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.

scholarly journals A Novel Synthetic UV-Curable Fluorinated Siloxane Resin for Low Surface Energy Coating

Polymers ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 979 ◽  
Author(s):  
Chunfang Zhu ◽  
Haitao Yang ◽  
Hongbo Liang ◽  
Zhengyue Wang ◽  
Jun Dong ◽  
...  
Keyword(s):  
Surface Energy ◽  
Photoelectron Spectroscopy ◽  
Contact Angles ◽  
Proton Nuclear Magnetic Resonance ◽  
Energy Materials ◽  
Uv Curable ◽  
X Ray ◽  
Low Surface Energy ◽  
Low Concentrations ◽  
Siloxane Polymers

Low surface energy materials have attracted much attention due to their properties and various applications. In this work, we synthesized and characterized a series of ultraviolet (UV)-curable fluorinated siloxane polymers with various fluorinated acrylates—hexafluorobutyl acrylate, dodecafluoroheptyl acrylate, and trifluorooctyl methacrylate—grafted onto a hydrogen-containing poly(dimethylsiloxane) backbone. The structures of the fluorinated siloxane polymers were measured and confirmed by proton nuclear magnetic resonance and Fourier transform infrared spectroscopy. Then the polymers were used as surface modifiers of UV-curable commercial polyurethane (DR-U356) at different concentrations (1, 2, 3, 4, 5, and 10 wt %). Among three formulations of these fluorinated siloxane polymers modified with DR-U356, hydrophobic states (91°, 92°, and 98°) were obtained at low concentrations (1 wt %). The DR-U356 resin is only in the hydrophilic state at 59.41°. The fluorine and siloxane element contents were investigated by X-ray photoelectron spectroscopy and the results indicated that the fluorinated and siloxane elements were liable to migrate to the surface of resins. The results of the friction recovering assays showed that the recorded contact angles of the series of fluorinated siloxane resins were higher than the original values after the friction-annealing progressing.

scholarly journals A note on the effect of surface topography on adhesion of hard elastic rough bodies with low surface energy

2019 ◽  
Vol 28 (1) ◽  
pp. 8-12 ◽  
Author(s):  
Guido Violano ◽  
Giuseppe Demelio ◽  
Luciano Afferrante
Keyword(s):  
Surface Roughness ◽  
Surface Energy ◽  
Adhesive Contact ◽  
Low Surface Energy ◽  
Surface Gradient ◽  
Self Consistent ◽  
Remarkable Result ◽  
Roughness Amplitude ◽  
Adhesive Interactions ◽  
Effect Of Surface

AbstractAdhesion between bodies is strongly influenced by surface roughness. In this note, we try to clarify how the statistical properties of the contacting surfaces affect the adhesion under the assumption of long-range adhesive interactions.Specifically, we show that the adhesive interactions are influenced only by the roughness amplitude hrms, while the rms surface gradient h0rmsonly affects the non-adhesive contact force. This is a remarkable result if one takes into account the intrinsic difficulty in defining $h_{\mathrm{rms}}^{^{\prime }}.$Results are also corroborated by a comparison with self-consistent numerical calculations.

scholarly journals Superhydrophobic Fabrics with Mechanical Durability Prepared by a Two-Step Plasma Processing Method

Coatings ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 351 ◽  
Author(s):  
Kosmas Ellinas ◽  
Angeliki Tserepi ◽  
Evangelos Gogolides
Keyword(s):  
Surface Energy ◽  
Plasma Deposition ◽  
Contact Angle Hysteresis ◽  
Plasma Processing ◽  
High Water ◽  
Contact Angles ◽  
Processing Method ◽  
Static Contact ◽  
Mechanical Durability ◽  
Fabric Surface

Most studies on superhydrophobic fabrics focus on their realization using additive manufacturing (bottom-up) techniques. Here we present the direct modification of three different fabrics using a plasma-based method to obtain anti-adhesive and self-cleaning properties. A two-step plasma processing method is used: (a) for the creation of micro-nanoscale features on the fabric surface (plasma texturing step) and (b) the minimization of the fabric surface energy (by a short plasma deposition step of a very thin, low surface energy layer). The entire process takes only 14 min and all fabrics after processing exhibit high water static contact angles (WSCA > 150°), low contact angle hysteresis (CAH < 7°) and advantageous mechanical durability against hand-rumpling. The method is simple and generic, and it can be therefore expanded to other polymeric fabrics (i.e., acrylic) in addition to polyester, without any limitation rising from the weaving characteristics of the fabric or the starting nature of the material (i.e., hydrophobic or hydrophilic).

The Influence of Parameters of Microarc Oxidation on the Surface Roughness and Wettability of Calciumphosphate Coatings

2015 ◽  
Vol 1097 ◽  
pp. 35-38 ◽  
Author(s):  
Valentina V. Chebodaeva ◽  
Ekaterina G. Komarova ◽  
Yuri P. Sharkeev
Keyword(s):  
Surface Roughness ◽  
Surface Energy ◽  
Linear Growth ◽  
High Surface ◽  
Microarc Oxidation ◽  
Contact Angles ◽  
Free Surface Energy ◽  
Voltage Range ◽  
Micro Arc Oxidation ◽  
Coating Formation

The influence of the voltage of micro-arc oxidation on the physicochemical properties of the calciumphosphate coatings has been investigated. The linear growth of the roughness and hyperbolic decrease of the surface energy with growth of the oxidation voltage have been revealed. It was shown that the calciumphosphate coatings have low contact angle and high surface energy and, as a consequence, are hydrophilic. The optimal voltage range of the oxidation has been found. It varies from 200 to 250 V. This range provides the coating formation with the following specified parameters: surface roughness of 2 – 3.5 µm; contact angles with water and glycerol of 18 - 25º and 35 - 45º, respectively, and free surface energy of 73 - 80 mN/m.

