超疏水抗菌表面的研究进展

超疏水抗菌表面将疏水材料的特殊浸润性能与抗菌材料的优异杀菌性能结合,通过"双重保险"实现建筑、器械、织物等多种材料表面的长久抗菌,对保护人们身体健康及延长材料使用具有重要的作用.该文介绍了无机、有机、无机-有机三类超疏水抗菌表面的制备方法,综述了其在油水分离、涂层防污、医疗卫生应用领域的研究进展,最后对超疏水抗菌表面的发展进行了展望.     

Water condensation behavior on the surface of a network of superhydrophobic carbon fibers with high-aspect-ratio nanostructures

We have explored the condensation behavior of water on a superhydrophobic carbon fiber (CF) network with high-aspect-ratio hair-like nanostructures. Nanostructures ranging from nanopillars to hairy shapes were grown on CFs by preferential oxygen plasma etching. Superhydrophobic CF surfaces were achieved by application of a hydrophobic siloxane-based hydrocarbon coating, which increased the water contact angle from 147° to 163° and decreased the contact angle hysteresis from 71° to below 5°, sufficient to cause droplet roll-off from the surface. Water droplet nucleation and growth on the superhydrophobic CF were significantly retarded due to the high-aspect-ratio nanostructures under super-saturated vapor conditions. CFs are observed to wet with condensation between fibers of the pristine surface under super-saturated vapor conditions, which eventually leads to flooding. However, dropwise condensation became dominant in the superhydrophobic CF network, allowing for easy removal of the condensed droplets, which largely allowed the interstitial spaces of the fiber network to remain dry. It is implied that superhydrophobic CF can provide a passage for vapor or gas flow in wet environments such as a gas diffusion layer requiring the effective water removal in the operation of proton exchange membrane fuel cell.     

Robust superhydrophobic fabrics by infusing structured polydimethylsiloxane films

Superhydrophobic coatings have large application potential in self-cleaning textiles. Low durability, high cost of fabrication, and environmental concerns over the usage of chemicals such as fluorocarbons limit the utilization of superhydrophobic coatings. This study reports a convenient and inexpensive approach to fabricate robust and fluorine-free superhydrophobic fabrics based on the transfer of structured polymer films and hydrophobic nanoparticles. In this approach, polydimethylsiloxane (PDMS) is infused between sheets of fabric and paper, followed by curing and removal of the paper. This process results in a fabric infused with PDMS whose structure is a negative replica of the paper surface. Then, hydrophobic nanoparticles are sprayed onto the structured PDMS side of the fabric. The infusion of PDMS and subsequent deposition of the hydrophobic nanoparticles enables strong bonding, as shown by the excellent solvent stability of the superhydrophobic fabric under ultrasonication. The proposed approach is universal in that it can be applied to almost any textiles, which upon coating, exhibited superhydrophobicity with a water contact angle of 172° and a sliding angle of 3°. Furthermore, the superhydrophobic fabric showed robust durability against water spray impact and mechanical bending where it can keep superhydrophobicity for at least 200 cycles of each test.     

自修复超疏水多功能协同作用涂层研究进展

自修复超疏水涂层是近年来多功能涂层研究的热点之一。文中总结了超疏水自修复涂层的修复机理,包括表面形貌的恢复和低表面能物质的补充。表面形貌的恢复可采用动态化学键和气体补偿来实现;低表面能物质的补充依靠在外界条件刺激下表面能驱动底层的低表面能物质迁移至涂层表面。目前有利用形状记忆合金实现大尺度结构损伤自修复、减少对外界刺激依赖实现自主自修复进程、利用分子结构设计自修复、多层光滑浸渍多孔表面(SLIPS)设计自修复等新的研究方向。同时介绍了自修复超疏水性能结合其他功能的多功能协同作用涂层的应用,包括超疏水自修复多功能纤维、超疏水防腐蚀自修复涂层和超疏水导电自修复涂层,各个功能间不是简单的叠加而是协同作用使涂层整体性能达到最佳,这为多功能涂层的设计提供了新思路。最后展望了自修复超疏水涂层的发展方向。     

A hierarchical mesh film with superhydrophobic and superoleophilic properties for oil and water separation

