Preparation Of Superhydrophobic Coatings By Fluorinated Acrylic Copolymer Emulsion/SiO₂ Hybridization

Water contact angle(CA)> 150 °and water sliding angle(SA)< 10 °of the superhydrophobic layer can inhibit the adhesion of water droplets and make water droplets roll quickly from the surface.Therefore,it has broad application prospects in the fields of self-cleaning,non-wetting,anti-fogging and anti-icing.The superhydrophobic coating obtained by spraying method can facilitate large-scale production of superhydrophobic surfaces without matrix limitation.This coating is usually composed of low surface energy coatings and micro-nano particles.In this work,fluorinated acrylic emulsion prepared by water-based radical polymerization was reported,and self-crosslinking fluorinated acrylic nanocoatings with good dynamic water repellency and high mechanical strength were prepared.The use of highly active isocyanate groups in the coating not only facilitates the covalent bonding of the functional groups on the surface of the coating and the substrate,but also makes the isocyanate groups self-crosslink with the hydroxyl groups in the polymer.This crosslinking fixes the fluorinated chain on the surface,thereby alleviating the contact angle hysteresis,and the formed crosslinking network also significantly improves the mechanical strength of the coating.The superhydrophobic coating can be obtained by spraying the cross-linked fluorinated acrylic emulsion with nanoparticles,and the prepared coating can achieve excellent hydrophobicity(CA > 160 °,SA < 3 °).After a variety of harsh durability tests,this superhydrophobic performance is still well maintained.For example,the coating can withstand sandpaper wear up to 20 cycles;after soaking in acid,alkali and organic solvents for 24 h,superhydrophobicity can still be maintained.In summary,the self-crosslinked fluorinated acrylate nanocoatings with good dynamic water repellency and high mechanical strength prepared in this paper open up a new way for the environmentally friendly preparation of durable superhydrophobic coatings.On the other hand,the superhydrophobic coating prepared by water-based formulation is suitable for various substrate materials,and shows excellent performance in self-cleaning and anti-icing process.