Ultrasonication‐Assisted Waterborne Synthesis of Self‐Restorable Superhydrophobic Surfaces with Prolonged Lifespan in Oil Collection

Abstract Self‐restorable superhydrophobic surfaces have attracted increasing attention due to their important applications. However, great challenges in an easy and rapid way to accomplish superhydrophobic surfaces with tunable self‐restorability are retained. Here, a facile yet fast strategy is presented to endow commercial substrates with self‐restorable superhydrophobic surfaces irrespective of their surface chemistry and geometry. By ultrasonicating an aqueous solution comprising poly(dimethylsiloxane), bis(3‐aminopropyl)‐terminated (H₂N‐PDMS‐NH₂) and dopamine hydrochloride (DA) with substrates for 30 min, superhydrophobic surfaces are yielded. Under ultrasonication, H₂N‐PDMS‐NH₂ is dispersed as the microdroplets and produces a weakly alkaline environment to enhance self‐polymerization of DA to polydopamine (PDA). In turn, PDA reacts with microdroplets and simultaneously anchors them to substrates, creating hierarchical morphology. The diffusion of hydrophobic H₂N‐PDMS‐NH₂ from the interior to the surface of the coating leads to superhydrophobic surface. This superhydrophobicity is self‐restorable after it is destroyed by air‐plasma or amphiphilic molecules, presumably because the H₂N‐PDMS‐NH₂ diffusion from the interior to the particles’ surface minimizes the overall interfacial‐energy. The self‐restoration is significantly accelerated by heating or rubbing the substrates. This self‐restoration offers superhydrophobic materials with a considerably prolonged life‐span, promising a wide range of applications, e.g., sustainable oil/water separation.