Zhao Guanlei, Zou Guisheng, Wang Wengan, Geng Ruikun, Yan Xiao, He Zhiyuan, Liu Lei, Zhou Xin, Lv Jianyong, Wang Jianjun
Department of Mechanical Engineering, State Key Laboratory of Tribology, Key Laboratory for Advanced Manufacturing by Materials Processing Technology, Ministry of Education of PR China , Tsinghua University , Beijing 100084 , China.
Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190 , China.
ACS Appl Mater Interfaces. 2020 Feb 12;12(6):7805-7814. doi: 10.1021/acsami.9b21704. Epub 2020 Jan 29.
Preventing condensation frosting is crucial for air conditioning units, refrigeration systems, and other cryogenic equipment. Coalescence-induced self-propelled jumping of condensed microdroplets on superhydrophobic surfaces serves as a favorable strategy against condensation frosting. In previous reports, efforts were dedicated to enhance the efficiency of self-propelled jumping by constructing appropriate surface structures on superhydrophobic surfaces. However, the incorporation of surface structures results in larger area available for condensation to occur, leading to an increase in total amount of condensed water on the surface and partially counteracts the effect of promoted jumping on removing condensed water from the surface. In this paper, we focus on the competing effects between condensing and self-propelled jumping on promoting and preventing water accumulation, respectively. A series of micro- and nanostructured superhydrophobic surfaces are designed and prepared. The condensation process and self-propelled jumping behavior of microdroplets on the surfaces are investigated. Thousands of jumping events are statistically analyzed to acquire a comprehensive understanding of antifrosting potential of superhydrophobic surfaces with self-propelled jumping of condensed microdroplets. Further frosting experiments shows that the surface with the lowest amount of accumulated water exhibits the best antifrosting performance, which validates our design strategy. This work offers new insights into the rational design and fabrication of antifrosting materials.
防止结霜对于空调机组、制冷系统及其他低温设备至关重要。凝聚诱导冷凝微滴在超疏水表面上的自驱动跳跃是一种对抗结霜的有效策略。在以往的报道中，人们致力于通过在超疏水表面构建合适的表面结构来提高自驱动跳跃的效率。然而，表面结构的引入导致了更大的可用于发生冷凝的面积，从而导致表面上冷凝水总量增加，并部分抵消了促进跳跃对从表面去除冷凝水的作用。在本文中，我们分别关注冷凝和自驱动跳跃在促进和防止积水方面的竞争效应。设计并制备了一系列微纳结构超疏水表面。研究了微滴在这些表面上的冷凝过程和自驱动跳跃行为。对数千次跳跃事件进行了统计分析，以全面了解具有冷凝微滴自驱动跳跃的超疏水表面的防霜潜力。进一步的结霜实验表明，积水最少的表面表现出最佳的防霜性能，这验证了我们的设计策略。这项工作为防霜材料的合理设计和制造提供了新的见解。
