Liquid-Infused Smooth Coating with Transparency, Super-Durability, and Extraordinary Hydrophobicity

Liquid-infused coatings are because of their fluidity of considerable technological importance for hydrophobic materials with multifunctional properties, such as self-healing, transmittance, and durability. However, conventional coatings absorb viscous liquid into their sponge-like structured surface, causing uncontrollable liquid layer formation or liquid transport. In addition, a hydrophobic-liquid-retained surface can cause instability and lead to limitation of the hydrophobicity, optical properties, and flexibility due to liquid layer evaporation. Here, we report a strategy for controllable liquid-layer formation on smooth surfaces (R _rms < 1 nm) by π -electron interactions. Using this technology, superoleophilic wetting of decyltrimethoxysilane results in the design of a surface with π -interaction liquid adsorption, smoothness, and hydrophobicity (SPLASH), that shows extraordinary hydrophobicity (CAH = 0.75°), and stable repellence for various water-based solutions including micrometer-sized mist. The smoothness of the solid under a liquid layer enabled the SPLASH to exhibit stable hydrophobicity, transparency (>90%), structure damage durability and flexibility, regardless of the liquid layer thickness by bending or evaporation. Furthermore, the patterned π -electrons' localization on the smooth coating enables controlled liquid-layer formation and liquid transport. This strategy may provide new insights into designing functional liquid surfaces and our designed surface with multifunctional properties could be developed for various applications.