Functional interface based on silicon artificial chamfer nanocylinder arrays (CNCAs) with underwater superoleophobicity and anisotropic properties

Abstract

A functional interface based on silicon chamfer nanocylinder arrays (CNCAs) was successfully fabricated by carrying out secondary etching of silicon nanopillar arrays via a facile inclined etching method. The structure of the novel CNCAs was finely modulated by varying the nanopillar array structure and the etching conditions. The underwater oil wetting behavior of this CNCAs-based interface can be easily modulated from superoleophilic (oil contact angle (OCA) of ~8.13°) state to superoleophobic (OCA of ~163.79°) state by modifying the surface using different substances. Moreover, a reversible transformation of underwater oil wetting behavior from superoleophobic (OCA of ~155.67°) state to oleophilic (OCA of ~31.27°) state was achieved by grafting a temperature-responsive polymer onto this specific asymmetric structure. The functional interface exhibited isotropic wetting behavior under certain oleophilic conditions. Chemically heterogeneous structures, obtained via asymmetry modification of CNCAs, exhibited amphiphobic properties while maintaining their anisotropic wetting ability.