scholarly journals A General Strategy towards Superhydrophobic Self-Cleaning and Anti-Corrosion Metallic Surfaces: An Example with Aluminum Alloy

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 788
Author(s):  
Shunli Zheng ◽  
Cheng Li ◽  
Yupeng Zhang ◽  
Tengfei Xiang ◽  
Ying Cao ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Hierarchical Structures ◽  
Corrosion Current ◽  
Al Alloy ◽  
General Strategy ◽  
Sliding Angle ◽  
Water Contact ◽  
Metallic Structures ◽  
Humid Condition ◽  
Self Cleaning

Corrosion and contamination of metallic structures can cause loss of their functionality as well as aesthetic values. In this study, we describe a general strategy to prepare superhydrophobic self-cleaning and anti-corrosion surfaces for metallic structures. As a specific example, a superhydrophobic coating (SHC) on aluminum alloy was prepared by a simple etching combined with the decoration of a low-surface-energy material. The optimal SHC has a water contact angle (CA) at ~157.4° and a sliding angle (SA) of ~8.3° due to the synergy of binary hierarchical structures and chemical modification. The SHC showed low adhesion to dry contaminants and a series of liquids, displaying a good self-cleaning effect. The SHC maintained superhydrophobicity after exposure to air and humid condition at 60 °C for 7 days. In addition, the electrochemical measurements reveal that the anti-corrosion performance was enhanced by reducing the corrosion current density (Jcorr) by 1 order of magnitude and increasing the corrosion potential (Ecorr) by 0.527 V as compared to the bare Al alloy substrate after immersion for 168 h.

scholarly journals Fabrication of Self-Cleaning Superhydrophobic Surfaces with Improved Corrosion Resistance on 6061 Aluminum Alloys

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 159 ◽  
Author(s):  
Xiaojuan Dong ◽  
Jianbing Meng ◽  
Yizhong Hu ◽  
Xiuting Wei ◽  
Xiaosheng Luan ◽  
...  
Keyword(s):  
Contact Angle ◽  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Superhydrophobic Surface ◽  
Al Alloy ◽  
Alloy Sample ◽  
Sliding Angle ◽  
Water Contact ◽  
Self Cleaning

Aluminum alloys are widely used, but they are prone to contamination or damage under harsh working environments. In this paper, a self-cleaning superhydrophobic aluminum alloy surface with good corrosion resistance was successfully fabricated via the combination of sand peening and electrochemical oxidation, and it was subsequently covered with a fluoroalkylsilane (FAS) film. The surface morphology, surface wettability, and corrosion resistance were investigated using a scanning electron microscope (SEM), an optical contact angle measurement, and an electrochemical workstation. The results show that binary rough structures and an FAS film with a low surface energy on the Al alloy surfaces confer good superhydrophobicity with a water contact angle of 167.5 ± 1.1° and a sliding angle of 2.5 ± 0.7°. Meanwhile, the potentiodynamic polarization curve shows that the corrosion potential has a positively shifted trend, and the corrosion current density decreases by three orders of magnitude compared with that of the original aluminum alloy sample. In addition, the chemical stability of the as-prepared superhydrophobic surface was evaluated by dripping test using solutions with different pH values for different immersion time. It indicates that the superhydrophobic surface could provide long-term corrosion protection for aluminum alloys. Consequently, the as-prepared superhydrophobic surface has excellent contamination resistance and self-cleaning efficacy, which are important for practical applications.

scholarly journals Superhydrophobic Self-Assembled Silane Monolayers on Hierarchical 6082 Aluminum Alloy for Anti-Corrosion Applications

2020 ◽  
Vol 10 (8) ◽  
pp. 2656 ◽  
Author(s):  
Amani Khaskhoussi ◽  
Luigi Calabrese ◽  
Edoardo Proverbio
Keyword(s):  
Aluminum Alloy ◽  
Surface Energy ◽  
High Water ◽  
Dip Coating ◽  
Aluminum Surface ◽  
Sliding Angle ◽  
Water Contact ◽  
Electrochemical Tests ◽  
Self Assembled ◽  
6082 Aluminum Alloy

