Wetting behavior and remarkable durability of amphiphobic aluminum alloys surfaces in a wide range of environmental conditions

• Aluminum alloys surfaces with strong repellence against water and low-surface tension liquids were obtained.
• Favorable wetting/dewetting behavior is preserved after chemical attack and ageing tests.
• A wide range of exposure and wearing conditions were evaluated.
• Materials with coated surfaces can be thought as “smart” component in many industrial fields.

In this work the amphiphobic behavior and durability of engineered aluminum alloy surfaces are highlighted. Functional, hybrid organic–inorganic coatings were obtained by a classic sol–gel route, followed by a controlled dipping on the substrate in order to achieve surface nanostructuring. The characterization of surfaces revealed outstanding results in terms of static contact angle (higher than 170°) and hysteresis (lower than 5°) with water, as well of contact angle (about 145°) with low-surface tension liquids. In relationship with the latest scientific improvements on this topic, the development of materials coupling favorable static and dynamic repellence against low-surface tension liquids can find applications as corrosion protective components, stain-resistant and self-cleaning materials, de-icing or anti-biofouling paints, and so on. In each area, one of the most important issue to be concerned is the materials’ ability to withstand adverse conditions (i.e. attacks by chemical agents and wearing phenomena), avoiding the quick loss of superhydrophobicity/oleophobicity. In this context, functional coatings developed on aluminum alloy stand out for the excellent capability of keeping unchanged their performances over the time and after simulation of rather severe working environments, matching by this way some of the basic requirements connected with their employment as innovative industrial structural materials and components.