Pipeline steel has been widely used in modern industry such as the transportation of natural gas and oil. However, its service life is mainly affected by the corrosion because of its hydrophilic and oleophilic properties. In this study, the surface of X80 pipeline steel was converted to be of super-hydrophobicity and oleophobicity by acid etching and fluoride modification. The steel was first etched by a mixed acid solution to roughen its surface, and then modified with a kind of low surface energy material, 1H, 1H, 2H, 2H-Perfluorodecyltriethoxysilane. The fluoride modification can reduce the surface energy, which is an essential step to prepare the amphiphobic surface. The influence of acid etching and modification on the morphology and the wetting behavior of the modified surface was characterized and the corrosion behavior of the amphiphobic surface was studied by potentiodynamic scanning. The result showed that the modified amphiphobic surface exhibits excellent both of hydrophobicity and oleophobicity, for substances such as water, glycerin and ethylene glycol, as well as hexadecane. After 4 h etching and fluoride modification, the contact angles of the modified steel with deionized water, glycerin, ethylene glycol and hexadecane were 161°, 156°, 151.5° and 146° respectively. The modified surface can enhance the corrosion resistance of the pipeline steel and such amphiphobic surface can be easily repaired.
材料的润湿性是物体表面的一个重要特征,在人们的日常与工农业生产中都发挥着重要的作用。润湿通常是指固体表面上的气体被液体取代的过程。常用接触角 (CA) 作为液体对固体润湿程度的判据,将CA<90°的表面称为亲液表面,把CA>90° 的表面称为疏液表面。特别地,CA=0°为完全润湿表面;CA=180°为完全不润湿表面。通过对实际运用中固体表面润湿现象的研究,人们提出了超亲液和超疏液的概念。当CA<5°时,固体表面为超亲液表面;当CA>150°时,固体表面为超疏液表面[1-8]。自然界中许多动植物表面具有疏水疏油甚至是超疏水疏油的特性,比如荷叶、蝴蝶的翅膀、蝉的翼面和水黾的腿表面等。研究自然界动植物现有的超疏水表面结构,研究结构与性能之间的关系,对人工制备具有超疏水功能的表面有重要的意义[9-15]。
本文通过混合酸液的刻蚀方法,成功地在X80管线钢表面制备出超疏水疏油表面,并通过电化学测试方法研究了双疏表面在3.5% (质量分数) NaCl溶液中的耐蚀性能。
实验采用X80管线钢作为研究对象,样品尺寸为20 mm×10 mm×3 mm,整个表面用环氧树脂固封后用抛光机打磨至完整地裸露一个表面。混酸溶液配置方法如下：在磁力搅拌的作用下,将20 mL双氧水和30 mL浓度为10 mol/L的尿素溶液缓慢的倒入80 mL去离子水中,然后加入70 mL浓度为25 mol/L的草酸溶液,再滴入若干滴丙三醇,最后依次加入700 μL硫酸和50 μL盐酸并搅拌均匀。以上所用的试剂纯度规格全部为分析纯。
将预处理过的X80钢试样放入酸性溶液中刻蚀一定的时间,刻蚀结束后取出,分别用蒸馏水和无水乙醇洗净、吹干备用。配制一定体积分数的十七氟癸基三乙氧基硅烷 (HFTTMS) 的乙醇溶液：使用移液枪量取45 μL的氟硅烷,注入到15 mL乙醇溶液中,然后超声分散20 min。将刻蚀后的试样浸泡在氟化液中修饰20 min,修饰结束后取出,放入60 ℃真空干燥箱中烘干30 min即可。
通过JC2000C1型接触角测量仪表征试样与去离子水、丙三醇、乙二醇和十六烷的接触角,每一种液体与试样的接触角测量5次,最后取平均值。通过JSM-6700F型冷场发射扫描电子显微镜 (FE-SEM) 观察试样经过酸性刻蚀后的表面微观形貌。通过D8 ADVANCE 型X射线衍射仪 (XRD) 表征酸性刻蚀前后样品的化学组分。通过INCA Energy, Oxford135Ins 型能谱仪 (EDS) 和ESCALAB 250Xi 型X射线光电子能谱 (XPS) 表征氟化处理前后样品表面化学成分及存在状态。通过CHI600E型电化学分析仪测试试样的动电位极化曲线。
通过电化学三电极体系测试了X80管线钢初始试样和酸性刻蚀4 h并经氟化处理的双疏试样在3.5%NaCl溶液中的极化曲线。测试之前,试样需要浸泡在NaCl溶液中约40 min,以使电极电位稳定。极化曲线测试结果如
The authors have declared that no competing interests exist.
