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>

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 Improving the Hydrophobicity of ZnO by PTFE Incorporation

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Meenu Srivastava ◽  
Bharathi Bai J. Basu ◽  
K. S. Rajam
Keyword(s):  
Thermal Treatment ◽  
Stearic Acid ◽  
Superhydrophobic Surface ◽  
Cost Effective ◽  
Electrical Energy ◽  
High Water ◽  
Superhydrophobic Coating ◽  
Water Contact ◽  
Low Surface Energy ◽  
Effective Manner

The objective of the present study is to obtain a zinc oxide- (ZnO-) based superhydrophobic surface in a simple and cost-effective manner. Chemical immersion deposition being simple and economical has been adopted to develop modified ZnO coating on glass substrate. Several modifications of ZnO like treatment with alkanoic acid (stearic acid) and fluoroalkylsilane to tune the surface wettability (hydrophobicity) were attempted. The effect of thermal treatment on the hydrophobic performance was also studied. It was observed that thermal treatment at 70°C for 16 hrs followed by immersion in stearic acid resulted in high water contact angle (WCA), that is, a superhydrophobic surface. Thus, a modified ZnO superhydrophobic surface involves the consumption of large amount of electrical energy and time. Hence, the alternate involved the incorporation of low surface energy fluoropolymer polytetrafluoroethylene (PTFE) in the ZnO coating. The immersion deposited ZnO-PTFE composite coating on modification with either stearic acid or fluoroalkylsilane resulted in a better superhydrophobic surface. The coatings were characterized using Scanning Electron Microscope (SEM) for the surface morphology. It was found that microstructure of the coating was influenced by the additives employed. A flower-like morphology comprising of needle-like structure arranged in a radial manner was exhibited by the superhydrophobic coating.

Study on Anti-Freezing Performance of Organic Fluorine Siloxane Nano Coating

2013 ◽  
Vol 475-476 ◽  
pp. 1325-1328
Author(s):  
Dong Bo Guan ◽  
Zhong Yi Cai ◽  
Yang Jiang ◽  
Shou Jun Wang ◽  
Hui An ◽  
...  
Keyword(s):  
Surface Energy ◽  
Material Surface ◽  
Superhydrophobic Coating ◽  
Low Surface Energy ◽  
Nano Coating ◽  
Optimum Proportion ◽  
The Times ◽  
Organic Fluorine ◽  
Pendulum Impact ◽  
Long Chain

a low surface energy coating with a long chain fluorine siloxane is prepared, and the performance in anti-freezing adhesive is studied. It is determined that the optimum proportion of (Heptadecafluoro-1,1,2,2-tetradecyl) trimethoxysilane (FAS) and SiO2 nanopowder are 1.1% and 1.6%,respectively. the times of coating bear pendulum impact is least in this proportion. the conclusion is that bionic superhydrophobic coating plays a certain guiding role on solving material surface frozen sticky problem.

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.

Rapid physical preparation of a superhydrophobic surface on copper foil without low-surface-energy materials coating

2021 ◽  
Vol 11 (1) ◽  
pp. 93-99
Author(s):  
Jian Wang ◽  
Hong Chen ◽  
Xinyuan Li
Keyword(s):  
Surface Energy ◽  
Superhydrophobic Surface ◽  
Copper Foil ◽  
Traditional Approach ◽  
Substrate Surface ◽  
Copper Surface ◽  
Energy Materials ◽  
New Approach ◽  
Low Surface Energy ◽  
Physical Preparation

A method is proposed to directly obtain superhydrophobic properties by depositing a coating made of candle soot upon the copper foil surface. The process to prepare a surface of superhydrophobicity is simple and rapid, which was performed just by placing the copper foil over the flame of a burned candle for no more than 10 minutes. The surface contact and slide angles of water were 159° ± 1.8° and 2°, respectively. Furthermore, the wettability on the copper surface of superhydrophobicity was also investigated. We found that the copper superhydrophobic surface prepared by the method had excellent superhydrophobicity for water; acid, alkali and salt solutions; and other liquids. In contrast to the traditional approach to prepare superhydrophobic surfaces, the method proposed in this study not only did not damage the mechanical properties of the substrate surface but also did not require low surface energy materials to be modified. This study provides a new approach for the protection of copper and other metallic materials.

scholarly journals Self-Stratifying Particulate Coating for Robust Superhydrophobic and Latex-Repellent Surface

2020 ◽  
Vol 8 (3) ◽  
pp. 1111-1117
Keyword(s):  
Surface Roughness ◽  
Surface Energy ◽  
Film Surface ◽  
Contact Angles ◽  
Polymer Binder ◽  
Drying Temperature ◽  
Low Surface Energy ◽  
Mechanical Durability ◽  
Film Substrate ◽  
Convection Dominated

A technique for preparing superhydrophobic and natural latex-repellent surface requires at least two fabrication components: surface roughness, and surface layer with low free energy. Here, multiscale surface roughness in micro-/nanoscales with low surface energy can be simultaneously achieved through the deposition of fluoroalkyl-functionalized silica aggregates. However, the mechanical durability of such film remains problematic. Therefore, third component such as polymer binder was incorporated carefully to improve adhesion between film-substrate interface without deteriorating surface roughness and surface energy. In this work, we employed self-stratifying coating technique to induce vertical phase separation between particles and polymer during film drying, such that the silica aggregates densely accumulated on the top surface, while polymer binder concentrated near the film bottom. The governing transports during film stratification process involve diffusion and convection driven by evaporation. Thus, this research focused on the effect of drying temperature and evaporation rate on the anti-wetting performance of the coating. The results showed that the liquid-repellent properties of the surface improve with increasing drying temperature, indicating the convection-dominated transport that induced substantial particle trap at the film surface. With polymer binder added, the coatings still showed decent superhydrophobic and natural latex-repellent properties with maximum contact angles 166.4°±0.6° and 157.5°±0.5°, as well as minimum sliding angles 2.7°±0.3° and 2.9°±0.2° for water and natural latex respectively. Also, AFM result revealed that significant surface roughness of 581 ± 18 nm was still achievable even at high blending mass ratio of polymer binder up to half of the silica weight.

Molding processed multi-layered and multi-functional nanocomposites with high structural ability, electrical conductivity and durable superhydrophobicity

Nanoscale ◽  
2018 ◽  
Vol 10 (42) ◽  
pp. 19916-19926 ◽  
Author(s):  
Binrui Wu ◽  
Chaoyi Peng ◽  
Ying Hu ◽  
Suli Xing ◽  
Dazhi Jiang ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Surface Energy ◽  
Superhydrophobic Surfaces ◽  
Energy Materials ◽  
Low Surface Energy ◽  
Exciting Potential ◽  
Self Cleaning ◽  
Water Proofing

Bioinspired superhydrophobic surfaces mainly attributed to the nano/micro textures and low surface energy materials, have exciting potential usage in fields such as self-cleaning, water-proofing and so forth.

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