耐腐蚀超疏水超亲油不锈钢网的制备及其在油水分离过程中的应用

以不锈钢网为基底,通过化学刻蚀法制备微米级粗糙表面,通过一步浸泡法将st9ber法制得的疏水亲油纳米Si O2颗粒沉积到粗糙的不锈钢网表面,制备了具有微纳二级粗糙结构的超疏水超亲油不锈钢网。利用扫描电子显微镜(SEM)、傅里叶变换红外光谱仪(FT-IR)和接触角测量仪(CA)表征了超疏水超亲油不锈钢网的表面形貌、化学组成和润湿性能,并将其用于油水分离过程中。结果表明,疏水亲油纳米Si O2颗粒成功的沉积到不锈钢网表面;水滴在超疏水超亲油不锈钢网上的接触角最大为151°,煤油的接触角为0°;制备的超疏水超亲油不锈钢网不仅能高效的分离不同种类油和水的混合物,还能高效的分离油和腐蚀性液体(强酸或强碱水溶液)的混合物,其耐腐蚀特性可满足复杂环境下的油水分离要求。     

High stability superhydrophobic glass-ceramic surface with micro–nano hierarchical structure

Inspired by the surface structure of lotus leaves, micro–nano hierarchical surface structures have been widely used for designing superhydrophobic surfaces. However, the conventionally designed superhydrophobic surface structures are fragile. In this study, a layer of micron-sized mullite whiskers was grown using molten salt on the surface of BaAl₂Si₂O₈ (BAS) glass ceramics. Subsquently, SiO₂ nanoparticles modified with 1H,1H,2H,2H-perfluorodecyltriethoxysilane were sprayed onto the whisker layer to form a superhydrophobic surface. The nanoparticles exhibit superhydrophobicity, which is protected by the whisker layer containing pores and bulges. This prohibits direct contact between the nanoparticles and external objects. Contact and rolling angle tests indicated that the surface contact angle of the micro–nano hierarchical structure is 158° and the rolling angle is less than 10°. The stability of the superhydrophobic surface was tested through ultraviolet light, long-time immersion in solutions with various pH values, water scouring, and sandpaper abrasion. The results showed that the contact angle is greater than 150°. This study is expected to provide a simple and effective method for fabricating superhydrophobic surfaces on ceramics on a large scale.     

A rapid two-step electroless deposition process to fabricate superhydrophobic coatings on steel substrates

The present study reports a simple, highly effective, and safe two-step electroless deposition process for rapidly fabricating superhydrophobic Ag coatings on steel substrates. The steel plates were first immersed in the 1?mol/L aqueous CuSO₄ solution for 20?s, and then immersed in the 0.03?mol/L aqueous AgNO₃ solution containing 1?wt% fluoroalkylsilane (FAS) for 2?min. The sample surfaces were characterized by energy-dispersive x-ray spectroscopy, Fourier transform infrared spectrophotometry (FTIR), x-ray diffraction, scanning electron microscopy, step profiler, and optical contact angle measurements. The results show that, after the two-step electroless deposition process, the Ag coatings composed of the binary micro/nanometer-scale rough structures containing the FAS molecules with a low surface energy are formed on the steel surfaces. The as-prepared Ag coatings exhibit a good superhydrophobicity with a 163.4?±?1.8° water contact angle and 1.5?±?0.5° rolling angle.     

Superhydrophobic and oleophilic micro‐nano hierarchical Pd‐decorated SiO2 layers

This paper reports a novel fluorinated micro‐nano hierarchical Pd‐decorated SiO₂ structure (hereafter called Pd/SiO₂), which was formed by the deposition of Pd nanoparticles (NPs) on SiO₂ microspheres. The SiO₂ layers with microscale roughness were fabricated by electrospraying a solution prepared using the sol‐gel process. Subsequently, the Pd NPs were deposited using an ultraviolet reduction process. The resulting surfaces exhibited a micro‐nano hierarchical morphology. After fluorination, the micro‐nano hierarchical surface exhibited outstanding water repellency with a water contact angle (WCA) of 170° and a sliding angle <5°, indicating excellent superhydrophobic properties. The layers exhibited good long‐term durability and excellent ultraviolet resistance. Interestingly, the surface was oleophilic (CA of oil ~10°). These results show the potential of employing superhydrophobic fluorinated Pd/SiO₂ layers in smart devices, such as self‐cleanable surfaces and intelligent water/oil separation systems.     

