铝合金表面原位自组装超疏水膜层的制备及耐蚀性能

采用阳极氧化法在铝合金表面原位构造粗糙结构, 经表面自组装硅氧烷后得到超疏水自清洁表面, 与水滴的接触角最大可达157.5°±2.0°, 接触角滞后小于3°. 通过傅立叶变换红外(FT-IR)光谱分析仪、场发射扫描电子显微镜(FE-SEM)、能谱仪(EDS)、原子力显微镜(AFM)和接触角测试对阳极氧化电流密度、硅氧烷溶液中水的含量和自组装时间等参数进行了分析, 并得到制备超疏水自清洁表面的最优工艺参数. FE-SEM及AFM的测试结果表明, 由自组装硅氧烷膜层的无序性形成的纳米结构和阳极氧化构造的微米级粗糙结构与硅氧烷膜层的低表面能的协同作用构成了稳定的超疏水表面. 电化学测试(动电位极化)的结果表明, 原位自组装超疏水膜层极大地提高了铝合金的耐蚀性.     

Facile preparation of superhydrophobic nanorod surfaces through ion-beam irradiation

Obtaining superhydrophobic surfaces for their application in electronics and flexible wearable devices remains a significant challenge. Most previously reported methods for obtaining superhydrophobic surfaces involve complex and expensive preparation techniques and thus cannot be used for practical applications. Ion-beam irradiation is a simple and promising method for fabricating superhydrophobic nanostructures on large areas at a low cost. Ion-beam irradiation using argon and oxygen gases was used to prepare silica nanorod structures on glass substrates. This study is not just a modification of the surface of nanoparticles, but a change in nanoparticle shape. The nanorods were subsequently treated with perfluorooctyltriethoxysilane to obtain superhydrophobicity. The surface of the silica nanorods exhibited a static water contact angle of 153°, indicating superhydrophobicity. The combination of rough structures of silica nanorods and low surface energy resulted in superhydrophobicity. The surface properties were evaluated in detail using Fourier-transform infrared spectroscopy, field-emission scanning electron microscopy, and X-ray photoelectron spectroscopy. The proposed method is facile, inexpensive, and can be used for the large-scale production of nanorod structures for potential industrial applications.     

Novel superhydrophobic silica/poly(siloxane‐fluoroacrylate) hybrid nanoparticles prepared via two‐step surface‐initiated ATRP: Synthesis,characterization, and wettability

Poly(siloxane‐fluoroacrylate)‐grafted silica hybrid nanoparticles were prepared by surface‐initiated atom transfer radical polymerization (SI‐ATRP). The silica nanoparticles with α‐bromo‐ester initiator group for copper‐mediated ATRP were prepared by the self‐assembled monolayers of (3‐aminopropyl)triethoxysilane and 2‐bromoisobutyrate bromide. Well‐defined diblock copolymer brushes consisting of poly(methacryloxypropyltrimethoxysilane) and poly(2,2,3,3,4,4,4‐heptafluorobutyl methacrylate) blocks were obtained by using initial homopolymer brushes as the macroinitiators for the SI‐ATRP of the second monomer. Chemical compositions and structures of the nanoparticles were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and gel permeation chromatography. Surface properties and morphology of the nanoparticles were investigated with X‐ray photoelectron spectroscopy, scanning electron microscopy, atomic force microscopy, and water contact angle measurement. It is revealed that the surfaces of the nanocomposites are rough at the microscale and nanoscale. The formation reason of the superhydrophobic surfaces was also discussed in this work. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010     

Electrospun poly(styrene-block-dimethylsiloxane) block copolymer fibers exhibiting superhydrophobicity

Block copolymer poly(styrene-b-dimethylsiloxane) fibers with submicrometer diameters in the range 150-400 nm were produced by electrospinning from solution in tetrahydrofuran and dimethylformamide. Contact angle measurements indicate that the nonwoven fibrous mats are superhydrophobic, with a contact angle of 163 degrees and contact angle hysteresis of 15 degrees . The superhydrophobicity is attributed to the combined effects of surface enrichment in siloxane as revealed by X-ray photoelectron spectroscopy and surface roughness of the electrospun mat itself. Additionally, the fibers are shown by transmission electron microscopy to exhibit microphase-separated internal structures. Calorimetric studies confirm the strong segregation between the polystyrene and poly(dimethylsiloxane) blocks.     

