Experimental Investigation of Superhydrophobicity on Three Scale Hierarchical Surface Structures

摘要

The present study involves assessment of superhydrophobicity on three-scale surface structures with varying micro-scale surface roughness. The three-scale hierarchical surface structures were prepared using a simple, fast and cost-effective method, with nano-porous anodized aluminium as base and stearic acid as coating materials. The effect of surface roughness on the superhydrophobic behaviour of anodized aluminium samples was analyzed over a wide range of average surface roughness (Ra from 0.1 μm to 6.5 μm). The developed surfaces displayed excellent superhydrophobic properties with water contact angles as high as 171.71°±1.95 corresponding to an average surface roughness value of 6.48 μm. The effect of surface roughness on superhydrophobicity was found to be significant. The prepared samples also showed visible air pockets at the solid-liquid interface for higher values of surface roughness.