Mechanical,chemical and wetting properties of a superhydrophobic surface based on functionalized ZrO2 on stainless steel

A stable superhydrophobic FAS-ZrO₂ (FZr-ESS) surface was created by chemically etching and modifying a 304 stainless steel substrate. The effect of etching parameters such as time and temperature on the surface wetting properties was studied and optimized. The etched steel surface exhibited a honeycomb-like microstructure that, coupled with the low surface energy of the fluorinated ZrO₂ nanoparticles, produced a FZr-ESS surface with a surface contact angle (CA) of 165.9° and a sliding angle (SA) of 1.7°. The presence of highly stable functionalized ZrO₂ conjugated to the steel matrix contributed to the surface's outstanding mechanical stability, as confirmed by tape peeling and sandpaper abrasion tests. Furthermore, the FZr-ESS surface demonstrated exceptional chemical stability under a variety of pH conditions due to its excellent water repellency. An electrochemical test showed that the resulting surface was highly resistant to corrosion, with the corrosion current density reduced by nearly two orders of magnitude compared to bare stainless steel. The superhydrophobic FZr-ESS surface also displayed excellent long-term stability, wetting diversity, and self-cleaning behavior, making it highly versatile for a range of applications.     

CNCs增强相分离法构建PVDF/PDMS超疏水表面

采用非诱导相分离法，通过将纤维素纳米晶（CNCs）与两种聚合物（聚偏二氟乙烯和聚二甲基硅氧烷）进行结合，利用CNCs之间的静电排斥力及其高比表面积特性，有效降低相分离过程中聚合物的聚集，减小了颗粒尺寸，增强了颗粒分散性，在棉布、木板和玻璃表面构造了精细均匀的微纳米粗糙结构。采用FTIR、SEM、AFM、接触角测量仪、3D光学轮廓仪对CNCs和超疏水表面的形貌、结构和超疏水性进行表征。研究发现，棉布、木板和玻璃表面的水接触角分别最高可达158 °、156.8 °和153.8 °，滚动角最低分别为2 °、2.7 °和3.4 °，呈现出明显的超疏水特征。经过机械摩擦（500余次）、酸碱处理（pH 1～13）、温度变化（–40～40°C）以及紫外光照射（0～320 h）后，基材表面仍具有较好的超疏水性。此外，基材具有优异的自清洁性和油水分离效率，超疏水棉布的最高分离效率可达98.4%。     

Preparation, characterization and wettability of porous superhydrophobic poly (vinyl chloride) surface

A porous superhydrophobic poly (vinyl chloride) surface was obtained by a simple approach. The water contact angle and the sliding angle of the superhydrophobic poly(vinyl chloride) surface were 154 ± 2.3o and 7o, respectively. The porous superhydrophobic PVC surface remained superhydrophobic property in the pH range from 1 to 13. When the superhydrophobic PVC surface was immersed in water with the temperatures ranging from 5 °C to 50 °C for 1 h to 30 days, the water contact angle remained higher than 150°. After outdoor exposure for 30 days, the contact angle still remained 150o.     

粉煤灰超疏水不锈钢网的制备及油水分离

采用树脂粘接法，将硬脂酸修饰后的粉煤灰用环氧树脂粘接在不锈钢网骨架表面，制备了超疏水不锈钢网，并对其进行了TEM、SEM、FTIR和接触角等表征。结果显示：在高倍显微镜下改性后的超疏水不锈钢网表面呈一定粗糙度的微纳米分级结构，静态水接触角高达153°。此外，该超疏水不锈钢网具有良好的机械稳定性和超疏水耐久性，其表面经机械磨损试验100次后水静态接触角仍高达141°。该材料用于多种油/有机溶剂与水的混合液的分离中，分离效率均高于94%。     

