Superhydrophobic Coating Containing Silver and Silica Nanoparticles for Mold-Resistant Wood Surfaces

Wood is widely used in construction and engineering owing to its sustainability; however, its susceptibility to mold growth poses challenges to both durability and human health. In this study, a superhydrophobic surface is built on wood through a one-step waterborne coating incorporating silver nanoparticles (AgNPs), silica nanoparticles (SiO2NPs), and a fluorine-containing water repellent. The designed coating imparts excellent antimold performance through a synergic “repel-block-kill” mechanism, where initial spore adhesion is minimized by superhydrophobicity, subsequent moisture and nutrient supply for spore germination is effectively blocked by a continuous hydrophobic barrier, and ultimate hyphal integrity disruption and lethal oxidative stress are induced by the embedded AgNPs and released Ag+ ions. Specifically, the growth ratings against the three most destructive molds of Aspergillus niger, Penicillium citrinum, and Trichoderma viride are equally below level 1, which obviously surpass those of the control wood only using water repellent or AgNPs by more than 25 and 50%, respectively. Meanwhile, this structure reduces Ag release from 34.74 to 1.94% and further promotes the use of eco-friendly waterproofing and nano antimicrobial components. This study validates the feasibility of constructing highly mold-resistant superhydrophobic wood surfaces and provides a reference for advancing antimold technologies toward the green and sustainable development of the wood industry.