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

2021 ◽  
Author(s):  
Rosaria Ciriminna ◽  
Cristina Scolaro ◽  
Antonino Scurria ◽  
Silvia Sfameni ◽  
Gabriella Di Carlo ◽  
...  
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 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 Superhydrophobic organosilicon-based coating system by a novel ultravoilet-curable method

2017 ◽  
Vol 7 ◽  
pp. 184798041770279 ◽  
Author(s):  
Baojiang Liu ◽  
Taizhou Tian ◽  
Jinlong Yao ◽  
Changgen Huang ◽  
Wenjun Tang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Silica Nanoparticles ◽  
Water Contact Angle ◽  
Cotton Fabric ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Water Repellent ◽  
Step Method ◽  
Water Contact

A robust superhydrophobic organosilica sol-gel-based coating on a cotton fabric substrate was successfully fabricated via a cost-effective one-step method. The coating was prepared by modification of silica nanoparticles with siloxane having long alkyl chain that allow to reduce surface energy. The coating on cotton fabric exhibited water contact angle of 151.6°. The surface morphology was evaluated by scanning electron microscopy, and surface chemical composition was measured with X-ray photoelectron spectroscopy. Results showed the enhanced superhydrophobicity that was attributed to the synergistic effect of roughness created by the random distribution of silica nanoparticles and the low surface energy imparted of long-chain alkane siloxane. In addition, the coating also showed excellent durability against washing treatments. Even after washed for 30 times, the specimen still had a water contact angle of 130°, indicating an obvious water-repellent property. With this outstanding property, the robust superhydrophobic coating exhibited a prospective application in textiles and plastics.

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.

Sustained Protection for Transparent Electrodes in Touch Panels and Smart Windows: Template Assisted Encapsulation of Fluorinated Silanes in Sol-Gel Silica Films for Sustained Hydrophobic-Oleophobic Functionality

2012 ◽  
Vol 1400 ◽  
Author(s):  
Aaron J. Kessman ◽  
Elizabeth E. DeFusco ◽  
Andrew W. Hoover ◽  
Konstantinos A. Sierros ◽  
Darran R. Cairns
Keyword(s):  
Surface Energy ◽  
Sol Gel ◽  
Silica Film ◽  
Transparent Electrodes ◽  
Silica Films ◽  
Smart Windows ◽  
Rich Phase ◽  
Low Surface Energy ◽  
Internal Surfaces ◽  
Touch Panels

ABSTRACTHydrophobic-oleophobic coatings are often used to provide the transparent electrodes in devices like touch panels and smart windows with protection from fingerprints and other contaminants which may degrade electronic and optical performance. Conventional fluorosilane monolayers or co-condensed films are often surface-enriched with fluorinated moieties due to the thermodynamic drive of these components to migrate to low-surface energy interfaces. Consequently, these conventional coatings may be strongly non-wetting and have low-surface energy when pristine, but upon wear and exposure of the bulk subsurface regions, the films are much less functional. This work explores the use of surfactant templated sol-gel silica films as scaffolds for encapsulating surface-segregating functional organic moieties as a mesoscopically dispersed phase with the goal of imparting sustained functionality. The results show that surfactant template concentration may be used to tune the dispersion of the fluorosilane-rich phase within the silica film in order to allow worn and exposed internal surfaces to maintain much of the original functionality of the pristine top surface.

The Effect of Thermal Resistance for Dropwise Condensation on Hydrophobic Micro-Pillared Structures

2012 ◽  
Author(s):  
Sara S. Beaini ◽  
Hector Mendoza ◽  
Van P. Carey
Keyword(s):  
Heat Transfer ◽  
Contact Angle ◽  
Surface Energy ◽  
Thermal Resistance ◽  
Droplet Growth ◽  
Dropwise Condensation ◽  
Textured Surfaces ◽  
Critical Question ◽  
Low Surface Energy ◽  
The Continuum

