Unlocking Room-Temperature Self-Healing in Solid Omniphobic Slippery Coatings via Ionic Liquid Anion–Cation Synergy

Abstract

The current application of self-healing solid omniphobic slippery coatings is severely constrained by the elevated temperature requirements for their self-healing mechanisms. This work presents the first room-temperature self-healing solid omniphobic slippery coating with exceptional transparency and robust liquid repellency across a wide range of surface tensions. This breakthrough is accomplished by incorporating a minute quantity of 1-hexyl-3-methylimidazolium chloride ([Hmim]Cl) into a rationally engineered amorphous polyurethane comprising perfluoroalkyl side chains. In-depth studies reveal that, unlike other ionic liquids, the synergistic formation of hydrogen bonds between the anions and cations of [Hmim]Cl and the hard segments of the polyurethane uniquely diminishes the size of the hard phase domains and enhances their dynamics within the coating. This endows the coating with the capability to spontaneously, efficiently, and repeatedly heal both mechanical and chemical damage through the migration of polymer chains to the sites of injury at ambient temperature. To highlight its practical applicability, this coating is utilized to fabricate a transparent triboelectric nanogenerator (TENG). Compared to conventional TENGs, the proposed TENG not only exhibits superior antifouling and self-cleaning capabilities but also demonstrates an unparalleled capacity to convert the dripping of alkanes, edible oils, polyols, and water into electric energy.