scholarly journals Facile Fabrication of a Hierarchical Superhydrophobic Coating with Aluminate Coupling Agent Modified Kaolin

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Hui Li ◽  
Mengnan Qu ◽  
Zhe Sun ◽  
Jinmei He ◽  
Anning Zhou
Keyword(s):  
Surface Modification ◽  
Coupling Agent ◽  
Cost Effective ◽  
Surface Coatings ◽  
Water Repellent ◽  
Superhydrophobic Coating ◽  
Sliding Angle ◽  
Water Contact ◽  
Facile Fabrication ◽  
Large Water

A superhydrophobic coating was fabricated from the dispersion of unmodified kaolin particles and aluminate coupling agent in anhydrous ethanol. Through surface modification, water contact angle of the coating prepared by modified kaolin particles increased dramatically from 0° to 152°, and the sliding angle decreased from 90° to 3°. Scanning electron microscopy was used to examine the surface morphology. A structure composed of micro-nano hierarchical component, combined with the surface modification by aluminate coupling agent which reduced the surface energy greatly, was found to be responsible for the superhydrophobicity. The method adopted is relatively simple, facile, and cost-effective and can potentially be applied to large water-repellent surface coatings.

The Synthesis and Surface Properties of Newly Eco-Resin Based Coconut Oil for Superhydrophobic Coating

2017 ◽  
Vol 266 ◽  
pp. 59-63
Author(s):  
Noraini Marsi ◽  
Anika Zafiah Mohd Rus ◽  
Ibrahim Mohd Razali ◽  
Syahir Arif Samsuddin ◽  
Azrin Hani Abdul Rashid
Keyword(s):  
Coconut Oil ◽  
Cost Effective ◽  
Scratch Resistance ◽  
Water Repellent ◽  
Superhydrophobic Coating ◽  
Water Contact ◽  
Pencil Hardness ◽  
Weight Percentage ◽  
Third Phase ◽  
Effective Source

The paper presents the synthesis of newly eco-resin based on coconut oil for superhydrophobic coating. Superhydrophobicity of the coating provide a self-cleaning or water-repellent characteristic that prevents peeling, thereby extend the life expectancy of the coating. The use of newly synthesized eco-resin offer a sustainable, eco-friendly and cost effective source of nature. The synthesis and formulation of different percentages of coconut oil which is 20, 40, 60 and 80 weight by weight percentage (wt/wt%) consists of three phases to form superhydrophobic coating. The first phase involved alcoholysis step, condensation step and third phase purification through alcoholysis. The adhesion test (ASTM D3359-03) results was obtained the highest classification grading of 5B for coating at 80% (wt/wt) of coconut oil with 9 layer whereas the rate of adhesion is 9.87% of the area affected. It is shows that the small flakes of coating are detached at intersections. Scratch resistance test was evaluated in terms of pencil hardness grade, which is increased from grade HB to 6H and there is minor scratch occurs for 9 layer coating. The water droplet test was demonstrated that the advancing water contact angle up to 60% of coconut oil at 169.22o with the smooth surface roughness at 0.2448 μm.

Facile Fabrication of Super-Hydrophobic Surfaces by Spray PTFE

2015 ◽  
Vol 645-646 ◽  
pp. 115-119
Author(s):  
Yang Wang ◽  
Hai Feng Zhang ◽  
Xiao Wei Liu
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
High Water ◽  
Water Repellent ◽  
Sliding Angle ◽  
Hydrophobic Property ◽  
Water Contact ◽  
Electro Deposition ◽  
Long Term Stability ◽  
Facile Fabrication

We have developed a combination of electro –deposition and spraying methods to prepare water-repellent tin oxide/ polytetrafluoroethylene(SnO2/PTFE) coating. The coating has a high water contact angle. The resulting porous and lowest surface energy hydrophobic groups (－CF3) has a water contact angle of 165° and a sliding angle of 7°, showing super-hydrophobic property. The coating with good adhesion on substrates and the long-term stability can be fabricated on various metal substrates.

scholarly journals Fabrication of superhydrophobic composite coating based on fluorosilicone resin and silica nanoparticles

2018 ◽  
Vol 5 (7) ◽  
pp. 180598 ◽  
Author(s):  
Xiaoming Wang ◽  
Xingeng Li ◽  
Qingquan Lei ◽  
Yaping Wu ◽  
Wenjing Li
Keyword(s):  
Silica Nanoparticles ◽  
Composite Coating ◽  
Room Temperature ◽  
Silica Content ◽  
Superhydrophobic Coating ◽  
Polymer Model ◽  
Modified Silica ◽  
Sliding Angle ◽  
Water Contact ◽  
Modified Silica Nanoparticles

Composite superhydrophobic coating built with film former and filler is attracting much attention for its facile and convenient fabrication, but significant limitations and disadvantages still remain. In this paper, a composite superhydrophobic coating is introduced which can be cured at room temperature and made by dispersing modified silica nanoparticles with 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane in fluorosilicone resin. Silica content and dispersion time showed obvious influences on the morphology and topography of composite coating by reuniting dispersed nanoparticles to form peaks on the surface. Excessively large distances between these peaks would decrease water contact angle value. Increasing slope of peaks, appropriate distance between peaks and decreasing diameter size of peaks would diminish sliding angle value. Formation mechanism of the composite coating based on fluorosilicone resin and modified nanoparticles was explained using interpenetrating polymer model.

