Superhydrophobic surfaces can effectively prevent the freezing of supercooled droplets in technological systems. Droplets on superhydrophobic surfaces commonly not only wet the top asperities (Cassie State), but also partially penetrate into microstructure due to surface properties, environment, and droplet impact occurring in real-world applications. Implications on ice nucleation can be expected and are little explored. It remains elusive how anti-icing surfaces can be designed to exploit intermediate wetting phenomena. We utilized engineered micro-/nanostructures, specifically micropillars, to modulate the wetting fraction in the microstructure. The behavior of intermediate wetting with supercooling and resulting implications on ice nucleation delay when potential nucleation sites are formed in the microcavities were investigated using experimental, theoretical, and simulation components. The temperature-dependent wetting fraction in the microstructure increased at supercooled temperatures, partly activated by condensation in the microcavities. At -10/-20 °C, a critical wetting fraction led to maximum ice nucleation delays, with experimental results consistent with theoretical predictions. This critical wetting fraction minimized the effective contact area solid-to-liquid along the partially wetted microstructure. The study establishes physical relations between ice nucleation delays, geometrical surface parameters and wettability properties in the intermediate wetting regime, providing guidance for the design of ice resistant microstructured surfaces.

This study details the fabrication of an icephobic coating for steel produced using a silicone–epoxy hybrid resin; the coating has good mechanical properties and weathering resistance for outdoor applications. Silicone–epoxy hybrid resins and amino‐functional silane‐curing agents were selected for investigation and applied to steel samples. Wettability, ice adhesion strength, and the mechanical and weathering resistance properties of the developed coatings were assessed using a drop‐shape analyzer, Fourier transform infrared, X‐ray photoelectron spectroscopy, as well as push‐off, tensile, and QUV tests. The possible correlation between ice adhesion strength and Young modulus was also investigated. The best‐performing matrix in terms of mechanical properties and weathering resistance had its surface energy characteristics altered—via two fluorinated silicone additives at various concentrations—to lower ice adhesion strength. For the steel substrates, the optimized additive‐altered surface showed a lower ice adhesion strength (decreasing from 362 to 94 kPa) with an adhesion reduction factor of 10.6. The fabricated coatings can serve as a protective layer for marine harbor infrastructures.