scholarly journals A Superhydrophilic Aluminum Surface with Fast Water Evaporation Based on Anodic Alumina Bundle Structures via Anodizing in Pyrophosphoric Acid

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3497 ◽  
Author(s):  
Daiki Nakajima ◽  
Tatsuya Kikuchi ◽  
Taiki Yoshioka ◽  
Hisayoshi Matsushima ◽  
Mikito Ueda ◽  
...  
Keyword(s):  
Contact Angle ◽  
Oxide Film ◽  
High Speed ◽  
Porous Alumina ◽  
Aluminum Surface ◽  
Water Evaporation ◽  
Water Contact ◽  
Initial Stage ◽  
Angle Measuring ◽  
Pyrophosphoric Acid

A superhydrophilic aluminum surface with fast water evaporation based on nanostructured aluminum oxide was fabricated via anodizing in pyrophosphoric acid. Anodizing aluminum in pyrophosphoric acid caused the successive formation of a barrier oxide film, a porous oxide film, pyramidal bundle structures with alumina nanofibers, and completely bent nanofibers. During the water contact angle measurements at 1 s after the water droplet was placed on the anodized surface, the contact angle rapidly decreased to less than 10°, and superhydrophilic behavior with the lowest contact angle measuring 2.0° was exhibited on the surface covered with the pyramidal bundle structures. As the measurement time of the contact angle decreased to 200–33 ms after the water placement, although the contact angle slightly increased in the initial stage due to the formation of porous alumina, at 33 ms after the water placement, the contact angle was 9.8°, indicating that superhydrophilicity with fast water evaporation was successfully obtained on the surface covered with the pyramidal bundle structures. We found that the shape of the pyramidal bundle structures was maintained in water without separation by in situ high-speed atomic force microscopy measurements.

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 ◽  
...  
Keyword(s):  
Contact Angle ◽  
Stearic Acid ◽  
Contact Angle Hysteresis ◽  
Hydrophobic Surface ◽  
Aluminum Surface ◽  
Anodized Aluminum ◽  
Water Contact ◽  
Static Water ◽  
Superhydrophobic Property ◽  
Device Associated Infection

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.

Microsecond Laser Texturing of an Aerospace Grade Aluminum Alloy to Synthesize Superhydrophobic, Anti-Water Clogging Surfaces

2021 ◽  
Vol 875 ◽  
pp. 322-328
Author(s):  
Aneeqa Naeem ◽  
Esham Butt ◽  
Hamza Khawaja ◽  
Irfan Nadeem ◽  
Rehan Akhter ◽  
...  
Keyword(s):  
Contact Angle ◽  
Titanium Nitride ◽  
Water Contact Angle ◽  
Laser Pulses ◽  
Superhydrophobic Surfaces ◽  
Aluminum Surface ◽  
Laser Texturing ◽  
Water Contact ◽  
Line Separation ◽  
Aluminum Surfaces

Traditionally superhydrophobic surfaces are prepared by applying liquid repellant organic coatings or nano-based coatings. These superhydrophobic coatings are prone to wear and can be easily damaged by abrasion and cleaning. Recently researchers are switching interest to more efficient and promising technology of pulse laser texturing for engineering sub-micron topographies to have superhydrophobic surfaces. In this research, the micro-second Laser Pulses are used to feature sub-micron textures on titanium nitride coated aluminum and polished aluminum surfaces in order to achieve the water contact angle greater than 150°. Titanium nitride coated aluminum surface with scan line separation of 50 µm shows superior hydrophobicity having a water contact angle of 156º. These superhydrophobic aluminum surfaces have applications for anti-water clogging and anti-corrosion use.

