Controllable wettability by tailoring one-dimensional tellurium micro-nanostructures

Controllable wettability is significant for fundamental research and practical applications such as smart and fluid-controllable devices, cell proliferation and inkjet printing. In this work, four one-dimensional Te micro-nanostructures have been fabricated by one-step physical vapor deposition method on the surface of the widely used engineering material FeCoCr alloy. The top morphology and framework of the one-dimensional Te micro-nanostructures can be precisely controlled by the source and deposition temperature, which enables us to design the desired wettability of a solid surface. The wettability of the FeCoCr alloy surface dramatically changes from the near-superhydrophilicity of a Te microscale triangle array to the complete superhydrophobicity of a random-oriented Te nanoscale needle array. Significantly, a complete non-stick superhydrophobic surface with a contact angle of 171 degrees is achieved, for the first time, by adjusting the framework of Te micro-nanostructures from needle microrod arrays to random-oriented needle nanowire networks, which form a special three dimensional (3D) nanoporous network structure. The controllable wettability is suggested to arise from the synergy between the roughness and the framework of Te micro-nanostructures. Our finding not only opens an avenue for the application of Te micro-nanostructures but also paves a way towards the design for controlling the wettability of one-dimensional micro-nanostructure arrays.