Control of zinc corrosion in acidic media: Green fenugreek inhibitor

Fenugreek seeds extract was examined as a green corrosion inhibitor for Zn in 2.0 mol/L H2SO4 and 2.0 mol/L HClsolutions by mass loss and electrochemical measurements. Scanning electron microscope （SEM） images show that the surfacedamage is decreased in the presence of the inhibitor. X-rays photoelectron spectroscopy （XPS） analysis was performed to identify thecorrosion product, ZnO, and to prove the inhibitor adsorption mechanism. The maximum inhibition efficiency values are 90.7% after1 h and 66.6% after 0.5 h by 200 mL/L of fenugreek extract in H2SO4 and HCl solutions, respectively. Addition of I^- ion greatlyimproves the inhibition efficiency of fenugreek seeds extract for Zn corrosion in HCl due to the synergistic effect. Potentiodynamicpolarization and EIS measurements prove the inhibition ability of fenugreek for Zn corrosion in HCl as indicated by the decreasedcorrosion current density and increased charge transfer resistance values in the presence of fenugreek.

Composite corrosion inhibitors for secondary alkaline zinc anodes

The corrosion inhibition property of PEG600 and In（OH）3 as composite corrosion inhibitors for （second-）（ary） alkaline zinc electrodes was studied, and the inhibition efficiency was determined as 81.9%. The research focused on the mechanism by the methods of electrochemical impedance spectroscopy, polarization curves and IR spectroscopy. The results indicate that the corrosion inhibition effectiveness is attributed to the joint inhibition of anodic zinc dissolution and cathodic hydrogen evolution. And the anodic process is depressed to a greater extent than the cathodic process. The synergistic mechanism of the composite inhinbitors proves to be the enhancement of adsorption of PEG600 by In（OH）3. Potentiostatic experiment results and SEM images verify the inhibition of dendritic growth by the composite inhibitors.

Synergic Mechanism of an Organic Corrosion Inhibitor for Preventing Carbon Steel Corrosion in Chloride Solution

The inhibition effect of dimethylethanolamine（DMEA） and its composite with carboxylic acid was studied with the electrochemical tests. The experimental results indicate that DMEA is not a good inhibitor but the composite of DMEA with caprylic acid exhibits excellent inhibiting efficiency. The synergic mechanism of the organic corrosion inhibitors（OCIs） was studied with quantum chemical calculations. It is found that the DMEA forms a quaternary ammonium salt with the proton in carboxylic acid, and a cyclic complex formed between the salt and Fe may be responsible for the enhancement of inhibiting efficiency. The possible hydrogen bond formed between DMEA and carboxylic acid is not enough for the inhibiting effect. This work is helpful to proposing theoretical interpretation as well as developing a functional organic inhibitor to improve the durability of reinforced concrete contaminated with chloride.

Effect of Organic Coating Corrosion Inhibitor on Protection of Reinforced Mortar

Corrosion of reinforced concrete is the most important cause of concrete structure deterioration. In the present study, the protective effect of the reinforcement mortars against corrosion is examined. In particular, the chloride penetration resistance on reinforced cement mortars using organic coating as additive containing was studied. The aforementioned additive consists of corrosion inhibitor for protection of steel rebars against pitting corrosion. For the experimental procedure, four (4) different types of reinforced mortars were prepared. The corrosion protection of the additive was evaluated by electrochemical methods, (linear polarization resistance, Half-cell Potential Resistance and Electrochemical Impedance Spectroscopy). In addition, the mass loss of steel rebars against time of partially immersed in NaCl solution was carried out in the lab. The experimental results showed that in all examined cases the organic coating provides anticorrosion protection on steel rebars against chlorides.

Inhibiting Effect and Mechanism of Organic Additive DA on Corrosiom of Zinc in Alkaline Solution

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Effects of Organic Corrosion Inhibitor and Chloride Ion Concentration on Steel Depassivation and Repassivation in Solution

Effect of an organic corrosion inhibitor(OCI) named PCI-2014 added in chloride solution on the critical chloride concentration of mild steel depassivation and the critical OCI concentrations for repairing the steel in different chloride solution were investigated.The results show that the critical chloride concentration increases exponentially with raises of PCI-2014 concentration in the solution.Within a certain chloride ion concentration range,the critical PCI-2014 concentration for repairing the corroded steel is also increases exponentially with enhancement of chloride content in the solution.Atomic force microscopy images display the molecular particles of inhibitor are adsorbed on the steel surface and formed a protective layer.Analysis of X-ray photoelectron spectroscopy shows the chloride ions at the surface of steel are displaced by atoms or molecules of the inhibitor in chloride condition.