Anodic Oxide Film Formed on Ti-6Al-4V at a Low Current Density in Monocalciumphosphate Monohydrate (MCPM) Electrolyte and its Biocompatibility

2014 ◽  
Vol 608 ◽  
pp. 212-217
Author(s):  
Sutthima Sriprasertsuk ◽  
Phanawan Whangdee ◽  
Supatra Jinawath ◽  
Pasutha Thunyakitpisal ◽  
Dujreutai Pongkao Kashima
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Oxide Film ◽  
Water Contact Angle ◽  
Current Density ◽  
Chemical Species ◽  
Anodic Oxide ◽  
Anodic Oxide Film ◽  
Key Factors ◽  
Water Contact

Anodic oxide film on titanium alloy (Ti-6Al-4V) substrate was prepared by anodization. The reaction was done by applying low current densities from 0.25 to 2 mA/cm2 for 30 minutes using monocalciumphosphate monohydrate (MCPM) solution as an electrolyte. Essential parameters which affected to the formation of anodic oxide film were studied. The properties of the anodic oxide film would be optimized when the parameters were appropriately controlled. Increasing of the current density and the concentration of MCPM electrolyte could promote hydrophilicity and surface roughness of the film. After anodization, the anodic oxide film formed at 2 mA/cm2 in 1M MCPM showed the best hydrophilicity (lowest water contact angle) and the film formed at 0.25 mA/cm2 in 0.5M MCPM showed the lowest hydrophilicity (highest water contact angle). XPS analyses confirmed that the chemical species of as-anodized film formed at 2 mA/cm2 in 1M MCPM changed. Ti2p spectra scarcely changed while the O1s spectra significantly changed due to the presence of chemisorbed water and Ti-OH formed during anodization. The SEM micrographs also revealed the biocompatibility from the growth of the cementoblast cell on anodized surface. It was indicated that anodization using MCPM as an electrolyte at 2 mA/cm2 in 1M MCPM could modify the surface roughness and chemical species and that both are likely to be crucial key factors for enhancing of hydrophilicity of as-anodized film which would enhance the biocompatibility of Ti-6Al-4V as a result.

Numerical and Experimental Investigation on Evaporation of Water Droplet on Surfaces With Mixed Wettability

2020 ◽  
Author(s):  
Akam Aboubakri ◽  
Cenk Yanik ◽  
Yiğit Akkuş ◽  
Ali Koşar ◽  
Ali K. Sadaghiani
Keyword(s):  
Contact Angle ◽  
High Speed ◽  
Droplet Evaporation ◽  
Water Evaporation ◽  
Contact Radius ◽  
Sessile Droplet ◽  
Droplet Dynamics ◽  
Mixed Wettability ◽  
Receding Contact ◽  
Receding Contact Angle

Abstract Droplet evaporation is one of the most commonly observed phenomena and plays an important role in many applications such as in spray cooling, coating, and inkjet printing. Mechanisms such as dynamics of the contact line, evaporation-induced phase transitions, and formation of patterns on the substrate interact with each other in the evaporation of droplets. In this study, we investigated the effect of surface mixed wettability on water sessile droplet evaporation. The transient contact angle, center-height, contact radius, surface area, and droplet volume were experimentally measured and numerically estimated. Surfaces with mixed wettability consisting of hydrophilic islands surrounded by less hydrophilic area were fabricated. Visualization was conducted to capture droplet dynamics during evaporation using two high-speed cameras. According to the obtained results, there were three distinct stages in the water evaporation process: a constant contact radius mode, a constant contact angle mode, and a mixed-mode. The COMSOL 5.4 software was used for numerical analysis. According to the results, the receding contact angle and Marangoni instability in the droplet are two main factors that alter droplet dynamics and droplet evaporation.