Through evolution, nature has arrived at what is optimal. Inspired by the biomaterials with special wettability, superhydrophobic materials have been well-investigated and -covered by several excellent reviews. The construction of superoleophobicity is more difficult than that of superhydrophobicity because the surface tension of oil or other organic liquids is lower than that of water. However, superoleophobic surfaces have drawn a great deal of attention for both fundamental research and practical applications in a variety of fields. In this contribution, we focus on recent research progress in the design, fabrication, and application of bio-inspired superoleophobic and smart surfaces, including superoleophobic鈥搒uperhydrophobic surfaces, oleophobic鈥揾ydrophilic surfaces, underwater superoleophobic surfaces, and smart surfaces. Although the research of bio-inspired superoleophobicity is in its infancy, it is a rapidly growing and enormously promising field. The remaining challenges and future outlook of this field are also addressed. Multifunctional integration is a inherent characteristic for biological materials. Learning from nature has long been a source of bio-inspiration for scientists and engineers. Therefore, further cross-disciplinary cooperation is essential for the construction of multifunctional advanced superoleophobic surfaces through learning the optimized biological solutions from nature. We hope this review will provide some inspirations to the researchers in the field of material science, chemistry, physics, biology, and engineering.
We have demonstrated a simple and cost-effective technique for the large-area fabrication of a superoleophobic surface using copper as a substrate. The whole process included three simple steps: First, the copper substrate was oxidized under hot alkaline conditions to fabricate flower-like copper oxide microspheres by heating at a particular temperature for an interval of time. Second, the copper-oxide-covered copper substrate was further heated in a solution of cobalt nitrate and ammonium nitrate in the presence of an ammonia solution to fabricate cobalt oxide nanostructures. We applied this second step to increase the surface roughness because it is an important criterion for improved superoleophobicity. Finally, to reduce the surface energy of the fabricated structures, the surfaces were chemically modified with perfluorooctyltrichlorosilane. Contact-angle measurements indicate that the micro鈥搉ano binary (MNB) hierarchical structures fabricated on the copper substrate became super-repellent toward a broad range of liquids with surface tension in the range of 21.5鈥72mN/m. In an attempt to significantly improve the superoleophobic property of the surface, we also examined and compared the role of nanostructures in MNB hierarchical structures with only micro-fabricated surfaces. The fabricated MNB hierarchical structures also displays thermal stability and excellent long-term stability after exposure in air for more than 9 months. Our method might provide a general route toward the preparation of novel hierarchical films on metal substrates for various industrial applications.
Hydrophobicity and sliding behavior of water droplets were investigated on various hydrophobic pillarlike and groove structures prepared on a silicon wafer by dicing and subsequently coating with fluoroalkylsilane. The dominant hydrophobicity mode was changed from Wenzel's mode to Cassie's mode at a smaller roughness than that expected from the calculation based on the sinusoidal surface by Johnson and Dettre. The effect of water intrusion on the microstructure due to droplet weight was revealed to be an important factor governing the water sliding angle on the surface. In a comparison of the sliding behavior of water droplets over pillarlike and groove structures, it was demonstrated that a proper design of the surface with respect to shape and extent of the three-phase line is more effective than the increase of contact angles merely by decreasing the solid-water contact area.
