自修复防腐涂层研究进展

自修复防腐涂层在遭到外力破坏或环境损伤后,可自行恢复或在一定条件下恢复其原有的防腐作用,是一种新兴的智能防护材料。综述自修复防腐涂层的研究进展,将现有自修复防腐涂层的体系分为两种,评价两种方法的优缺点,并提出新兴的形状记忆自修复涂层。现有自修复防腐涂层一种是通过在涂层内包埋成膜物质或缓蚀剂实现涂层缺陷修复的自主型修复机制。另一种则是以温度、光等外界条件刺激响应实现涂层缺陷修复的非自主型修复机制。新兴的形状记忆涂层,具有修复较大缺陷的能力,同时结合缓蚀剂等自主型修复机制,可以实现涂层破损处的双重修复,为金属基材提供更为长久稳定的防护。现有大多数自修复涂层都是基于单一的修复机制实现对涂层缺陷的修复,目前自修复防腐涂层还需要在多重修复方面进行更为深入具体的研究。自主型和非自主型修复机制相互结合,实现涂层防护性能和功能性的长效修复,将会是未来自修复防腐涂层发展的主要方向。     

自感知发光涂层在腐蚀监测中的研究进展

在工程结构中采用自感知发光涂层，为大面积结构的腐蚀检测提供了一种简便高效、结果直观的新手段，且能够实现对检测人员或设备难以触及的结构区域的腐蚀检测，因而自感知发光涂层越来越受到腐蚀科学研究者的关注。本文结合近些年自感知发光涂层的研究进展，介绍了自感知发光涂层的种类和实现腐蚀检测的作用机制，重点围绕具有工程应用前景的pH自感知发光涂层、微裂纹自感知发光涂层、离子自感知发光涂层、多功能感知发光涂层等展开讨论，对涂层中指示剂和微胶囊的存在形式、颜色变化、稳定性等方面进行剖析，明确涂层中指示剂的不同存在形式对感知效果的影响，从自感知涂层荧光效果、荧光状态、微胶囊稳定性、多功能性等角度分类阐述了自感知发光涂层在发展过程中出现的问题、解决办法以及发展状况，最后对自感知发光涂层的发展趋势进行了展望。     

光引发自修复微胶囊的制备及涂层自修复性能

以光固化树脂脂肪族聚氨酯丙烯酸酯和光引发剂为芯材,脲醛树脂为壁材,采用原位聚合法制备了可用于光引发自修复的微胶囊。通过红外光谱、扫描电镜观察了微胶囊的形态及结构,采用光学显微镜、激光粒度分析仪、热重分析仪对自修复微胶囊的粒径、热稳定性及修复效果进行了表征。结果表明,芯材被成功包覆在微胶囊中,微胶囊合成的优化转速为500 r/min,在此转速下,微胶囊的平均粒径为101.9μm,包覆率为51.46%,微胶囊热稳定温度为226℃。将所制备的微胶囊埋置于涂层中,通过光学显微镜可观察到涂层中的裂纹在UV光照20 min之后得到了明显的修复,且修复过程绿色高效。     

光引发自修复微胶囊的制备及涂层自修复性能EI北大核心CSCD

以光固化树脂脂肪族聚氨酯丙烯酸酯和光引发剂为芯材,脲醛树脂为壁材,采用原位聚合法制备了可用于光引发自修复的微胶囊。通过红外光谱、扫描电镜观察了微胶囊的形态及结构,采用光学显微镜、激光粒度分析仪、热重分析仪对自修复微胶囊的粒径、热稳定性及修复效果进行了表征。结果表明,芯材被成功包覆在微胶囊中,微胶囊合成的优化转速为500 r/min,在此转速下,微胶囊的平均粒径为101.9μm,包覆率为51.46%,微胶囊热稳定温度为226℃。将所制备的微胶囊埋置于涂层中,通过光学显微镜可观察到涂层中的裂纹在UV光照20 min之后得到了明显的修复,且修复过程绿色高效。     

盐渍土腐蚀环境下微胶囊自修复混凝土抗腐蚀性能研究

为保证盐渍土地区混凝土服役寿命,区别于以往自修复材料,合成一种可以感知外界腐蚀离子并释放内部修复剂的微胶囊,以合成温度为变量控制引发剂分解速率得到了具有不同包裹率的微胶囊。选取其中包裹率、腐蚀离子响应能力较好的微胶囊,将其掺入混凝土中得到具有自修复功能的混凝土。改变微胶囊掺量测试混凝土动弹性模量及抗腐蚀能力。研究结果表明：在合成温度为75℃环境条件下的微胶囊包裹率优于65和85℃环境条件下。盐渍土-硫酸盐干湿循环腐蚀下混凝土构件动弹性模量均呈现先上升后下降的趋势,在20次干湿循环后未掺微胶囊的混凝土动弹性模量急速下降,在40次干湿循环后为掺微胶囊的混凝土内部侵入了更多的硫酸盐,试验拌制的自修复混凝土具有良好的抗硫酸盐侵蚀能力,对实际工程中建筑结构应对硫酸盐腐蚀具有十分重要的借鉴意义。     