In this work, a two-stage methodology to design super-hydrophobic surfaces was proposed. The first step consists of creating a rough nano/micro-structure and the second step consists of reducing the surface energy using octadecyltrimethoxysilane. The surface roughening was realized by three different short-term pretreatments: (i) Boiling water, (ii) HNO3/HCl etching, or (iii) HF/HCl etching. Then, the surface energy was reduced by dip-coating in diluted solution of octadecyltrimethoxysilane to allow the formation of self-assembled silane monolayers on a 6082-T6 aluminum alloy surface. Super-hydrophobic aluminum surfaces were investigated by SEM-EDS, FTIR, profilometry, and contact and sliding angles measurements. The resulting surface morphologies by the three approaches were structured by a dual hierarchical nano/micro-roughness. The surface wettability varied with the applied roughening pretreatment. In particular, an extremely high water contact angle (around 180°) and low sliding angle (0°) were evidenced for the HF/HCl-etched silanized surface. The results of electrochemical tests demonstrate a remarkable enhancement of the aluminum alloy corrosion resistance through the proposed superhydrophobic surface modifications. Thus, the obtained results evidenced that the anti-wetting behavior of the aluminum surface can be optimized by coupling an appropriate roughening pretreatment with a self-assembled silane monolayer deposition (to reduce surface energy) for anticorrosion application.

scholarly journals Bio-Inspired Fluorine-Free Self-Cleaning Polymer Coatings

Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 436 ◽  
Author(s):  
Lionel Wasser ◽  
Sara Dalle Vacche ◽  
Feyza Karasu ◽  
Luca Müller ◽  
Micaela Castellino ◽  
...  
Keyword(s):  
Self Assembly ◽  
Polymer Coatings ◽  
Sliding Angle ◽  
Water Contact ◽  
Uv Curable ◽  
Molecular Weights ◽  
Air Interface ◽  
Creep Time ◽  
Self Cleaning ◽  
Printing Processes

Bio-inspired fluorine-free and self-cleaning polymer coatings were developed using a combination of self-assembly and UV-printing processes. Nasturtium and lotus leaves were selected as natural template surfaces. A UV-curable acrylate oligomer and three acrylated siloxane comonomers with different molecular weights were used. The spontaneous migration of the comonomers towards the polymer–air interface was found to be faster for comonomers with higher molecular weight, and enabled to create hydrophobic surfaces with a water contact angle (WCA) of 105°. The replication fidelity was limited for the nasturtium surface, due to a lack of replication of the sub-micron features. It was accurate for the lotus leaf surface whose hierarchical texture, comprising micropapillae and sub-micron crystalloids, was well reproduced in the acrylate/comonomer material. The WCA of synthetic replica of lotus increased from 144° to 152° with increasing creep time under pressure to 5 min prior to polymerization. In spite of a water sliding angle above 10°, the synthetic lotus surface was self-cleaning with water droplets when contaminated with hydrophobic pepper particles, provided that the droplets had some kinetic energy.

Fabrication of Superhydrophobic Surfaces on Aluminum Alloy by Simple Chemical Etching Method

2011 ◽  
Vol 239-242 ◽  
pp. 2270-2273 ◽  
Author(s):  
Yong Feng Luo ◽  
Hai Yan Lang ◽  
Jin Liang ◽  
Guo Sheng Peng ◽  
You Hua Fan ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Chemical Etching ◽  
Optical Methods ◽  
Hydrophobic Surfaces ◽  
Sliding Angle ◽  
Water Contact ◽  
Binary Structure ◽  
Etching Method ◽  
Simple Chemical ◽  
Scanning Electron

A facial chemical etching method was developed for fabricating stable super-hydrophobic surfaces on aluminum alloy foils. The microstructure and wettability of super-hydrophobic surfaces were characterized by scanning electron microscopy, water contact angle (CA) measurement, and optical methods. The surfaces of the modified aluminum alloy substrates exhibit superhydrophobicity, with a CA of 164.8°±1.6° and a water sliding angle of about 5°. The etched surfaces have binary structure consisting of the irregular microscale plateaus and caves in which there are the nanoscale block-like convexes and hollows.

