Tian Ze, Wang Lizhong, Zhu Dongyu, Chen Changhao, Zhao Huanyu, Peng Rui, Zhang Hongjun, Fan Peixun, Zhong Minlin
Laser Materials Processing Research Center, Key Laboratory for Advanced Materials Processing Technology (Ministry of Education), Joint Research Center for Advanced Materials and Anti-icing of Tsinghua University (SMSE)-AVIC Aerodynamics Research Institute, School of Materials Science and Engineering, Tsinghua University, Beijing100084, China.
Shenyang Key Laboratory of Aircraft Icing and Ice Protection, AVIC Aerodynamics Research Institute, Shenyang, Liaoning110034, China.
ACS Appl Mater Interfaces. 2023 Feb 1;15(4):6013-6024. doi: 10.1021/acsami.2c15253. Epub 2023 Jan 19.
Overcoming ice accretion on external aircraft wing surfaces plays a crucial role in aviation, and developing environmentally friendly passive anti-icing surfaces is considered to be a promising strategy. Superhydrophobic surfaces (SHSs) have attracted increasing attention due to their potential advantages of keeping the airframe dry without causing additional aerodynamic losses. However, the passive anti-icing performances of SHSs reported to date varied a lot under different icing test conditions. Therefore, a systematic investigation is necessary to elucidate the icing conditions where SHSs can remain effective and pave the way for SHSs toward practical anti-icing applications. Herein, we designed and fabricated a typical type of SHS featuring dual-scale hierarchical structures with arrayed micromountains (with both spacings and heights of tens of micrometers) covered by single-scale sandy-corrugation-like periodic structures (with both spacings and heights of only several micrometers) (termed SS1). Its anti-icing performances under three representative icing conditions, including static water freezing, dynamic supercooled-droplet impinging, and icing wind tunnel conditions, were comparatively investigated. The SS1 SHS maintained a lower static ice-adhesion strength (<60 kPa even after 50 deicing cycles at temperatures as low as -25 °C), which was attributed to a cumulative cracking effect facilitating the ice detachment. Within the laboratory dynamic icing tests, the SS1 SHSs with micromountain heights of 20-30 μm performed optimally in the antiadhesion of supercooled droplets (at an impinging velocity of 3.4 m/s and temperatures of -5 to -25 °C). In spite of the significant anti-icing performances of the SS1 SHSs in both static and dynamic laboratory tests, they could hardly sustain reliable passive anti-icing performances in harsher icing wind tunnel tests with supercooled droplets impinging their surfaces at velocities of up to 50 m/s at a temperature of -5 °C for 10 min. This study can inspire the development of improved SHSs for achieving satisfactory anti-icing performances in real-aviation conditions.
克服飞机机翼外表面的结冰现象在航空领域起着至关重要的作用，开发环境友好型被动防冰表面被认为是一种很有前景的策略。超疏水表面（SHS）因其具有保持机身干燥且不会造成额外气动损失的潜在优势而受到越来越多的关注。然而，迄今为止报道的超疏水表面在不同结冰测试条件下的被动防冰性能差异很大。因此，有必要进行系统研究，以阐明超疏水表面能够保持有效防冰的结冰条件，并为超疏水表面走向实际防冰应用铺平道路。在此，我们设计并制造了一种典型的超疏水表面，其具有双尺度分级结构，由排列的微山（间距和高度均为几十微米）覆盖着单尺度沙波纹状周期性结构（间距和高度仅为几微米）（称为SS1）。比较研究了其在三种代表性结冰条件下的防冰性能，包括静态水结冰、动态过冷液滴撞击和结冰风洞条件。SS1超疏水表面保持较低的静态冰附着力（即使在低至-25°C的温度下经过50次除冰循环后，冰附着力仍<60 kPa），这归因于促进冰脱落的累积裂纹效应。在实验室动态结冰测试中，微山高度为20 - 30μm的SS1超疏水表面在过冷液滴的防粘方面表现最佳（撞击速度为3.4 m/s，温度为-5至-25°C）。尽管SS1超疏水表面在静态和动态实验室测试中都具有显著的防冰性能，但在更恶劣的结冰风洞测试中，当温度为-5°C、过冷液滴以高达50 m/s的速度撞击其表面持续10分钟时，它们几乎无法维持可靠的被动防冰性能。这项研究能够启发人们开发改进的超疏水表面，以在实际航空条件下实现令人满意的防冰性能。
