Superhydrophobicity from microstructured surface

Superhydrophobicity is referred to the wettability of a solid surface which has a water apparent contact angle greater than 150degrees. It has attracted great interest in both fundamental researches and practical applications. This paper discusses two models: Wenzel model and Cassie model, to describe the superhydrophobic states of surface. The effects of surface morphology and microstructure on superhydrophobicity are discussed, and the internal relationship between Wenzel and Cassie states is presented. These two superhydrophobic states can coexist and they present different properties on contact angle hysteresis. It is reported that the irreversible transition can be realized from Cassie state to Wenzel state under some certain conditions. This paper also gives a review of recent progresses in the strategies of fabricating superhydrophobic surfaces by designing microstructured or microtextured surfaces. Finally, the fundamental research and applications of superhydrophobic surfaces are prospected.