A Bioinspired Hierarchical Underwater Superoleophobic Surface with Reversible pH Response

The development of oil-repellent surfaces in liquid environments has received considerable attention because of the urgent demand for antifouling coatings in marine industry. Inspired by the unique nanostructure surface of filefish scale, hierarchical films that consist of poly(pentafluorophenyl acrylate) free standing micropillars grafted with pH responsive poly(methacrylic acid) nanobrushes are fabricated by anodic aluminum oxide templating method combined with a subsequent post-polymerization modification strategy. The obtained films exhibit constantly underwater superoleophobicity, furthermore,
a pH sensitive functionality, which enables reversible switching between low and high oil adhesion as a result of the adjustable oil sliding angle. This particular study provides a very mild method for the facile fabrication of bioinspired nanostructures with excellent oil-repellent performance and switchable oil-adhesion properties, thus paving the way toward novel functional materials with smart structures for promising applications, such as smart microfluidics, controllable bioadhesion, and intelligent materials for oil removal treatment and marine antifouling.