Stable superhydrophobic coatings from thiol-ligand nanocrystals and their application in oil/water separation

Abstract

Stable superhydrophobic coatings were successfully achieved from thiol-ligand nanocrystals. Nanocrystals included VIII and IB metals and oxide nanoparticles, such as Fe, Co, Ni, Cu and Ag. We present a simple and available method that facilitates the synthesis of superhydrophobic textiles and sponges, in which the interaction between the nanocrystals and thiol plays a significant role in the formation of a special wetting surface. Meanwhile, the superhydrophobic textiles could also be endowed with new functionalities. For example, textiles with Fe3O4 nanocoatings possess magnetic properties, and Ag nanocrystals provide an antibacterial effect. If perfluoroalkyl thiol was used to replace alkyl thiol, the as-modified surfaces became oleophobic from superoleophilic. The proposed strategy was fit for various nanoparticles from as-established methods, including the preparation in different polar solvents, and the usage of surfactants as capping agents. As-prepared superhydrophobic nanocoatings show good durability towards hot water, surfactant aqueous solutions, and ultrasonic treatment in nonpolar solvents. The superhydrophobic and superoleophilic nanocoatings were effectively used for application in oil/water separation.