Fabrication of a Super-Hydrophobic Micro-Nanoporous Aluminum Surface by Anodic Oxidation

2012 ◽  
Vol 200 ◽  
pp. 190-193 ◽  
Author(s):  
Ruo Mei Wu ◽  
Shu Quan Liang ◽  
Hong Chen ◽  
An Qiang Pan ◽  
Hai Yun Jiang ◽  
...  

A novel and stable super-hydrophobic film was prepared by stearic acid (C18H36O2), which was chemically adsorbed onto the anodized aluminum surface. The maximum static water contact angle (WCA) of the super-hydrophobic surface was 157.5º ± 2.0º and the contact angle hysteresis was less than 3º. The superhydrophobic property is attributed to the micro-nanoporous surface morphology and stearic acid. The pore size on the surface of anodic aluminum oxide is an important factor for controlling the superhydrophobic adhesiveness. The superhydrophobic surface is a factor to reduce device-associated infection and can be used in metal packaging practice.

2012 ◽  
Vol 706-709 ◽  
pp. 2874-2879 ◽  
Author(s):  
R. Jafari ◽  
Masoud Farzaneh

Superhydrophobic surfaces were prepared using a very simple and low-cost method by spray coating. A high static water contact angle of about 154° was obtained by deposition of stearic acid on an aluminium alloy. However, this coating demonstrated a high contact angle hysteresis (~ 30º). On the other hand, superhydrophobic surfaces with a static contact angle of about 162º and 158º, and a low contact angle hysteresis of about 3º and 5º were respectively obtained by incorporating nanoparticles of SiO2and CaCO3in stearic acid. The excellent resulting hydrophobicity is attributed to the synergistic effects of micro/nanoroughness and low surface energy. A study of the wettability of these surfaces at temperatures ranging from 20 to-10 °C showed that the superhydrophobic surface becomes rather hydrophobic at supercooled temperatures.


Micromachines ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 677 ◽  
Author(s):  
Zhengyong Huang ◽  
Wenjie Xu ◽  
Yu Wang ◽  
Haohuan Wang ◽  
Ruiqi Zhang ◽  
...  

In this study, we develop a facial one-step approach to prepare durable super-hydrophobic coatings on glass surfaces. The hydrophobic characteristics, corrosive liquid resistance, and mechanical durability of the super-hydrophobic surface are presented. The as-prepared super-hydrophobic surface exhibits a water contact angle (WCA) of 157.2° and contact angle hysteresis of 2.3°. Mico/nano hierarchical structures and elements of silicon and fluorine is observed on super-hydrophobic surfaces. The adhesion strength and hardness of the surface are determined to be 1st level and 4H, respectively. The coating is, thus, capable of maintaining super-hydrophobic state after sand grinding with a load of 200 g and wear distances of 700 mm. The rough surface retained after severe mechanical abrasion observed by atomic force microscope (AFM) microscopically proves the durable origin of the super-hydrophobic coating. Results demonstrate the feasibility of production of the durable super-hydrophobic coating via enhancing its adhesion strength and surface hardness.


2020 ◽  
Vol 15 (2) ◽  
pp. 264-268
Author(s):  
Hongxing Han ◽  
Lin Pan ◽  
Manying Zhang ◽  
Lei Zhao ◽  
Zhifeng Liu

In this paper, we successfully prepare hydrophobic surface of ZnO/ZnS nanorods arrays modified by stearic acid. The morphology, microstructure, optical transmittance and self-cleaning property are examined by SEM, XRD, UV-vis and water contact angle measurements, respectively. The ZnO/ZnS core/shell nanoarrays shows a higher value of water contact angle in compare with that of pure ZnO nanorods arrays. After treatment by stearic acid, the resulting ZnO/ZnS nanostructure exhibits the best hydrophobicity with water droplets about 146.5 . The results show that the surface hydrophobicity of ZnO/ZnS nanoarrays can be improved by using stearic acid with low-surface-energy.


Author(s):  
Konstantinos Ritos ◽  
Nishanth Dongari ◽  
Yonghao Zhang ◽  
Jason M. Reese

We report molecular dynamics (MD) simulations of the dynamic wetting of nanoscale droplets on moving surfaces. The dynamic water contact angle and contact angle hysteresis are measured as a function of capillary number on smooth silicon and graphite surfaces. The hydrogen bonding and density profile variations are also reported, and the width of the water depletion layer is evaluated for droplets on three different static surfaces: silicon, graphite and a fictitious super-hydrophobic surface. Our results show that molecular displacements at the contact line are mostly influenced by interactions with the solid surface, while the viscous dissipation effects induced through the movement of surfaces are found to be negligible, especially for hydrophobic surfaces. This finding is in contrast with the wetting dynamics of macroscale droplets, which show significant dependence on the capillary number. This study may yield new insight into surface-wettability characteristics of nano droplets, in particular, developing new boundary conditions for continuum solvers for liquid flows in micro- and nanoscale devices.