A facile laser-etching method was used for the one-step creation of various controllable dimensions of anisotropic micropatterns consisting of an alternating arrangement of microgrooves and microstripes with rugged nanoprotrusions, which after modified with fluoroalkylsilane reagent, showed perfect isotropic superhydrophobicity without apparent CA hystereses, water adhesion, and drag resistance, other than the conventional view of anisotropic surface microstructures with anisotropic surface dewetting. The detailed experiments and analyses have indicated that the introduction of the rugged nanoprotrusions on the surface of microstripes provided ideal 3D roughness, which could not only enhance the apparent contact angles close to 180 degrees by the "point" contact fashion to maximally reduce the liquid-solid contact area but, most importantly, make droplets easily roll off the surface without apparent CA hysteresis by regulating the triple-phase contact line (TCL) to become extremely discrete. These findings would be helpful in understanding the role of complex micro- and nanostructures on natural superhydrophobic biosurfaces and guiding the design of perfect artificial superhydrophobic materials for technological innovations such as the raindrop easy-cleaning, aquatic super-floating, and drag-reducing coatings.
Coating is an essential step in adjusting the surface properties of materials. Superhydrophobic coatings with contact angles greater than 150° and roll-off angles below 10° for water have been developed, based on low-energy surfaces and roughness on the nano- and micrometer scales. However, these surfaces are still wetted by organic liquids such as surfactant-based solutions, alcohols, or alkanes. Coatings that are simultaneously superhydrophobic and superoleophobic are rare. We designed an easily fabricated, transparent, and oil-rebounding superamphiphobic coating. A porous deposit of candle soot was coated with a 25-nanometer-thick silica shell. The black coating became transparent after calcination at 600°C. After silanization, the coating was superamphiphobic and remained so even after its top layer was damaged by sand impingement.
In the 19th century, Oscar Wilde stated "We live, I regret to say, in an age of surfaces". Today, we do so even more, and we do not regret it: key advances in the understanding and fabrication of surfaces with controlled wetting properties are about to make the dream of a contamination-free (or 'no-clean') surface come true. Two routes to self-cleaning are emerging, which work by the removal of dirt by either film or droplet flow. Although a detailed understanding of the mechanisms underlying the behaviour of liquids on such surfaces is still a basic research topic, the first commercial products in the household-commodity sector and for applications in biotechnology are coming within reach of the marketplace. This progress report describes the current status of understanding of the underlying mechanisms, the concepts for making such surfaces, and some of their first applications.
Abstract Silicon surface hydrophobicity has been varied by using silane treatments on silicon pyramid surfaces generated by KOH anisotropic etching. Results demonstrated that by altering the surface hydrophobicity, the apparent contact angle changed in accord with the Wenzel equation for surface structures with inclined side walls. Hierarchical structures were also constructed from Si pyramids where nanostructures were added by Au-assisted electroless HF/H2O2 etching. Surface hydrophobicity and superhydrophobicity were achieved by surface modification with a variety of silanes. Stability of the Cassie state of superhydrophobicity is described with respect to the Laplace pressure as indicated by the water droplet meniscus in contact with the hierarchical structures. The contact angle hysteresis observed is also discussed with respect to water/substrate adhesion.
AbstractA superamphiphobic (super-repellent) surface with both water and rapeseed oil contact angle higher than 150° was prepared on a common cast iron substrate. The water and rapeseed oil contact angles were 15802±021.9° and 15102±021.7°, respectively. The sliding angles of water and rapeseed oil on the superamphiphobic surface were 2° and 16°, respectively. Scanning electron microscope images showed that many interesting microflower-like microstructures comprised many nanorods with the average diameter of about 20002nm, which were distributed on the superamphiphobic cast iron substrate. Each nanorod was composed of many smaller nanostructures and nano particles, which created interesting micro–nano binary structures similar to the surface microstructures of lotus leaves. When kept in an ambient environment for 602months, no rust was observed on the superamphiphobic cast iron substrate surface, which showed excellent corrosion resistance.
