In-situ self-compensation strategy for superhard, universal superhydrophilic/underwater superoleophobic coatings

Superhydrophilic and underwater superoleophobic surfaces are considered promising to maintain clean surfaces and sustain their functionalities. These surfaces, however, are often substrate specific, mechanically weak and can be damaged easily, resulting in short lifetimes. To address this, we propose a novel in situ self-compensation strategy for preparing a reconstructable hybrid polysiloxane network. This network can enhance surface roughness when hydrophilic chemistry is lost due to progressive water erosion, thus affording long-period superhydrophilic and underwater superoleophobic coatings that can survive rainfall or long-term underwater applications. For a diverse range of substrates with sustainable superhydrophilicity and underwater superoleophobicity, we developed a waterborne suspension containing metal nanoparticles and inorganic silicate adhesive applicable for the industrially viable spray-, dip-, or paint-coating techniques. This universal, superhard (exceeding 9H), long-period coating represents an applicable solution for preventing dirt or oil contamination and oil–water separation. It is expected to be widely used in industries and daily life.