scholarly journals Robust Superhydrophobic Surface on Polypropylene with Thick Hydrophobic Silica Nanoparticle-Coated Films Prepared by Facile Compression Molding

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3155
Author(s):  
Oyunchimeg Erdene-Ochir ◽  
Doo-Man Chun
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Alkaline Medium ◽  
Superhydrophobic Surface ◽  
Thick Layer ◽  
Scratch Test ◽  
Superhydrophobic Surfaces ◽  
Sliding Angle ◽  
Hydrophobic Silica ◽  
Low Surface Energy

Superhydrophobic surfaces have been extensively studied for their unique interfacial interaction between water and the surface, and they can be used for self-cleaning, drag reduction, anti-icing, and other applications. To make the superhydrophobic surfaces, nano/microscale structures and a low surface energy should be realized. The development of a durable superhydrophobic surface was hindered by the vulnerability of the surface to mechanical contact. To improve the robustness of the superhydrophobic surface toward mechanical damage, the hydrophobic polypropylene (PP) surface was coated with a thick layer of hydrophobic silica nanoparticles (SNPs) using a simple compression molding process. The thick layer consists of SNPs and PP, and the roles of SNPs and PP are nano/microscale structures with a low surface energy and binder for nanoparticles, respectively. This revealed improvement in the superhydrophobic tendency, with an apparent contact angle of about 170° and a sliding angle of less than 5°. The morphology and the corresponding elemental analysis of the PP/SNPs coated films were investigated using field emission scanning electron microscopy and energy-dispersive spectrometry. The mechanical durability of the superhydrophobic surface was evaluated by the scotch tape test and scratch test with sandpaper. The coated films with SNPs showed the superhydrophobic behavior after 25 tape tests. In addition, the coated films with SNPs showed a contact angle greater than 150° and a sliding angle less than 10° after a 100-cm scratch test with 1000 grit sandpaper, under a weight of 500 g, on an area of 40 × 40 mm2. The chemical stability of PP/SNPs coated films was also investigated in acidic, neutral, and alkaline medium solutions. The films showed good stability under the acidic and neutral medium solutions even after 24 h, but an alkaline medium could damage the surface. The obtained results demonstrated the robustness of the superhydrophobic coating with SNPs.

scholarly journals Facile Electrochemical Method for the Fabrication of Stable Corrosion-Resistant Superhydrophobic Surfaces on Zr-Based Bulk Metallic Glasses

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1558
Author(s):  
Mengmeng Yu ◽  
Ming Zhang ◽  
Jing Sun ◽  
Feng Liu ◽  
Yujia Wang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Corrosion Resistance ◽  
Surface Energy ◽  
Metallic Glasses ◽  
Composite Structures ◽  
Superhydrophobic Surface ◽  
Electrochemical Method ◽  
Electrochemical Etching ◽  
Superhydrophobic Surfaces ◽  
Nano Composite

Both surface microstructure and low surface energy modification play a vital role in the preparation of superhydrophobic surfaces. In this study, a safe and simple electrochemical method was developed to fabricate superhydrophobic surfaces of Zr-based metallic glasses with high corrosion resistance. First, micro–nano composite structures were generated on the surface of Zr-based metallic glasses by electrochemical etching in NaCl solution. Next, stearic acid was used to decrease surface energy. The effects of electrochemical etching time on surface morphology and wettability were also investigated through scanning electron microscopy and contact angle measurements. Furthermore, the influence of micro–nano composite structures and roughness on the wettability of Zr-based metallic glasses was analysed on the basis of the Cassie–Baxter model. The water contact angle of the surface was 154.3° ± 2.2°, and the sliding angle was < 5°, indicating good superhydrophobicity. Moreover, the potentiodynamic polarisation test and electrochemical impedance spectroscopy suggested excellent corrosion resistance performance, and the inhibition efficiency of the superhydrophobic surface reached 99.6%. Finally, the prepared superhydrophobic surface revealed excellent temperature-resistant and self-cleaning properties.