BACKGROUND: Solid surfaces possessing both superhydrophobic and superoleophilic properties have attracted great interest for fundamental research and potential application. However, fabrication of the reported surfaces is usually time‐consuming and the wetability of the surfaces could not be achieved to the desired level in rugged environments. RESULTS: A hierarchical stainless steel mesh film comprising structures with three scales of roughness was synthesized by a simple chemical bath deposition method. After being modified with a low surface energy material e.g. Teflon, these films exhibit superhydrophobic and superoleophilic properties. In this study it was demonstrated that the unique properties of the as‐prepared films match well with the requirements for the effective separation of oil and water mixtures. CONCLUSION: It was confirmed that the unique surface wetability of the surface is due to the cooperative effect of the hierarchical structures of the stainless steel mesh films and the natural low surface tension of Teflon. Furthermore, fabrication is simple and economic, and the surface exhibited robust durability even in a rugged environment. Copyright © 2011 Society of Chemical Industry     

A novel composite protective coating with UV and corrosion resistance: Load floating and self-cleaning performance

The research in functional materials has been the focus in studying industrial applications, particularly in the field of superhydrophobic functional bionic material. Although many studies of superhydrophobic surfaces have been published at this stage, the performance remain unsatisfactory, especially in a variety of harsh environments in practical applications, such as extremely cold weather, acidic or alkaline environment, prolonged exposure to light, high temperature, or oily wastewater, etc. The mechanical strength and corrosion resistance of coatings in such environments are all mighty challenges. In this study, we propose a fluoro silane-modified zinc oxide (FAS-ZnO) as a nano-filler. A superhydrophobic and oleophobic composite coating was successfully prepared through a single step by spraying suspensions containing attapulgite (ATP), FAS-ZnO, and carboxylated polyphenylene sulfide (PPS–COOH) onto desired substrates. In addition, stearic acid was added as a binder and used to enhance the bonding strength between the filler and the substrate. The composite coatings were characterized by FE-SEM, XRD and FT-IR on substrates, and the corrosion resistance of the coatings was evaluated by electrochemical impedance spectroscopy (EIS) and salt spray chamber experiments. The composite coatings showed excellent corrosion resistance due to the synergistic effect of FAS-ZnO and ATP. It was found that the composite coating had good hydrophobic and oleophobic contact angles of 161 ± 1.5° and 159 ± 1°, respectively, which were mainly attributed to the construction of nano-scale structures. It is worth noting that the composite coating performed excellently in chemical stability, self-cleaning performance, UV resistance, anti-fouling function, mechanical strength, and load-bearing floating ability. The coating maintained its highly hydrophobic surface after being stretched through a universal testing machine. Based on the multiple key properties in the composite coating, it can be expected to be applied to large equipment and instrument surfaces in extreme outdoor environments.     

Oligosilazane cured by moisture as fluorine-free hydrophobic coating for waterproof polymer-matrix composite materials

Preceramic oligosilazane was applied as a waterproof hydrophobic surface coating for electromagnetic wave-transmitting material (silica cloth-reinforced bismaleimide laminated composite). Oligosilazane spread readily on the surface of the material, due to its good wetting ability, enabling formation of silazane coatings using various processing methods such as spraying, dipping, wiping, etc. When using oligosilazane containing micrometer-sized silica particles as filler, a hydrophobic surface was realized after moisture curing under ambient condition. The hydrophobic surface with oligosilazane coating inhibited water absorption shows promise for application as a waterproof surface coating of electromagnetic wave-transmitting materials.     

One‐Step Fabrication of Superhydrophobic/Superoleophilic Electrodeposited Polythiophene for Oil and Water Separation

A facile, one‐step, and single‐component fabrication of superhydrophobic and superoleophilic coating by electropolymerization of polythiophene on a stainless steel mesh is presented. The resulting coating has low surface energy and shows surface morphology bearing both micro‐ and nano‐features without the need to add nanofillers, or pretreatment of the substrate to make it rough. The polythiophene coating also shows reversible wetting property (superhydrophobic to superhydrophilic, and vice versa) by electrochemical doping and dedoping. The coated mesh is shown to repel water of different pH (1, 7, and 14) and salt content. On the other hand, oil such as dichloromethane, gasoline, kerosene, dodecane, and crude oil can easily pass through the mesh. Therefore, the coated mesh is an excellent material for the separation of oil and water.     

