Fluorine‐Free Soft Nanocomposites for High‐Speed Liquid Impact Repellence

ABSTRACT The practical adoption of liquid‐repellent coatings is limited by two key factors: dependence on fluorinated (specifically per‐ and polyfluoroalkyl) substances (PFAS) and poor durability, specifically, under high‐speed liquid impacts. As potential solutions, here we introduce fluorine‐free nanocomposite coating formulations comprising an alkylated amine epoxy, mixed with pre‐functionalised nanoparticles and silicone oil. The rational constituents enable several non‐incremental features. First, spraying the mixture results in ‘dry’ coatings with liquid repellence built through their thickness. Second, the oil inclusion helps lower the mechanical stiffness and obtain a superhydrophobic coating withstanding ∼60 m/s water jets. Third, by lowering the nanoparticle loading and increasing the oil contents, we achieve optically transparent (>90%) and amphiphobic coatings, which repel even low surface tension alcohol drops and jets at ∼35 m/s. Lastly, several additional desirable properties, such as good corrosion resistance (I corr ∼ 0.81 µA cm −2 in 3.5 wt.% NaCl), low ice‐adhesion (<50 kPa at −20°C), etc., should broaden the industrial use for these coatings.