Zinc and Copper Nanoparticles for Coconut Wood Preservation

Coconut wood, valued for its affordability, durability, and aesthetic appeal, faces challenges such as decay, termite attack, and weathering. Traditional preservatives have limitations, while nanotechnology offers eco-friendly solutions. Nano-Cu and nano-Zn enhance wood durability, water resistance, and antifungal and antimicrobial properties with low toxicity and environmental impact compared to other nanomaterials. This study aims to treat coconut wood with nano-Cu and nano-Zn with the objective of enhancing its durability. Nano-Cu and nano-Zn, prepared at 1%, 2.5%, and 5% concentrations, were first pressure-treated into medium-density coconut wood (MDCW) and high-density coconut wood (HDCW). Subsequently, the conditioned treated sample was subjected to various tests to study the properties enhancing nanotreated coconut wood compared to untreated wood. The study revealed that nanoparticles’ small size and unique properties significantly enhanced the durability and performance as a coconut wood preservative. The nanoparticles inside the nanotreated coconut wood were evident from the visual observation and SEM–EDX. Among the treated samples, MDCW exhibited higher retention and weight gain percentage than HDCW, particularly with 5% nano-Zn and nano-Cu treatment. Nano-Zn exhibited less leachability than nano-Cu in both densities. The leaching test also revealed that the highest leaching occurred within the first 24 h, followed by a gradual decrease over time. Subterranean termite tests revealed significant variability in mass loss and visual appearance, highlighting the susceptibility of untreated MDCW and HDCW to termite attacks. Nano-Zn- and nano-Cu-treated samples demonstrated greater resistance against natural weathering than the untreated samples concerning mass loss and greying. Furthermore, water absorption tests indicated reduced water absorption and volume swelling properties in nanoparticle-treated samples compared with the untreated samples. In conclusion, MDCW showed enhanced wood resistance against degrading factors compared with HDCW. These findings highlight the potential of nanoparticle-based preservatives as sustainable solutions for improving the lifespan and utility of coconut wood in various applications.