Preparation of Superhydrophobic ZnO Films on Zinc Substrate by Chemical Solution Method

Superhydrophobic surface was prepared on the zinc substrate by chemical solution method via immersing clean pure zinc substrate into a water solution of zinc nitrate hexahydrate[Zn(NO₃)₂·6H₂O] and hexamethylenetetraamine( C₆H₁₂N₄) at 95 ℃ in water bath for 1.5 h, then modified with 18 alkanethiol. The best resulting surface shows superhydrophobic properties with a water contact angle of about 158° and a low water roll-off angle of around 3°. The prepared samples were characterized by powder X-ray diffraction(XRD), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy(EDX), transmission electron microscopy(TEM), and scanning electron microscopy(SEM). SEM images of the films show that the resulting surface exhibits flower-shaped micro- and nano-structure. The surfaces of the prepared films were composed of ZnO nanorods which were wurtzite structure. The special flower-like micro- and nano-structure along with the low surface energy leads to the surface superhydrophobicity.     

Fabrication of superhydrophobic surfaces with hierarchical structure through a solution-immersion process on copper and galvanized iron substrates

Superhydrophobic surfaces were obtained on copper and galvanized iron substrates by means of a simple solution-immersion process: immersing the clean metal substrates into a methanol solution of hydrolyzed 1H,1H,2H,2H-perfluorooctyltrichlorosilane (CF3(CF2)5(CH2) 2SiCl3, FOTMS) for 3-4 days at room temperature and then heated at 130 degrees C in air for 1 h. Both of the resulting surfaces have a high water contact angle (CA) of larger than 150.0 degrees as well as a small sliding angle (SA) of less than 5 degrees . The formation and structure of the superhydrophobic surfaces were characterized by means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectrometry (EDX). SEM images showed that both of the resulting surfaces exhibited special hierarchical structure. The special hierarchical structure along with the low surface energy leads to the high surface superhydrophobicity.     

Fabrication of Superhydrophobic Surface with Different Metal Films on Aluminum Alloy

A simple technique was developed for the fabrication of a superhydrophobic surface on the aluminum alloy sheets. Different hierarchical structures(Ag, Co, Ni and Zn) were formed on the aluminum surface by the galvanic replacement reactions. After the chemical modification of them with fluorination, the wettability of the surfaces was changed from superhydrophilicity to superhydrophobicity. Scanning electron microscopy(SEM), energy dispersive spectrometry(EDS) and water contact angle measurement were performed to characterize the morphological characteristic, chemical composition and superhydrophobicity of the surfaces. The as-prepared superhydrophobic surfaces showed a water contact angle as high as ca.160° and sliding angle as low as ca.3°. We hope the method to produce superhydrophobic surface can be used in many fields.     

Facile Electrochemical Method for the Fabrication of Stable Corrosion-Resistant Superhydrophobic Surfaces on Zr-Based Bulk Metallic Glasses

Both surface microstructure and low surface energy modification play a vital role in the preparation of superhydrophobic surfaces. In this study, a safe and simple electrochemical method was developed to fabricate superhydrophobic surfaces of Zr-based metallic glasses with high corrosion resistance. First, micro–nano composite structures were generated on the surface of Zr-based metallic glasses by electrochemical etching in NaCl solution. Next, stearic acid was used to decrease surface energy. The effects of electrochemical etching time on surface morphology and wettability were also investigated through scanning electron microscopy and contact angle measurements. Furthermore, the influence of micro–nano composite structures and roughness on the wettability of Zr-based metallic glasses was analysed on the basis of the Cassie–Baxter model. The water contact angle of the surface was 154.3° ± 2.2°, and the sliding angle was <5°, indicating good superhydrophobicity. Moreover, the potentiodynamic polarisation test and electrochemical impedance spectroscopy suggested excellent corrosion resistance performance, and the inhibition efficiency of the superhydrophobic surface reached 99.6%. Finally, the prepared superhydrophobic surface revealed excellent temperature-resistant and self-cleaning properties.     

