Asymmetrical ring-shaped colloidal particles for self-assembly and superhydrophobic coatings.

A frame-guided wetting strategy is reported to synthesize highly uniform but asymmetrical colloidal particles from rings to oblate ellipsoids through symmetrical discs, which can self-assemble into diversified highly open 2D superstructures. In particular, ring-shaped particle monolayers have a higher contact angle of water than similar spherical ones, suggesting an attractive particle material for self-cleaning superhydrophobic coatings.