基于单宁酸制备可喷涂超疏水材料

通过正硅酸乙酯水解合成了二氧化硅纳米粒子并形成凝胶颗粒,加入单宁酸以优化其形貌,以六甲基二硅氮烷为表面改性剂,合成了具有低表面能的超疏水喷涂材料。并用动态光散射仪(DLS)与扫描电镜(SEM)对其表征。将其分散于乙醇,并对纸张、玻璃、铝箔、木板、棉质纺织物、塑料泡沫等常见表面进行喷涂,均在短时间内构成了超疏水表面,水接触角均在150.0°以上。随后,考察了所制备超疏水涂层在受外力破坏后的自修复性与耐磨性。结果显示:1 g/L的喷涂液仅需喷三层即可构建超疏水表面,得到的涂层具有良好的透明性;超疏水涂层在受外力损坏后可用有机溶剂进行快速简易的自修复;且喷涂后的玻璃片在砂纸上负重磨损距离达到1000 mm后,接触角从153.5°降至105.5°,再喷一层即可恢复到154.0°。     

Facile fabrication of superhydrophobic polyimide/polytetrafluoroethylene composite coatings with high water adhesion

A facile casting method was used to fabricate superhydrophobic polyimide/polytetrafluoroethylene composite coatings with high water adhesion. The water contact angles of the composite coatings were larger than 150 °, expressing superhydrophobic property. But water droplets pinned tightly on the composite coating, even if it was upside down. The X‐ray photoelectron spectrum analysis indicated that polyimide and polytetrafluoroethylene coexisted in the resulting coating. The observation with scanning electron microscopy showed that the composite coating formed lotus‐like structure with many spherical polyimide papillae randomly bonding on the surface. But the tops of the polyimide papillae were not covered by lance‐shaped Teflon fibres, forming an inhomogenous and discontinuous surface structure. This special surface chemical distribution and lotus‐like structure combined to contribute to the high adhesive superhydrophobicity. This simple method may greatly extend the application range of high adhesive superhydrophobic surfaces in microcontrollable and microfluidic application. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42810.     

超疏水PET织物的制备及其抗菌性能

纺织物表面的超疏水特性将赋予其优异的自清洁性能。以PET无纺布为基材,探索了利用溶胶-凝胶法在预处理后的PET织物表面构筑具有微纳结构的超疏水涂层的方法;并利用扫描电镜（SEM）、接触角测量仪表征了改性PET织物表面的微观结构和润湿性。进一步地,分别以大肠杆菌和金黄色葡萄球菌为试验菌株,通过细菌转移法和抑菌圈法评价与分析了改性PET织物表面的抗菌性能。研究表明：利用改进的Stöber溶胶-凝胶过程能够在经碱减量法预处理的PET表面原位形成SiO₂纳米粒子;再用含疏水性长链的十二烷基硅烷对这一表面进行改性,并经过表面热处理,就能够成功地在PET织物表面构筑多层次的微/纳结构,从而制得表面具有超疏水特性的PET织物,其接触角可达到163°。这一超疏水PET织物能够抑制细菌在其表面的生长繁殖,表现出了明显的抗菌特性。     

Papillae mimetic hairy composite spheres towards lotus leaf effect coatings

An effective approach is proposed to fabricate a robust superhydrophobic coating constructed from hairy composite spheres. The hairy spheres mimic structure of the papillae on the surface of lotus leaf. The synthesis is based on template method and the corresponding PANi hairy spheres are prepared by polymerization induced diffusion growth via nanosized channels of a polymer cage. The composite spheres become more robust by coating a layer of inorganic materials onto the PANi hairy spheres. By using a middle adhesive layer of epoxy resin, the hairy spheres can be tightly attached to the substrate. The superhydrophobic coating is achieved with a contact angle of 159.9 ± 1.9° and tilt angle below 2° by a post hydrophobic modification with octadecyltrichlorosilane. Such coating is robust enough to resist water flushing and organic solvents. This method can be scaled up for almost all kinds of substrates.     

Prevention of Ice Accretion on Aluminum Surfaces by Enhancing Their Hydrophobic Properties

The accretion of ice on the surfaces of power network systems, aircraft, communication networks, etc., is known to cause serious problems that often lead to costly safety issues. An ideal solution would be to prevent ice from accumulating in the first place, rather than waiting for ice to accrete and then to de-ice which is both time-consuming and expensive. This may be accomplished by depositing coating materials that are icephobic. A low dielectric constant surface is expected to reduce the adhesion of ice due to the screening of mirror charges, thereby eliminating one of the strongest interaction forces — the electrostatic force of attraction — at the ice–surface interface. Superhydrophobic surfaces, which demonstrate high water-repellency due to the negligible contact area of water with these surfaces, are also expected to minimize the contact area of ice. In the present research work, both concepts were studied by producing superhydrophobic nanorough low-ε (dielectric) surfaces on aluminum. Superhydrophobic properties were achieved on surfaces of aluminum by creating a certain nanoroughness using a chemical etch followed by 'passivation' of the surface by a low surface energy coating of rf-sputtered Teflon, providing a water contact angle greater than 160°. The same behavior is reported even when the nanorough substrates were coated with dielectric thin films of ZnO (lower ε) or TiO 2 (higher ε) prior to passivation. It is found that the superhydrophobic nanorough low energy surfaces are also icephobic and the presence of a low dielectric constant surface coating of Teflon (ε = 2) allows a considerable reduction of the ice adhesion strength. Ice adhesion strengths were determined using a centrifugal ice adhesion test apparatus.     

