Superhydrophobic surface on Al alloy with self-healing performance via snakeskin-like shedding

The micro-nano structures which are necessary factors to generate superhydrophobic performance are easily destroyed, especially by scraping with tough objects. As a result of the damage, superhydrophobicity will be lost. Herein, water-soluble polyvinyl alcohol(PVA) polymer binder is introduced to act as a cushion and sacrifice layer. In this approach, the aluminum surface with superhydrophobic is at the bottom. The PVA binder is in the middle. The topmost layer is the superhydrophobic polydimethylsiloxane (PDMS) and SiO2 layer. When the external force is weak, the bonding layer will act as a buffer to protect the underlying nanostructure. When the topmost layer is destroyed, the superhydrophobicity will be disappeared temporarily. Water can contact with the sacrifice layer, leading it to dissolution. Thus, the bonding layer is shedding, an intact aluminum superhydrophobic surface behind the sacrifice layer is uncovered. The method is critical to the applications of superhydrophobic Al materials in engineering.