微滴在微纳米复合结构超疏水表面上滚动/黏附的可控研究

It is a new topic for the study of droplet’s rolling/adhesion controlled behavior on superhydrophobic surface. At present, most of the investigations are focused on big droplet’s behavior. When the size of the droplet turns to micrometer, due to size effect, the rolling and adhesion behavior for micro-droplet on superhydrophobic surface will present many difference. In this project, by using the combination technology of the microscope and high-speed camera, we will investigate the movement of the microdroplet on natural and biomimetic superhydrophobic surfaces with micro/nano binary architectures. The influence factors and the control mechanism for the transition between rolling and adhesion will be revealed. The main content is as follows: studying the microdroplet’s rolling and adhesion behavior on biomimetic superhydrophobic surfaces; and exploring the influence of the surface microstructure, chemical composition, and size on the critical roll angle. Under different conditions, investigating the movement behavior of the microdroplet on superhydrophobic surfaces is responsive to light, temperature, magnetic field, etc. By analyzing the experimental data, the decision mechanism for the microdroplet’s rolling/adhesion behavior will be revealed at last. The research result will provide theoretical support and practical guidance for the preparation of superhydrophobic surface with controlled rolling/adhesion behavior.

液滴在超疏水表面滚动/黏附的可控性是近年来一个新兴的研究热点。但是，目前的研究主要集中在对宏观液滴的滚动/黏附调控上。当液滴的尺寸由宏观变成微观时，由于尺寸效应，微观液滴在超疏水表面上的滚动、黏附行为将呈现诸多不同。本项目拟利用显微镜与高速摄像联合应用技术，以不同粗糙度的微纳米复合结构超疏水表面（自然的和仿生的）为研究对象，系统研究微滴滚动/黏附转变的影响因素及控制机制。主要研究内容如下：研究微滴在仿生超疏水表面上的滚动、黏附行为；探索微滴发生滚动/黏附转变时，临界滚动角与微滴大小、超疏水表面微观结构、尺寸以及表面化学组成之间的关系；考察微滴在外场响应性超疏水表面上的滚动、黏附行为，揭示导致微滴滚动/黏附转变的物理机制和控制机制。研究成果将为滚动/黏附可控的仿生超疏水表面的制备及应用提供一定的理论支持和实际指导。

本项目通过多种方法构筑出不同粗糙度的微纳米二元复合结构超疏水表面，通过对不同实验条件的选择来精确调控微纳米复合表面的微观结构与尺寸。系统研究了微滴在不同微观结构超疏水表面的滚动、粘附行为；考察了微滴与超疏水表面粘附力的大小与微滴体积、超疏水表面微观结构、尺寸以及表面化学组成之间的关系。研究表明，在微观结构相同的超疏水表面，微滴与表面的黏附力随微滴体积的增大而减小；在不同的超疏水表面上，相同大小的微滴发生滚动时的临界滚动角随着表面粗糙度的增加而减小；超疏水表面的表面能越低，相同大小的微滴发生滚动时的临界滚动角越小。同时，对微滴在超疏水表面的动态行为进行人工智能数据分析，揭示了微滴在超疏水表面发生滚动/粘附的主要影响因素、各影响因素之间的相关关系以及微滴发生滚动/黏附的控制机制。本项目共发表论文9篇，其中SCI论文7篇，申报国家发明专利4件。