Effects of plasma treatments for improving extreme wettability behavior of cotton fabrics

A simple, environmentally benign and energy efficient process for fabricating single faced superhydrophilic/hydrophobic cotton fabrics by controlling surface texture and chemistry at the nano/microscale is reported here. Stable ultra-hydrophobic surfaces with advancing and receding water droplet contact angles in excess of 146° as well as extreme superhydrophilic surfaces are obtained. Hydrophobic water-repellent cotton fabrics were obtained following plasma treatment through diamond-like carbon (DLC) coating by plasma enhanced chemical vapour deposition. The influence of changing different precursor’s plasma pre-treatments such as H₂, Ar or O₂ on the properties of DLC coatings is also evaluated using atomic force microscopy, X-ray photoelectron spectroscopy, attenuated total reflection Fourier transform infrared spectroscopy, and analysed in terms of contact angle measurements. Because of the DLC coating, the coated fabric showed to endure its superhydrophobic character even after 12 months.     

Fabrication of superhydrophobic surfaces by self-assembly and their water-adhesion properties

The self-assembled films of methyloctyldimethoxysilane (MODMS) and fluorooctylmethyldimethoxysilane (FODMS) were prepared on silicon surfaces and evaluated with AFM, water contact angle measurement, and X-ray photoelectron spectroscopy. Superhydrophobic surfaces were obtained by cooperation of MODMS and FODMS self-assembly with surface roughening. The results showed that preparing closely packed self-assembled films and fabricating surface nanometer-scale and micrometer-scale binary roughness can achieve superhydrophobic films with a water contact angle larger than 156 degrees. The difference between solution deposition and chemical vapor deposition is also investigated. Moreover, superhydrophobic surfaces created with MODMS and FODMS show the different water-adhesion effects, which could have great significance on liquid microtransport in microfluid devices.     

Novel strategy in enhancing stability and corrosion resistance for hydrophobic functional films on copper surfaces

A rod-like 1-dodecanethiol film assisted with the preferential adhesion of polydopamine was prepared on the non-etching copper surfaces by a simple dip-coating method. The formation and surface structure of the film were characterized by water contact angle measurement, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Once the 1-dodecanethiol film formed on the polydopamine-coated copper surface, the hydrophilic surface changed to hydrophobic. The corrosion behavior of the functional films was evaluated by the electrochemical impedance spectroscopy (EIS). The excellent corrosion resistance property could be ascribed to the compact film structure and good seawater stability for modified copper surface, especially in limiting the infiltration of Cl⁻.     

A facial approach to fabricate superhydrophobic aluminum surface

A facial chemical etching method was developed for fabricating superhydrophobic aluminum surfaces. The resultant surfaces were characterized by scanning electron microscopy, water contact angle (WCA) measurement, and optical methods. The surfaces of the modified aluminum substrates exhibit superhydrophobicity, with a WCA of 154.8° ± 1.6° and a water sliding angle of about 5°. The etched surfaces have binary structure consisting of the irregular microscale plateaus and caves in which there are the nanoscale block‐like convexes and hollows. The superhydrophobicity of aluminum substrates occurs only in some structures in which the plateaus and caves are appropriately ordered. The resulted surfaces have good self‐cleaning properties. The results demonstrate that it is possible to construct superhydrophobic surface on hydrophilic substrates by tailoring the surface structure to providing more spaces to trap air. Copyright © 2009 John Wiley & Sons, Ltd.     

