水下超疏油仿生特殊粘附界面材料的研究进展

水下超疏油表面由于在防污材料、微流控技术、生物粘附等方面具有广泛的应用前景,已经引起人们的普遍关注。本文简单介绍了浸润性在液相体系的相关概念及基础理论,综述了自然界中的水下超疏油低粘附生物体典型实例以及水下超疏油仿生特殊粘附界面材料的仿生制备和智能调控,并对水下超疏油仿生界面材料的发展进行了展望。     

仿生水下超疏油表面

水下超疏油表面是指在油/水/固三相体系中,对油的接触角大于150°的固体表面.从鱼体表面和荷叶下表面2种具有水下超疏油性质的生物体系出发,讨论了影响水下超疏油性质的因素,并据此提出了仿生水下超疏油表面的设计方法.通过介绍目前典型的人造水下超疏油表面的制备手段和研究进展,概括了水下超疏油体系的发展现状.对浸润性和黏附性响应性可控的智能水下超疏油体系以及水下超疏油体系在液滴操控、抗生物黏附和油水分离等领域的应用进行了简要介绍.最后对仿生水下超疏油体系目前研究存在的问题及挑战进行了总结,在此基础上展望了该领域未来的发展方向.     

自修复超疏水涂层材料研究进展

超疏水涂层材料具有自清洁、减阻、防雾、防黏附等特点,被广泛应用于防腐涂层、管道运输、油水分离等领域。但超疏水涂层材料在使用过程中由于物理磨损和化学腐蚀等原因易使其丧失超疏水性能,限制了其在工业中的实际应用,因此自修复超疏水涂层材料应运而生,且成为近年来的研究热点。本文综述了自修复超疏水涂层材料的最新研究进展,总结并对比了外援型自修复超疏水涂层材料和本征型自修复超疏水涂层材料的优缺点,同时对该领域的未来发展前景进行了简要展望。     

金属基仿生超滑表面制造及其应用

金属是人类社会赖以生存和发展的重要物质基础,是构成现代文明社会的支撑材料,增加金属材料的特殊性能,拓宽金属材料的应用范围,已经成为自然科学交叉研究的热点。受自然界启发,研究人员通过探究猪笼草口缘区的超滑行为,在微/纳米结构基底中注入低表面能润滑液,形成固液复合涂层,设计并制备出具有特殊润湿性的仿生超滑表面,显现出优异的自愈、防冰、防污、耐腐蚀、抗生物黏附、自清洁等性能。该方法为金属基体上设计构建仿生超滑表面,并实现其表面多功能性,进而为其在海洋防污、生物医疗、航空航天、制冷、工业生产等领域实现更广泛的应用提供了可能。本文从仿生超滑表面的设计原理、制备工艺、金属基体仿生超滑表面的应用以及未来发展趋势和挑战四个方面对金属基体仿生超滑表面的研究进展进行了综述。     

形状记忆聚合物表面水下油黏附性的可逆调控

采用模板法在形状记忆聚合物表面获得一种具有形状记忆特征的表面微结构, 在氧等离子作用下, 表面呈现低黏附的水下超疏油特性. 在外压作用下, 表面微结构发生坍塌, 失去水下超疏油性, 同时表面对油滴呈高黏附特征. 在120 ℃热处理后, 表面微结构恢复到了原始状态, 在等离子进一步作用下, 表面即可恢复到最初的低黏附水下超疏油状态. 因此通过外压、 热处理及等离子作用即可实现对表面微结构及其水下油黏附性能的可逆调控. 研究表明, 表面不同的微结构状态赋予表面不同的黏附性能, 在原始表面液滴处于低黏附的Cassie态, 而在坍塌结构表面水滴处于高黏附的Wenzel态.     

仿生沉积法制备水下低气体黏附透明材料

透明材料常用于水下设备中,而聚合物透明材料多较为疏水,在水下易黏附气泡,影响其光学性能.利用多巴胺(DA)和聚乙烯亚胺(PEI)共沉积技术,在多种透明聚合物材料表面构建了亲水/水下超疏气涂层.结果表明,聚多巴胺(PDA)与PEI可通过Michael加成或Schiff碱反应在此类材料表面形成亲水交联网络,显著提高其表面亲水性.表现为水接触角显著降低,而水下气接触角显著提高(140?),气泡在材料表面的黏附力显著下降.沉积时间在6 h以下时,XPS和椭圆偏振测试的结果表明,虽然所选用的透明材料表面沉积量和沉积厚度随时间有所上升,但其透光性不会受到显著影响.该方法具有较强的普适性,可用于多种水下气体黏附性较强的透明高分子材料,如聚苯乙烯(PS)、聚对苯二甲酸乙二醇酯(PET)、聚甲基丙烯酸甲酯(PMMA)、聚丙烯(PP)和聚酰亚胺(PI)等.同时,该方法形成的涂层的长期稳定性也较好,材料在水中浸泡振荡10天之后仍能保持较好的抗气泡黏附能力.该方法适用于如潜水艇舷窗、护目镜、水下光学镜头及其防护罩等水下设备中.     

