Structure correlated static and dynamic wettability properties of superhydrophobic leaves of Cassiatora, Adiantum capillas veneris (ACV), and Bauhinia variegata Linn .

In this article, for the first time, superhydrophobic leaf surfaces of Cassiatora, Adiantum capillas veneris (ACV), and Bauhinia variegata Linn. Indian have been studied using contact angle measurements and water drop impact experiments. Superhydrophobicity of Adiantum capillas veneris (ACV) leaves are reported for the first time. Field Emission Scanning Electron Microscopy (FESEM) characterization was done on these leaves to understand their surface morphology and how it affects wettability. A special drying method was employed to ensure minimal surface damage under the ultra vacuum of FESEM. Contact angle measurements show that the receding contact angle is the lowest in the Cassiatora leaf because of the widely spaced low aspect ratio nano petals and bumpy blunt microtextures. Other plant surfaces showed a very low roll-off angle less than 10° and very low contact angle hysteresis due to the presence of higher aspect ratio and closely spaced nano textures, re-entrant morphologies, and ridge structures. Droplet impact studies on these surfaces performed at weber numbers of 9,30,62 and105 showed different behaviour due to different micro nano textures. Significant differences such as secondary droplet formation after droplet complete rebound and maximum droplet spreading at higher We no were observed and showed the influence of observed micro nano textured on these leaf surfaces.