UV-blocking properties of Zn/ZnO coatings on wood deposited by cold plasma spraying at atmospheric pressure

摘要

Highlights•Zn/ZnO mixed systems were deposited by cold plasma spraying.•The coatings significantly reduced photodiscolouration of wood upon UV irradiation.•An additional alkyd sealing underwent photocatalytic degradation.•A system composed of a Zn/ZnO coating and additional PUR sealing strongly reduced photodiscolouration and proved to be chemically stable.AbstractIn this study, artificial ageing of beech wood coated with Zn/ZnO particles by means of a cold plasma spraying process as well as coating systems including a Zn/ZnO layer and additional conventional sealings were examined. As ascertained by colour measurements, the particle coatings significantly decreased UV light-induced discolouration. Even though no significant colour changes were observed for particle-coated and alkyd-sealed samples, ATR-FTIR measurements revealed photocatalytic degradation of the alkyd matrix. In contrast, the polyurethane sealing appeared to be stabilised by the Zn/ZnO coating. Furthermore, morphologic properties of the pure particle coatings were studied by SEM and roughness measurements. SEM measurements confirmed a melting and solidifying process during deposition.