Green corrosion inhibitors intercalated Mg:Al layered double hydroxide coatings to protect Mg alloy

Mg alloy was protected with Mg:Al layered double hydroxide(LDH)coating intercalated with three green corrosion inhibitors(sodium benzoate,3-aminopropyltriethoxysilane and 8-hydroxyquinoline).The in-situ hydrothermal approach was adopted to intercalate corrosion inhibitors into Mg:Al LDH coating.The intercalated Mg:Al LDH coating was successfully acquired,and the crystalline structure of Mg:Al LDH coating was verified with X-ray diffraction(XRD).The organic functional groups of corrosion inhibitors were identified with the help of Fourier transform infrared spectroscopy(FTIR)and X-ray photoelectron spectroscopy(XPS).The compact and uniform morphology was confirmed by scanning electron microscopy(SEM).The electrochemical measurement revealed better corrosion resistance of corrosion inhibitorintercalated Mg:Al LDH coatings as compared to that of pristine Mg alloy.The corrosion protection mechanism of corrosion inhibitors was described and unearthed the corrosion inhibitor with the best performance.

碳钢表面电镀锌镍/有机富铝复合涂层的制备与性能

为提高碳钢表面电镀锌镍的防护性能和应用限制,采用电镀锌镍层作为底层,有机富铝涂层作为顶层,设计出一种复合涂层防护体系。采用扫描电镜(SEM)、能谱(EDS)、中性盐雾试验、电化学测试等手段对电镀锌镍/有机富铝复合涂层的表面/截面形貌及耐蚀性进行表征与分析。结果表明:电镀锌镍/有机富铝复合涂层表面光滑平整,无明显缺陷,复合涂层体系界面结合良好,无分层现象,经1500 h中性盐雾试验后复合涂层无红锈。复合涂层较单独的电镀锌镍合金层腐蚀电流密度降低了2个数量级,表现出受控的牺牲阳级作用,并实现了在海洋防护领域的应用。复合涂层有效提升了电镀锌镍层的耐腐蚀性能,拓宽了电镀锌镍层在腐蚀防护领域的应用范围。

离子液体缓蚀剂与氧化石墨烯在环氧磷酸锌涂料中的应用探究

为了研究自制咪唑溴盐离子液体缓蚀剂及氧化石墨烯对环氧磷酸锌防腐涂料综合性能的影响,向环氧磷酸锌底漆中引入咪唑溴盐离子液体缓蚀剂、氧化石墨烯及其复配体系,表征涂层表面形貌和元素分布,考察涂层力学性能和防腐性能。结果表明:加咪唑溴盐、氧化石墨烯及其复配体系能够不同程度地增强涂层的柔韧性和拉伸强度等力学性能;电化学腐蚀试验中,2种组分复配加入后,涂层的自腐蚀电流密度变小,防腐性能有效提高;盐雾试验中,2种组分复配更有利于改善涂层耐盐雾性能。

维生素在含氯混凝土模拟孔隙液中对钢筋的缓蚀作用

为研究钢筋混凝土体系中维生素缓蚀剂的缓蚀作用,本文采用动电位极化和电化学阻抗谱测试,研究了硫胺素(VitB1)、烟酸(VitB3)、吡哆醇(VitB6)和抗坏血酸(VitC)在含氯混凝土模拟孔隙液中对钢筋的缓蚀作用,并基于密度泛函理论进行了量子化学计算,讨论了维生素对钢筋的缓蚀机理。结果表明,在含0.05 mol/L NaCl的混凝土模拟孔隙液中,VitB6的缓蚀效果最好,因为其最高占据分子轨道和Fe 3d轨道间的键合稳定性最强。每种维生素都存在一个达到最佳缓蚀率IE的特定浓度添加值,此时VitB1和VitB3表现为阳极型缓蚀剂,VitB6和VitC为混合型缓蚀剂。随着维生素浓度的增加,IE出现反向波动的趋势,这是由于缓蚀剂的极性基团吸附于钢筋表面,抑制了阴极反应,进一步加剧了阴、阳极间的不平衡。

