Ultrathin Zwitterionic Coatings for Roughness‐Independent Underwater Superoleophobicity and Gravity‐Driven Oil–Water Separation

A novel approach to render virtually any surface superoleophobic underwater is developed via forming an ultrathin hydrophilic zwitterionic coating by initiated chemical vapor deposition. The superoleophobicity does not rely on nano-fabricated hierarchical surface structures that have been considered necessary for underwater superoleophobicity.