Synergistic thermal insulation enhancement of an Al2O3/MnO2 @ fumed silica composite thermal insulation coating with high-temperature resistance up to 1200 °C.

Thermal insulating coatings effectively reduce heat loss, helping to save energy and reduce emissions. However, their thermal insulation performance decreases notably as temperature rises due to a single inhibition for heat transfer. Additionally, they have limited high-temperature resistance. To overcome these challenges. We developed a composite thermal insulation coating (CTIC). It was prepared through simple physical blending and can be effectively combined with various substrates. It achieves effective suppression of heat conduction and heat radiation, demonstrating excellent thermal insulation capabilities owing to the synergistic effect of fumed silica, Al 2 O 3 , and MnO 2. It exhibited a low thermal conductivity of 0.0843 W/(m·K) at 500 °C. The 10 mm CTIC decreased the high temperature from 1008.9 °C to 339.5 °C. Moreover, the CTIC could withstand temperatures of up to 1200 °C. This work offers fresh insights into the design of thermal insulating coatings. • Al 2 O 3 and MnO 2 can enhance radiation thermal insulation. • Fumed silica significantly inhibits both solid and gaseous thermal conduction • Simultaneously inhibiting heat conduction and heat radiation can significantly improve thermal insulation performance in high-temperature environments. [ABSTRACT FROM AUTHOR]