One-step fabrication of Salvinia-inspired superhydrophobic surfaces with High adhesion

Superhydrophobic surfaces with either low or high adhesion have great significance in numerous engineering domains. Salvinia, a common aquatic plant which has hydrophobic micro hair with a hydrophilic tip on the top, is a nature superhydrophobic surface with high adhesion. Here, inspired by salvinia, a superhydrophobic surface with high adhesion is fabricated by simple polymerization of dopamine (DA) onto nanotips of micro/nanostructured superhydrophobic surface. When the rough superhydrophobic surface is immersed in the DA solution, air is trapped in valley between the micro/nanostructures and discontinuous three-phase contact line (TCL) forms immediately. The polydopamine (PDA) adhesion only occurs on very tips of the micro/nanostructures, while the other ravine part of the micro/nanostructures remained hydrophobic, what endows the superhydrophobic surface numerous hydrophilic tiny tips like the hairs of salvinia leaf. The salvinia-like surface showed superhydrophobic but high adhesive property. This work unfolds more applicabilities of superhydrophobic surface and promotes the application of the superhydrophobic surface.