仿鲨鱼皮微沟槽结构疏水机理实验研究

Experimental study of hydrophobic mechanism of micro-riblets on imitative shark skin

从理论分析和实验测量两个方面对鲨鱼皮微沟槽结构的疏水性进行了研究.首先,利用扫描电子显微镜和表面轮廓仪对鲨鱼皮的微观结构进行研究,并结合基本的疏水理论,建立了Cassie修正模型,Cassie修正模型从理论上揭示了鲨鱼皮微沟槽结构的疏水机理.其次,采用对比实验,利用液滴形状测量仪分别对真空浇铸法制备的硅橡胶仿鲨鱼皮表面和光滑硅橡胶表面的接触角进行了测量.研究发现,硅橡胶仿鲨鱼皮表面具有明显的疏水性,同时,仿鲨鱼皮表面接触角的实际测量值与Cassie修正模型计算的理论值之间的误差仅为3.1%,也证明了所提出的Cassie修正模型的正确性和有效性.

The hydrophobic property of micro-riblets on shark skin is studied in aspects of theoretical analysis and experimental measurement. Firstly, micro-structure of shark skin is investigated using scanning electron microscopy and form talysurf, and based on the basic hydrophobic theory, a Cassie modified model is proposed, which reveals the hydrophobic mechanism of micro-riblets on shark skin theoretically. Secondly, using contrast tests, the contact angles of water droplets on PDMS imitative shark skin fabricated by vacuum casting method and smooth PDMS are measured by drop shape analysis system. The studies demonstrate that the PDMS imitative shark skin shows the obvious hydrophobic property. In addition, due to the low error of 3.1% between the actual measured value of contact angle on the PDMS imitative shark skin and theoretical value computed with Cassie modified model, Cassie modified model is proved to be correct and valid.