Daphnia-inspired dynamic slippery chemically bonded liquid surface for the active prevention of covalently attached foulant adhesion

Engineering anti-adhesion coatings always focuses on a specific hierarchy and surface free energy, which passively endures water scouring to wash away the loosely attached foulants. Certain foulants, however, especially those that are highly adhesive or covalently attached on the coatings, cannot be removed off the designed surfaces easily. Inspired by the active self-hunting behavior of the filter-feeding animal Daphnia, herein, we propose a universal antifouling strategy with both passive and active adhesion repellency capabilities. The premise for this protocol is that the as-fabricated liquid-like surface is able to repel the settlement of general foulants upon static conditions. Under steady thermal stimuli, the dynamic liquid-like surface behaves like a boxer with an active prevention ability against highly adhesive foulant adhesion, e.g., proteins, crude oils, and even covalently adhered mussel species. The enhanced biocide-free anti-adhesion performance is attributed to the reversible non-covalent interactions of pollutants in the initial contact with the surface, which was innovatively proved by AFM tapping tests to elucidate the physicochemical interactions between the foulants and coating surfaces. We envision that such an active anti-covalent adhesion surface may have great potential in diverse fields, including marine antifouling, fluid handling and transportation, and energy-harvesting devices.

Automated summary

Engineering anti-adhesion coatings typically rely on hierarchical structures and surface free energy to passively remove loosely attached foulants through water scouring. However, highly adhesive or covalently attached foulants are difficult to remove. Inspired by the filtering behavior of Daphnia, a universal antifouling strategy with both passive and active adhesion repellency capabilities is proposed. The liquid-like surface repels general foulants under static conditions and actively prevents the adhesion of highly adhesive foulants under thermal stimuli.