprising embedded inorganic nanoparticles originating from nanostructured ZnO and MgO, respectively, in the role of antibacterial agents. The incorporation of surface-untreated powdered nanostructured oxides into the latex was performed during the latex synthesis carried out by a two-step emulsion polymerization technique. With this technological approach, latexes comprising dispersed inorganic nanoparticles in the content of ca 0.5 - 1.1 wt. % (based on solids) were successfully prepared. For obtaining high-performance coating films, ketohydrazide self-crosslinking chemistry was introduced into latexes. The antibacterial efficiency of the coatings was evaluated with respect to the type and concentration of incorporated nanoparticles. It was determined that all the latex coating compositions containing inorganic nanoparticles exhibited a long-term storage stability and provided smooth transparent coating films of enhanced solvent and water resistance due to the combination of covalent and ionic interfacial crosslinking. The latex films displayed significant antibacterial activity, which was more pronounced with the increased content of nanoparticles. It was also found that the addition of nanostructured MgO enabled significant savings of a commercial biocidal additive while maintaining a high antibacterial efficiency.