长效抗冷凝诱导润湿性转变的超疏水表面设计与机理研究

超疏水表面在集水防雾、流体减阻和冷凝传热等领域的应用过程中往往面临高湿度或过冷度环境，难以避免冷凝诱导的润湿性转变，导致超疏水性失效的难题。本项目拟系统研究超疏水表面因结构内冷凝引起的多尺度润湿性转变机制，找准传统表面冷凝失效的关键共性问题和抗冷凝失效能力存在差异的根本原因，指导长效抗冷凝失效超疏水表面的设计。基于失效机理研究，提出向纳米级超疏水表面引入连续微结构的思想，将微/纳结构的表面化学、导热和固-液粘附等性质差异耦合于同一表面，协同实现液滴成核、生长、去除的高度空间选择性，维持超疏水纳米结构区域的长效稳定从而保证整个表面的超疏水性；分析抗冷凝失效机制并调控浸润性能与抗冷凝失效性能之间的平衡。最终将构建出在高湿度或高温差环境中其浸润性能和状态均长效稳定的超疏水表面，并建立一种解决超疏水表面冷凝失效问题的普适性方法和策略，探究其在凝雾集水和高过冷度条件下的传热传质应用。

The superhydrophobic surface is often faced with a high humidity environment or surface subcooling in the application of water harvesting and anti-fog, drag reduction and condensation heat transfer. It is difficult to avoid the condensation-induced wettability transition, which leads to failure of the superhydrophobicity. This project intends to design of superhydrophobic surface with long-term resistance to condensation-induced wetting transition directed by systematically studying the general mechanism of multi-scale wetting transition of the superhydrophobic surface caused by the condensation in the surface structures, and identifying the primary cause of the robustness differences of resistance to condensation-induced wetting transition. Based on the failure mechanism, the idea of introducing the interconnective microstructures into nanoscale superhydrophobic surfaces is proposed, which couples the differences of the surface chemistry, thermal conductivity, and solid-liquid adhesion of the micro- and nano-structures to the same surface. The designed superhydrophobic surface will carry out the high spatial selectivity of condensation drops nucleation, growth, and removal, and maintain the long-term stability of the superhydrophobic surface. This project will construct a superhydrophobic surface with long-term resistance to wetting transition in high humidity or surface subcooling environment. We envision this universal strategy to solve the problem of condensation-induced failure of superhydrophobicity and apply it to the fields of fog collection and heat transfer under subcooling conditions.