Superhydrophobic Film on Hot-Dip Galvanized Steel with Corrosion Resistance and Self-Cleaning Properties

Abstract

Super-hydrophobic film with hierarchical micro/nano structures was prepared by galvanic replacement reaction process on the surface of galvanized steel. The effects of the etching time and copper nitrate concentration on the wetting property of the as-prepared surfaces were studied. Scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and electrochemical technique were employed to characterize the surface morphology, chemical composition, and corrosion resistance. The stability and self-cleaning property of the as-fabricated super-hydrophobic film were also evaluated. The super-hydrophobic film can be obtained within 3 min and possesses a water contact angle of 164.3° ± 2°. Potentiodynamic polarization measurements indicated that the super-hydrophobic film greatly improved the corrosion resistance of the galvanized steel in 3.5 wt % NaCl aqueous solution. The highest inhibition efficiency was estimated to be 96.6%. The obtained super-hydrophobic film showed good stability and self-cleaning property.

Improving the Processability of a One-Step Hydrophobic Coating for Hot-Dipped Galvanised Steel for Industrial Applications

“…SiO2 can also be seen in the XRD pattern, showcasing that SiO2 has been encapsulated within the coating by physical action and not changing physical composition. The notable peak, which is observed in the uncoated sample and not the coated sample is that of zinc carbonate hydroxide and zinc hydroxide [6,13,[39][40][41]. This is created via the mechanisms: FTIR analysis was completed alongside XRD to corroborate the observation of carbonate ((CO3) 2− ) bonds within the uncoated sample, this data is presented in Figure 15.…”

“…When comparing this methodology to other one-step processes by Li et al, we observed that, despite a longer processing time, the use of more commercially available, economically viable and safer constituents within the formulation justifies its development. The methodology displays significantly reduced health and safety risks and avoids the use of toxic chemical nitrates [6,26]. In comparison to Laing et al, the processing times were reduced by 67%, and the use of chemical additions, such as fumed silica, provided a vastly cheaper and safer alternative to nano-silica [13].…”

“…There has been growing interest in the use of hydrophobic coatings (HCs) to improve corrosion resistance of metallic substrates and to provide functionality, such as self-cleaning [4][5][6][7][8][9]. These coatings are inspired by the natural surface of lotus leaves, which have nano-structured surfaces coated with low-surface-energy materials that provide an interface between the coating and liquid [10].…”

“…These coatings are inspired by the natural surface of lotus leaves, which have nano-structured surfaces coated with low-surface-energy materials that provide an interface between the coating and liquid [10]. The interface is created by retaining air within the nano-scale topography of the surface, which reduces the contact area of water droplets, producing a highly non-wetting, low adherence surface [6,7,11]. A superhydrophobic surface (SHS) refers to a surface with a contact angle of more than 150° [8,12,13].…”

Morphology and corrosion behavior of ZnO passive films for galvanized steel applications: effects of anodizing parameters

“…This ZnO film formation with hexagonal nano-flake structures took about 72 h, needing improvements for purposes of economy. C Li et al (2018) [25] also prepared corrosion-resistant superhydrophobic film on galvanized steel by a galvanic replacement process. Nevertheless, most artificially fabricated superhydrophobic surfaces modified with organic chemicals can be easily damaged in normal service due to poor adhesion and stability.…”