Thermal safety of hydrophobic silica aerogels under controlled incorporation of phytic acid-modified graphene oxide

With growing demands for flame retardancy and energy saving, increasing attention has been attracted toward the development of flame-retardant hydrophobic silica aerogels (HSAs). In this work, phytic acid-modified graphene oxide (PA-GO) was synthesized via a hydrothermal method and incorporated into silica aerogel matrices to prepare flame-resistant aerogel composites (PA-GO/SA). The introduction of PA-GO substantially improved the thermal stability of the aerogel composites. For instance, the temperature of peak heat flow of PA-GO/SA-0.45% (containing 0.45 wt.% PA-GO) increased to 341.1 °C. Flame-retardant performance analysis revealed a 13.4% reduction in peak of heat release rate of the composite and a 13.8% decrease in gross calorific value relative to those of pure sample. Furthermore, the incorporation of PA-GO had negligible impact on the fundamental physicochemical properties of the aerogels. Specifically, the PA-GO/SA-0.45% maintained low density, with a water contact angle of 141.4° and a low thermal conductivity of 24.1 mW/(m·K). These findings offer a promising strategy for developing multifunctional aerogels for flame-retardant thermal insulation applications.