环境友好型缓蚀剂的研究进展

本文综述了金属缓蚀剂的研究进展。近年来,随着科学技术的不断发展,金属材料的需求与日俱增,金属材料因机械强度高、耐久性好而在许多有前景的领域中都是不可或缺的。但是金属材料易腐蚀,缓蚀剂的存在可以阻滞或减缓金属的腐蚀进程。人们对可持续发展认识的不断提高,环境友好型缓蚀剂必将成为今后的发展趋势。环境友好型缓蚀剂可分为无机缓蚀剂、有机缓蚀剂,本文着重介绍了一些常用的环境友好型缓蚀剂,并对其发展前景进行了展望。

抗腐蚀蔓延水性环氧富锌涂料的制备与性能

[目的]要延长涂层的使用寿命,需阻止腐蚀介质沿着涂层被划伤的部位侵入而腐蚀金属基材,抑制腐蚀蔓延。[方法]选用环氧树脂乳液、胺类固化剂、颜填料、腐蚀抑制剂及其他助剂制备了一种具有优异抗腐蚀蔓延能力的水性环氧富锌涂料,讨论了成膜物质含量、固化剂种类和颜填料复配形式对涂层耐蚀性的影响,探讨了涂层抗腐蚀蔓延的机理。[结果]在成膜物质的质量分数为15%,选用聚酰胺固化剂,以绢云母、超磷锌白和石墨烯作为颜填料,并加入适量腐蚀抑制剂的情况下,所制备的涂料综合性能最好,其涂层经中性盐雾试验2 160 h后依然具有良好的附着力,平均扩蚀宽度仅为1.43 mm。[结论]腐蚀抑制剂对涂层湿态附着力的提升,以及石墨烯对锌粉利用率的提升,共同赋予了该涂层优异的抗腐蚀蔓延性能。

聚噻吩氧化锌纳米防腐聚合物涂层材料制备及性能研究

通过水热法制备了氧化锌纳米纤维团簇,并将其加入噻吩单体作为负载填充物,经由自由基聚合过程制备了适用于低碳钢的聚噻吩-氧化锌防腐蚀涂料。利用扫描及透射电子显微镜、红外光谱、X射线衍射等对上述材料的物化结构进行了分析表征。通过电化学工作站测定其多种电化学腐蚀参数,研究了聚合物复合涂层对Q235碳钢的缓蚀性能。试验结果表明,聚噻吩负载氧化锌纳米纤维团簇涂层的引入可极大地减缓Q235碳钢板的电化学腐蚀效应。当聚噻吩负载氧化锌涂覆次数为2次时,钢片的抗腐蚀性能最优,其线性极化电阻为312.31Ω。

原子力显微镜在有机缓蚀剂研究中的应用

有机缓蚀剂具有低毒性和高性价比等优点,在低浓度的注射剂量下可以实现优良的缓蚀效果,被广泛应用于石油化工(碳钢)、电子工业(铜)、车辆船舶和航空航天工业(铝),保护合金材料免受腐蚀危害。现有的电化学测试技术已经在有机缓蚀剂领域得以广泛应用,这种传统的研究方法可以提供有关界面电化学反应的平均动力学信息,但是无法直接解析缓蚀剂的吸附及作用机制。随着金属腐蚀与缓蚀剂研究的微观化和系统化发展,电化学分析手段逐渐与其他分析技术(如扫描电镜、X射线光电子能谱、拉曼光谱等)紧密结合,开展了对缓蚀剂作用机制的深入研究。在这些分析技术中,原子力显微镜(AFM)由于空间分辨率成像能力高,受工作环境和样品性质的局限较少,在有机缓蚀剂于金属/溶液界面的直观研究中起到了重要作用。本文结合近年来原子力显微镜在有机缓蚀剂领域的研究进展,简述了原子力显微镜的工作原理和几种操作模式,详述了AFM的接触模式在有机缓蚀剂研究中的普遍应用和其局限性,总结了AFM的敲击模式在表面活性剂吸附研究中的重要作用和研究现状并延伸到有机缓蚀剂的吸附研究,综述了AFM几个衍生功能(包括纳米刮擦、力-距离曲线、摩擦力和电化学原子力显微镜)在有机缓蚀剂研究中获得的缓蚀剂膜的力学和电化学相关信息,最后对AFM在有机缓蚀剂领域当前研究中存在的问题和未来发展趋势进行了展望。

