Superhydrophobic Hybrid Inorganic-Organic Thiol-ene Surfaces Fabricated via Spray-Deposition and Photopolymerization

We report a simple and versatile method for the fabrication of superhydrophobic inorganic–organic thiol-ene coatings via sequential spray-deposition and photopolymerization under ambient conditions. The coatings are obtained by spray-deposition of UV-curable hybrid inorganic–organic thiol-ene resins consisting of pentaerythritol tetra(3-mercaptopropionate) (PETMP), triallyl isocyanurate (TTT), 2,4,6,8-tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane (TMTVSi), and hydrophobic fumed silica nanoparticles. The spray-deposition process and nanoparticle agglomeration/dispersion provide surfaces with hierarchical morphologies exhibiting both micro- and nanoscale roughness. The wetting behavior, dependent on the concentration of TMTVSi and hydrophobic silica nanoparticles, can be varied over a broad range to ultimately provide coatings with high static water contact angles (\u3e150°), low contact angle hysteresis, and low roll off angles