A multifunctional cellulose coating integrating anti-icing/de-icing, fire warning and flame retardancy

Outdoor facilities such as charging infrastructure and box-type transformers face simultaneous threats from icing in cold environments and fire hazards during service, creating a strong demand for multifunctional protective coatings. This study proposes a hierarchical coating design that synergistically combines a flame-retardant matrix with a photothermal superhydrophobic surface to achieve integrated anti-icing/de-icing and fire-safety functions. To realize this concept, dopamine-modified TiO₂ and flame-retardant modified cellulose were used to construct the coating matrix, while multi-walled carbon nanotubes and fumed silica were deposited on the surface to create a micro/nanostructured hydrophobic layer with enhanced light-to-heat conversion capability. This architecture enabled the composite coating to achieve a water contact angle of ∼147°, an icing delay time of 1902 s, and a maximum surface temperature of 71.8 °C under one-sun irradiation, demonstrating effective photothermal de-icing capability. Additionally, it exhibited ultrafast fire-alarm response (<3.5 s), stable alarm cycling behavior, and excellent flame retardancy, together with robust durability under extreme temperatures, water-flow erosion, and mechanical abrasion. Overall, this study demonstrates a cost-effective and scalable strategy for integrating flame retardancy, rapid fire warning, and efficient anti-/de-icing capabilities within a single coating system, offering considerable potential for protecting outdoor equipment in harsh environments.