In this Article, superhydrophobic CuO surfaces with di02erent topographies have been fabricated by combining both a simple solution-immersion process and self-assembly of 04uoroalk- ylsilane. We regulate the solution-immersion process by changing the immersion time, the growing temperature, and the solution compositions to control di02erent topographies of CuO surfaces. The as-prepared superhydrophobic surfaces possess tunable water adhesion that ranges from extremely low to very high, on which the sliding angle is 3 ( 1, 12 ( 1, 28 ( 2, 39 ( 2, and 90 (the water droplet is 03rmly pinned on the superhydrophobic surface without any movement at any tilted angles), respectively. Our work provides a facile and promising strategy to fabricate superhydrophobic surfaces with tunable adhesion.
A superhydrophobic-carbon fibre (CF) layer with enhanced corrosion inhibition ability was catalytically grown on a Zn surface. Cu, which was produced by a galvanic replacement reaction, acted as a catalyst for CF growth. The contact angle and water repellence properties of the grown materials were measured to determine their superhydrophobicity. The potentiodynamic polarisation technique revealed the corrosion inhibition capabilities of the different materials used. Compared with bare Zn, the superhydrophobic Zn-CF material showed enhanced corrosion inhibition properties. During immersion in NaCl solution, perforations caused by capillary condensation decreased the superhydrophobicity of the materials and limited their corrosion inhibition capabilities. (C) 2012 Elsevier Ltd. All rights reserved.
This work reports a novel method involving anodic oxidation and a self-assembly process for controllable fabrication of a robust superhydrophobic aluminum (Al) alloy surface. The superhydrophobic surface with a water contact angle of 157.5 卤 0.5掳 and a sliding angle of 3 卤 0.7掳 is derived from its hierarchical micro-nanostructure and the assembly of low surface energy fluorinated components on it. Furthermore, the transformation from superhydrophilicity to superhydrophobicity can be achieved by adjusting the modification process for the constructed surface. The anti-scratch tests show that the superhydrophobic surface has good mechanical stability. It maintains superhydrophobicity after mechanical abrasion against P400 grit SiC sandpaper for 0.4 m and P800 grit sandpaper for 0.8 m, at the applied pressure of 3.60 kPa. The potentiodynamic polarization and electrochemical impedance spectroscopy tests show that the as-prepared superhydrophobic surface has excellent corrosion resistance. In addition, the as-prepared superhydrophobic surface has self-cleaning ability and good long-term stability. It is believed that the facile fabrication process offers an effective and promising application for fabricating a robust, anticorrosive and large scale superhydrophobic Al alloy surface.
Zinc oxide (ZnO) films with well-controlled morphologies have been prepared by electrochemical deposition. The different morphologies investigated are (i) flat and compact films, (ii) arrays of hexagonal nanocolumns, (iii) mesoporous films with open pores, and (iv) mesoporous films with pores filled with a surfactant (sodium dodecyl sulfate). Increasing the volume of voids in the film or the roughness gives rise to a dramatic increase in the layer wettability. The presence of surfactant in the film and/or the post-deposition binding of an alkylsilane (octadecylsilane) yield hydrophobic surfaces with contact angles measured as high as 145 鈭 after an optimized silane adsorption process.
Biomimetic research indicates that many phenomena regarding wettability in nature, such as the self-cleaning effect on a lotus leaf and cicada wing, the anisotropic dewetting behavior on a rice leaf, and striking superhydrophobic force provided by a water strider's leg, are all related to the unique micro- and nanostructures on the surfaces. It gives us much inspiration to realize special wettability on functional surfaces through the cooperation between the chemical composition and the surface micro- and nanostructures, which may bring great advantages in a wide variety of applications in daily life, industry, and agriculture. This Account reviews recent progress in these aspects.
