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.

Preparation of Stable Superhydrophobic Coatings on Complex‐Shaped Substrates

“…In addition, the mechanical stability of superhydrophobic surfaces are often very low. [20,[28][29][30] Even weak abrasion or scratching can cause loss of superhydrophobicity due to damages to their microstructure. The mechanical stability of superhydrophobic surfaces can be enhanced by strengthening their bonding with the substrates, [31,32] protecting nanostructures using robust armor, [33] and making the surfaces self-healing [27,34] or self-similar, [35] etc.…”

Multifunctional CuO‐Coated Mesh for Wastewater Treatment: Effective Oil/Water Separation, Organic Contaminants Photodegradation, and Bacterial Photodynamic Inactivation

“…[7][8][9][10][11][12] Therefore, developing multifunctional materials that can deal with multiple contaminants simultaneously to achieve the complex wastewater cleanup are greatly favored.Inspired by nature, the materials with special superwetting surfaces have received more considerable attention for wastewater cleanup because of their low energy consumption, high efficiency and specific selectivity. [13][14][15][16][17][18][19][20][21] In the past decade, a rich library of superhydrophobic/ superoleophilic materials that can selectively absorb or filter the oils out from oil/ water mixtures, has been developed for the purpose of wastewater treatment. [22][23][24][25] A common drawback in using those materials is that they are easily fouled or even clogged by the permeated oils, consequently, leading to a dramatic decline of their separation capacity and recyclability in the subsequent use.…”