The effect of silver nanoparticles on the black-stain resistance of acrylic resin for translucent wood coating application

Abstract

Translucent coatings applied to wood that is used for exterior applications often fail because of photodegradation and colonisation by black-stain fungi. This paper reports the effect of silver nanoparticles on the black-stain resistance of acrylic latex coatings. Acrylic latexes that contained various concentrations of silver nanoparticles were mixed with a commercial acrylic resin. The formulations were then applied to red pine (Pinus resinosa) sapwood, which was later evaluated for fungal resistance to Aureobasidium pullulans, Sclerophoma pityophila, and Eppicoccum nigrum. Latexes with silver nanoparticle concentrations as low as 0.03% (total coating formulation weight) were able to limit S. pityophila and E. nigrum growth, while higher concentrations were needed to limit the growth of A. pullulans. The influences of silver nanoparticles on the optical properties of the coating (i.e., colour, opacity, and gloss) were evaluated. It was demonstrated that the addition of silver nanoparticles to the formulation does not compromise the development of a translucent coating.