Fabrication of room temperature self-healing, robust superhydrophobic coatings via spraying dual cross-linking supramolecular silicone polymer/ SiO₂ composite

Endowing superhydrophobic surfaces (SHS) with self-healing capability has been considered a promising approach to prolonging the lifespan of SHS. However, the reported SHS consisted of self-healing polymers and adhesive nanoparticles are still subject to the contradictions between robustness and complicated repairing conditions. In this work, a room-temperature self-healable, robust superhydrophobic coating was fabricated by combining dual cross-linking supramolecular silicone polymer (BPDI), which contains multiple hydrogen interactions and reversible nitrogen-coordinated boroxines, and SiO2 nanoparticles via facile spraying methods. Benefiting from the synergetic dual reversible bonds and high mobility of BPDI polymer chains, the supramolecular resin exhibits excellent self-healing ability, recyclability, and high adhesive strength to the substrates. After the incorporation of SiO2 nanoparticles, the surface of composite coatings revealed lotus-leaf-like morphology with an averaged roughness of 105 nm and superhydrophobicity with a WCA of 158.6 degrees. More importantly, the obtained coatings could repair themselves spontaneously and repeatedly at room temperature via surface reorganization when the composites suffer chemical deterioration such as plasma etching. Furthermore, the coated surface can maintain superhydrophobicity even after being exposed to repeated mechanical or chemical damages, including sandpaper abrasion, solvent immersion, water dripping, and UV aging. The facts are reasonably attributed to the excellent stability of BPDI resins and robust interfacial adhesion with the substrate. Moreover, the prepared superhydrophobic composites with room-temperature self-healing capability and mechanochemical durability have been applied for self-cleaning and antifouling aspects on diverse substrates.