Superhydrophobic/hydrophobic surfaces, developed to promote dropwise condensation, can be produced by modifying the surface chemically with low surface energy films, and/or structurally by fabricating micro-textured surfaces. Some research has reported the increased thermal resistance from the added chemical layer and its effect on condensation heat transfer. A critical question of interest is the thermal resistance due to micro-pillared structures and their influence on droplet growth during condensation as compared to smooth or non-textured surfaces. Though idealized, this paper presents a theoretical and computational model for evaluating and quantifying the effects of the pillared structures thermal resistance, as well as the continuum versus non-continuum mechanisms affecting droplet growth during dropwise condensation. The model is used to compare different micro-pillared surfaces, cited in the literature, and to predict which micro-pillar dimensions contribute to slower condensate growth despite the higher contact angle advantage during dropwise condensation.

Study on Fluorocarbon Antifouling Coatings with Low Surface Energy

2011 ◽  
Vol 689 ◽  
pp. 445-449
Author(s):  
Chun Hong Qiu ◽  
Yu Hong Qi ◽  
Zhan Ping Zhang ◽  
Hui Gao
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Water Contact Angle ◽  
Dynamic Testing ◽  
Marine Diatom ◽  
Silicone Resin ◽  
Water Contact ◽  
Antifouling Coating ◽  
Low Surface Energy ◽  
Antifouling Coatings

To develop non-toxic marine antifouling coating, a series of antifouling coatings were prepared based on fluorocarbon copolymer. Based on the measurement of roughness and water contact angle, the attachment test of marine diatom and bacteria before and after dynamic testing in seawater, it has been investigated that the influence of three functional fillings and silicone resin on the performance of the antifouling coatings with low surface energy. The erosion rate of the coatings was measured by the samples rotated 72h at the 12 knots of simulating sailing speed. The results showed that the roughness of coatings changes from 0.2um to 3um, it does influenced slightly by the rotating test. Water contact angle of all coatings is about 100° before rotating test. It decreases to about 70° after the rotating test in seawater. Due to the increase of surface energy of the coatings, both the amount of diatom and bacteria on samples increases after rotating test in seawater.

scholarly journals The Comparison of Biocompatibility Properties between Ti Alloys and Fluorinated Diamond-Like Carbon Films

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Chavin Jongwannasiri ◽  
Nutthanun Moolsradoo ◽  
Anak Khantachawana ◽  
Pongpan Kaewtatip ◽  
Shuichi Watanabe
Keyword(s):  
Contact Angle ◽  
Surface Energy ◽  
Protein Adsorption ◽  
Electrochemical Corrosion ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Low Surface Energy ◽  
Ti Alloys ◽  
Adsorption Surface ◽  
Electrochemical Corrosion Behavior

Titanium and titanium alloys have found several applications in the biomedical field due to their unique biocompatibility. However, there are problems associated with these materials in applications in which there is direct contact with blood, for instance, thrombogenesis and protein adsorption. Surface modification is one of the effective methods used to improve the performance of Ti and Ti alloys in these circumstances. In this study, fluorinated diamond-like carbon (F-DLC) films are chosen to take into account the biocompatible properties compared with Ti alloys. F-DLC films were prepared on NiTi substrates by a plasma-based ion implantation (PBII) technique using acetylene (C2H2) and tetrafluoromethane (CF4) as plasma sources. The structure of the films was characterized by Raman spectroscopy. The contact angle and surface energy were also measured. Protein adsorption was performed by treating the films with bovine serum albumin and fibrinogen. The electrochemical corrosion behavior was investigated in Hanks’ solution by means of a potentiodynamic polarization technique. Cytotoxicity tests were performed using MTT assay and dyed fluorescence. The results indicate that F-DLC films present their hydrophobic surfaces due to a high contact angle and low surface energy. These films can support the higher albumin-to-fibrinogen ratio as compared to Ti alloys. They tend to suppress the platelet adhesion. Furthermore, F-DLC films exhibit better corrosion resistance and less cytotoxicity on their surfaces. It can be concluded that F-DLC films can improve the biocompatibility properties of Ti alloys.

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.

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