Corrosion Resistance Of Superhydrophobic Surface Research Articles

Biomimetic liquid infused surface based on nano-porous array: Corrosion resistance for tin metal and self-healing property

Tin material corrosion has been recognized as an important problem for electronic products. Biomimetics strategies have been adopted to develop intriguing materials to combat corrosion. In this paper, by anodic oxidation, mussel inspired dopamine hydrochloride modification and thiol grafting, lotus leaf inspired superhydrophobic surface (SHS) based on porous SnO2 coating is prepared on tin. Further, a stable liquid infused surface (LIS) enlightened by Nepenthes plant is formed by infusing dimethyl silicone oil into SHS. The wettability, microstructure and chemical composition of tin surface with different modification are characterized by contact angle, scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and so forth. The porous SnO2 structure endows superhydrophobicity with a contact angle up to 155.9°. The corrosion resistance of SHS and LIS coating is revealed by scanning Kelvin probe (SKP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) curves. Corrosion data show that the prepared LIS exhibits better corrosion resistance than SHS. After being soaked in a representative 3.5 wt% NaCl solution for 180 h, the corrosion inhibition efficiency of LIS maintains 99.6%, which is much better than that of SHS. In addition, when being fold or bent to induce cracks, the LIS shows slight change in corrosion inhibition efficiency, indicating the high tolerance to mechanical torsion. Moreover, in response to externally imposed mechanical scratching, LIS demonstrates good self-healing capability, illustrating the high potential for practical usage.

Preparation of super-hydrophobic surface with micro-nano layered structure on 316 stainless steel by one-step wet chemical method

In order to simplify the traditional preparation procedure of super-hydrophobic stainless steel (SLS), a novel one-step method was developed to produce super-hydrophobic surface on 316 SLS under the simultaneous chemical etching and surface modification with cofunction of hydrogen peroxide (H2O2), hydrofluoric acid (HF) and perfluorooctyl trichlorosilane (PFOS). The effects of the mixing ratio of reagents (H2O2, HF and PFOS) and reaction time were explored by orthogonal experiments. The results indicated that H2O2 showed the most significant effect on the hydrophobicity of SLS. When the molar ratio of H2O2/HF ranged between 0.2/1–0.4/1, the prepared samples showed excellent super-hydrophobicity, with the maximum water contact angle of 161.78° and the minimum slip angle of 1.94°. The influencing mechanism of H2O2 on the etching and modification was further explored by X-ray photoelectron spectroscopy (XPS) and Scanning electron microscopy (SEM). The results showed that the ratio of H2O2/HF markedly affected the grafting of PFOS onto the surface of SLS. According to the tests of corrosion resistance and durability, the corrosion resistance of super-hydrophobic surface was 6 times higher than that of raw SLS, and the super-hydrophobicity of SLS hardly changed after 3 months of exposure in the ambient air. The water contact angle was still close to 150° after peeling adhesive tape for 12 times. The results of this study indicated a promising perspective for industrial application of the one-step method.

How surface orientation affects coalescence-induced droplet jumping behavior and subsequent atmospheric corrosion resistance of a superhydrophobic surface?

In this study, the effect of the surface orientation on the coalescence-induced droplet jumping behavior (CIDJB) and the subsequent atmospheric corrosion resistance of the knife-like structure CuO superhydrophobic surface were studied. And the corresponding atmospheric corrosion protection mechanism on the basis of the CIDJB was revealed. The results indicate that the horizontally oriented superhydrophobic surface exhibits a bigger droplet size distribution and surface coverage during the condensation process because of the droplets falling back to the surface. And compared with the vertically oriented superhydrophobic surface, the horizontally oriented superhydrophobic surface exhibits a better corrosion resistance after condensation.

Study on corrosion resistance of superhydrophobic surface on aluminum alloy

Anti-corrosion of aluminum alloys with different roughness were researched in this study. To further verify the relationship between anti-corrosion and surface roughness, surface with micro structure alloy was successfully fabricated via anode oxidation on aluminum. The water contact angle of aluminum alloy surface after coating polypropylene film was 154° and sliding angle was 3°. The micro-nano structure was constructed by adding nano-SiO2. The contacts angle of surface was 165° and the sliding angle was 1.8°. The superhydrophobic samples were used to test corrosion resistance. Compared with aluminum coated with unmodified film, the corrosion potential for modified superhydrophobic aluminum alloy increased by about 0.05 V. When nano-SiO2 particles were added, the corrosion resistance for the sample was also improved.