Superhydrophobic surface fabricated by modifying silica coated multiwalled carbon nanotubes composites

A superhydrophobic surface with maximum static water contact angle of 156° and sliding angle of 3.5° was fabricated by modifying the silica coated multiwalled carbon nanotube composites (SiO₂/MWCNTs) using a silane coupling agent vinyltriethoxysilane. The structures of SiO₂/MWCNTs and superhydrophobic surface were investigated by infrared spectrometer and transmission electron microscopy. The results indicated that silica had been successfully grafted onto MWCNTs and the SiO₂/MWCNTs had been chemical modified by vinyl triethoxy successfully. The morphology of our prepared superhydrophobic surface, investigated by scanning electron microscopy, showed a characteristic rough structure. The effects of pH value and exposure time on the stability of the superhydrophobic surface were also investigated. The superhydrophobic film shows reliable acid and alkali resistance and aging resistance, indicating that it will have a wide range of applications.     

Radiation induced graft polymerization of multi-walled carbon nanotubes for superhydrophobic composite membrane preparation

Highly soluble multi-walled carbon nanotubes (MWNTs) were prepared by radiation-induced free radical graft polymerization of vinyl acetate (VAc) onto pristine MWNT surfaces. High resolution transmission electron microscopy (HR-TEM), Fourier transform infrared (FTIR) spectroscopy, and micro-Raman spectroscopy were used to confirm that poly(vinyl acetate) (PVAc) had been successfully grafted onto the surface of the MWNTs. The effects of experimental parameters on the degree of grafting (DG) of PVAc were also investigated, including adsorbed dose, dose rate, initial monomer concentration, and solvents. The grafted MWNTs (MWNTs-g-PVAc) exhibited good solubility in common organic solvents at high mass fraction. In addition, a superhydrophobic composite membrane could be readily fabricated by vacuum filtration of MWNTs-g-PVAc onto a supporting membrane, as was confirmed by water contact angle testing and visualization by scanning electron microscopy.     

ELECTROSPRAYING/ELECTROSPINNING OF POLY(γ-STEARYL-L-GLUTAMATE): FORMATION OF SURFACES WITH SUPERHYDROPHOBICITY

  Electrospraying/electrospinning of poly(γ-stearyl-L-glutamate) (PSLG) was investigated on a series solutions with different concentrations in chloroform. Field emission scanning electron microscopy (FESEM) and attenuated total reflectance Fourier transform infrared spectroscopy (FT-IR/ATR) were used to characterize the morphology and structure of the electrosprayed/electrospun polypeptide mats. It was found that electrospraying of PSLG with concentrations lower than 16 wt% afforded beads, while microfibers could be electrospun at the concentration of 22 wt%. The hydrophobicity of the electrosprayed/electrospun PSLG mats was investigated with static water contact angle (WCA) and tilt angle measurements. It was demonstrated that the superhydrophobic surfaces of PSLG with WCAs and tilt angles in the ranges of 150°-170° and 16.5°-4.2°, respectively, were obtained through electrospraying/electrospinning process.     

Self-assembled biomimetic superhydrophobic CaCO3 coating inspired from fouling mineralization in geothermal water

Inspired from fouling self-mineralization in geothermal water, a novel biomimetic cactuslike CaCO(3) coating with superhydrophobic features is reported in this letter. The structure, morphologies, and phases of the CaCO(3) coating were characterized by X-ray diffractometry, scanning electron microscopy, transmission electron microscopy, and infrared spectrophotometry. After prenucleation treatment, a continuous cactuslike CaCO(3) coating with hierarchical nano- and microstructures was self-assembled on stainless steel surfaces after immersion in simulated geothermal water at 50 °C for 48 h. After being modified with a low-surface-energy monolayer of sodium stearate, the as-prepared coating exhibited superhydrophobic properties with a water contact angle of 158.9° and a sliding angle of 2°. Therefore, this work might open up a new application field of geothermal resources and provide insight into designing multidimensional structures with functional applications, including superhydrophobic surfaces.     