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.

scholarly journals A Durable PVDF/PFOTES-SiO2 Superhydrophobic Coating on AZ31B Mg Alloy with Enhanced Abrasion Resistance Performance and Anti-Corrosion Properties

2021 ◽  
Vol 11 (23) ◽  
pp. 11172
Author(s):  
Zhiqiang Qian ◽  
Zhong Liu ◽  
Shidong Wang ◽  
XiuShen Ye ◽  
Zhijian Wu
Keyword(s):  
Contact Angle ◽  
Wear Resistance ◽  
Salt Spray ◽  
Mg Alloy ◽  
Superhydrophobic Coating ◽  
Friction Test ◽  
Sliding Angle ◽  
Sio2 Coating ◽  
Corrosion Properties ◽  
Water Contact

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.

scholarly journals Strength and Water-Repelling Properties of Cement Mortar Mixed with Water Repellents

Materials ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5407
Author(s):  
Hyeju Kang ◽  
Sukpyo Kang ◽  
Byoungky Lee
Keyword(s):  
Contact Angle ◽  
Compressive Strength ◽  
Water Contact Angle ◽  
Cement Mortar ◽  
Contact Angles ◽  
Water Repellent ◽  
Water Contact ◽  
Rapid Hardening ◽  
Before And After ◽  
Large Water

In this study, the compressive strength and water contact angle of mortar specimens prepared by mixing two types of water repellent with ordinary Portland cement (OPC) and rapid-hardening cement mortar were measured before and after surface abrasion. In addition, the hydration products and chemical bonding of cement mortar with the repellents were examined using X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (TG-DTA), and Fourier-transform infrared spectroscopy (FT-IR) to evaluate the performance of these cement mortar mixtures as repair materials. We found that the fast-hardening cement mortar mixture containing the oligomer water repellent showed the best performance with a high compressive strength and large water contact angle. With the oligomer water repellent, the rapid-hardening cement mortar mixture showed contact angles of 131° and 126° even after a 2 mm abrasion, thereby confirming that the water repellent secured hydrophobicity through strong bonding with the entire cement mortar as well as its surface. The compressive strengths were found to be 34.5 MPa at 3 h and 54.8 MPa at 28 days, confirming that hydration occurred well despite the addition of water repellent.

scholarly journals Functional Superhydrophobic Coating Systems for Possible Corrosion Mitigation

2020 ◽  
Vol 14 (2) ◽  
pp. 148-158 ◽  
Author(s):  
Sarah F. Jurak ◽  
◽  
Emil F. Jurak ◽  
Md. Nizam Uddin ◽  
Ramazan Asmatulu
Keyword(s):  
Sol Gel ◽  
Chemical Vapor ◽  
Layer By Layer ◽  
Superhydrophobic Coating ◽  
Sliding Angle ◽  
One Pot ◽  
Water Contact ◽  
Superhydrophobic Coatings ◽  
Run Off ◽  
Self Cleaning

Because of their repellent, corrosion-mitigating, anti-icing, and self-cleaning properties, superhydrophobic coatings have numerous applications from windshields to textiles. A superhydrophobic coating is defined as one having a water contact angle (WCA) greater than 150° with a surface sliding angle less than 10°, and very low hysteresis between the advancing and receding angles. Its surface exhibits the so-called “lotus leaf effect,” whereby water bounces and balls up on contact. Here, water droplets run off readily, taking along dirt and dust for a self-cleaning effect that keeps the surface dry. The chemical composition of a surface affects the WCA, which can rise to 120°, but to achieve a WCA greater than 150°, which is considered superhydrophobic, an additional micro- and nanostructural component is needed. This functional hierarchical micro- and nanomorphology is exhibited in nature by plants and insects. A superhydrophobic coating on metallic substrates promises to provide corrosion mitigation by blocking oxygen and electrolytes, which are needed for the initiation of corrosion at the surface and interface. The methods used for preparing functional superhydrophobic coatings include sol-gel processing, layer-by-layer assembly, etching, lithography, chemical and electrochemical depositions, chemical vapor deposition, electrospinning, hydrothermal synthesis, and one-pot reactions. In this work, some research studies conducted to develop robust and durable superhydrophobic coatings are discussed in detail and analyzed for possible corrosion mitigation on the surfaces of metals and alloys. Scientists, engineers, students, and other participants in automotive, aircraft, energy, defense, electronics, and other industries will benefit greatly from this work.

scholarly journals Superhydrophobic Al2O3–Polymer Composite Coating for Self-Cleaning Applications

