Enhancing durable fire safety and Anti-Corrosion performance of wood through controlled In-Situ Self-Assembly synthesis of Ag-PW nanospheres

In this work, we present a simple and effective approach to enhance the fire safety and anti-corrosion performance of wood by forming in-situ self-assembled amphiphilic Ag-PW nanospheres (NSP) at room temperature. The morphology and acid capacity of the NSP were optimized by changing the ratio of phosphotungstic acid (HPW) and silver nitrate. The Ag-PW NSP were successfully integrated into the bulk of the wood, resulting in a durable treatment with minimal leaching. Comprehensive characterization techniques, including FTIR, XPS, XRD, SEM, TEM, and nitrogen adsorption–desorption analysis, confirmed the in-situ formation of Ag-PW NSP in the wood. The treatment exhibited low-leaching properties with only 5.89% of Ag-PW1a leaching out. The treated wood demonstrated excellent flame-retardant (FR) properties, as evidenced by a limiting oxygen index value > 28% and easy passage of the UL-94 test, with the formation of a high-density char layer. The flammable pyrolysis products released during combustion were found to be significantly altered, with a change in the depolymerization route of conversion of LGO under acid conditions to HMF, which was verified by DFT calculations. The treated wood also exhibited outstanding anti-corrosion properties, with a mass loss rate of less than 1%, compared to at least 32.3% for bare wood after the anti-white or brown-rot fungus tests. Moreover, the treated wood samples maintained their excellent FR properties even after leaching. Our study provides valuable insights for the rational design of nano-material additives for wood protection, thereby improving the usage of wood resources while mitigating health and environmental hazards.