scholarly journals Fabrication of a Low Adhesive Superhydrophobic Surface on Ti6Al4V Alloys Using TiO2/Ni Composite Electrodeposition

Micromachines ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 121 ◽  
Author(s):  
Jianbing Meng ◽  
Xiaojuan Dong ◽  
Yugang Zhao ◽  
Rufeng Xu ◽  
Xue Bai ◽  
...  

A superhydrophobic surface with low adhesion and good wear resistance was fabricated on Ti6Al4V substrates via TiO2/Ni composite electrodeposition, and subsequently modified with a fluoroalkylsilane (FAS) film. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and optical contact angle measurements were used to characterize the surface morphologies, chemical compositions, and surface wettability. The superhydrophobicity of the as-prepared surface results from the fabrication of a hierarchical structure and the assembly of low-surface energy fluorinated components. The as-prepared surface had a water contact angle as high as 162.6° and a sliding angle close to 1.8°. Scratch and abrasion tests showed that the superhydrophobic coating provided a superior wear resistance and stable mechanical abrasion protection. In addition, the influence of processing conditions, such as working voltage, deposited time, pH value, and TiO2 concentration, was also investigated.

2021 ◽  
Vol 11 (23) ◽  
pp. 11172
Author(s):  
Zhiqiang Qian ◽  
Zhong Liu ◽  
Shidong Wang ◽  
XiuShen Ye ◽  
Zhijian Wu

A simple and practical spray method is employed to prepare a PVDF/PFOTES-SiO2 superhydrophobic composite coating on the AZ31B Mg alloy substrate. The morphology, composition, and water contact angle (CA) were measured by Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope (FESEM) and contact angle measuring instrument. Hydrophilic nano-SiO2 is modified by PFOTES to obtain hydrophobicity. The influence of the mass of PFOTES-SiO2 to PVDF on the hydrophobic properties was studied. The wear resistance and stability of the composite coating have been investigated by immersion test, cross-cut adhesion test and friction test. Additionally, the corrosion resistance was measured by electrochemical workstation and salt spray corrosion test. The CA of PVDF/PFOTES-SiO2 coating is 161.3° and the sliding angle (SAs) is less than 2°. After 10× the sandpaper friction test, the superhydrophobic contact angle of the coating remained above 155°, and the sliding angle was less than 5°, which indicated that the prepared coating is a strong superhydrophobic coating with good wear resistance. The results of the electrochemical tests show that the superhydrophobic coating improved the anti-corrosion performance of Mg alloy, and the water contact angle is greater than 150° after 168 h salt spray corrosion test. Due to its excellent superhydrophobicity, wear resistance and anti-corrosion properties, the robust PVDF/PFOTES-SiO2 coating is considered to have great potential for future applications in the automotive and marine industries.


2018 ◽  
Vol 71 (11) ◽  
pp. 855
Author(s):  
Lei Wang ◽  
Lei Chen ◽  
Zhanxiong Li

In this study, three novel side-chain fluoroalkyl oligoethers with different molecular weights were synthesised via a ring-opening reaction of 2,2,3,3,4,4,5,5,5-nonafluoropentyloxirane. The fluorooligoethers were then silanized and characterised by FT-IR,1H, and 19F NMR spectroscopies. These silanlized fluorooligoethers were used to fabricate hydrophobic coatings on silicon substrates, which were pre-treated with O2 plasma, by the method of liquid phase deposition. The chemical compositions and structures of the film surfaces were analysed by X-ray photoelectron spectroscopy and the results showed that silanized fluorooligoethers formed self-assembled films on the silicon wafer. The surface wettability of the coatings was measured by water contact angles. It is noted that the annealing process can improve the hydrophobicity with the highest water contact angle being 115.2 ± 1° and hexadecane contact angle being 67.2 ± 1°. The surface morphologies and roughness of the self-assembled films were measured by atomic force microscopy (AFM), as a result, the surface was found to be rougher with the increment of the molecular weight of the fluorooligoethers.


Micromachines ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 64 ◽  
Author(s):  
Xiaojuan Dong ◽  
Jianbing Meng ◽  
Haian Zhou ◽  
Rufeng Xu ◽  
Xue Bai ◽  
...  

Anti-adhesive Ni coatings with low wettability were successfully fabricated on Ti6Al4V substrates via an electro-brush plating method, and subsequently modified with a fluoroalkylsilane (FAS) film. The surface morphology, chemical compositions, and wettability of the as-prepared coatings were measured using scanning electron microscopy (SEM), X-ray diffractometer (XRD), Fourier transform infrared spectrophotometry (FTIR), and contact angle measurements. The results showed that the surface of Ti6Al4V substrate was endowed with flower-like structures. Each flower-like cluster was constituted by a large number of Ni ions. After surface modification of FAS, the as-prepared Ti6Al4V surface had a water contact angle as high as 151.5°, a sliding angle close to 2.1°, and a solid surface energy as low as 0.97 mJ/m2. Potentiodynamic polarization tests showed that the Ni coating could provide a stable corrosion protection. In addition, the effects of processing conditions, such as working voltage, relative velocity, electrolyte concentration, and processing time, were investigated. The mechanism of the adhesive resistance was proposed, and the low wettability of Ti6Al4V surfaces was explained by Cassie–Baxter model. As a result, it was necessary to reduce the fraction of the solid–liquid interface in order to achieve anti-adhesive surface.


