Improving the flame resistance and smoke suppression capabilities of wood using biomimetic inorganic mineralized flame retardants

To enhance the flame resistance and smoke suppression capacity of fast-growing wood and improve the utilization efficiency of wood resources, we developed a biomimetic inorganic mineralization strategy inspired by volcanic ash. Volcanic ash, rich in silicate minerals, forms a physical barrier that protects vegetation during eruptions. Based on this mechanism, Na₂SiO₃ and CaCl₂ were employed as inorganic mineralizing flame retardants for the impregnation treatment of Eucalyptus grandis × urophylla wood. The resulting flame-retardant wood achieved a limiting oxygen index(LOI) of 30.45 %. Cone calorimeter tests revealed that, compared with natural wood, the treated wood exhibited reductions in total heat release(THR), peak heat release rate(HRR), total smoke production(TSP), and smoke production rate(SPR) by 45.5 %, 51.5 %, 59.3 %, and 65.0 %, respectively. Thermogravimetric(TG) analysis revealed that the modified wood MW exhibited a significantly higher residual mass of 24.83 %, compared to only 11.70 % for natural wood NW. Moreover, the maximum mass loss rate for MW occurred at a notably lower temperature of 306.5 °C, whereas that of NW was observed at 358.6 °C. This study demonstrates that the proposed flame-retardant system achieves a well-balanced performance in both flame retardancy and smoke suppression, offering a sustainable strategy for fabricating high-performance wood building materials. • Inspired by volcanic ash, a biomimetic mineralization method is developed to fabricate CaSiO₃ flame-retarded wood using Na₂SiO₃ and CaCl₂, with H₃PO₄ and H₃BO₃ added to promote gel formation and prevent flame retardant precipitation. • The resulting flame-retardant wood achieved a limiting oxygen index(LOI) of 30.45 %. Cone calorimeter tests revealed that, compared with natural wood, the treated wood exhibited reductions in total heat release(THR), peak heat release rate(HRR), total smoke production(TSP), and smoke production rate(SPR) by 45.5 %, 51.5 %, 59.3 %, and 65.0 %, respectively. • This low-cost, low-carbon, and eco-friendly process improves fast-growing wood utilization efficiency, offering a practical strategy for flame-retardant, smoke-suppressing green wood materials in construction, furniture, and transportation fields.