Rapid formation of superhydrophobic surfaces with fast response wettability transition.

We have developed a facile and time-saving method to prepare superhydrophobic surfaces on copper sheets. Various surface textures composed of Cu(OH)2 nanorod arrays and CuO microflowers/Cu(OH)2 nanorod arrays hierarchical structure were prepared by a simple solution-immersion process. After chemical modification with stearic acid, the wettability of the as-prepared surfaces was changed from superhydrophilicity to superhydrophobicity. The shortest processing time for fabricating a superhydrophobic surface was 1.5 min. Interestingly, the rapid wettability transition between superhydrophobicity and superhydrophilicity can be realized on the prepared surfaces with ease by the alternation of air-plasma treatment and stearic acid coating. It took just 2 min to complete the whole wettability transition. Additionally, the regeneration of the superhydrophobic surface is also considered regarding its application.