超疏水结构表面液滴撞击行为研究进展

Advances in the Study of Droplet Impact Behaviour on the Surface of Superhydrophobic Structures

摘要:

固体表面的液滴撞击是实际应用中遇到的许多现象的重要部分，如微流控设备、冷却喷雾、喷墨打印、农药喷洒等。此外，通过超疏水结构表面修饰应用设备的功能表面能够显著提高设备的防污、抗粘附等功能，但是这种基于微纳结构的功能性表面抵抗液滴钉扎效应的能力很大程度限制了其应用。因此，研究液滴撞击超疏水表面行为对提高设备的抗腐蚀、自清洁等性能具有重要意义。首先介绍了非均匀表面的润湿理论，然后总结了近年来针对超疏水表面静态和动态液滴润湿行为的研究成果，着重阐述了结构润湿性、物理形貌及冲击速度对液滴接触时间和最大铺展系数的重要影响，介绍了液滴最大铺展系数预测模型的研究进展，进而指出了目前研究的不足之处。最后，对液滴回弹机制和最大铺展系数的研究进展进行了展望。

Abstract:

Droplet impingement on solid surfaces is an important part of many phenomena encountered in practical applications， such as microfluidic devices， cooling sprays， inkjet printing， pesticide spraying， etc. Furthermore， functional surfaces of applied devices modified by superhydrophobic structured surfaces can significantly improve the anti-fouling and anti-adhesion of the devices， but the ability of such functional surfaces based on micro and nano structures to resist the droplet nailing effect largely limits their applications. Therefore， it is important to study the behaviour of droplet-impacting superhydrophobic surfaces in order to improve the corrosion resistance and self-cleaning properties of devices. This paper first introduces the wetting theory of non-uniform surfaces， and then reviews recent research results on static and dynamic droplet wetting behaviour of superhydrophobic surfaces， highlighting the important effects of structural wettability and physical morphology， impact velocity on droplet contact time and maximum spreading coefficient， introducing the progress of research on prediction models for maximum droplet spreading coefficient， and then points out the shortcomings of current findings. Finally， the research progress on droplet rebound mechanisms and maximum spreading coefficients is presented.