scholarly journals Fabrication of Hydrophobic Ni Surface by Chemical Etching

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3546 ◽  
Author(s):  
Xiaojing Qian ◽  
Tao Tang ◽  
Huan Wang ◽  
Changan Chen ◽  
Junhong Luo ◽  
...  

Hydrophobic surfaces were successfully fabricated on pure nickel substrates by a one-step chemical etching process with different acidic solutions. The static water contact angle (SCA) of the etched Ni surfaces reached higher than 125°, showing excellent hydrophobicity. The examination of surface chemical compositions implied that there were almost no polar moieties on the surface after chemical etching, except part of the surface was oxidized. After chemical etching, the nickel surfaces became much rough with packed terrace-/crater-/thorn-like clusters. According to the analysis of surface composition and morphology, the hydrophobicity was evidently attributed to the rough microstructures on the etched Ni surface. The best hydrophobicity on Ni surface was produced with the SCAs as high as 140.0° by optimizing the etching time and etchants. The results demonstrate that it is possible to construct hydrophobic surfaces on hydrophilic substrates by tailoring the surface microstructure using a simple chemical etching process without any further hydrophobic modifications by low surface energy materials.

2011 ◽  
Vol 239-242 ◽  
pp. 2270-2273 ◽  
Author(s):  
Yong Feng Luo ◽  
Hai Yan Lang ◽  
Jin Liang ◽  
Guo Sheng Peng ◽  
You Hua Fan ◽  
...  

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.


Author(s):  
Madhavi Karanam ◽  
G. Mohan Rao ◽  
Shaik Habibuddin ◽  
R. Padmasuvarna

Porous Silicon (PSi) is synthesized by Ag assisted electroless etching and characterized by Scanning electron microscopy (SEM). The effect of etching time on the optical reflectivity, optical absorbance of PSi is investigated. Reflectivity measurements showed that 45% reflectivity Si wafers drops from 45% to 10% for 2 hours etching and 6% for 3 hours etching. The decrease in the reflectivity shows that the PSi can be employed as an anti reflecting substrate in optoelectronic devices. The absorbance measurements reveal that the average absorbance of PSi is 0.60 in the wavelength range 300-800 nm after 2 hours etching. From the photoluminescence spectra it was found that PL intensity of PSi is high compared to bare silicon wafer. Static water contact angle measurements were performed to examine the hydrophobic properties of the PSi prepared under different conditions.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Chin-Guo Kuo ◽  
Cheng-Fu Yang ◽  
Mu-Jung Kao ◽  
Wen-Pin Weng ◽  
Chi-Cheng Chang ◽  
...  

Classical photoelectrodes for Dye Sensitized Solar Cells (DSSCs) were fabricated by using the electrochemical method on the titanium (Ti) template, for that the fabrication process would influence the characteristics of the DSSCs. In this study, at first three different methods were used to etch Ti templates from 10 to 17 min, (1) polishing-chemical etching: Ti template was annealed at 450°C for 1 h, abraded using number 80 to 1500 SiC sheet, and then etched in a solution of 5% HF + 95% H2O; (2) electrochemical polishing-chemical etching: Ti template was annealed at 450°C for 1 h, electrolytic polishing with 42% CH3OH + 5% HClO4 + 53% HOCH2CH2OC4H9solution, and the chemical-etching in a solution of 5% HF + 95% H2O; (3) chemical etching: Ti template was etched in a solution of 5% HF + 95% H2O and annealed at 450°C for 1 h. When the etching time was changed from 10 to 17 min, the thicknesses of Ti templates decreased from 75.3 μm to 14.8 μm, depending on the etching method. After etching process, the TiO2nanotube arrays were fabricated as the photoelectrode of DSSCs by electrochemical process, in which the Ti as anode and platinum (Pt) as cathode. The electrolyte solution included C2H4(OH)2, NH4F, and deionized water. After annealing the grown TiO2nanotube arrays at 450°C for 3 h, we would show that the etching process had large effect on the structure and transmittance ratio of the TiO2nanotube arrays.