scholarly journals A Durable and Self-Cleaning Superhydrophobic Surface Prepared by Precipitating Flower-Like Crystals on a Glass-Ceramic Surface

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1642
Author(s):  
Haiqing Fu ◽  
Shuo Liu ◽  
Lanlin Yi ◽  
Hong Jiang ◽  
Changjiu Li ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Superhydrophobic Surface ◽  
Three Dimensional ◽  
Strong Acid ◽  
Ceramic Surface ◽  
Sliding Angle ◽  
Water Contact ◽  
Prepared Glass ◽  
Self Cleaning ◽  
Dual Scale

Herein, a superhydrophobic surface with superior durability was fabricated on a glass-ceramic surface by crystallization, hydrofluoric acid (HF) etching, and surface grafting. The as-prepared glass-ceramic surface was composed of three-dimensional flower-like micro-clusters, which were self-assembled from numerous nanosheets. Such a dual-scale rough surface exhibited superhydrophobicity, with a water contact angle (WCA) of 170.3° ± 0.1° and a sliding angle (SA) of ~2° after grafting with 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane (FAS-17). This can be attributed to the synergistic effect between the dual-scale structure and surface chemistry. Furthermore, this surface exhibited excellent self-cleaning properties, stability against strong acid and strong alkali corrosion, and anti-stripping properties.

scholarly journals Facile approach to develop anti-corrosive superhydrophobic aluminium with high mechanical, chemical and thermal durability

2018 ◽  
Vol 377 (2138) ◽  
pp. 20180272 ◽  
Author(s):  
Balraj Krishnan Tudu ◽  
Aditya Kumar ◽  
Bharat Bhushan
Keyword(s):  
Tilt Angle ◽  
Corrosion Current ◽  
Industrial Applications ◽  
Corrosion Properties ◽  
Water Contact ◽  
Droplet Dynamics ◽  
Electrochemical Tests ◽  
High Corrosion ◽  
Self Cleaning ◽  
Coated Surfaces

Durable, superhydrophobic and self-cleaning aluminium surfaces with high corrosion resistance are desirable in many industrial applications. In this study, a facile approach is used to produce aluminium surfaces with superhydrophobicity with a low tilt angle by creating desired roughness structure by immersing in NaOH solution followed by lowering the surface energy by immersing in hexadecyltrimethoxysilane solution. The coated samples show water contact angle of 164 ± 7° and tilt angle of 5 ± 1°. Droplet dynamics of the coated surfaces was investigated. Surfaces exhibited self-cleaning properties. In addition, mechanical, chemical and thermal stability tests were performed. Electrochemical tests of coated surfaces demonstrated anti-corrosion properties with low corrosion current density and high corrosion potential. This article is part of the theme issue ‘Bioinspired materials and surfaces for green science and technology’.

scholarly journals Phragmites Communis Leaves with Anisotropy, Superhydrophobicity and Self-Cleaning Effect and Biomimetic Polydimethylsiloxane (PDMS) Replicas

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 541 ◽  
Author(s):  
Huiying Guan ◽  
Xiaoming Feng ◽  
Junqiu Zhang ◽  
Shichao Niu ◽  
Zhiwu Han
Keyword(s):  
Enhancement Effect ◽  
Phragmites Communis ◽  
Sliding Angle ◽  
Water Contact ◽  
Ridge Structure ◽  
Cassie State ◽  
Key Factor ◽  
Fluidic Control ◽  
Self Cleaning ◽  
Non Destructive

Phragmites communis leaf (PCL) is anisotropic, superhydrophobic and shows a self-cleaning effect. The water contact angle (WCA) values along the vertical and parallel vein directions on PCL are 153° ± 2° and 148° ± 2°, respectively. In contrast, the water sliding angle (WSA) values along the vertical and parallel vein directions for PCL are 12° ± 2° and 7° ± 2°, respectively. The epidermal wax makes the leaves intrinsically hydrophobic. The microstructure of the PCL surface shows sub-millimetre-, micron- and nanometre-scale structures. The sub-millimetre ridge structure is the main reason for the anisotropy of the leaves. The micron-scale papillae structure has a strong hydrophobic enhancement effect, and the nanoscale sheet structure is the key factor in achieving a stable Cassie state, as well as superhydrophobicity and self-cleaning activities. PCL-like polydimethylsiloxane (PDMS) samples fabricated by template transfer technology exhibited the sub-millimetre ridge structure and micron-scale papillae from the natural PCL; they also show obvious anisotropy and strong hydrophobicity and have a certain self-cleaning effect. The WCA and WSA values along the vertical and parallel vein directions on PCL are 146° ± 2°, 23° ± 2°, 142° ± 2° and 19° ± 2°, respectively. The preparation of a biomimetic PCL surface has broad application prospects in micro-fluidic control and the non-destructive transmission of liquids.

