Fabrication of polydopamine-coated superhydrophobic fabrics for oil/water separation and self-cleaning

We report a fabric coating method inspired the superhydrophobic properties of lotus leaves and the strong adhesion of the adhesive proteins in mussels. Dopamine, which mimics the single units of the adhesive mussel proteins, was polymerized in an alkaline aqueous solution to coat the surface of fabrics. The versatile reactivity of polydopamine allows subsequent Ag deposition to form a lotus-leaf-like rough structure on the fabric surface. The composite fabric exhibited high water repellence after fluorination. Because dopamine can adhere to all kinds of materials, this method can be applied to many fabrics regardless of their properties and chemical compositions using a universal process. The modified fabrics exhibited excellent anti-wetting and self-cleaning properties with contact angles of >150 degrees and sliding angles lower than 9. The fabrics also efficiently separated oil from oil/water mixtures under various conditions. Our method is versatile and simple compared with other hydrophobic treatment methods, which usually only work on one type of fabric. (C) 2016 Elsevier B.V. All rights reserved.