A scalable method toward robust underwater superoleophobic surfaces with microstructure arrays on 304 stainless steel substrates

Abstract

Underwater superoleophobic surfaces have huge application prospects due to their multiple functions such as antifouling, self-cleaning, manipulation of oil microdroplets, and oil − water separation. However, efficient and low-damage methods for the scalable fabrication of robust underwater superoleophobic surfaces on stainless steel substrates are still lacking. Here, a maskless electrochemical machining technology was developed to fabricate robust underwater superoleophobic surfaces on 304 stainless steel substrates. The square micro pit array was obtained on the surface, and the surface showed excellent superoleophobicity with a contact angle of 154.93 ± 1.42° when submerged in water. In addition, the fabricated underwater superoleophobic surface with the square micro pit array showed good chemical stability, mechanical stability, and anti-friction performance. The friction coefficient of the fabricated underwater superoleophobic surface was 0.0748, which was 60.7% lower than the friction coefficient of a smooth surface. Compared with traditional methods, the proposed technology will promote the practical applications of underwater superoleophobic surfaces in complex underwater environments.