Study on corrosion resistance of superhydrophobic surface on aluminum alloy

2021 ◽  
Vol 11 (12) ◽  
pp. 2004-2009
Author(s):  
Ruomei Wu ◽  
Shuai Wu ◽  
Haiyun Jiang ◽  
Zigong Chang ◽  
Zhiqing Yuan ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Corrosion Potential ◽  
Polypropylene Film ◽  
Sliding Angle ◽  
Water Contact ◽  
Nano Structure ◽  
Anode Oxidation ◽  
The Relationship ◽  
Aluminum Alloy Surface

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.

Study on self-cleaning performance and hydrophobicity of TiO2/silane coatings

2018 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
A. Syafiq ◽  
A.K. Pandey ◽  
Vengadaesvaran Balakrishnan ◽  
Nasrudin Abd Rahim
Keyword(s):  
Glass Substrate ◽  
Substrate Surface ◽  
Phase Interface ◽  
Dip Coating ◽  
Vacuum Furnace ◽  
Coating Film ◽  
Sliding Angle ◽  
Water Contact ◽  
Content Type ◽  
Self Cleaning

PurposeThe paper aims to investigate the effect of Degussa P-25 Titanium Dioxide (TiO2) nanoparticles on hydrophobicity and self-cleaning ability as a single organic coating on glass substrate.Design/methodology/approachTwo methods have been used to enhance the hydrophobicity on glass substrates, namely, surface modification by using low surface energy isooctyltrimethoxysilane (ITMS) solution and construction of rough surface morphology using Degussa P-25 TiO2nanoparticles with simple bottom-up approach. The prepared sol was applied onto glass substrate using dip-coating technique and stoved in the vacuum furnace 350°C.FindingsThe ITMS coating with nano TiO2pigment has modified the glass substrate surface by achieving the water contact angle as high as 169° ± 2° and low sliding angle of 0° with simple and low-cost operation. The solid and air phase interface has created excellent anti-dirt and self-cleaning properties against dilute ketchup solution, mud and silicon powder.Research limitations/implicationsFindings will be useful in the development of self-cleaning and anti-dirt coating for photovoltaic panels.Practical implicationsSol method provides the suitable medium for the combination of organic–inorganic network to achieve high superhydrophobicity and optimum self-cleaning ability.Originality/valueApplication of blended organic–inorganic sol as self-cleaning and anti-dirt coating film.

Fabrication of a Superhydrophobic Aluminum Alloy Surface by Phosphoric Acid-Dichromate Method

2013 ◽  
Vol 312 ◽  
pp. 350-353
Author(s):  
Ruo Mei Wu ◽  
Guang Hua Chao ◽  
Hai Yun Jiang
Keyword(s):  
Aluminum Alloy ◽  
Phosphoric Acid ◽  
Superhydrophobic Surface ◽  
Preparation Method ◽  
Sliding Angle ◽  
Water Contact ◽  
Static Water Contact Angle ◽  
Static Water ◽  
Acid Coating ◽  
Aluminum Alloy Surface

The preparation method of the superhydrophobic surface on aluminum alloys was investigated, the method is novel by phosphoric acid-dichromate process and stearic acid coating, superhydrophobic aluminum alloy surfaces were successful prepared, the maximum static water contact angle and sliding angle on the superhydrophobic surface was 151±1.8° and 10°, respectively. In this work, the microstructure and self-cleaning properties of the superhydrophobic surface were studied. The superhydrophobic surface is a factor to reduce device-associated contamination and can be used in metal packaging practice.

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