Preparation of super‐hydrophobic film with fluorinated‐copolymer

Organic superhydrophobic films were prepared by utilizing TA‐N fluoroalkylate (TAN) and methyl methacrylate (MMA) copolymer as water‐repellent materials and inorganic silica powder as surface roughness material has been developed. Coating solutions prepared by adding silica powders into copolymer solution directly (one‐step method) and by adding silica powders into monomers and allowing them to react (two‐step method). The results showed that contact angles of the films prepared by one‐step method (37.6 wt % of silica powders in the coating solution) were greater than 150°, but the transmittance of the film at visible light was only 30%. On the other hand, the contact angle of films prepared by two‐step method (20 wt % of silica powders in the coating solution) was greater than 160° and the transmittance of the film was greater than 90%. The contact angle of the film prepared by poly(octyl acrylate), POA, was 32.1°, but while introducing silica powder into the system, the contact angle of the film was reduced to be smaller than 5°. Thus, superhydrophobic and superhydrophilic films can be obtained by introducing a roughening material on the hydrophobic surface and the hydrophilic surface, respectively. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1646–1653, 2007     

水性超疏水涂层的制备、调控与应用的研究进展

基于可持续发展和绿色环保的要求,以水替代有机挥发性溶剂的新型水性超疏水涂层逐渐成为研究热点,但是水性涂料的分散性及涂层的疏水稳定性、涂层性能等相关问题也随之而来。本文介绍了水性超疏水涂层制备方法的发展现状,针对水性超疏水涂层力学耐久性能差的问题提出可行性方案,例如制备内外一致的一体化复合结构,加强涂层内界面相互作用,交联作用或设计自修复水性超疏水涂层等。此外,还对水性超疏水涂层在油水分离、防结冰、自清洁等领域的进展进行阐述,并探讨了水性超疏水涂层的规模化制备、涂层力学性能的强化和耐久性研究将成为主要探索方向,只有夯实水性超疏水涂层的基础研究,工业应用才能突破。     

辊式涂布法构建纸基牢固超疏水表面

采用辊式涂布的方法在纸基材料上构建超疏水表面,并对超疏水表面的牢固性、自清洁性和疏水性能进行评价。用γ-氨丙基三乙氧基硅烷和1H,1H,2H,2H-全氟辛基三乙氧基硅烷（POTS）对微米级和纳米级两种尺寸的TiO₂粒子进行疏水改性处理,然后将改性后的微/纳米TiO₂涂布在纸基材料表面。采用红外光谱（FTIR）对改性后的微/纳米TiO₂的化学组成进行了分析,采用扫描电镜（SEM）对涂布纸表面结构进行了表征,通过接触角、耐磨性和自洁净测试评价了涂层表面的超疏水性、牢固性和自清洁性。改性TiO₂的FTIR分析显示在1000～1500cm^-1之间出现多个C—F键的伸缩振动峰,表明POTS通过化学键与TiO₂表面发生了结合。涂布纸表面的SEM分析可以看出,纸基材料表面上均匀分布了微米和纳米尺寸的TiO₂颗粒,具备了类似荷叶表面微-纳结构的粗糙表面。涂层表面的水接触角为153°±1.5°,滚动角为3.5°±0.5°,水滴在涂层表面呈球形,极易滑落,涂层在水中浸泡7天后,接触角没有发生明显变化,表明纸张表面具备了优异的超疏水性能,且疏水稳定性较好。涂层表面经过10次循环磨损试验后,接触角仍能达到150°,滚动角为9°,表明机械摩擦没有对涂布纸表面的化学成分和粗糙结构造成明显的破坏,超疏水表面的牢固性较好。自洁净测试表明,涂布纸表面具有良好的自清洁和防污性能。该工艺过程操作简单,易于实现工业化生产,为在纸基表面构建综合性能优异的超疏水表面提供了一种新的便利途径。     

Influence of the coating method on the formation of superhydrophobic silicone–urea surfaces modified with fumed silica nanoparticles