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1162
Author(s):  
Rajaram S. Sutar ◽  
Saravanan Nagappan ◽  
Appasaheb K. Bhosale ◽  
Kishor Kumar Sadasivuni ◽  
Kang-Hyun Park ◽  
...  
Keyword(s):  
Composite Coating ◽  
Research Work ◽  
Water Repellency ◽  
Dip Coating ◽  
Industrial Applications ◽  
Water Repellent ◽  
Al2o3 Nanoparticles ◽  
Sliding Angle ◽  
Water Contact ◽  
Self Cleaning

Superhydrophobic coatings have a huge impact in various applications due to their extreme water-repellent properties. The main novelty of the current research work lies in the development of cheap, stable, superhydrophobic and self-cleaning coatings with extreme water-repellency. In this work, a composite of hydrothermally synthesized alumina (Al2O3), polymethylhydrosiloxane (PMHS) and polystyrene (PS) was deposited on a glass surface by a dip-coating technique. The Al2O3 nanoparticles form a rough structure, and low-surface-energy PHMS enhances the water-repellent properties. The composite coating revealed a water contact angle (WCA) of 171 ± 2° and a sliding angle (SA) of 3°. In the chemical analysis, Al2p, Si2p, O1s, and C1s elements were detected in the XPS survey. The prepared coating showed a self-cleaning property through the rolling action of water drops. Such a type of coating could have various industrial applications in the future.

scholarly journals One-Step Potentiostatic Deposition of Micro-Particles on Al Alloy as Superhydrophobic Surface for Enhanced Corrosion Resistance by Reducing Interfacial Interactions

Coatings ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 392 ◽  
Author(s):  
Tian Shi ◽  
Xuewu Li ◽  
Qiaoxin Zhang ◽  
Ben Li
Keyword(s):  
Corrosion Resistance ◽  
Al Alloys ◽  
Water Repellent ◽  
Al Alloy ◽  
Interfacial Interactions ◽  
Sliding Angle ◽  
Water Contact ◽  
Corrosion Failure ◽  
Micro Particles ◽  
One Step

Corrosion failure is a thorny problem that restricts the application of Al alloys. As a new technique for functional realization, hydrophobic preparation offers an efficient approach to solve corrosion problem. This work has developed a facile and low-cost method to endow Al alloy with enhanced water-repellent and anticorrosion abilities. The micro-particles have been firstly prepared by one-step deposition process. Furthermore, wetting and electrochemical behaviors of as-prepared structures have been investigated after silicone modification. Results show that the fabricated surface possesses excellent superhydrophobicity with a water contact angle (CA) of 154.7° and a sliding angle (SA) of 6.7°. Meanwhile, the resultant surface is proved with enhanced corrosion resistance by reducing interfacial interactions with seawater, owing to newly-generated solid-air-liquid interfaces. This work sheds positive insights into extending applications of Al alloys, especially in oceaneering fields.

Hydrophobization of epoxy nanocomposite surface with 1H,1H,2H,2H-perfluorooctyltrichlorosilane for superhydrophobic properties

Open Physics ◽  
2012 ◽  
Vol 10 (5) ◽  
Author(s):  
Maciej Psarski ◽  
Jacek Marczak ◽  
Grzegorz Celichowski ◽  
Grzegorz Sobieraj ◽  
Konrad Gumowski ◽  
...  
Keyword(s):  
Surface Treatment ◽  
Contact Angles ◽  
Alumina Nanoparticles ◽  
Water Repellent ◽  
Sliding Angle ◽  
Water Contact ◽  
Epoxy Nanocomposite ◽  
Liquid Phases ◽  
Modified Surfaces ◽  
The Hierarchical Structure

AbstractNature inspires the design of synthetic materials with superhydrophobic properties, which can be used for applications ranging from self-cleaning surfaces to microfluidic devices. Their water repellent properties are due to hierarchical (micrometer- and nanometre-scale) surface morphological structures, either made of hydrophobic substances or hydrophobized by appropriate surface treatment. In this work, the efficiency of two surface treatment procedures, with a hydrophobic fluoropolymer, synthesized and deposited from 1H,1H,2H,2H-perfluorooctyltrichlorosilane (PFOTS) is investigated. The procedures involved reactions from the gas and liquid phases of the PFOTS/hexane solutions. The hierarchical structure is created in an epoxy nanocomposite surface, by filling the resin with alumina nanoparticles and micron-sized glass beads and subsequent sandblasting with corundum microparticles. The chemical structure of the deposited fluoropolymer was examined using XPS spectroscopy. The topography of the modified surfaces was characterized using scanning electron microscopy (SEM), and atomic force microscopy (AFM). The hydrophobic properties of the modified surfaces were investigated by water contact and sliding angles measurements. The surfaces exhibited water contact angles of above 150° for both modification procedures, however only the gas phase modification provided the non-sticking behaviour of water droplets (sliding angle of 3°). The discrepancy is attributed to extra surface roughness provided by the latter procedure.

Sign in / Sign up

Export Citation Format

Share Document