Robust Underwater Oil-Repellent Biomimetic Ceramic Surfaces: Combining the Stability and Reproducibility of Functional Structures.

Robust underwater oil-repellent materials combining high mechanical strength and durability with superwettability and low oil adhesion are needed to build oil-repellent devices able to work in water, to manipulate droplet behavior, etc. However, combining all of these properties within a single, durable material remains a challenge. Herein, we fabricate a robust underwater oil-resistant material (Al 2 O 3 ) with all of the above properties by gel casting. The micro/nanoceramic particles distributed on the surface endow the material with excellent underwater superoleophobicity (∼160°) and low oil adhesion (<4 μN). In addition, the substrate exhibits typical ceramic characteristics such as good antiacid/alkali properties, high salt resistance, and high load tolerance. These excellent properties make the material not only applicable to various liquid environments but also resistant to the impact of particles and other physical damage. More importantly, the substrate could still exhibit underwater superoleophobicity after being worn under specific conditions, as wear will create new surfaces with similar particle size distribution. This approach is easily scalable for mass production, which could open a pathway for the fabrication of practical underwater long-lasting functional interfacial materials.