Fabrication of Stable Superhydrophobic Surface with Low Adhesion on Aluminum Foil

2014 ◽  
Vol 697 ◽  
pp. 80-84
Author(s):  
Yong Mei Xia ◽  
You Fa Zhang ◽  
Xin Quan Yu ◽  
Feng Chen
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Superhydrophobic Surface ◽  
Research Work ◽  
Aluminum Foil ◽  
Industrial Applications ◽  
Angle Measurement ◽  
Aluminum Surface ◽  
Chemical Compositions ◽  
Water Contact

Metal aluminum surface can be corroded easily in acid and alkaline environment. Inspired by the self-cleaning lotus leaf, the development of superhydrophobic metal surfaces to prevent metals from corroding is enjoying tremendous popularity amongst scientists and engineers. In this work, superhydrophobic surface was obtained on aluminum foils via a facile neutral sol solution immersion process and post-modification in ethanol solution of heptadecafluoro-1,1,2,2-tetradecyl trimethoxysilane (FAS-17) solution through a hydrothermal synthesis technique. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and water contact angle measurement are used to investigate the morphologies, microstructures, chemical compositions and wettability of the produced films on aluminum substrates. The results indicated that the superhydrophobic surface, configured of a rough labyrinth structure with convexity and notch, has robust hydrophobility, which had a static water contact angle of 165.6 ± 2.8° and a water roll-off angle of <1°, exhibited long-term durability and stability in air. The present research work provides a new strategy for the simple preparation superhydrophobic films on aluminum foil for practical industrial applications.

scholarly journals Fabrication of Mechanically Stable Superhydrophobic Aluminium Surface with Excellent Self-Cleaning and Anti-Fogging Properties

2017 ◽  
Author(s):  
Priya Varshney ◽  
Soumya Mohapatra ◽  
Aditya Kumar
Keyword(s):  
High Speed ◽  
Materials Science ◽  
Industrial Applications ◽  
Aluminum Surface ◽  
Water Repellent ◽  
Adhesive Tape ◽  
Sliding Angle ◽  
Etching Technique ◽  
Water Contact ◽  
Self Cleaning

Development of the self-cleaning and anti-fogging superhydrophobic coating for aluminum surfaces which is durable in the aggressive conditions has raised tremendous interest in materials science. In this work, by employing chemical etching technique with mixture of hydrochloric and nitric acid, followed by passivation with lauric acid, superhydrophobic aluminum surface was synthesized. The surface morphology analysis reveals the presence of rough microstructures on coated aluminium surface. Superhydrophobicity with water contact angle of 170 &plusmn; 3.9&deg; and sliding angle of 4 &plusmn; 0.5&deg; is achieved. Surface bounces off the high speed water jet, indicating excellent water-repellent nature of coating. It is also continuously floated on water surface for several weeks, showing excellent buoyancy nature. Additionally, coating maintains its superhydrophobicity after undergoing 100 cycles of adhesive tape peeling test. Its superhydrophobic nature withstands 90&deg; and 180&deg; bending, and repeated folding and de-folding. Coating exhibits the excellent self-cleaning property. In low temperature condensation test, almost no accumulation of water drops on the surface, showing the excellent anti-fogging property of coating. This approach can be applied to any size and shape of aluminium surface and hence has great industrial applications.

Morphology and Wettability of Nanoporous Aluminium Oxide Film Prepared by Anodization

2017 ◽  
Vol 737 ◽  
pp. 174-178
Author(s):  
Apichon Watcharenwong ◽  
Narudon Saijaioup ◽  
Yotsapon Bailuang ◽  
Puangrat Kajitvichyanukul
Keyword(s):  
Contact Angle ◽  
Oxide Film ◽  
Water Contact Angle ◽  
Aluminium Oxide ◽  
Oxide Surface ◽  
High Porosity ◽  
Sem Images ◽  
Water Contact ◽  
High Purity Aluminium ◽  
Aluminium Oxide Film

Anodic aluminium oxide (AAO) is a well-known material for nanofabrication. To obtain highly ordered nanoporous array, there is anodization process. AAO were fabricated by anodization method utilizing high purity aluminium foil as the substrate. The substrate was degreased with ultrasonic cleaner for 15 minutes. Then the substrate was anodized in an electrolyte of 0.3 M oxalic acid with various potentials: 10, 20, 30, and 40 V and various durations: 10, 30, 60, 120, and 180 minutes at room temperature. Field emission scanning electron microscope (FE-SEM) was used to investigate surface morphology of nanoporous aluminium oxide film. The wettability of nanoporous aluminium oxide surface was estimated by measuring water contact angle (WCA) of water droplets on the nanoporous aluminium oxide surface. The FE-SEM images showed that the pore size was in the range of 12 - 81 nm. This result can indicated that nanopore size of AAO film increased with the increasing of anodization potentials and anodization time. The water contact angle of AAO samples were approximately 90.55 - 44.33 degrees. The result of measurement proved that super hydrophilic surface obtained with the increasing of nanopore size and high porosity of AAO.

