Realization of laser textured brass surface via temperature tuning for surface wettability transition

Superhydrophobic surfaces have attracted extensive interests and researches into their fundamentals and potential applications. Laser texturing provides the convenience to fabricate the hierarchical micro/nanostructures for superhydrophobicity. However, after laser texturing, long wettability transition time from superhydrophilicity to superhydrophobicity is a barrier to mass production and practical industrial applications. External stimuli have been applied to change the surface composition and/or the surface morphology to reduce wettability transition time. Herein, by temperature tuning, wettability transition of laser textured brass surfaces is investigated. Scanning electron microscopy and surface contact angle measurement are employed to characterize the surface morphology and wettability behavior of the textured brass surfaces. By low-temperature heating (100 ℃~150 ℃), partial deoxidation of the top CuO layer occurs to form hydrophobic Cu2O. Therefore, superhydrophobicity without any chemical coating and surface modification could be achieved in a short time. Furthermore, after low-temperature heating, the low adhesive force between the water droplet and the sample surface is demonstrated for the laser textured brass surface. This study provides a simple method to fabricate the micro/nanostructure surfaces with controllable wettability for the potential applications.