Fabrication of Superhydrophobic Ni-Co-BN Nanocomposite Coatings by Two-Step Jet Electrodeposition

The stability of hydrophobic surface has an important influence on the application of superhydrophobic function. The destruction of hydrophobic micro-nano structures on the material surface is the main factor leading to the loss of superhydrophobic property. In order to improve the corrosion resistance of superhydrophobic surface, Ni-Co-BN nanocomposite coatings with superhydrophobic property were prepared on 45 steel by two-step jet electrodeposition. The surface morphology, water contact angle, and corrosion resistance of the samples were measured and characterized by scanning electron microscope, surface contact angle measuring instrument, and electrochemical workstation. The results of electrochemical analysis show that the superhydrophobic property improved the corrosion resistance of Ni-Co-BN nanocomposite coating. The enhanced corrosion resistance is of great significance to the integrity of the microstructure and the durability of the superhydrophobic function.

Corrosion resistance and mechanism of micro-nano structure super-hydrophobic surface prepared by laser etching combined with coating process

Purpose The purpose of this paper is to evaluate the effect of micro-nano mixed super-hydrophobic structure on corrosion resistance and mechanism of magnesium alloys. Design/methodology/approach A super-hydrophobic surface was fabricated on AZ91 and WE43 magnesium alloys by laser etching and micro-arc oxidation (MAO) with SiO2 nanoparticles coating and low surface energy material modification. The corrosion resistance properties of the prepared super-hydrophobic surfaces were studied based on polarization curves and immersion tests. Findings Compared with bare substrates, the corrosion resistance of super-hydrophobic surfaces was improved significantly. The corrosion resistance of super-hydrophobic surface is related to micro-nano composite structure, static contact angle and pretreatment method. The more uniform the microstructure and the larger the static contact angle, the better the corrosion resistance of the super-hydrophobic surface. The corrosion resistance of super-hydrophobic by MAO is better than that of laser machining. Corrosion of super-hydrophobic surface can be divided into air valley action, physical shielding, pretreatment layer action and substrate corrosion. Originality/value The super-hydrophobic coatings can reduce the contact of matrix with water so that a super-hydrophobic coating would be an effective way for magnesium alloy anti-corrosion. Therefore, the corrosion resistance properties and mechanism of the prepared super-hydrophobic magnesium alloys were investigated in detail.

Corrosion resistance controllable of biomimetic superhydrophobic microstructured magnesium alloy by controlled adhesion

Super-hydrophobic surfaces have attracted a lot of interest in basic research and application. In this paper, periodic micro-structures of micro-scale papillary-like pits with a different center distance were fabricated on Mg-3Al-1Zn (AZ31) magnesium surface via laser ablation. After being chemical etched by AgNO3 and surface modified with stearic acid, the as-prepared surfaces showed super-hydrophobic properties and the maximum contact angles reached 158.2°. Besides, a conversion from low adhesion to high adhesion was achieved by adjusting the micro-structure of magnesium alloy. The corrosion resistance of super-hydrophobic surfaces in Cassie state (low adhesion) is better than that in Wenzel state (high adhesion). Compared with bare substrates, the corrosion resistance of as-prepared surfaces was improved significantly according to electrochemical measurements. Moreover, the super-hydrophobic surfaces exhibited excellent chemical and thermal stability at a large range of pH solutions and temperatures. This method can be extended to other engineering materials easily and especially would be used in liquid corrosion and changeable corrosion rate according to requirement in industrial field.

Stability and corrosion resistance of superhydrophobic surface on oxidized aluminum in NaCl aqueous solution

Superhydrophobic surface (SHS) was fabricated on aluminum via surface roughening by NaClO and surface passivation by hexadecyltrimethoxysilane. The long-term durability for storing the sample in air and the chemical stability for contacting the sample with NaCl solution were investigated. The short-term corrosion resistance for immersing the sample in NaCl solution for 1h was investigated by potentiodynamic polarization, and the long-term corrosion resistance for immersing the sample in NaCl solution for 7 days was investigated by variation analyses on surface wettability, surface morphology, and surface chemistry. All experimental results suggested that the so-obtained SHS possessed good stability and good corrosion resistance under the testing conditions.

Corrosion behavior of superhydrophobic surfaces of Ti alloys in NaCl solutions

Superhydrophobic surfaces (SHS) are successfully prepared by 1H, 1H, 2H, 2H-perfluorooctyltrichlorosilane (coded as PFOTS) chemically and physically adsorbed onto the etched Ti alloy substrate. The film formation and its structures are characterized by the measurements of water contact angle (WCA), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The corrosion behavior of the SHS in the NaCl solutions is investigated using the potentiodynamic polarization. The results show that the corrosion resistance of the substrate is improved greatly due to the composite wetting states or interfaces with numerous air pockets between SHS and NaCl solutions. Moreover, it is found that the stability and corrosion resistance of SHS is influenced greatly by the interfacial bonding between PFOTS and the substrate. The strong chemical interfacial bonding (i.e., TiOSi) between PFOTS and the oxidized titanium substrate accounts for a higher stability and much lower corrosion current density as compared by SHS with physically adsorbed PFOTS outerlayer.

Corrosion Resistance of Superhydrophobic Surface on Magnesium Alloy Coated with Cerium Oxide Film

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