Simultaneous Realization of Superoleophobicity and Strong Substrate Adhesion in Water via a Unique Segment Orientation Mechanism

The underwater superoleophobicity of a coating is often caused by its preferential water affinity, which, however, normally weakens the substrate adhesion property. In this work, a new strategy is reported for achieving strong underwater adhesion between a well‐designed amphiphilic polyurethane coating and a diverse range of substrates while also rendering the coating surface's superoleophobicity. When the coating, which is a mixture of an amphiphilic polyurethane and a water miscible solvent, is immersed in water, the hydrophobic segments aggregate to orientate and pile along the surface of substrates via a segment orientation mechanism triggered by solvent exchange with water penetration to exert strong adhesion. At the same time, the hydrophilic segments will physically crosslink to form a hydrogel coating, endowing the substrate with underwater superoleophobicity. This work provides a facile, versatile, and scalable approach for the future design of superoleophobic coatings in a water environment. A facile and versatile noncovalent coating strategy is provided to simultaneously realize underwater superoleophobicity and strong substrate adhesion based on a mixture of amphiphilic polyurethane and a water‐miscible solvent. By immersing the coating in water, hydrophobic segments will orientate and pile along the substrate surface via a segment orientation mechanism. Hydrophilic segments will physically crosslink to a hydrogel surface.