Rapid reversible superhydrophobicity-to-superhydrophilicity transition on alternating current etched brass.

Reversible surface wetting behavior is a hot topic of research because of the potential engineering applications. In the present work, a hierarchical micro/nanostructure is fabricated on brass by alternate current (AC) etching. The superhydrophilic as-prepared etched brass (EB) turns into superhydrophobic after the modification of stearic acid for 1 min. After annealing at 350 °C for 5 min, the superhydrophobic modified EB surface becomes superhydrophilic again. Furthermore, the annealed EB can restore the superhydrophobicity with the remodification of stearic acid. The wetting transition is realized by stearic acid modification and annealing rapidly in 6 min. The wetting transition mechanism is discussed based on the surface chemical analysis. This method is facile and suitable for the construction of large-scale and complex brass surfaces with tunable wetting behaviors.