Tuning surface wettability by designing hairy structures

Abstract

We present a molecular dynamics simulation study on the controlling factors that influence the wettability of a hairy surface. By adopting the hairs with appropriate grafting density, hair length, and hair rigidity, the hairy surface shows good performance on droplet repellency. When the droplet sits on the hairy surface, the flexible hairs can spontaneously bundle with the appropriate amount of neighboring hairs to enhance the surface hydrophobicity, thus providing a new possibility to control the surface wettability. The hairy surface with tunable grafting density and hair rigidity, bridges the gap between surfaces with soft polymer brushes and surfaces that are completely hard but porous.