Superamphiphobic surfaces

2014 ◽  
Vol 43 (8) ◽  
pp. 2784-2798 ◽  
Author(s):  
Zonglin Chu ◽  
Stefan Seeger
Keyword(s):  
Surface Roughness ◽  
Surface Modification ◽  
Surface Energy ◽  
Energy Materials ◽  
Low Surface Energy

Progress in superamphiphobic surfaces, including the characterization, different techniques towards the fabrication of surface roughness and surface modification with low-surface-energy materials as well as their applications, is reviewed.

scholarly journals Towards a Long-Chain Perfluoroalkyl Replacement: Water and Oil Repellent Perfluoropolyether-Based Polyurethane Oligomers

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1128
Author(s):  
Liying Wei ◽  
Tugba D. Caliskan ◽  
Philip J. Brown ◽  
Igor Luzinov
Keyword(s):  
Surface Energy ◽  
Film Surface ◽  
Energy Materials ◽  
Low Surface Energy ◽  
One Step ◽  
Pet Film ◽  
Oil Repellent ◽  
Macromolecular Architecture ◽  
End Group ◽  
Long Chain

Original perfluoropolyether (PFPE)-based oligomeric polyurethanes (FOPUs) with different macromolecular architecture were synthesized (in one step) as low-surface-energy materials. It is demonstrated that the oligomers, especially the ones terminated with CF3 moieties, can be employed as safer replacements to long-chain perfluoroalkyl substances/additives. The FOPU macromolecules, when added to an engineering thermoplastic (polyethylene terephthalate, PET) film, readily migrate to the film surface and bring significant water and oil repellency to the thermoplastic boundary. The best performing FOPU/PET films have reached the level of oil wettability and surface energy significantly lower than that of polytetrafluoroethylene, a fully perfluorinated polymer. Specifically, the highest level of the repellency is observed with an oligomeric additive, which was made using aromatic diisocyanate as a comonomer and has CF3 end-group. This semicrystalline oligomer has a glass transition temperature (Tg) well above room temperature, and we associate the superiority of the material in achieving low water and oil wettability with its ability to effectively retain CF3 and CF2 moieties in contact with the test wetting liquids.

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>

Self‐Generation of Surface Roughness by Low‐Surface‐Energy Alkyl Chains for Highly Stable Superhydrophobic/Superoleophilic MOFs with Multiple Functionalities

2019 ◽  
Vol 131 (47) ◽  
pp. 17189-17196 ◽  
Author(s):  
Neng‐Xiu Zhu ◽  
Zhang‐Wen Wei ◽  
Cheng‐Xia Chen ◽  
Dawei Wang ◽  
Chen‐Chen Cao ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Energy ◽  
Alkyl Chains ◽  
Low Surface Energy

Development of non-fluorine superhydrophobic textiles using polypropylene resins

2019 ◽  
Vol 89 (19-20) ◽  
pp. 4015-4027 ◽  
Author(s):  
Jung Yoon Kim ◽  
Changsang Yun ◽  
Chung Hee Park
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Water Contact Angle ◽  
Vapor Permeability ◽  
Mixing Ratio ◽  
Water Contact ◽  
Environmental Friendliness ◽  
Drying Temperature ◽  
Low Surface Energy ◽  
Develop Environment

This study aims to develop environment-friendly superhydrophobic textiles forming nanoparticles of polypropylene that have intrinsically low surface energy, and thus achieving the requirements for superhydrophobicity, such as hierarchical roughness and low surface energy at once. This work mainly studies the influences of tacticity (isotactic, atactic), concentration (10, 20, 30 and 40 mg/ml), drying temperature (30℃ and 70℃) and the mixing ratio of the solvent/non-solvent (9:1, 8:2, 7:3 and 6:4) on the coating morphology and wettability. In the case of isotactic polypropylene, the optimal condition showing the water contact angle of 173° and the water shedding angle of 4° was at 70℃ drying temperature, 30 mg/ml concentration and 6:4 solvent/non-solvent mixing ratio. Amorphous polypropylene showed the water contact angle of 163° and the water shedding angle of 9° at the condition of 30℃ drying temperature, 40 mg/ml concentration and 8:2 solvent/non-solvent mixing ratio. It was revealed that superhydrophobicity by amorphous polypropylene was exhibited at lower drying temperature and lower mixing ratio for the non-solvent. This is attributed to the different evaporation temperature or speed of the solvent/non-solvent mixing according to the tacticity of polypropylene. This study demonstrated that environmental-friendliness was improved in that superhydrophobic textiles were developed without fluorine compounds, maintaining vapor permeability. This study also developed a finishing method using amorphous polypropylene under a mild condition in terms of drying temperature and solvent toxicity, which is expected to be applicable not only to polyester but also to various fabrics.

Self‐Generation of Surface Roughness by Low‐Surface‐Energy Alkyl Chains for Highly Stable Superhydrophobic/Superoleophilic MOFs with Multiple Functionalities

2019 ◽  
Vol 58 (47) ◽  
pp. 17033-17040 ◽  
Author(s):  
Neng‐Xiu Zhu ◽  
Zhang‐Wen Wei ◽  
Cheng‐Xia Chen ◽  
Dawei Wang ◽  
Chen‐Chen Cao ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Energy ◽  
Alkyl Chains ◽  
Low Surface Energy
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