Comparative Study on Wettability of Typical Plant Leaves and Biomimetic Preparation of Superhydrophobic Surface of Aluminum Alloy

Abstract

The water droplets spread observation, contact angle measurement and SEM analysis, data processing and other means, comparative study of different states of the lotus leaf, rice leaf and nasturtium leaf are carried out. The results show that their surface contact angle of three kinds of plant leaves are all over 140°, they have hydrophobic or superhydrophobic properties; dehydration degree of leaves has little effect on the wettability, will not change its hydrophobic property; the same point of wettability is that they have micro nano composite microstructure. The difference is, the wettability of the lotus and nasturtium is isotropic, while the rice is anisotropic, that is, in a direction parallel to the edge of hydrophobic than perpendicular to the blade edge enhancement. Based on the theoretical research, the hydrophobic surface is copied to the surface of aluminum alloy. The superhydrophobic surface of aluminum alloy matrix was successfully prepared by chemical etching combined with surface fluorination. The super hydrophobic aluminum alloy surface has micron-nano scale double roughness structure; its surface contact angle reached 156°.