Water repellent coatings with hierarchal structures obtained on anodized aluminum with femtosecond laser ablation

The hierarchical structures were created on the surface of anodized aluminium. The micro-level of the structure was obtained in a mesh and point patterns by laser ablation using a femtosecond laser followed by polymethylhydrosiloxane. The nano-level of the structure was created using pre-hydrophobized pyrogenic silica coating. The Zisman Plot method was used to determine the critical energy of surface wetting. It is shown that a decrease in the values ​​of the contact angle with a decrease in the surface tension of the mixture occurs stepwise. The first stage is observed at a surface tension of the mixture below 44 mN / m, the second stage at 42–38 mN / m. It was shown that the mesh structure is more stable than the point structure.