Durable,self-cleaning and superhydrophobic bamboo timber surfaces based on TiO2 films combined with fluoroalkylsilane

Decorative materials, including bamboo timber, have been proposed to exploit their superhydrophobic and self-cleaning properties, but a comprehensive appraisal of their environmental adaptability is still deficient. In this paper, a robust and durable superhydrophobic surface was formed on bamboo timber substrate through a process combining chemical solution deposition and chemical modification. The superhydrophobic surface resulted from micro-nanoscale binary-structured TiO₂ films and the assembly of low-surface-energy fluorinated components, which exhibited a water contact angle of 163±1° and a sliding angle of 3±1°. The surface maintained superhydrophobicity after mechanical abrasion against 1500 mesh SiC sandpaper for 800 mm at the applied pressure of 1.2 kPa, indicating good mechanical stability. Moreover, the superhydrophobic surface exhibited good chemical stability against both acidic and basic aqueous solutions (e.g., simulated acid rain). After exposure to atmosphere for more than 180 days, the obtained surface still maintained a contact angle of 155±2° and a sliding angle of 6±2°, revealing good long-term stability. In addition, the as-prepared superhydrophobic surface exhibited almost complete wet self-cleaning of dirt particles with water droplets. It is believed that the method presented in this study can provide a straightforward and effective route to fabricate a large-area, mechanically robust, anticorrosive and self-cleaning superhydrophobic surface on woody materials for a great number of potential applications.     

Preparation and characterization of superhydrophobic surface based on polydimethylsiloxane (PDMS)

Biomimetic superhydrophobic surfaces exhibit excellent self-cleaning properties due to their special micro/nano-scale binary structures. In order to prepare the superhydrophobic surface of the polydimethylsiloxane (PDMS), a facile fabrication method for replicating micro/nano-scale binary aluminium structures into PDMS is presented. The microscopic morphology, composition, surface roughness (Ra) and wettability of the sample surface were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy, roughness measurement equipment and contact angle meter respectively. Based on the measurements of the contact angles of deionized water (DI water) and ethanediol, surface free energies of the coatings were estimated according to the Owens two-liquid method. The superhydrophobic PDMS exhibited lower surface free energy than flat PDMS with a DI water contact angle (WCA) of 165°. The surface roughness (Ra) increased with the increasing of etching time in the range 0–80?min, and then decreased with the change of etching time, similar to the variation of contact angle with etching time. Moreover, the prepared surface had different micro-morphologies and its wettability was changed by regulating the chemical etching time. In addition, the superhydrophobic PDMS also showed good self-cleaning properties and the bouncing effect of the water droplets.     

室温下ZnO超疏水表面的制备及油水分离性能

利用简便的液相法,在室温下于不锈钢网上沉积ZnO纳米片和纳米花粗糙结构,接着通过浸渍法修饰低表面能物质硬脂酸,制备了超疏水不锈钢网。对沉积后的不锈钢网表面形貌、晶体结构、润湿性能、耐磨性能、油水分离性能等进行表征与测定。结果表明,该不锈钢网表面由纳米片和纳米花组成的微纳米结构ZnO构成,具有超疏水性,水接触角161 °;油水分离效率达98%,循环使用20次后分离效率仍保持在95.5%以上;具有良好的机械耐磨性,在高盐环境中表现出化学稳定性。     

Superhydrophobic/superoleophilic micro/nanostructure nickel particles for oil/water mixture and emulsion separation

Nowadays, developing reusable and highly efficient materials for separating nano/micro-sized oil droplets from oil/water mixture and emulsion remains very challenging. Herein, hedgehog-like micro/nanostructure nickel particles were fabricated via a hydrothermal route. Thanks to its unique morphology, the octadecyltrichlorosilane (ODTS)-modified nickel particles show suitable superhydrophobicity/superoleophilicity properties with water contact angle, oil contact angle, and contact angle hysteresis values of 169.17° ± 2.13°, 0°, and 2.32°± 0.34°, respectively, making the potential sorbent for oil/water separation. The dense narrow thorns of superhydrophobic/superoleophilic nickel particles help the maximum scattering of particles on the surface and in the solutions. Hence, superhydrophobic/superoleophilic nickel particles demonstrated outstanding sorption capacity ranging from 3.86 to 5.27 (g/g) for a wide range of organic solvents and oils. Also, sorption capacities were retained even after 10 sorption cycles. Additionally, sorption capacities remain steady under acidic, alkaline, and high-saline conditions, indicating the high resistance in the harsh media. More importantly, ODTS-modified particles could also be used in oil/water emulsion separation with efficiencies of higher 99%. The appropriate resistance of hedgehog-like micro/nanostructure nickel particles to various environmental conditions as well as reusability and recyclability provides good opportunities for industrial applications of oil uptake from the oil/water mixture and emulsion.     