Improving the Mechanical Durability of Superhydrophobic Coating by Deposition on to a Mesh Structure

2017 ◽  
Author(s):  
Weihua Hu ◽  
De-Quan Yang ◽  
Edward Sacher
Keyword(s):  
Surface Energy ◽  
Superhydrophobic Surface ◽  
Impact Resistance ◽  
Superhydrophobic Surfaces ◽  
Superhydrophobic Coating ◽  
Mesh Structure ◽  
Mechanical Abrasion ◽  
Low Surface Energy ◽  
Jet Impact ◽  
Mechanical Durability

<p>Superhydrophobic surfaces (SHSs) require a combination of a rough nano- or microscale structured surface topography and a low surface energy. However, its superydrophobicity is easily lost, even under relatively mild mechanical abrasion, when the surface is mechanically weak. Here, we develop a method that significantly increases the mechanical durability of a superhydrophobic surface, by introducing a mesh layer beneath the superhydrophobic layer. The hardness, abrasion distance, flexibility and water-jet impact resistance all increase for the commercially available Ultra-ever Dry superhydrophobic coating. This is attributed to the increased mechanical durability offered by the mesh, whose construction not only increases the porosity of the SHS coating but acts as a third, larger structure, so that the superhydrophobic layer is now composed of a three-level hierarchical structure: the mesh, micropillars and nanoparticles.</p>

Improving the Mechanical Durability of Superhydrophobic Coating by Deposition on to a Mesh Structure

2017 ◽  
Author(s):  
Weihua Hu ◽  
De-Quan Yang ◽  
Edward Sacher
Keyword(s):  
Surface Energy ◽  
Superhydrophobic Surface ◽  
Impact Resistance ◽  
Superhydrophobic Surfaces ◽  
Superhydrophobic Coating ◽  
Mesh Structure ◽  
Mechanical Abrasion ◽  
Low Surface Energy ◽  
Jet Impact ◽  
Mechanical Durability

<p>Superhydrophobic surfaces (SHSs) require a combination of a rough nano- or microscale structured surface topography and a low surface energy. However, its superydrophobicity is easily lost, even under relatively mild mechanical abrasion, when the surface is mechanically weak. Here, we develop a method that significantly increases the mechanical durability of a superhydrophobic surface, by introducing a mesh layer beneath the superhydrophobic layer. The hardness, abrasion distance, flexibility and water-jet impact resistance all increase for the commercially available Ultra-ever Dry superhydrophobic coating. This is attributed to the increased mechanical durability offered by the mesh, whose construction not only increases the porosity of the SHS coating but acts as a third, larger structure, so that the superhydrophobic layer is now composed of a three-level hierarchical structure: the mesh, micropillars and nanoparticles.</p>

Preparation of Superhydrophobic Surface on Copper Foils by a Facile Method

2013 ◽  
Vol 834-836 ◽  
pp. 42-45
Author(s):  
Zhi Qing Yuan ◽  
Xian Wang ◽  
Ji Ping Bing ◽  
Meng Lei Wang ◽  
Juan Huang
Keyword(s):  
Contact Angle ◽  
Superhydrophobic Surface ◽  
Solution Concentration ◽  
Copper Surface ◽  
Ethanol Solution ◽  
Superhydrophobic Surfaces ◽  
Sliding Angle ◽  
Water Contact ◽  
Copper Foils ◽  
Immersing Method

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°.

scholarly journals Glaze Icing on Superhydrophobic Coating Prepared by Nanoparticles Filling Combined with Etching Method for Insulators

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Chao Guo ◽  
Ruijin Liao ◽  
Yuan Yuan ◽  
Zhiping Zuo ◽  
Aoyun Zhuang
Keyword(s):  
Contact Angle ◽  
Photoelectron Spectroscopy ◽  
Superhydrophobic Surface ◽  
Power Transmission ◽  
Contact Angle Hysteresis ◽  
Transmission System ◽  
Sliding Angle ◽  
Power Transmission System ◽  
Etching Method ◽  
Xps Characterization

Icing on insulators may cause flashover or even blackout accidents in the power transmission system. However, there are few anti-icing techniques for insulators which consume energy or manpower. Considering the water repelling property, the superhydrophobic surface is introduced for anti-icing of insulators. Among the icing forms, the glaze icing owns the highest density, strongest adhesion, and greatest risk to the power transmission system but lacks researches on superhydrophobic surface. In this paper, superhydrophobic surfaces with contact angle of 166.4°, contact angle hysteresis of 0.9°, and sliding angle of less than 1° are prepared by nanoparticle filling combined with etching method. The coated glass slide and glass insulator showed excellent anti-icing performance in the glaze icing test at −5°C. The superhydrophobicity and anti-icing property of the coatings benefit from the low surface energy and hierarchical rough structure containing micron scale pits and nanoscale coralloid bulges supported by scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) characterization.

scholarly journals Towards AquaSun practical utilization: strong adhesion and lack of ecotoxicity of solar-driven antifouling sol-gel coating