2014 ◽  
Vol 697 ◽  
pp. 80-84
Author(s):  
Yong Mei Xia ◽  
You Fa Zhang ◽  
Xin Quan Yu ◽  
Feng Chen

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.


Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 159 ◽  
Author(s):  
Xiaojuan Dong ◽  
Jianbing Meng ◽  
Yizhong Hu ◽  
Xiuting Wei ◽  
Xiaosheng Luan ◽  
...  

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.


2019 ◽  
Vol 9 (8) ◽  
pp. 978-983 ◽  
Author(s):  
ElZahraa Eldwakhly ◽  
Selma Adnan Saadaldin ◽  
Abdulaziz Abdullah Al-Khureif ◽  
Mai S. Soliman

Plenty of surface treatments to zirconia (ZrO2) are available. However, the long-term hydrolytic stability is still a major concern for the investigators. This paper explores the effects of different monomer systems on mold enclosed shear bond strength (ME-SBS) of bonding cement to zirconia (ZrO2) using commercially available silane primers with different monomer systems. Eighteen ZrO2 blanks (KaVo™ Everest) were subjected to tribo-chemical silica coating and divided into the following primer groups: (1) Sil (control); (2) Composite; (3) G-Multi; and (4) Monobond Plus. Each group was then subdivided into three subgroups (n = 6) depending on storage conditions: (1) 24-h dry storage, (2) 2-month water aging, and (3) 4-month water aging. Elemental analyses and contact angle measurements were conducted. The ME-SBSs and failure modes were analyzed. The data were subjected to the two-way analysis of variance (ANOVA) followed by Tukey's post hoc test for pairwise comparisons (p < 0.05). Similar chemical compositions with marginal differences in content weight (%) were observed. The water contact angle measurements on treated ZrO2 were <32° in all groups. After 4-month water aging, the highest ME-SBS was exhibited by Group 4 (18.3 ± 6.5 MPa). The Monobond Plus primer systems have the ability to resist hydrolysis at the bonding cement/ZrO2 interface.


2014 ◽  
Vol 936 ◽  
pp. 233-237
Author(s):  
You Hua Fan ◽  
Ze Jun Chen ◽  
La Yun Deng ◽  
Hong Chen

A superhydrophobic copper oxygen (CuO) surface with hierarchical micro- and nanostructure was obtained by hydrothermally synthesized. The CuO surface was endowed with superhydrophobic property by modifying with stearic acid, which was referred to the STA-modified CuO film. The surface morphological study showed that different structures, such as petal-shaped, bulk-shaped, carambola-shaped CuO and cauliflower-shaped particles distributed on the copper substrate under the different synthesis conditions. The water contact angle and sliding angle of the as-prepared CuO surface were 157 ± 2.3º and 3º, respectively.


2012 ◽  
Vol 557-559 ◽  
pp. 1807-1810 ◽  
Author(s):  
Zhi Qing Yuan ◽  
Xi Hai Hao ◽  
Ji Ping Bin ◽  
Xian Wang ◽  
Hong Chen

A superhydrophobic nickel oxide (NiO) surface with hierarchical micro- and nanostructures was obtained by a novel and facile method. The water contact angle and sliding angle of the superhydrophobic NiO surface were 156±1.9º and 3º, respectively. The superhydrophobic NiO surface made the substrate float on the water surface and showed high buoyancy. Execept for pure water, the superhydrophobicity of the superhydrophobic NiO surface remained unchanged when contacting with salt aqueous solutions. After being stored in ambient environment for 8 months, the superhydrophobic property remained constant, and no contamination was observed on the superhydrophobic NiO surface.


2013 ◽  
Vol 834-836 ◽  
pp. 42-45
Author(s):  
Zhi Qing Yuan ◽  
Xian Wang ◽  
Ji Ping Bing ◽  
Meng Lei Wang ◽  
Juan Huang

In the paper, we prepared superhydrophobic surfaces on copper foils via a facile solution-immersing method. The influence of experiment conditions, such as solution concentration, immersing time and temperature, on the surface structure is investigated in detail. When the concentration of stearic acid-ethanol solution, the immersing time and the temperature are 2 g/L, 120 min and 40°,respectively, the resulting copper surface possesses great superhydrophobicity with a water contact angle of up to 159° and a sliding angle of only 3°.


2011 ◽  
Vol 295-297 ◽  
pp. 1680-1683
Author(s):  
Shu Liang Wang ◽  
Chang Yu Liu ◽  
Hui Ming Du ◽  
Hua Ma ◽  
Cheng Xie ◽  
...  

A layer of sword-like super-hydrophobic film was fabricated on wood surface through an alkaline hydrothermal method. The super-hydrophobic property of the wood surface was measured by contact angle measurements (CA). The microstructure and chemical composition of the super-hydrophobic film was analyzed by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR). Analytical characterization revealed that the micro-scale roughness sword-like particles uniformly erect on the wood surface and create the rough surface. Also, a monolayer of stearic acid was adsorbed on the rough surface which contributes to reduce the surface energy. With the combination of roughness and low surface energy of wood surface, the wood has turned its wetting property from hydrophilic into super-hydrophobic with a water contact angle 151o, and the sliding angle is about 5o.


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