Fabrication of durable superhydrophobic coatings based on a novel branched fluorinated epoxy

Low durability is a potential Achilles heel for superhydrophobic coatings, which greatly prevents applications of superhydrophobic materials for various daily living activities. In this paper, a novel branched epoxy, dangling long fluoroalkyl tail, was designed and synthesized. The coating shows contact angles of 165° 147° and 144° to water, glycol and colza oil, respectively, and shows superhydrophobicity. This coating is also highly durable, withstanding at least 1000 abrasion cycles under 45 kPa. After abrasion testing, its contact angle to water is maintained at 152°. Furthermore, this coating also shows a remarkable stability towards strong acid, UV light, thermal and smudge treatment without apparently losing its superhydrophobicity. The epoxy groups of the T-FAE can form high crosslinking network by the ring-opening reaction and reacting with the Si–OH and –NH₂, and long-fluorine chain offers low surface energy. All these are responsible for the excellent performance of the coating.