Hydrophobic mechanism and criterion of lotus-leaf-like micro-convex-concave surface |
| |
Authors: | DingYi Zhu Wei Qiao LianDeng Wang |
| |
Institution: | (1) School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA, USA |
| |
Abstract: | 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°. 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
a
′ was proposed as a criterion for measuring the hydrophobic ability of the solid surface. |
| |
Keywords: | limited liquid-solid interfaces hydrophobicity contact angle critical radius work of adhesion |
本文献已被 CNKI 维普 SpringerLink 等数据库收录! |