Tunability of the Adhesion of Water Drops on a Superhydrophobic Paper Surface via Selective Plasma Etching

We report the fabrication of a sticky superhydrophobic paper surface with extremely high contact angle hysteresis: advancing contact angle ～150° (superhydrophobic) and receding contact angle ～10° (superhydrophilic). In addition, we report the controlled tunability of the contact angle hysteresis from 149.8 ± 5.8° to 3.5 ± 1.1°, while maintaining superhydrophobicity, as defined through an advancing contact angle above 150°. The hysteresis was tuned through the controlled fabrication of nano-scale features on the paper fibers via selective plasma etching. The variations in contact angle hysteresis are attributed to a transition of the liquid–surface interaction from a Wenzel state to a Cassie state on the nano-scale, while maintaining a Cassie state on the micro-scale. Superhydrophobic cellulosic surfaces with tunable stickiness or adhesion have potential applications in the control of aqueous drop mobility and the transfer of drops on inexpensive, renewable substrates.     

Facile preparation of robust superhydrophobic surface based on multi-scales nanoparticle

A new superhydrophobic surface based on multi-scales nanoparticle was designed and prepared to enhance the robustness and reproducibility. The influence of multi-scale nanoparticles on the structure and property of the superhydrophobic surface was further investigated. The superhydrophobic surface with optimized composition did not only show high contact angle of 160°-166.3° but also exhibited good durability to the mechanical, chemical, and thermal environments. Furthermore, the superhydrophobic surface was evaluated for application in anticorrosion, anti-icing, and self-cleaning. This study provides a new method to prepare robust superhydrophobic surface based on polymer nanocomposite coating for various potential applications.     

Superhydrophobic durable coating based on UV‐photoreactive silica nanoparticles

Superhydrophobic surfaces can be obtained by tailoring both the chemistry and roughness topography, mimicking the Lotus leaf characteristics. Most of the synthetic superhydrophobic surfaces reported have been composed of micro and nanoparticles (NPs) embedded in polymer‐based coatings. The particles which tailor the topography are bonded to the base polymers by weak secondary forces. Consequently, the topography integrity is highly affected by handling and surface drag making them unsuitable for long term applications. This work is focused on promoting covalent bonding between the NPs and the base polymer to obtain durable superhydrophobic surfaces. The rough topography was achieved by ultraviolet (UV) curing of SiO₂ NPs containing a photoreactive benzophenone moiety in addition to methylated fumed silica NPs which can bind covalently to the polymer base coating, on UV radiation. The hydrophobic chemistry was obtained by fluoroalkylsilane top coating. Coating durability was evaluated using surface air drag and accelerated weathering conditions (UV radiation, humidity and temperature). Results indicated that the proposed approach resulted in superhydrophobic surfaces having high contact angle (>150°) and low sliding angle (<10°) with improved long term durability. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41122.     

