Effect of Different Nanoparticle Treatments on the Decay Resistance of Wood

The efficacy of five different nanoparticles (zinc-oxide, zinc-borate, silver, copper, and copper-borate) were evaluated after application at different concentrations for protection against Coniophora puteana and Coriolus versicolor. Tests were performed with two different wood species (beech and pine sapwood). Furthermore, tests were done to investigate the resistance of the nanoparticles to leaching. Overall, the results of the efficiency of the investigated nanoparticles against the brown and white rot fungi were diverse. One of the investigated fungi showed a tolerance to the nanoparticles in some cases (zinc-oxide, silver nanocubes, and copper). The most effective nanoparticle treatments were those containing borate. However, only the zinc-oxide, copper, and silver nanoparticles showed a high resistance to leaching. Unfortunately, zinc-borate and copper-borate showed a low resistance to leaching, as the treated samples showed a similar decay compared with that of the control. Thus, only the zinc-oxide at the highest investigated concentration (5% m/m) provided effective protection after leaching for both of the investigated fungi. Also, the copper nanoparticles showed potential as an effective treatment at higher concentrations.