Robust Organic–Inorganic Composite Films with Multifunctional Properties of Superhydrophobicity, Self-Healing, and Drag Reduction

Multifunctional films have attracted wide attention in scientific research and engineering applications. Based on thermodynamically driven metathesis reactions of disulfide bonds, a self-healing film with disulfide bonds was designed and prepared, which was hot-pressed by fluorinated silica particles (F-SiO2) to prepare an organic–inorganic composite film with superhydrophobicity and self-healing properties of 70.29% self-healing efficiency, measured by tensile experiments. The increasing amount of F-SiO2 showed various hierarchical structures on the composite films, resulting in elevated contact angles with the maximum up to 168° at an F-SiO2 surface density of 2.0 mg/cm2. Having been hot-pressed into four layers of F-SiO2, the composite films had excellent wear resistance while maintaining superhydrophobicity after 10 m sandpaper abrasion scan. When subjected to acidic solution, bend, finger-wiping, and knife-scratch damage, the composite films still had excellent superhydrophobicity. In addition, the organic–inorganic composite films exhibited excellent drag reduction property, with drag reduction rates up to 27.7%.