Formation conditions and mechanism of wetting state on micro-/nanostructured superhydrophobic surface

Due to its unique wetting properties, the superhydrophobic surface caused by the micro-/nanostructure has shown good application prospects in many fields. Therefore, the relationship between the wetting state and the surface structure should have a deeper understanding. The thermodynamic method, based on the principle of minimum energy, is used to analyze all the nine wetting states of droplet on a micro-/nanostructured superhydrophobic surface, and the existence conditions and corresponding contact angle expressions of each wetting state are derived. On this basis, taking lotus-simulating surfaces as an example, the validity and sufficiency of the two-level micro-/nanostructure on superhydrophobicity is quantitatively clarified. The correlation between the wetting states as well as the transformation process of its structure is further analyzed. The results in this paper provide a reference for designing stable micro-/nanostructured superhydrophobic surface.