Breathable Nanorod-Embedded Hierarchical Photothermal Coatings with Anti-Soiling and Safe Thermal Regulation for Efficient Anti-Icing and De-Icing

Photothermal hydrophobic surfaces offer a promising solution for mitigating ice hazards under low-temperature, high-humidity conditions via solar-driven de-icing. However, surface contamination can compromise photothermal efficiency, while fabric-applicable coatings must also provide flexibility, breathability, durability, and safe thermal regulation (≈50 °C). Current systems require further optimization to balance these demands for practical use. Here, a nanorod-embedded photothermal strategy is presented that integrates superhydrophobicity, anti-icing, and de-icing capabilities with environmental robustness in fabrics. The composite comprises a polypyrrole-loaded cellulose nanocrystal inner layer for photothermal conversion and a fluoroalkyl silane-modified silica top layer for superhydrophobicity. The synergy between hierarchical micro–nano roughness and photothermal activation enables an “external repellency, internal heating” mechanism, effectively overcoming the limitations of passive coatings. This dual-functional architecture achieves a solar absorption rate of 97.2% and reaches 53.1 °C under 100 mW cm⁻² irradiation, while remaining safe for human contact and maintaining breathability (moisture permeability: 6.86 × 10³ g·m⁻²·d⁻¹). It delays freezing by 417 s at −15 °C and reduces the melting time of an ice cube by 53.2% under 1-sun illumination. The fabric exhibits appreciable chemical stability, abrasion resistance, flexibility, and robustness under extreme conditions, ensuring long-term performance. This work offers a scalable solution for outdoor and personal protective equipment in cold environments.