微胶囊智能自修复材料研究进展

微胶囊自修复材料是由生物体受伤愈合机制启发所构建的智能自修复体系。微胶囊自修复材料可智能地实现自身能量和物质的补充,在一定程度上增强材料的机械性能,延长材料的使用寿命。研究了自修复微胶囊的制备工艺,以及微胶囊自修复材料的自修复机理和自修复体系,简要概述了自复效果的评价方法。展望了微胶囊自修材料的发展前景。     

自修复环氧胶粘剂分子设计

在自修复聚合物复合材料中,修复剂黏度和高聚物强度是保证自修复过程实现的重要因素。文中以合成用于自修复材料的环氧树脂微胶囊为目的,在双酚A型环氧树脂(E-51)中加入稀释剂正丁基缩水甘油醚(BGE)降低黏度,采用傅里叶红外(FT-IR)分析稀释剂对环氧胶粘剂与微胶囊咪唑类固化剂交联反应的影响,表征了在固化过程中稀释剂参与环氧胶粘剂与咪唑类固化剂的交联反应;使用差示扫描量热(DSC)技术对该固化反应进行动力学研究,确定出稀释剂的最佳用量;通过拉伸实验测定了环氧树脂固化产物的强度,表明BGE的加入增强了环氧树脂的胶粘性能。     

基于微纳米胶囊型填料提升防腐涂层耐久性的研究进展

金属涂层的完整性和耐久性对钢结构的耐介质腐蚀影响很大。微纳米胶囊型填料能在防腐涂层发生局部破损或者出现微裂纹时,对涂层下微环境变化产生应激响应,释放出缓蚀性物质或者聚合物单体,实现对涂层的自修复,填充空隙,从而显著提高涂层的抗介质腐蚀能力。首先介绍了微纳米自修复涂层的原理,并以介孔SiO₂、层状双氢氧化物、埃洛石纳米管和金属有机框架化合物等几种新型微纳米填料为代表,对其在自修复高耐蚀涂层上的应用和优缺点进行了简单的总结和展望,为高耐蚀长效涂层的开发提供一些思路。     

一种聚合物基自修复复合材料的制备与表征

针对聚合物基自修复复合材料研究中存在的问题并结合硅氢化反应及其催化剂的特点,基于埋植式自修复体系的最新进展,提出了一种新的自修复体系。该体系由分散于基体中的包覆有修复单体的微胶囊和负载有催化剂的增强粒子或纤维填料构成。体系中的催化剂选用能在常温常压下快速高效催化硅氢化反应的负载型铂基催化剂。修复剂选用兼有多个硅氢键(Siv—H)和硅乙烯键(Si—Vi)的低聚有机硅氧烷。研究了所制备的自修复单体Ⅰ和Ⅱ在Karstedt催化剂和GF—Pt催化下的聚合反应,结果表明自修复单体能顺利聚合。用SEM研究了用修复单体Ⅱ处理负载有催化剂的玻璃纤维增强环氧树脂复合材料的断面前后的形貌变化,结果表明修复反应可以在复合材料内部发生,修复反应发生后对界面结合有利。     

Q235/Ni-Co基自修复涂层的制备和耐蚀性能

结合自修复微胶囊防腐涂层与合金镀层的优点,在Q235碳钢基体制备Ni-Co/Cap(T+Y)复合涂层以提高碳钢材料的耐侯性和服役周期。首先采用恒电流合金电镀法在Q235碳钢基体生成Ni-Co合金镀层,然后将以桐油和金属缓蚀剂做囊芯的双组份自修复胶囊均匀分散在醇酸树脂防腐涂层中制备有机防腐涂层,得到Ni-Co/Cap(T+Y)复合涂层。SEM观测和热重分析结果表明,合成的双组份自修复微胶囊的平均粒径约为3 μm,囊芯包覆率达到49%。中性盐雾试验和微区电化学测试结果表明,经历380 h中性盐雾试验后复合防腐涂层只在划痕交点处出现轻微腐蚀,其他部位仍旧完整,没有出现鼓泡和腐蚀。以Ni-Co合金镀层与自修复涂层相结合的复合涂层,能长期保护Q235碳钢。     

