激光加工超疏水表面抗结冰性能研究进展

在低温环境中，表面结冰会严重影响户外装备的运行效率和安全，基于疏水材料的新型被动式防除冰方法引起了广泛关注。超疏水表面凭借其优越的拒水、抑制冰核形成和降低冰黏附强度等能力，在防除冰技术领域表现出广阔的应用前景。激光加工技术具有高效率和灵活性，成为制备超疏水表面的有效方法，并被进一步用来研究表面的抗结冰性能。首先，概述了固体表面润湿理论和结冰机理。其次，综合评估了激光加工超疏水表面的抗结冰性能，包括静态水滴延迟结冰时间、动态水滴累积、冰黏附强度、延迟结霜与抗冻能力、表面积冰与除冰等方面。静态水滴延迟结冰时间受到水滴与表面接触界面的成核速率和传热速率的影响，动态水滴累积与表面润湿性密切相关，冰黏附强度反映了表面对冰的附着性和除冰的难易程度。超疏水表面具有显著的延迟结冰能力，但在低温高湿条件下，表面的超疏水性可能会减弱，甚至失效。除冰过程也可能破坏超疏水表面的微观结构，进而影响其持续的抗结冰性能。最后，对超疏水表面激光加工与抗结冰性能的未来研究方向进行了展望。

Research Progress on Anti-icing Performance of Laser Processed Superhydrophobic Surfaces

The ice accumulation on solid surfaces in low temperature environments seriously affects the operating efficiency and safety of outdoor equipment, such as aerospace, wind turbine, power line, etc. In recent years, a new passive anti-icing method based on superhydrophobic materials has attracted wide attention. The superhydrophobicity is generally achieved through constructing mirco/nano structures of low surface energy. On a superhydrophobic surface, a sessile water droplet has a high contact angle and a low roll-off angle. An impacting droplet could also bounce off the non-wetting surface over a certain Weber number range. The rough structures on a superhydrophobic surface reduce the interfacial heat transfer efficiency, which suppresses the nucleation of ice. The low surface energy may also benefit the removal of ice from the surface, once the icing has occurred. Therefore, the superhydrophobic surfaces show a broad application prospect in the field of anti/de-icing technology because of the excellent water repellency, ice nucleation inhibition, and ice adhesion strength reduction. As a non-traditional technique, laser processing shows high efficiency in fabricating micro/nano structures on solid surfaces. Therefore, laser processing has become an effective method to prepare superhydrophobic surfaces, and has been further used to study the anti-icing performance of the fabricated surfaces. In this review, the wetting theory and the icing mechanism of water droplets on solid surfaces were firstly summarized. Then, the anti-icing performance of laser-processed superhydrophobic surfaces was evaluated comprehensively, including icing delay time of sessile water droplets, accumulation of dynamic droplets, ice adhesion strength, frost delay or anti-frost, as well as surface ice accumulation and deicing. The droplet icing delay time was affected by the nucleation rate and the heat transfer rate at the interface, while the droplet accumulation was closely related to surface wettability. The ice adhesion strength reflected the adhesion of ice on the superhydrophobic surfaces and the difficulty of deicing. Superhydrophobic surfaces had a significant capacity to delay icing, but the performance of the surfaces might become weak or even failed under low temperature and high humidity conditions. In addition, the deicing process might also damage the microstructures of the superhydrophobic surfaces, which in turn reduced their anti-icing properties. Finally, the future research direction for the laser processing of superhydrophobic surfaces and the anti-icing performance was prospected.