Effect of silver nanoparticles on white-rot wood decay and some physical properties of three tropical wood species

Wood is one of the most widely usedmaterials and is used in many applications. However, decay resistance of wood is limited in tropical conditions. Nanotechnology applications have potential for improving materials. In this study, a solution with a concentration of 50 ppm silver nanoparticles was incorporated by pressure into three commercial species (Acacia mangium, Cedrela odorata, and Vochysia guatemalensis) of Costa Rica. The white-rot fungus (Trametes versicolor) was tested, and some physical properties were also measured. According to the results, synthetized silver nanoparticles (10-25 nm) presented little agglomeration and were adequately distributed. The retention achieved was 25-102 silver mg/kg^-1 of wood, varying among species and with presence of sapwood and heartwood. Mass loss was less than 5% in wood treated with silver nanoparticles; thus, the wood was classified as highly resistant or class A. Meanwhile, untreated wood presented losses greater than 20% with white-rot fungi. Also, water absorption capacity decreased for wood treated with silver nanoparticles in the three species tested, and dimensional stability increased for Cedrela odorata and Vochysia guatemalensis treated with silver nanoparticles.