自修复功能防腐涂膜研究进展

金属的腐蚀是一普遍现象,开发新的防腐技术来减缓、抑制腐蚀具有重要意义。"自愈合"防腐涂膜是一种智能型涂膜,它在表面破损、腐蚀发生时,在不借助外部条件下具有自行修复表面抑制腐蚀的功能,是目前功能性防腐涂膜中的研究热点,就近年来自愈合功能性防腐涂膜方面的研究进展作一综述,并展望了其研究前景。     

A mussel-inspired delivery system for enhancing self-healing property of epoxy coatings

Dopamine (DA),one type of mussel-inspired biological molecules with adhesive nature and corrosion inhibitor property,are often used to functionalize the surfaces of various materials.Herein,we report the application of polydopamine (PDA) microcapsules as novel nanocontainers for the purpose,loading corrosion inhibitor (benzotriazole) in its shell structure,and then were embedded into epoxy coatings to provide self-healing and anti-corrosion protection for carbon steel.Fast release of benzotriazole in acidic environment caused by local corrosion and the chelating effect of PDA-Fe3+ can synergistically promote the formation of protective film on bare steel surface,which endows coatings with self-healing func-tionality.Electrochemical impedance spectroscopy (EIS),local electrochemical impedance spectroscopy(LEIS),and spray tests were conducted to evaluate the active inhibition and corrosion resistance of the loaded coatings.The scratched coating with incorporation of nanocontainers presented better protection performance,exhibiting increased Ro (oxide layer resistance) and Rct (charge transfer resistance) during initial immersion periods.The EIS tests in long-term immersion were also performed to confirm the anti-corrosion effect of composited coatings.These results demonstrated that benzotriazole-decorated PDA capsules dramatically enhanced the self-healing properties and anti-corrosion performance of epoxy coatings with the synergistic help of PDA and benzotriazole.     

Particle-induced damage and subsequent healing of materials: Erosion,corrosion and self-healing coatings

This review summarizes research on particle-induced damage and the subsequent repair of metallic materials. Metallic materials are damaged by solid particle impact via two damage processes: repeated plastic deformation and cutting. At a certain low-impact velocity, the particle does not skid, resulting in only plastic deformation with no damage by cutting. The critical impact velocity has been theoretically derived. Self-healing coatings for repair of damaged materials have been investigated. A fluorine polymer coating has self-healing properties, which are improved by the addition of metal particles. A self-healing coating that uses particles and an organic healing agent has also been developed.     

基于动态共价交联网络自修复涂层的研究进展

涂层是材料抵御外界应力损伤的重要屏障,且随着科技的发展,智能涂层可在原先的基础上赋予涂层荧光、抗菌、检测、传感等先进功能。然而,此类涂层在使用过程中不可避免会受到机械破坏(如擦痕、刮伤等)及与内部各组分应力不匹配引发的宏观或者微观损伤,导致裂纹甚至开裂,结构损伤会引起功能的减弱甚至消失。因此,对涂层结构稳定性和功能持续性提出了更高要求。基于动态共价交联网络的自修复涂层是以动态共价键可逆反应为基础,在一定的外界刺激下建立原料分子与产物分子之间的热力学平衡,通过动态网络“重组”实现对涂层自修复。动态网络活化能的大小不仅能直接反映修复难易程度(反应速率),也能间接反映材料的力学表现。因此,本文将从化学热/动力学角度出发,分析自修复网络构筑与反应活化能之间的关系,并进一步概述基于动态共价交联网络的自修复涂层在传统涂料(层)、智能传感、光学变色、生物医药领域的应用。最后对动态共价自修复涂层目前存在的局限和未来的发展进行展望。     

微胶囊型自愈合聚合物基复合材料研究进展

自愈合材料是一种可以模仿生物体自行愈合的新型智能材料,具有广泛的应用前景。微胶囊型自愈合聚合物基复合材料是近年来复合材料自愈合方法领域内的研究热点之一。本文对目前聚合物基复合材料自愈合方法进行了综述,着重介绍了微胶囊型自愈合聚合物基复合材料的自愈合概念和机制、微胶囊结构及其技术发展状况,并详细介绍了微胶囊的芯材、壁材、自愈合基体材料及微胶囊临界应力等因素对复合材料自愈合性能的影响,以及自愈合效率的评估方法。最后讨论了微胶囊型自愈合聚合物基复合材料的发展趋势和面临挑战。     