仿海豚皮减阻研究进展

减阻材料可广泛应用于国防、工业、生产生活,具有极大的应用价值。而仿生减阻作为减阻研究新的分枝,受到广泛关注。由Gray计算海豚游动阻力与肌肉力量不匹配而产生的“Gray悖论”开启了对海豚减阻机理的探索。本文介绍了基于海豚表皮的几种减阻机理,并介绍由其发展出的相应减阻材料的设计与测试,最后对仿海豚皮减阻研究的未来发展进行展望。     

仿贻贝黏附高分子的研究进展

贻贝具有极强的水下黏附能力,其分泌的黏附蛋白能够黏附在包括聚四氟乙烯（PTFE）在内的几乎所有基底材料上。贻贝不受水或者潮湿环境影响的特殊黏附性能有望指导制备新型水下黏附剂,因而引起了研究人员极大的关注。受贻贝水下黏附机理的启发,通过模仿贻贝黏附蛋白分子结构,研究人员设计制备了多种具有强黏附功能的高分子并探索了相关应用...     

基于微纳结构液体灌注的超滑表面的制备与应用

超滑表面利用其基底上的微纳结构通过毛细作用将润滑油等液体锁定在孔隙中,孔隙中浸润的润滑油在基底形成一层动态油膜,油膜与不溶液体的液-液界面代替了固体与液体的固-液界面,从而大幅减少了滑动阻力。与传统具有类似低滚动角特性的超疏水和超疏油表面相比,孔隙中填充润滑油比空气具有更好的压力稳定性,而且润滑油的毛细流动性使得超滑表面具有良好的自修复能力。由于其明显的优势,近些年超滑表面已成为国际学术界研究热点,应用也拓展到防结冰、强化传热、减阻、抗生物黏附、微流控等领域。目前超滑表面研究仍存在重要挑战,例如如何避免润滑油的挥发带来的性能退化、如何针对各种材质和结构设计合适的加工工艺制备微纳结构等,这些问题限制了超滑表面的广泛应用。本文综述了超滑表面的制备工艺以及应用,分析了现存的问题,并且对超滑表面未来的发展趋势进行了展望。     

在不同溶剂中制备生物质基超疏水材料的研究进展

超疏水材料因具有超高的拒水性以及自清洁能力而备受关注,但是在制备过程中也因所选用溶剂和低表面能物质不同给环境带来不同程度的压力。生物质材料可再生、价格低并且绿色无污染,常用于超疏水材料的制备。本文介绍了生物质基超疏水材料的制备方法,并按照制备技术中所用溶剂不同分类,将生物质基超疏水材料分为有机溶剂型、水基/半水基型、无溶剂型三类,同时分析了三种不同类型超疏水材料的优势以及劣势。最后,总结了制备环保型超疏水材料的方法,并且展望了生物质基超疏水材料未来的发展方向。     

A Simple,Low-cost Method to Fabricate Drag-reducing Coatings on a Macroscopic Model Ship

A low-cost method was used to fabricate superhydrophobic coatings on a macroscopic model ship and the drag-reducing effect was investigated at both low and high speed. Hierarchical structures of the superhydrophobic copper coatings were characterized by means of scanning electron microscopy(SEM) and X-ray diffraction(XRD). Drag coefficient tests on surfaces with different wettability(superhydrophilic, hydrophilic, hydrophobic and superhydrophobic surfaces) showed that the as-prepared superhydrophobic surface exhibited a high remarkable drag reduction of 81% at a low speed of 1 mm/s. In the drag-reducing tests with model ship, the superhydrophobic coatings also exhibited around 16% drag reduction at a velocity of 0.3 m/s.     

Ultraviolet-durable superhydrophobic zinc oxide-coated mesh films for surface and underwater-oil capture and transportation

In this paper, we report a simple and an inexpensive method for fabricating superhydrophobic/superoleophilic mesh films from microstructured ZnO coatings. The microstructured ZnO coatings, which do not contain any fluorinated compounds, maintain their superhydrophobicity and superoleophilicity after ultraviolet irradiation and display environmental stability. Furthermore, those microstructured ZnO-coated mesh films exhibit good selectivity (even underwater) and excellent recyclability, making them promising candidates for many potential applications, including liquid-liquid separation, water treatment, and liquid transportation.     

Influence of flow on longevity of superhydrophobic coatings

Previous studies have demonstrated the capability of superhydrophobic surfaces to produce slip flow and drag reduction, which properties hold considerable promise for a broad range of applications. However, in order to implement such surfaces for practical utilizations, environmental factors such as water movement over the surface must be observed and understood. In this work, experiments were carried out to present a proof-of-concept study on the impact of flow on longevity of polystyrene fibrous coatings. The time-dependent hydrophobicity of a submerged coating in a pressure vessel was determined while exposing the coating to a rudimentary wall-jet flow. Rheological studies were also performed to determine the effect of the flow on drag reduction. The results show that the longevity of the surface deteriorates by increasing the flow rate. The flow appears to enhance the dissolution of air into water, which leads to a loss of drag reduction.     

