典型植物叶面微结构特征与润湿异性研究

A nisotropic wetted surfaces have broad application potential in areas, such as microfluidics, biomedicine, mist collection and fuel cell drainage, because of their special wetting properties. In this study, the surfaces of typical plant leaves with anisotropic wetting properties (e. g., ophiopogon bodinieri leaves, phragmites australis leaves and ginkgo biloba leaves) were observed using contact-angle measuring instrument and scanning electron microscope. Results reveal as following: leaves with a groove-like structure similar to that of rice paddy leaves, such as ophiopogon bodinieri and phragmites australis, exhibit anisotropic wetting properties; leaves without a notable groove-like structure, such as ginkgo biloba, similarly display marked anisotropic wetting properties. The evidence suggests that regular banded micro-grooves are not the only decisive feature that results in anisotropic wetting properties. A two-dimensional variable-density papillary micro-morphological layout similar to that on the surface of ginkgo biloba leaves can also lead to a similar anisotropic wetting state. Furthermore, the mechanism by which this type of anisotropic wetting phenomenon occurs can be preliminarily explained based on the asymmetrical distribution pattern of three-phase contact lines.