Robust, self-healing, superhydrophobic coatings highlighted by a novel branched thiol-ene fluorinated siloxane nanocomposites

In this work, we present one-step dip-coating strategy for fabricating robust, self-healing and superhydrophobic coatings using a coating solution that contains a novel branched thiol-ene fluorinated siloxane (T-FAS), polydimethylsiloxane (PDMS) elastomer and hydrophobic fumed silica nanoparticles (SiO₂ NPs). The novel branched T-FAS, with low fluorinated surface energy and high sol-gel reactivity, was prepared by introducing (N-methyl-perfluorohexane-1-sulfonamide) ethyl acrylate (FSA) and γ-methacryloxypropyltrimethoxysilane (MPS) into pentaerythritol tetra (3-mercaptopropionate) (PETMP) via thiol-ene click reaction. The superhydrophobic coating, being high stable to strong acid, UV, thermal and smudge treatment, has a water contact angle of 165 ± 2° and shedding angle of 4 ± 1°. It can withstand at least 100 cycles of abrasion with 1500 grit sandpaper under 45 KPa due to the interpenetrating polymer networks (IPN) constructed by T-FAS/PDMS. The IPN is also self-healing to chemically etching using long perfluoro-terminated chains of T-FAS which can spontaneously reorient to new air interfaces. The robust self-healing IPN may lead to the development of new efficient strategies for durable protective coatings in various applications.