Thiol appended, fluorinated phosphonium ionic liquids as covalent superhydrophobic coatings

The synthesis and characterization of thiol terminated fluorinated phosphonium ionic liquids and their application as superhydrophobic coatings are reported. The thiol functionality enables a covalent link to rough silver substrates installing a durable, non-wetting, ionic film. Variables such as the fluorine loading and the mode of interaction of the salt at the surface of the substrate were adapted and their corresponding effects on the wettability were examined. It was found that a thiolated phosphonium ionic liquid could tolerate a lower fluorine loading and maintain flexibility in the type of anion while still imposing superhydrophobic behaviour.