Self-assembly of hierarchical MXene@SnO2 nanostructure for enhancing the flame retardancy, solar de-icing, and mechanical property of polyurethane resin

Taking into consideration the frigid and thunderstorms, the flame retardancy and de-icing performance are simultaneously desiderated for some open-air key equipment, such as air fuselage and wind turbine blades. Here, inspired by the anti-reflection phenomenon of moth eyes and cicada wings, a multi-functionalized and biomimetic MXene@SnO 2 hierarchical nanostructure is prepared to effectively impart flame retardancy and solar de-icing performance to thermoplastic polyurethane (TPU) resin used widely as the finishing coat of protective materials of open-air equipment. Based on the catalytic effect and barrier function, the addition of hierarchical MXene@SnO 2 nanostructures also effectively decreases the release of heat and toxic smoke from PU resin, as confirmed by reductions of 50.5% and 33.1% in the peak heat release rate and smoke production rate, respectively. Due to the appropriate refractive index , the light reflection phenomenon is effectively suppressed, thus promoting solar absorption (∼90% at 0.4 mm film) and photo-thermal conversion (∼74.2 °C with simulated solar illumination of 1.0 kW/m 2 ) in TPU-MXene@SnO 2 nanocomposites. Within the environment of −20 °C, the surface temperature of TPU-MXene@SnO 2 nanocomposites is still up to 32.7 °C and the surface ice pellet begins to melt at ∼40s, much earlier than 600s of pure TPU resin. In addition, the practical application of functionalized TPU nanocomposites is further improved by the higher mechanical properties, attributed to the strong interfacial interaction . Inspired by moth eyes and cicada wings, flame retardancy and solar de-icing performance are first integrated into polymer materials, thus effectively promoting their application in some extreme environments.