In vitro corrosion testing of PVD coatings applied to a surgical grade Co–Cr–Mo alloy

Toxic effects and biological reaction of metallic corrosion and wear products are an important concern for metal on metal artificial joints. Corrosion tests were conducted to study the susceptibility to pitting and localized corrosion, with three coatings, CrN, TiN and DLC, applied to a wrought high carbon Co–Cr–Mo alloy substrate material. Corrosion testing involved the measurement of potential time transients during immersion in a physiological solution and cyclic polarization of specimen potentials into the transpassive range followed by reversal of the potential to scan in the cathodic direction to regain the rest potential E_rest. Resistance to pitting and localized corrosion was assessed by determining the transpassive breakdown potential E _bd and if any hysteresis generated during the reverse cyclic scan may have caused crossover with the original anodic scan. Three different surface coating conditions were tested namely: (1) as-coated, (2) polished, and (3) indented to penetrate the coating by diamond pyramid hardness indentor. Results showed that all three coatings produced significant improvements in corrosion resistance compared to performance of the wrought cobalt alloy but that some corrosive attack to both the CrN and TiN coatings occurred and some risk of attack to the cobalt alloy substrate existed due to coating defects or when damage to the coating occurred. TiN coatings were highly effective in preventing corrosion provided they were thick enough to produce complete coverage. Thin TiN coatings displayed some tendency to encourage localized attack of the cobalt alloy at coating defects or where the coating suffered mechanical damage. CrN coatings underwent transpassive breakdown more easily and some degree of pitting at defects within the coating was observed, especially when the CrN coating was polished before the test. No corrosive attack of the cobalt alloy substrate was observed when the CrN coating was mechanically damaged by indentation. DLC coatings produced were much thinner than either of the other two coatings and proved to be rather fragile. They were less effective in preventing apparently high corrosion currents and possibly high rates of corrosion.     

Self-healing coatings in anti-corrosion applications

Nonmetallic (based on polymers or oxides) and metallic protective coatings are used to protect metal products against the harmful action of the corrosion environment. In recent years, self-healing coatings have been the subject of increasing interest. The ability of such coatings to self-repair local damage caused by external factors is a major factor contributing to their attractiveness. Polymer layers, silica-organic layers, conversion layers, metallic layers and ceramic layers, to mention but a few, are used as self-healing coatings. This paper presents the main kinds of self-healing coatings and explains their self-healing mechanisms.     

舰船防污涂料的使用需求及研究进展

海洋生物附着导致的生物污损是舰船航行过程中面临的一大难题,涂装防污涂料被认为是防止海洋生物污损舰船最经济有效的方法。根据舰船的服役特点,介绍了舰船防污涂料对于长效性、动静普适性和海域广谱性的使用需求,提出研发环保型长效防污涂料是当前防污损研究领域的一大挑战。简单综述了自抛光型防污涂料、污损释放型防污涂料、仿生型防污涂料、表面自愈型防污涂料以及其他防污新技术的发展,指出自抛光型防污涂料仍是当前稳定批量应用的主流产品,其他新型防污技术的防污期效仍需经过实际应用验证。随着环保要求的日趋严格,防污损机理研究的不断深入以及防污性能评价方法的不断完善,新型环保防污涂料的研制将逐渐加快并得到广泛推广应用。     

微胶囊自修复材料的研究进展

自修复材料的概念受自然界生物可以自动修复受损部位的启发而产生,在工程应用中受到广泛重视。研究了自修复体系,概述了常见的微胶囊制备工艺,并对自修复复合材料的性能评价指标进行了阐述,提出了今后研究的发展方向。     

Healing substrates with mobile, particle-filled microcapsules: designing a ‘repair and go’ system

We model the rolling motion of a fluid-driven, particle-filled microcapsule along a heterogeneous, adhesive substrate to determine how the release of the encapsulated nanoparticles can be harnessed to repair damage on the underlying surface. We integrate the lattice Boltzmann model for hydrodynamics and the lattice spring model for the micromechanics of elastic solids to capture the interactions between the elastic shell of the microcapsule and the surrounding fluids. A Brownian dynamics model is used to simulate the release of nanoparticles from the capsule and their diffusion into the surrounding solution. We focus on a substrate that contains a damaged region (e.g. a crack or eroded surface coating), which prevents the otherwise mobile capsule from rolling along the surface. We isolate conditions where nanoparticles released from the arrested capsule can repair the damage and thereby enable the capsules to again move along the substrate. Through these studies, we establish guidelines for designing particle-filled microcapsules that perform a ‘repair and go’ function and thus, can be utilized to repair damage in microchannels and microfluidic devices.