超疏水表面的饼状液滴弹跳的现象、机理以及应用

项目名称： 超疏水表面的饼状液滴弹跳的现象、机理以及应用

项目编号： No.51475401

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 机械、仪表工业

项目作者： 王钻开

作者单位： 香港城市大学深圳研究院

项目金额： 76万元

中文摘要： 开发能够让液滴快速脱离固体表面的超疏水材料，具有重要的科学意义和工程应用价值。在常规的超疏水材料的表面上，液滴能够完全弹性弹起，并且液滴与固体表面的接触作用时间遵守一个瑞利常数。最近我们在一种特殊的微纳米结构上发现了一种反常的饼状液滴弹跳现象，也就是液滴能够在达到最大横向铺展时纵向弹起，避免了经历常规弹性弹跳中的回缩过程，从而打破了液滴与衬底接触时间的理论极限（我们初步的实验显示可将理论接触时间缩短80%）。本项目中，我们将系统研究液滴与各种超疏水表面作用的动力学过程，研究结构参数对饼状弹跳的影响，从时间尺度和能量角度去解释这一物理现象的动力学机制。新型的饼状液滴弹跳的发现以及对其进行深入的研究不仅会加强我们对液体在微/纳米结构表面上的复杂动力学行为的理解，而且它大大缩短固液接触时间的优点将为开发新型防结冰材料提供新的思路。

中文关键词： 防结冰；超疏水；界面效应；纳米结构；表面改性

英文摘要： Engineering superhydrophobic surfaces that promote rapid drop detachment is of importance to a wide range of applications. The complete drop rebound from superhydrophobic surfaces is the most spectacular feature of water repellency, in which a drop typically undergoes both spreading and retraction before leaving the surface. The contact time between the droplet and underlying solid surface is constrained by a theoretical contact time limit. Recently, we discovered a counter-intuitive bouncing regime on the superhydropobic surface with special texture, allowing for a four-fold reduction in contact time compared to conventional complete rebound. Such a regime is characterized by drop detachment from the surface close to its maximum lateral extension, a behaviour that we shall term pancake bouncing. In this project, we will systemtically investigate the detailed impact dynamics of droplet on the superhydrophobic surface with different textures, elucidiate the fundamental mechanism from the timescale and energy criteria. The discovery of pancake bouncing which can achieve significantly shortened contact times not only enriches our fundamental understanding of wetting dynamics, but will also stimulate new applications such as anti-icing.

英文关键词： anti-icing;superhydrophobic;interface;nanostructure;surface modification