Fabrication and tribological properties of superhydrophobic nickel films with positive and negative biomimetic microtextures

Nickel (Ni) films with positive and negative textured surfaces of lotus and rice leaf patterns were fabricated through an inexpensive and effective method. The as-prepared Ni films were superhydrophobic and exhibited excellent tribological properties after chemical treatment. Experimental results indicated that the water contact angles (WCAs) on the surfaces of biomimetic textured Ni films (approximately 120°) were far greater than those on smooth films (65°). The biomimetic textured surfaces became superhydrophobic (WCA of approximately 150°) after perfluoropolyether (PFPE) treatment, which could be due to the combined effects of the special texture and the PFPE. The as-prepared biomimetic-textured Ni films modified with PFPE were improved with a low friction coefficient and excellent antiwear properties, which were due to the combination of the effective lubrication of PFPE and the special textures that served as a good lubricant and a debris reservoir. Moreover, the antiwear properties of the as-prepared Ni films with negative biomimetic microtextures modified with PFPE were much better than those of films with positive biomimetic microtextures modified with PFPE.