Enhancing fire resistance in wood with high-water retention silica gel: A promising flame-retardant solution

Abstract Wood is highly susceptible to fire due to its flammability, causing serious casualties and property damage; therefore, wood treated with fire retardants will be a major issue. In this work, the refractory properties of silica gel with a high water retention capacity were investigated. Testing the water retention while taking into account the characteristics of the silica gel by researching the impact of varied component concentrations. Furthermore, various analytical approaches were used to explore the flame-retardant mechanism of silica gel. According to the experimental findings, silica gel features an abundance of hydrophilic groups and amorphous silica, resulting in a boost in the number of water molecules on its surface. In addition, at high temperatures, silica gel also aids in the formation of a SiO2 layer and a charred layer that serve as an oxygen barrier. This layer protects the wood from combustion. At the same flame temperature, the overall weight degradation of wood treated with silica gel was decreased by 36% and 53%, suggesting that silica gel may prevent the decomposition of wood by heat response. Overall, the study provides valuable insights into the flame-retardant mechanism of silica gel and its potential application in enhancing the fire resistance of wood.