Facile preparation of self-healing waterborne superhydrophobic coatings based on fluoroalkyl silane-loaded microcapsules

Superhydrophobic surfaces have attracted tremendous attraction because of their novel aspects of surface physics and important applications ranging from self-cleaning materials to microfluidic devices. However, most artificial superhydrophobic surfaces easily lose their superhydrophobicity under natural sunlight irradiation, physical rubbing or organic contamination. Here, fluoroalkyl silane (FAS)-loaded microcapsules, photocatalytic TiO 2 nanoparticles and FAS modified SiO 2 nanoparticles were mixed with waterborne polysiloxane resins to obtain waterborne self-healing superhydrophobic coatings. Superhydrophobic surfaces were formed by casting the coatings on the substrates after UV-irradiation and could sustain their superhydrophobicity even after 360 h accelerated weathering test. Meanwhile, the coating was durable enough to withstand water blasting and the attacks of strong acid or basic solutions without apparently changing its superhydrophobicity. More importantly, after being mechanically damaged or contaminated with organics, these coatings could restore their superhydrophobicity under UV light. All these characteristics ensure that the coatings have excellent long-term superhydrophobicity for outdoor service. A self-healing waterborne superhydrophobic coating comprising polysiloxane latex, microcapsules, fluorinated silica and photocatalytic titania nanoparticles shows self-repairing ability after mechanical damage or oily contaminations.