Effect of the coating method on the formation of superhydrophobic polydimethylsiloxane–urea copolymer (TPSC) surfaces, modified by the incorporation of hydrophobic fumed silica nanoparticles was investigated. Four different coating methods employed were: (i) layer-by-layer spin-coating of hydrophobic fumed silica dispersed in an organic solvent onto TPSC films, (ii) spin-coating of silica–polymer mixture onto a glass substrate, (iii) spray coating of silica/polymer mixture by an air-brush onto a glass substrate, and (iv) direct coating of silica–polymer mixture by a doctor blade onto a glass substrate. Influence of the coating method, composition of the polymer/silica mixture and the number of silica layers applied on the topography and wetting behavior of the surfaces were determined. Surfaces obtained were characterized by scanning electron microscopy (SEM), white light interferometry (WLI) and advancing and receding water contact angle measurements. It was demonstrated that superhydrophobic surfaces could be obtained by all methods. Surfaces obtained displayed hierarchical micro-nano structures and superhydrophobic behavior with static and advancing water contact angles well above 150° and fairly low contact angle hysteresis values.     

Distillation of alcohol/water solution in hybrid metal–organic framework hollow fibers

Distillation with multitudinous structured packings has shown great potential for chemical separation. However, there still remains a big challenge to prepare porous structured packings with more productive separation and better mass transfer efficiency due to materials limitations. Metal–organic framework (MOF) membranes have commendable porous structures that provide enough pathways for fast mass transport and superhydrophobic character for efficient separation. Herein, novel MOFs-based hollow fiber structured packings were fabricated by a facile two-step blending and post-coating method and successfully applied in alcohol/water distillation. The ZIF-8 nanoparticles with high surface area and hydrophobic framework in PDMS matrix greatly accelerated mass transfer rate of membrane. Especially, as hydrophobic ZIF-8/PDMS layer was coated on the inner surface of fibers, the wetting behavior of membranes can be effectively prevented. The prepared ZIF-8/PDMS structured packings can be easily operated far above the normal flooding limit and held the height of mass transfer unit as small as desired.     

Heat‐resistant hydrophobic–oleophobic coatings

Thermally and chemically durable hydrophobic oleophobic coatings, containing different ceramic particles such as SiO₂, SiC, Al₂O₃, which can be alternative instead of Teflon, have been developed and applied on the aluminum substrates by spin‐coating method. Polyimides, which are high‐thermal resistant heteroaromatic polymers, were synthesized, and fluor oligomers were added to these polymers to obtain hydrophobic–oleophobic properties. After coating, Al surface was subjected to Taber‐abrasion, adhesion, corrosion, and thermal tests. The effects of the particle size of ceramic powders, organic matrix, and heat on the coating material were investigated. Coating material was characterized by FTIR spectrophotometer. Surface properties and thermal resistance of the coating materials were investigated by SEM and TGA analyses. After thermal curing, contact angles of these coatings with H₂O and n‐hexadecane were measured. It was observed that coatings like ceramic particles are more resistant against scratch and abrasion than the other coatings. Also, they are harder than coatings, which do not include ceramic particles. It was seen that coatings, containing Fluorolink D10H, have high‐contact angles with water and n‐hexadecane. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2386–2392, 2006     

超疏水三维多孔材料在乳化液油水分离中的应用研究进展

超疏水三维多孔材料基于润湿性和毛细作用可有效吸附回收水中浮油,近年来在乳化液的油水分离中也得到应用。本文重点从超疏水三维多孔材料的设计制备、对乳化液的油水分离效果、油滴在材料中的分离机制3个方面展开分析与评价。文中指出：材料设计制备方面,以海绵为主的多孔材料主要通过修饰低表面能物质和构建粗糙结构获得超亲油疏水性,疏水改性后的材料具备较高的油吸附容量（31～131g/g）。乳化液油水分离评价方面,超疏水三维多孔材料处理的对象多为O/W模型乳化液,油浓度低、表面活性剂浓度低、液滴粒径为微米级,少见对实际乳化液的处理;应用方式包括基于吸附作用的浸泡处理和吸附协同拦截作用的过滤处理两类;分析发现影响油水分离效果的关键是材料的孔径、表面疏水性和带电性。作用机制方面,疏水多孔材料吸附乳化油的作用过程仍停留在理论推测层面,主要观点为材料通过笼状孔道结构和疏水表面高效捕集和吸附油滴,油滴聚并破乳形成油层而被分离。虽然超疏水三维多孔材料在乳化液油水分离应用研究中取得了一定进展,但仍需探究其对实际废乳化液的适用性,设计开发连续分离设备以实现工程应用;结合原位观测、数值模拟、力学解析等方法解析油滴在多孔材料...