2021 ◽  
Author(s):  
Antonino Scurria ◽  
Silvia Sfameni ◽  
Gabriella Di Carlo ◽  
Mario Pagliaro ◽  
Anna Maria Visco ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Sol Gel ◽  
Scratch Resistance ◽  
Practical Utilization ◽  
Marine Coatings ◽  
Low Surface Energy ◽  
H2o2 Formation ◽  
Strong Adhesion ◽  
Ecotoxicity Tests

The outcomes of adhesion and ecotoxicity tests carried out on metal specimens faithfully representing the surface of real ships, including the primer and tie coat layers typically applied on ship hull prior to deposition of the antifouling paint, show the practical applicability of "AquaSun" antifouling sol-gel coatings. Newly developed AquaSun coatings share superhydrophicity (contact angle >115) and exceptionally high scratch resistance (ASTM 5B). Coupled to the ecofriendly antifouling mechanism based on continuous H2O2 formation upon exposure to solar light and foul release due to low surface energy, these results open the route to the practical utilization of these novel marine coatings.

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 ◽  
...  
Keyword(s):  
Contact Angle ◽  
Wear Resistance ◽  
Superhydrophobic Surface ◽  
Ph Value ◽  
Chemical Compositions ◽  
Sliding Angle ◽  
Water Contact ◽  
Angle Measurements ◽  
Surface Morphologies ◽  
Composite Electrodeposition

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.

Coalescence-induced jumping of nanodroplets on mixed-wettability superhydrophobic surfaces

2020 ◽  
Author(s):  
Fang-Fang Xie ◽  
Dan-Qi Wang ◽  
Yi-Bo Wang ◽  
Yan-Ru Yang ◽  
Xiao-Dong Wang
Keyword(s):  
Contact Angle ◽  
Superhydrophobic Surface ◽  
Apparent Contact Angle ◽  
Superhydrophobic Surfaces ◽  
Dominant Factor ◽  
Heterogeneous Surfaces ◽  
Transfer Enhancement ◽  
Stripe Width ◽  
Mixed Wettability ◽  
Dynamics Simulations

Coalescence-induced droplet jumping on superhydrophobic surfaces has been observed at microscale and even nanoscale. The enhancement in jumping velocity of coalescing droplets is crucial for condensation heat transfer enhancement, anti-icing, self-cleaning, and so forth. However, the research on how to acquire a higher jumping velocity is really very limited. In this paper, we use molecular dynamics simulations to study the coalescence-induced jumping of two equally-sized nanodroplets on chemically heterogeneous surfaces composed of alternating stripes with different hydrophobicity. We show that the jumping velocity is closely related to the stripe width and wettability contrast, and it can even exceed that on an ideal superhydrophobic surface with 180° contact angle when the striped surfaces are properly designed. We also demonstrate that there is always an optimal stripe width yielding the maximum jumping velocity, whereas its value is independent of the wettability contrast. We reveal that the dominant factor to determine the jumping velocity is the apparent contact angle of equilibrated droplets over heterogeneous surfaces for small stripe widths, it changes to the time of liquid bridges impacting surfaces for moderate stripe widths and to the contact area between equilibrated droplets and relatively hydrophobic stripes for large stripe widths. We believe the present simulations can provide useful guidance to design self-jumping superhydrophobic surfaces.

Facile Fabrication of Fluorine-Free Superhydrophobic Surfaces with SiO2 Monospheres

2021 ◽  
Vol 16 (2) ◽  
pp. 208-212
Author(s):  
Zhong-Peng Liu ◽  
Si-Nan Song ◽  
Mu Zhang
Keyword(s):  
Contact Angle ◽  
Superhydrophobic Surface ◽  
Hydrophobic Surface ◽  
Silica Particles ◽  
Superhydrophobic Surfaces ◽  
Particle Sizes ◽  
Stöber Method ◽  
Spherical Silica ◽  
Spherical Silica Particles ◽  
Facile Fabrication

Recently, superhydrophobic surface on various type of substrates have attracted much attentions in electronics field. In this work, the classic Stöber method was used to prepare spherical silica particles with different particle sizes by adding different amounts of electrolyte (potassium chloride), giving rise to size distribution ranging from 300 nm to 2.55 yitm. Herein we constructed a micro-nano lotus-like structure in a facile way, achieving a superhydrophobic surface with using any Fluorine related chemicals. In the sense, the silica particles modified with HMDS were sprayed to prepare hydrophobic surface with contact angle up to 152.96° by increasing the frequency of sprays.

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