Cathodic etching for fabrication of super-hydrophobic aluminum coating with micro/nano-hierarchical structure

A facile method for fabricating super-hydrophobic surfaces on the magnetron sputtering aluminum film by cathodic electrochemical etching followed by the modification of myristic acid was presented in this article. The morphologies and the compositions of the films were characterized by means of scanning electron microscopy (SEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS), respectively. The corrosion behavior of the super-hydrophobic film was evaluated by potentiodynamic polarization measurement, linear polarization measurement, and electrochemical impedance spectroscopy. After the treatment with cathodic electrochemical etching, the thin aluminum film remained unbroken and the bulk structure of the aluminum coating maintained a microcrystalline morphology while the surface of the coating presented a petal-shaped microstructure dotted with nano-sized floccules. Aluminum myristate was formed on the nano/microstructural surface of the coating when the sample was modified in melting myristic acid. The static water contact angle on the surface was larger than 165°, which demonstrated that a super-hydrophobic film was prepared on the magnetron sputtering aluminum coating. The corrosion resistance of the aluminum coating was enhanced remarkably because of the super-hydrophobic modification.     

聚二甲基硅氧烷/微纳米银/聚多巴胺修饰的超疏水海绵的制备和应用

受海洋贝类生物黏附蛋白的启发,在碱性环境下利用多巴胺的自聚合性质,在聚氨酯海绵表面聚合活性聚多巴胺薄层,采用葡萄糖还原银离子进一步沉积微纳米银粒子构筑表面微纳结构,并水解聚二甲基硅氧烷前驱体对表面进行疏水改性,制备出了接触角大于150°的超疏水表面。利用接触角测定、扫描电子显微镜及能量弥散X射线谱和傅里叶红外光谱等技术手段对制备的改性海绵进行了表征,表明微纳米银粒子和硅甲基疏水基团被成功修饰到了海绵表面。改性海绵对有机溶剂和油类物质具有高选择性和高吸收性。吸收的有机溶剂和油类物质的质量能够达到其自身质量的12倍以上。饱和吸收后的海绵仅通过物理挤压即可将吸收的物质回收并使海绵恢复弹性和吸附能力,得到再生。该研究为油水分离和废油回收提供了一种经济、高效、环境友好的方案。     

Functionalization of cotton fabrics with rutile TiO<Subscript>2</Subscript> nanoparticles: Applications for superhydrophobic,UV-shielding and self-cleaning properties

The superhydrophobic cotton fabrics were prepared by combining the coating of titanium dioxide (TiO₂) with the subsequent dodecafluoroheptyl-propyl-trimethoxysilane (DFTMS) modification. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) measurements revealed that the nanosized TiO₂ sphere consisted of granular rutile. The TiO₂ layer coated on the cotton altered both the surface roughness for enhancing the hydrophobicity and UV-shielding property. The cotton fabric samples showed excellent water repellency with a water contact angle as high as 162°. The UV-shielding was characterized by UV-vis spectrophotometry, and the results indicated that the fabrics could dramatically reduce the UV radiation. The photocatalytic progress showed that organic stains were successfully degraded by exposure of the stained fabric to UV radiation. Such multifunctional cotton fabrics may have potentials for commercial applications.     

Nanotexturing of polystyrene surface in fluorocarbon plasmas: from sticky to slippery superhydrophobicity

In this work plasma etching processes have been studied to roughen and fluorinate polystyrene surface as an easy method to achieve a superhydrophobic slippery character. Radiofrequency discharges have been fed with CF(4)/O(2) mixtures and the effect of the O(2):CF(4) ratio, the input power, and the treatment duration have been investigated in terms of wettability, with focus on sliding performances. For this purpose, surface morphological variations, evaluated by means of scanning electron microscopy and atomic force microscopy, together with the chemical assessment by X-ray photoelectron spectroscopy, have been correlated with water contact angle hysteresis and volume resolved sliding angle measurements. Results indicate that by increasing the height and decreasing the density of the structures formed by etching, within a tailored range, a transition from sticky to slippery superhydrophobicity occurs. A short treatment time (5 min) is sufficient to obtain such an effect, provided that a high power input is utilized. Optimized surfaces show a unaltered transparency to visible light according to the low roughness produced.