Preparation and anti‐icing property of a lotus‐leaf‐like superhydrophobic low‐density polyethylene coating with low sliding angle

A lotus‐leaf‐like superhydrophobic low‐density polyethylene (LDPE) coating with low sliding angle was prepared by a facile method. The water contact angle and sliding angle of the as‐prepared superhydrophobic LDPE coating were 156 ± 1.7° and 1°, respectively. The anti‐icing property of the as‐prepared LDPE coating with low sliding angle was investigated in a climatic chamber with a working temperature of ?5°C. The results showed that the superhydrophobic LDPE coating with low sliding angle can largely prevent ice formation on the surface, showing excellent anti‐icing property. The as‐prepared superhydrophobic LDPE coating with good anti‐icing property will be perfectly desirable for outdoor equipments to reduce ice formation on their surfaces in cold seasons. This work will provide a new way to fabricate anti‐icing coating and thus find applications in a variety of fields. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers     

Fabrication of Polyethylene Superhydrophobic Surfaces by Stretching‐Controlled Micromolding

This paper describes a novel process that is stretching‐controlled thermal micromolding, to fabricate bionic superhydrophobic polyethylene films. Low‐density polyethylene was thermally pressed in a vacuum oven onto PDMS stamps replicated from lotus leaves. After being cooled and peeled off from the stamps, the polyethylene films with superhydrophobic surface were created, exhibiting a water contact angle of 154.1 ± 3.5° and a rolling angle of ≈7°. SEM imaging showed that the superhydrophobic surface had micro‐papillas much higher than those on the lotus leaf, demonstrating the papillas had been stretched longer from the holes on the stamp during the separating process. This study shows that micromolding is a promising technique for large scale production of superhydrophobic films, even if the holes on the mold are not deep enough.

     

Single-step prepared hybrid ZnO/CuO nanopowders for water repellent and corrosion resistant coatings

In this study, ZnO/CuO hybrid hydrophobic nanopowders were synthesized using a common single-step chemical precipitation route without using modifiers. Influence of initial ZnO:CuO precursor concentrations and alkaline agent type on the wettability behavior of the prepared samples were investigated. Wettability properties of the prepared samples were assessed by measuring the water contact angle and contact angle hysteresis values. Fourier transform infrared spectra, scanning electron microscope micrographs and X-ray diffraction patterns were applied to identify the surface chemistry and morphological features. Scanning electron microscope images of the synthesized ZnO/CuO nanocomposites indicated flower-like morphologies containing plenty of nano-needles, -rods, and -sheets with thicknesses lower than 90 nm. The sample prepared under the optimum conditions was superhydrophobic having water contact angle and contact angle hysteresis of 162.6°±1 and 2°, respectively. It was applied to coat the surface of stainless steel meshes by spray deposition method. The resultant superhydrophobic surface exhibited excellent self-cleaning (water repellency) property and a suitable stabilities under the ambient and saline solution (NaCl, 3.5%) media. Additionally, electrochemical corrosion tests confirmed that the corrosion resistance of the fabricated ZnO–CuO coating was higher than the initial bare mesh.     

Superhydrophobic surfaces: a review on fundamentals,applications, and challenges

Superhydrophobicity is the tendency of a surface to repel water drops. A surface is qualified as a superhydrophobic surface only if the surface possesses a high apparent contact angle (>150°), low contact angle hysteresis (<10°), low sliding angle (<5°) and high stability of Cassie model state. Efforts have been made to mimic the superhydrophobicity found in nature (for example, lotus leaf), so that artificial superhydrophobic surfaces could be prepared for a variety of applications. Due to their versatile use in many applications, such as water-resistant surfaces, antifogging surfaces, anti-icing surfaces, anticorrosion surfaces etc., many methods have been developed to fabricate them. In this article, the fundamental principles of superhydrophobicity, some of the recent works in the preparation of superhydrophobic surfaces, their potential applications, and the challenges confronted in their new applications are reviewed and discussed.     

A stable porous superhydrophobic high‐density polyethylene surface prepared by adding ethanol in humid atmosphere

A stable porous superhydrophobic high‐density polyethylene (HDPE) surface with water contact angle of 160.0 ± 1.9° and sliding angle of 2.0 ± 1.6° was obtained by adding ethanol in humid atmosphere at 5°C. Soaked in water with temperatures ranging from 5 to 50°C for 15 days, even suffering compressive forces, and the water contact angles were still higher than 150°. After water flowed through the surface continuously for 30 min, even water droplets with a diameter of 4 mm dropped onto the HDPE surface from 30 cm high for 10 min, the water contact angles were also higher than 150°. A brief explanation to the formation of the porous superhydrophobic HDPE surface was put forward. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009