2013 ◽  
Vol 562-565 ◽  
pp. 33-38 ◽  
Author(s):  
Hai Feng Zhang ◽  
Xiao Wei Liu ◽  
Min Zhao ◽  
Dong Bo Wang ◽  
Chang Zhi Shi

Superhydrophobic surface have many applications such as drag reduction in the micro-electromechanical systems. A novel method of fabricating superhydrophobic surface is proposed using the simple wet chemical etching in this paper. Firstly, the surface of steel disc is polished by abrasive paper and then treated with chemical etching. Secondly, the surface of steel is modified with 1H,1H,2H,2H-Perfluorooctyltrimethoxysilane. The superhydrophobic surface was obtained on the stainless steel surface. Finally, the effects of the etching time and etching solution concentration were analyzed to the superhydrophobic performance. The experimentation results show that superhydrophobic performance is the best when the HCl concentration is 2mol/L, the etching time is 20 minute respectively. The water contact angle (CA) of the rotor surface is 152°. The water droplets are hardly able to stick to the steel surface.


2018 ◽  
Author(s):  
Ong Pei Hoon ◽  
Ng Kiong Kay ◽  
Gwee Hoon Yen

Abstract Chemical etching is commonly used in exposing the die surface from die front-side and die backside because of its quick etching time, burr-free and stress-free. However, this technique is risky when performing copper lead frame etching during backside preparation on small and non-exposed die paddle package. The drawback of this technique is that the copper leads will be over etched by 65% Acid Nitric Fuming even though the device’s leads are protected by chemical resistance tape. Consequently, the device is not able to proceed to any other further electrical measurements. Therefore, we introduced mechanical preparation as an alternative solution to replace the existing procedure. With the new method, we are able to ensure the copper leads are intact for the electrical measurements to improve the effectiveness and accuracy of physical failure analysis.


Author(s):  
Martin Ehrhardt ◽  
Pierre Lorenz ◽  
Jens Bauer ◽  
Robert Heinke ◽  
Mohammad Afaque Hossain ◽  
...  

AbstractHigh-quality, ultra-precise processing of surfaces is of high importance for high-tech industry and requires a good depth control of processing, a low roughness of the machined surface and as little as possible surface and subsurface damage but cannot be realized by laser ablation processes. Contrary, electron/ion beam, plasma processes and dry etching are utilized in microelectronics, optics and photonics. Here, we have demonstrated a laser-induced plasma (LIP) etching of single crystalline germanium by an optically pumped reactive plasma, resulting in high quality etching. A Ti:Sapphire laser (λ = 775 nm, EPulse/max. = 1 mJ, t = 150 fs, frep. = 1 kHz) has been used, after focusing with a 60 mm lens, for igniting a temporary plasma in a CF4/O2 gas at near atmospheric pressure. Typical etching rate of approximately ~ 100 nm / min and a surface roughness of less than 11 nm rms were found. The etching results were studied in dependence on laser pulse energy, etching time, and plasma – surface distance. The mechanism of the etching process is expected to be of chemical nature by the formation of volatile products from the chemical reaction of laser plasma activated species with the germanium surface. This proposed laser etching process can provide new processing capabilities of materials for ultra—high precision laser machining of semiconducting materials as can applied for infrared optics machining.


BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5794-5805
Author(s):  
Yating Wang ◽  
Xiaochun Chen ◽  
Yaqi Liang ◽  
Chenghua Yu

Despite previous efforts, the fabrication of superhydrophobic substrate via an environment friendly and easy approach remains a great challenge. In this study, a low cost, simple, and green procedure was developed to prepare a superhydrophobic paper surface that is acceptable for the papermaking industry. First, a wax mixture (beeswax & carnauba wax) was emulsified and coated on the filter paper surface. Then, the coated paper was annealed at different temperatures. The further heat-treatment-rendered wax-coated paper hydrophobic or superhydrophobic because submicrometer or micrometer wax structures were present on the paper surface. The water contact angle of the annealed filter paper sample reached 151.5° at 60 °C, and the sliding angle was under 10°. Further, the relationship between surface composition and the hydrophobic properties of the coated paper samples was discussed. The obtained paper samples showed great potential in water/oil separation, as they had an efficiency over 99%. This work proposed a new simple and mild approach to fabricate superhydrophobic filter papers and explored the hydrophobicity and water/oil separation properties.


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