Mechanically robust superhydrophobic copper surface with self-cleaning, anti-icing, and corrosion resistance

This paper uses a new method combining nanosecond laser processing technology and sol-gel to design and manufacture mechanically robust micro-nano structure and modified SiO2@PDMS coating on copper substrate. The superhydrophobic composite surface was successfully synthesized with a water contact angle of 159.5 degrees and a sliding angle of 0.5 degrees. The characterization of the prepared superhydrophobic surface #3 (laser-textur-ed@SiO2@PDMS protective layer) was studied by optical profilometry, scanning electron microscopy, FT-IR spectroscopy, and X-ray photoelectron spectroscopy. The composite structure of micron/nano and organic/ inorganic 3D interwoven network can be observed to improve the hydrophobic, wear-resistant, and compressive properties of the substrate surface. FT-IR spectra fully indicate the presence of PDMS and -Si (CH3) grafted onto SiO2 particles on the copper surface, and the presence of Si-O and Si-C detected by XPS fully proves the FT-IR results. In addition, self-cleaning, wear resistance, anti-icing, corrosion resistance, and NaCl deliquescence behavior were evaluated. The results show that surface #3 can efficiently remove contaminants within 200 s. In the anti-icing experiment, the delayed icing time and ice adhesion strength of surface #3 are 3.33 times and 1.99 % of that of the ordinary copper surface, respectively, which can make the icicle slide easily. In the electro-chemical test, the corrosion current density decreased by an order of magnitude, and the corrosion inhibition efficiency reached 90.57 %. Based on its excellent self-cleaning, mechanical robustness, anti-icing, and anti-corrosion properties, we believe that the composite modified surface of the laser-textured@SiO2@PDMS pro-tective layer designed and manufactured in this study is expected to be used in engineering fields such as refrigeration heat exchangers.