Dual scale roughness driven perfectly hydrophobic surfaces prepared by electrospraying a polymer in good solvent-poor solvent systems.

We demonstrated a facile method to produce perfectly hydrophobic surfaces (advancing and receding angles both 180°) via electrospraying. When a copolymer of styrene and a perfluoroacrylate monomer was electrosprayed in good solvents, surfaces composed of micrometer size beads were formed and fairly low threshold water sliding angles could be achieved. Addition of high boiling point poor solvents to the solutions resulted nanoscale roughness on the beads due to a possible phase separation that occurs in a predominantly poor solvent environment.