Hydrophobic mechanism and criterion of lotus-leaf-like micro-convex-concave surface  

作　　者：ZHU DingYi QIAO Wei WANG LianDeng 

机构地区：[1]Department of Materials Science and Engineering, Fuzhou University, Fuzhou 350108, China

出　　处：《Chinese Science Bulletin》2011年第15期1623-1628,共6页

基　　金：supported by the National Natural Science Foundation of China (50471007)

摘　　要：According to the principle that the contact angle of liquid droplet always increases on a limited liquid-solid interface,it is suggested that the integration of many small-size limited liquid-solid interfaces results in the increase of the hydrophobicity of lotus-leaf-like micro-convex-concave surfaces.Mathematical equations of the stability of liquid-droplets on the surface of lotus-leaf-like structure were established.The relationship between the theoretical critical-radius of the void of micro-convex-concave surface and the nature of the solid and the liquid was drawn.The three conditions of realizing hydrophobicity were described.The result of computation has shown that when the radius of the void of micro-concave-convex surface is less than the theoretical critical-radius r c,the droplets may always be in a stable state on the solid surface with the contact angle greater than 90°.Theminimum area of the liquid-solid interface and low surface energy of solids are important factors in realizing hydrophobicity.The effective work of adhesion W a ' was proposed as a criterion for measuring the hydrophobic ability of the solid surface.According to the principle that the contact angle of liquid droplet always increases on a limited liquid-solid interface, it is suggested that the integration of many small-size limited liquid-solid interfaces results in the increase of the hydrophobicity of lores-leaf-like micro-convex-concave surfaces. Mathematical equations of the stability of liquid-droplets on the surface of lotus-leaf-like structure were established. The relationship between the theoretical critical-radius of the void of micro-convex-concave surface and the nature of the solid and the liquid was drawn. The three conditions of realizing hydrophobicity were described. The result of computation has shown that when the radius of the void of micro-concave-convex surface is less than the theoretical critical-radius re, the droplets may always be in a stable state on the solid surface with the contact angle greater than 90~. The minimum area of the liquid-solid interface and low surface energy of solids are important factors in realizing hydrophobicity. The effective work of adhesion W＂ was proposed as a criterion for measuring the hydrophobic ability of the solid surface.

关 键 词：疏水性 凸面 标准 固体表面 机制 花叶 临界半径 凹凸表面 

分 类 号：O359.1[理学—流体力学]