Stable Superhydrophobic Porous Coatings from Hybrid ABC Triblock Copolymers and Their Anticorrosive Performance

Superhydrophobic porous surfaces with ultralow water adhesion were successfully fabricated via micelle fusion aggregation assembly of newly designed linear hybrid ABC triblock copolymers, where A, B, and C denote poly(dimethylsiloxane) (PDMS), polystyrene (PS), and poly(methacrylolsobutyl polyhedral oligomeric silsesquioxane) (PiBuPOSSMA), respectively. It was found that aggregation behavior in diluted solution and subsequent formation of nano-/ microscale hierarchical surfaces in condensed state were affected by the molar mass of the triblock copolymers, which were evidenced by dynamic light scattering (DLS), SEM, and TEM studies. Increasing of PiBuPOSSMA content can significantly increase roughness of the resulting coatings, leading to an increase of apparent water contact angles from 145.7 +/- 1 degrees to 157.3 +/- 1.1 degrees. The optimized PDMS PS PiBuPOSSMA surface possesses unique nano/microscale hierarchical morphology, large apparent water contact angle (157.3 +/- 1.1 degrees), small roll-off angle (similar to 3 degrees), low contact angle hysteresis (similar to 0.9 degrees), long-term stability, and good chemical and thermal resistance. Moreover, it exhibits superior performance in preventing corrosive species such as ions and water in contact with the underlying metallic substrate (stainless steel) in 3.5 wt % NaCl aqueous solution with high inhibition efficiency and long-term preservability, which could be attributed to the synergistic effect of superhydrophobic surface and capillary action arising from the underlying porous structure.