Fabrication of superhydrophobic iron with anti-corrosion property by ultrasound

The creation of superhydrophobic (SH) surfaces requires a combination of surface roughness and surface free energy reduction. For this purpose, wire-like ZnO particle (with micro scale in length and nano-scale in width) deposition was performed on iron surface by means of an ultrasound approach. After that, stearic acid (STA) ethanol solution was utilized for surface energy reduction. The optimization of various parameters was conducted based on Minitab software and Taguchi design method. After reaching a SH iron with ultrasound at optimized conditions, the corrosion resistance was compared between SH iron resulted by classical method (SH iron (C)) under the same conditions as ultrasound method (SH iron (U)). The potentiodynamic estimates indicated that when ultrasound was employed for particle deposition, the corrosion current (I-c) was 1000 times lower than that for bare iron one. However, using classical method for particle deposition had no dramatic effect on corrosion resistance. Moreover, when ultrasound was used for particle deposition, the stability of the resulted SH iron versus immersion in NaCl solution (3.5%) was higher compared to SH iron acquired by classical technique. Finally, different characterization methods were used for further study. For example, scanning electron micrograph (SEM) was carried out for topographical investigation of the surfaces obtained. Other techniques such as attenuated total reflection in combination with Fourier transform infrared (ATR-FTIR) and energy-dispersive X-ray spectroscopy (EDX) verified ZnO particle deposition. Moreover, for verification of STA grafting on SH iron, EDX analysis was helpful. (C) 2016 Elsevier B.V. All rights reserved.