scholarly journals The Effect of Sugar Content for the Wettability of Superhydrophobic Aluminum Substrate

2022 ◽  
Vol 2152 (1) ◽  
pp. 012023
Author(s):  
Shuwei Lv ◽  
Xinming Zhang ◽  
Xiaodong Yang ◽  
Ying Zhai
Keyword(s):  
Contact Angle ◽  
Glucose Solution ◽  
Sugar Content ◽  
Sample Surface ◽  
Solution Concentration ◽  
Aluminum Substrate ◽  
Aluminum Surface ◽  
Optical Contact ◽  
Etching Technique ◽  
Water Contact

Abstract A chemical etching technique is used to prepare a superhydrophobic surface with a honeycomb rough structure on the aluminum surface. Use SEM, Optical contact angle meter and Surface tension detector to characterize the etched aluminum substrate. After the 8th etching, the surface of the sample showed the morphology of micro/nano-scale honeycomb pores and protrusions, and the water contact angle (WCA) is 135°. After being modified with octadecanethiol methanol solution, WCA is 153.1°. After modification, the contact angle of the sample surface decreases with the increase of the glucose solution concentration. When the glucose solution concentration reaches 1000 mg/L, the superhydrophobicity is lost.

Superhydrophobic Film Make up of Corrosion Aluminum Plates and Polypropylene Coated

2013 ◽  
Vol 734-737 ◽  
pp. 2519-2522
Author(s):  
Ruo Mei Wu ◽  
Guang Hua Chao ◽  
Hai Yun Jiang ◽  
Hong Chen ◽  
Qi Long Liu
Keyword(s):  
Contact Angle ◽  
Aluminum Alloy ◽  
Superhydrophobic Surface ◽  
Surface Hydrophobicity ◽  
Aluminum Surface ◽  
Water Contact ◽  
Low Surface Energy ◽  
Special Surface ◽  
Superhydrophobic Property ◽  
Aluminum Plates

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.

scholarly journals Study on Preparation of Superhydrophobic Ni-Co Coating and Corrosion Resistance by Sandblasting–Electrodeposition

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1164
Author(s):  
Zhengwei Zhang ◽  
Zhenyu Shen ◽  
Hongbin Wu ◽  
Lingquan Li ◽  
Xiuqing Fu
Keyword(s):  
Contact Angle ◽  
Corrosion Resistance ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
X Ray Diffraction ◽  
Water Contact ◽  
Angle Measuring ◽  
Surface Contact Angle

To enhance the corrosion resistance of type C45E4 substrates, a superhydrophobic Ni-Co coating was prepared on a C45E4 surface by sandblasting pretreatment and electrodeposition. The surface microstructure, three-dimensional surface roughness, and crystal structure of the coating was characterized by scanning electron microscope, laser scanning confocal microscope, and X-ray diffraction. An optical surface contact angle measuring instrument and an electrochemical workstation was used to characterize the wettability and corrosion resistance of the surface. The results showed that the water contact angle reached 151.2 degrees on the Ni-Co coating surface. The surface was superhydrophobic and still had stable hydrophobicity after four months. In electrochemical corrosion experiments. Compared with polishing pretreatment, the corrosion current density of superhydrophobic Ni-Co coating prepared by sandblasting pretreatment reached Icorr = 5.05 × 10−7 A·cm−2, and the corrosion potential reached Ecorr = −0.33 V. The superhydrophobic Ni-Co coating had excellent corrosion resistance.

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