2018 ◽  
Vol 941 ◽  
pp. 1802-1807 ◽  
Author(s):  
Khosrow Maghsoudi ◽  
Gelareh Momen ◽  
Reza Jafari ◽  
Masoud Farzaneh ◽  
Tony Carreira

A facile method is introduced for production of micro-nanostructured silicone rubber surfaces by means of direct replication using a compression molding system. The fabricated samples possessing surface roughness display water contact angle of more than 160o and contact angle hysteresis (CAH) and sliding angle of less than 5o. Such low surface wettability of silicone specimens verifies the induced superhydrophobic property. Chemically etched aluminum surfaces could work excellently as templates whose patterns were replicated on the rubber surfaces successfully. Various etching conditions were examined. Surface characterization techniques revealed the presence of micro-nanostructures on the produced silicone surfaces.


Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 813
Author(s):  
Hengzheng Li ◽  
Yanjiang Li ◽  
Guangzhen Zhao ◽  
Binhui Zhang ◽  
Guang Zhu

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.


2013 ◽  
Vol 734-737 ◽  
pp. 2519-2522
Author(s):  
Ruo Mei Wu ◽  
Guang Hua Chao ◽  
Hai Yun Jiang ◽  
Hong Chen ◽  
Qi Long Liu

Polypropylene (PP) film was used as coating to improve the hydrophobicity of corrosive aluminum surface. A micro-porous film with compound nanoparticles was obtained on the aluminum alloy substrate using the corrosion method and coated PP. The water contact angle (WCA) of superhydrophobic surface is 157°. The superhydrophobic property is attributed to this special surface morphology and low surface energy PP. Aggregated nanoparticles would help to increase the surface hydrophobicity.


2012 ◽  
Vol 583 ◽  
pp. 346-349 ◽  
Author(s):  
Ruo Mei Wu ◽  
Hai Yun Jiang ◽  
Wen Yong Liu ◽  
Jing Deng ◽  
Zhi Qing Yuan ◽  
...  

We investigated the bacteriostasis of the super-hydrophobic surface on aluminum alloy by PP coating. The morphology of the surface was observed by a scanning electron microscopy. The contact angle (CA) was measured by an optical contact angle meter .Staphylococcus aureus and pathogenic escherichia coli adhesion on superhydrophobic surfaces were also evaluated. The inhibition ring test results show the inhibition of Escherichia coli and Staphylococcus aureus were 79.3% and 81.1%, respectively after 24 hours’ contact at 37oC, while the Quinn test demonstrates the surface possesses high resistance to bacterial contamination. The superhydrophobic surface is a factor to reduce device-associated infection and can be used in metal practice.


2021 ◽  
pp. 009524432110153
Author(s):  
Eroğlu Murat ◽  
Parmak Şam Ebru Devrim

In this research, a stretchable and non-sticky hydrophobic surface is developed using flexible polyurethane-based elastomer Vytaflex 20A. The hierarchical roughness of rose petals was replicated by soft molding method to achieve hydrophobicity. The morphological properties, wettability properties and mechanical properties of replicated micro/nanostructures were characterized. The replicated surface exhibited a similar micro/nanostructure to that of rose petal. Rose petal and replicated surface were highly hydrophobic and their static water contact angles (θ ≈ 124°) are nearly equal. Contact angle hysteresis of the produced surface was measured (10°) to be lower significantly than that of the fresh rose petal (50°). The proposed surface is also highly stretchable having an elongation value of approximately % 700. Such surfaces can be a great candidate for providing easy to clean ability to deformable elastomer products.


2016 ◽  
Vol 879 ◽  
pp. 2524-2527
Author(s):  
Masazumi Okido ◽  
Kensuke Kuroda

Surface hydrophilicity is considered to have a strong influence on the biological reactions of bone-substituting materials. However, the influence of a hydrophilic or hydrophobic surface on the osteoconductivity is not completely clear. In this study, we produced super-hydrophilic and hydrophobic surface on Ti-and Zr-alloys. Hydrothermal treatment at 180 oC for 180 min. in the distilled water and immersion in x5 PBS(-) brought the super-hydrophilic surface (water contact angle < 10 (deg.)) and heat treatment of as-hydrothermaled the hydrophobic surface. The osteoconductivity of the surface treated samples with several water contact angle was evaluated by in vivo testing. The surface properties, especially water contact angle, strongly affected the osteoconductivity and protein adsorbability, and not the surface substance.


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