Lubrication theory of drag on a scanning probe in structured water, near a hydrophilic surface

The drag is evaluated, in lubrication theory, on a parabolic-cylindrical tip moving parallel to a flat sample, in water, close enough that the presumed nanometer-thick, structured-water, "interphase" coatings of both it and the sample overlap. Assuming coatings of width, w, and of viscosity, eta, much larger than bulk water's, the friction force is predicted to equal -2pietacRphi(D/2w), where R is the tip's radius of curvature, c is its speed, D is the tip-sample separation, and Phi is a universal function whose value only differs noticeably from ln(2w/D) for D < w.     

电沉积非晶态铁—铬合金镀层的研究

本实验通过控制镀液组成和操作条件获得了非晶态铁－铬合金镀层，实验分析了ＰＨ值，电流密度以及镀层中铬含量对所形成镀层的非晶态结构的影响，阳极极化曲线测量结果表明，与晶态层相比，非晶态度层具有较高的耐蚀性。     

Properties of Ni-W alloy coatings on steel substrate

Ni-W alloy coatings were prepared on the steel substrate at the temperature of 60°C. The content of tungsten in coatings was increased with the growing cathodic current density. The increase of the corrosion resistance of Ni-W alloy coatings with the rising content of tungsten was confirmed by the measurement of anodic polarization curves. Annealed coatings showed better antioorrosion properties than the non-annealed ones. The properties of annealed coatings including their corrosion resistance depend on the tungsten content, too.     

Corrosion resistance of zinc electrodeposited from acidic and alkaline electrolytes using pulse current

Corrosion resistance of zinc coatings was investigated in an accelerated corrosion test in a condensation chamber. Zinc was electrodeposited from alkaline and acidic electrolytes using direct current (DC) or pulse current (PC). The zinc coating was subsequently protected against corrosion with a chrome (III) layer. Morphology and structure of the coatings was investigated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and X-ray diffraction analysis (XRD) before and after the corrosion test. Corrosion resistance of alkaline zinc coatings electrodeposited with DC and PC under test conditions was found to be comparable. The corrosion resistance of zinc coatings deposited from acidic electrolytes by PC was lower in comparison with corrosion resistance of zinc coatings deposited using DC. Presented at the 8th Conference on Solid State Chemistry, Bratislava, Slovakia, 6–11 July 2008.     

复合电沉积的最新研究动态

综述近年来国内外复合电沉积技术最新研究动态.重点探讨纳米复合镀层,电催化复合镀层以及光活性复合镀层等方面的研究现状和发展趋势.纳米复合镀层比一般的复合镀层具有更高的硬度,更好的耐磨性和耐蚀性;电催化复合镀层则可在纯金属电极,合金电极的基础上进一步降低电极反应的过电位.以金属氧化物,导电聚合物作为基质材料的电催化复合镀层已为现代复合电沉积技术开辟了一个新领域.     

Electrochemical corrosion resistance performance of sustainable resource-based nanoconducting polymer composites in alkaline medium

The corrosion resistance performance of poly (otoluidine) (POT)-dispersed castor oil-polyurethane, (COPU) nanocomposite coatings, POT/COPU, with three different compositions (i.e. 0.25, 0.5 and 1.0 wt%) in alkaline medium is studied. The coatings are applied on mild steel specimens by brushing. Corrosion resistance behaviour of these coatings is investigated using potentiodynamic polarization measurements, electrochemical impedance spectroscopy (EIS) and by weight loss. The morphological behaviour of corroded and uncorroded coated specimens is investigated by scanning electron microscopy (SEM). It is interesting to report that the presence of conducting polymer nanoparticles in POT/COPU coatings suppresses the saponification of COPU in an alkaline environment. These investigations show that the dispersion of POT in COPU remarkably improves the corrosion resistance performance of COPU in alkaline media. POT/COPU (1.0 wt%) coatings have potential as anticorrosive-coating materials in alkaline media at higher pH. These coatings have a higher resistance to alkaline medium in comparison to other compositions.     

Corrosion protection of AA6061-T4 alloy by sol–gel derived micro and nano-scale hydroxyapatite (HA) coating

Micron and nano-scale hydroxyapatite (HA) were coated successfully on AA6061-T4 substrates by sol–gel method. Besides, the effects of coating thickness on adhesion strength and corrosion behaviour of the coatings were studied. Corrosion resistance was measured by potentiodynamic polarization test using a potentiostat under in vitro conditions. The coatings before and after corrosion tests were characterized by adhesion tests, a scanning electron microscopy attached with EDS and X-ray diffraction analysis. The results revealed that all the coatings exhibit a passive behaviour in Ringer’s solution. Specimens coated with nano-scale HA had the higher corrosion resistance than micro-scale coatings. The highest corrosion resistance appeared to be for the ~30 μm nano-scale HA coated substrates. However, for micro-scale HA coatings, the highest adhesion resistance was obtained at ~30 μm film thickness.