Hierarchical structure of flower-like CuO standing on Cu(OH)
Bamboo remains a vital component of modern-day society; however, its use is severely limited in certain applications because of its hydrophilic and oleophilic properties. In this work, we present a method to render bamboo surfaces superamphiphobic by combining control of ZnO nanostructures and fluoropolymer deposition while maintaining their corrosion resistance. Large-scale rose-like ZnO nanoflowers (RZN) were planted on the bamboo surface by a hydrothermal method. After fluoroalkylsilane (FAS) film deposition to lower the surface energy, the resulting surface showed superamphiphobicity toward water, oil, and even certain corrosive liquids, including salt solutions and acidic and basic solutions at all pH values. The as-prepared superamphiphobic bamboo surface was durable and maintained its superhydrophobic property with water contact angles >150掳 when stored under ambient condition for two months or immersed in a hydrochloric acid solution of pH 1 and a sodium hydroxide solution of pH 14 for 3h at 50掳C.
Free energy was measured for the surface of regular aligned closest hexagonal packed -CF3 groups. n-Perfluoroeicosane was vapor deposited onto glass, which gave epitaxially grown single-like crystallites with their molecular axes perpendicular to the glass surface. The dynamic contact angle of water on its surface was 119 degrees, which corresponds to a surface free energy of 6.7 mJ/m(2). This value is considered to be the lowest surface free energy of any solid, based on the hexagonal closed alignment of -CF3 groups on the surface.
The fabrication of a superhydrophobic surface is demonstrated via a wet chemical route, and this method offers advantages of being cleanroom free, cost efficiency, and wide applicability. The preferable growth of ZnO crystalline forms a microstructured surface, and a variety of alkanoic acids were adopted to tune the surface wettability. Although all surfaces show an advancing contact angle greater than 150°, they substantially differ in the wetting mechanisms. It is found that only when the length of alkanoic acid is greater than 16, the microstructured surface shows a stable superhydrophobicity, in which the Cassie state dominates. While for those moderate-length alkanoic acids (C861C14), their corresponding surfaces have a tendency to fall into the Wenzel state and display a great contact angle hysteresis.
Preparation of superhydrophobic silica-based thin film by adjusting different concentration of reverse (W/O) emulsion of resorcinol formaldehyde resin (re-RF) which was hybridised with silica sol has been developed. The hybrid films were coated by the mixing solution which included precursor solution (sol–gel process) and re-RF (sol–gel process). Rough surfaces were obtained by removing the organic polymer at high temperature and then the hydrophobic groups bonded onto the films were obtained by the reaction with trimethylchlorosilane (TMCS). Characteristic properties of the as-prepared cross-section and surface of the films were analyzed by scanning electron microscopy (SEM) and atom force microscopy (AFM). The experimental parameters are mainly varied the weight ratio of re-RF to silica sol from 0.2 to 4.0. The result showed that the contact angle of the modified silica film was greater than 160° when the weight ratio of re-RF to silica sol was 2.0.
Eine blumenkohlartige Oberflche (siehe Bild, Maßstab: 8 μm) und Perfluorkohlenstoffketten am Polymerrückgrat bewirken, dass der Film aus dem gezeigten fluorierten Polythiophen, der elektrochemisch auf einer Indiumzinnoxid-Oberflche abgeschieden wurde, sowohl superwasser- als auch ölabstoßend ist. Der Einschub ist ein Foto eines Wassertropfens auf der Oberflche (Kontaktwinkel>150°).
ABSTRACT Super-hydrophobic surfaces, with a water contact angle (CA) greater than 150掳, have attracted much interest for both fundamental research and practical applications. Recent studies on lotus and rice leaves reveal that a super-hydrophobic surface with both a large CA and small sliding angle () needs the cooperation of micro- and nanostructures, and the arrangement of the microstructures on this surface can influence the way a water droplet tends to move. These results from the natural world provide a guide for constructing artificial super-hydrophobic surfaces and designing surfaces with controllable wettability. Accordingly, super-hydrophobic surfaces of polymer nanofibers and differently patterned aligned carbon nanotube (ACNT) films have been fabricated.
