Preparation of photothermal-superhydrophobic-phase change composite surfaces and their anti-icing mechanisms

Aircraft icing poses a critical threat to flight safety. Traditional active anti-/de-icing methods are limited by high energy consumption and reliance on external power sources, while single-function passive icephobic surfaces tend to fail in low-temperature, high-humidity environments. To address these challenges, this study presents the design and fabrication of multifunctional composite surfaces integrating photothermal response, phase-change thermal storage, and superhydrophobicity. Two photothermal superhydrophobic coatings were constructed on the composite phase-change substrate by displacement deposition and one-step spraying, respectively. Experiments were conducted to analyze the thermodynamic behavior of the entire process of droplet freezing, melting and shedding on the surface. The results show that the surface can rapidly heat up under solar irradiation, enabling ice droplets to roll off the inclined surfaces before complete melting, thereby achieving efficient self-de-icing. The surface maintains stable superhydrophobicity even at low temperatures, significantly delaying droplet freezing. Introducing copper foam can significantly enhance the thermal conductivity of phase-change materials, extending the active temperature control duration of the composite surface to over 1 000 s under dark conditions and improving its anti-icing reliability in intermittent illumination scenarios. In addition, through systematic analysis of the heat transfer processes during the full droplet freezing-melting cycle, the synergistic mechanisms of photothermal conversion, superhydrophobicity, and phase-change thermal storage across different stages of anti-icing and de-icing are elucidated.