title: Effects of system parameters on making aluminum alloy lotus.
abstract: In the present article, stable biomimetic superhydrophobic surfaces on aluminum alloy are obtained by wet chemical etching following modification with crosslinked silicone elastomer, perfluorononane (C9F20), and perfluoropolyether (PFPE), respectively. The formation and structure of superhydrophobic surfaces were characterized by means of scanning electron microscopy (SEM), water contact angle measurement, Fourier transform infrared spectroscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The effects of surface roughness resulted from the etching time, and the concentration of NaOH aqueous solution on the superhydrophobicity of the surfaces have been discussed in detail. The optimal surface roughness of starting material is about 0.05-0.5 microm and the resulting surface roughness should be controlled between 2.7 and 5.8 microm in order to realize the superhydrophobicity on aluminum alloy; if the concentration of NaOH aqueous solution is about 4 wt%, the best treatment time is between 2 and 4 h to form a surface roughness changing from 2.7 to 5.8 microm. The trapped air with the binary structure plays a key role in fabricating superhydrophobic surface on aluminum alloy. In other words, the unusual structure on the surface, which has a binary structure consisted of microprotrusions and nanoparticles, plays a very vital role in constructing of the stable biomimetic superhydrophobic surface on aluminum alloy.
authors.affiliation: State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China.
authors.forename: Zhiguang
authors.initials: Z
authors.lastname: Guo
authors.forename: Feng
authors.initials: F
authors.lastname: Zhou
authors.forename: Jingcheng
authors.initials: J
authors.lastname: Hao
authors.forename: Weimin
authors.initials: W
authors.lastname: Liu