Seawater-Induced Healable Underwater Superoleophobic Antifouling Coatings

Creating an artificial surface, mimicking a live fish scale that repels oil underwater and with self-healing properties, would be significant for the development of nontoxic marine antifouling coatings. Here, we report a seawater-induced strategy to create in situ an underwater superoleophobic surface, starting from the coatings of a self-polishing polymer and seawater-responsive polymer-grafted SiO₂ nanoparticles. The coatings' surfaces were able to renew in artificial seawater through the hydrolysis of the superficial self-polishing polymer and its subsequent dissolution. Particularly, the grafted poly(triisopropylsilyl acrylate- co-3-methacryloxypropyltrimethoxysilane) chains could transform into hydrophilic ones via seawater-induced hydrolysis, which additionally strengthened the oil-repellency (zero oil adhesive force) and endowed the surface with excellent antiprotein adsorption characteristics. Because the hydrolysis was limited to the superficial layer of the coatings, it could avoid the water-swelling that instead occurs with conventional underwater superoleophobic coatings, with significant benefits to its durability. We believe that the seawater-induced renewal of underwater superoleophobic surfaces will be useful in extreme marine environments.