A simple solution-immersion technique was developed for the fabrication of a superamphiphobic surface on the copper sheet. Hierarchical structure composed of nanorod arrays and microflowers was formed on the copper surface by an alkali assistant oxidation process; after fluorination, the surface became super-repellent toward water and several organic liquids possessing much lower surface tension than that of water, such as hexadecane. Such superamphiphobicity is attributed to the synergistic effect of their special surface chemicals and microscopic structures, which allows for the formation of a composite interface with all probing liquids tested. We also discuss the effects of surface chemical constituent and geometrical structure on hydrophobicity and oleophobicity; such information allows us to engineer surfaces with specific oleophobic behavior. Additionally, the stability of the composite interface on the created superamphiphobic surface is studied by the compression and immersion test.
The amphiphobic surface has extremely broad application prospects in industrial production and daily life, such as preventing the adhering and fouling of materials and prolonging service life. In order to prepare an amphiphobic surface on X70 pipeline steel, a simple method was presented. The rough surface was created by shot blasting and chemical etching, consisting of micro-nano composite structures. The surface was then chemically modified by a low surface energy material, which contains a fluorocarbon group. The surface morphology, roughness, chemical composition, and wettability with distilled water and peanut oil were studied by field emission scanning electron microscopy, confocal microscopy, energy dispersive spectrometer, and contact angle measurement instruments. The results indicated that a micro-nano composite structure was created on the steel surface after shot blasting and chemical etching. The amphiphilic surface with micro-nano structure turned into an oleophobic and superhydrophobic surface after being chemically modified by low surface energy material. The maximum contact angles of the amphiphobic surface with distilled water and peanut oil were up to 15002±021° and 14002±021°, respectively.
ABSTRACT The facile creation of a super-amphiphobic coating surface with bionic microstructure was discussed. The two easily synthesized polymeric materials, poly(methyl methacrylate) (PMMA) and fluorine-end-capped polyurethane (FPU) were captured for the coating. The scanning electron microscopy (SEM) was used to observe the microstructure of the polymer surface obtained by castings. It was found that the coating film prepared from a FPU/PMMA mixture had a rough micro-nano binary structure (MNBS), that was, every micro-papilla (300-700 nm) on the polymeric surface.
Zinc-laurylamine complex film with super-hydrophobicity is fabricated on zinc surface with electrolysis method. Super-hydrophobicity of film results from papillae and ridge-like structures, which form due to uneven corrosion of zinc at high anodic potential. The film obtained can maintain super-hydrophobic property in solution system, and can inhibit corrosion effectively. However, saline water penetrates into super-hydrophobic film during deliquescence process of NaCl particle in simulated marine environment. This behavior is induced by capillary condensation in groove of film, and it declines the advantage of using super-hydrophobic film as corrosion barrier in marine atmosphere. (C) 2012 Elsevier Ltd. All rights reserved.
The present work reports a simple and safe two-step process to render magnesium (Mg) alloy surfaces superhydrophobic via primary cell corrosion and subsequently cover it with a fluoroalkylsilane (FAS) film. The surfaces were characterized by scanning electron microscopy (SEM), optical microscopy, energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectrophotometry (FTIR), X-ray diffraction (XRD), and optical contact angle measurements. The power generated via the primary cell corrosion of copper and Mg alloys was also measured using a digital multimeter. The results show that micro/nanometer-scale binary rough structures and an FAS film with a low surface energy were present on the Mg alloy surfaces, both of which confer good superhydrophobicity with a water contact angle of 162.8 degrees and a tilting angle of 2 degrees. The micro/nanometer-scale binary rough structures consisted of micrometer-scale grains, cluster-like structures composed of nanometer-scale needles, and network-like structures composed of nanometer-scale sheets. Superhydrophobicity was analyzed by the Cassie-Baxter theory. Findings show that only about 6.3% of the water surface was in contact with the Mg alloy substrates, while the remaining 93.7% was in contact with the air cushion. The unique advantage of the proposed method is that power can be generated during the machining process of the superhydrophobic surfaces on the Mg alloy substrates.