乌干达KF油田完井液体系优选及性能评价

根据乌干达KF油田储层特征及其对完井液的技术需求,开展了完井液体系的优选及性能评价工作。通过对有机胺抑制剂、缓蚀助排剂的加量优选和完井液体系配方研究,形成了一套以抑制性能为主兼具防水锁和耐腐蚀性能的有机胺完井液体系,该完井液体系配方为配制水+1.5%(质量分数)缓蚀助排剂HZ-1+有机胺抑制剂YZ-1+10%(质量分数)KCl。结果表明:该体系的防膨率达到95.2%、表面张力为27.2 mN/m、界面张力为2.04 mN/m、腐蚀速率为0.047 mm/a,对储层的渗透率恢复率在85%以上。可见,构建的完井液体系可满足乌干达KF油田完井阶段的技术需求。

双子型有机缓蚀剂研究进展

工业生产中油井酸化压裂、CO_(2)驱油、酸洗除垢、污水管道锈蚀等过程中均涉及金属的腐蚀,加入缓蚀剂是解决各类腐蚀问题最便捷有效的方法之一,其中双子型有机缓蚀剂有双季铵盐、双席夫碱及双曼尼希碱等类型。本文对我国近年来双子型有机缓蚀剂的发展进行综述,详细介绍了各类双季铵盐、双席夫碱及双曼尼希碱有机缓蚀剂的制备及其在防腐蚀领域的应用,并对绿色高效有机缓蚀剂的未来发展进行了展望。

海洋防腐领域中有机缓蚀剂的研究进展

海洋环境(海水、海洋大气和海泥)是条件极为严苛的自然腐蚀环境。船舶和海洋工程等长期服役在海洋环境中的钢铁结构体极易被腐蚀。有机缓蚀剂具有分子结构可设计性强、缓蚀效率高、作用时间长等优点,可有效阻止或减缓金属的腐蚀。因此,在海洋防腐涂料中添加有机缓蚀剂是提升其耐蚀性能的有效方法。该文结合国内外最新研究进展,综述了有机小分子缓蚀剂和聚合物缓蚀剂的特性及其在海洋防腐涂料中的应用,包括总结归纳各种有机缓蚀剂的分子结构和性能影响因素,分析有机缓蚀剂的表征手段和作用机制,讨论不同添加工艺对有机缓蚀剂在防腐涂料中的应用研究。最后,对有机缓蚀剂未来发展方向进行了展望。

电站燃油锅炉腐蚀抑制剂的合成及作用机理

以硬脂酸、软脂酸、油酸、环烷酸4种有机酸和活性-60氧化镁(简称MgO)为主要原料,设计合成了复合无机-有机酸镁腐蚀抑制剂,考察了其使用性能,并对其作用机理进行了探究。结果表明,复合碳酸镁-环烷酸镁腐蚀抑制剂具有较好的效果,加量为1000μg/g时,烟气中SO_(3)含量降低了70.0%,钢片腐蚀速率降低了21.6%。合成的产品是一种纳米级MgCO_(3)粒子,其能在有机酸镁胶束包裹下形成稳定的胶体体系,有效解决了MgCO_(3)粒子在燃油中分散性差的问题,有利于发挥复合无机-有机镁盐的协同作用。随着燃油燃烧,腐蚀抑制剂产生的MgO与燃油产生的V_(2)O_(5)结合,降低了V2O5的浓度,减弱了其对SO_(2)向SO_(3)转化的催化作用,使烟气中SO_(3)含量降低,抑制了低温腐蚀。同时,MgO的存在使燃烧生成的钒酸盐种类由低熔点变为高熔点,高温腐蚀得到缓解。

有机缓蚀剂对低碳钢的缓蚀性能研究进展

概述离子液体、天然植物提取物、有机衍生物、新型希夫碱类缓蚀剂、药物类有机缓蚀剂对低碳钢在不同介质中缓蚀性能的国内外研究情况。介绍有机缓蚀剂机理,并且利用失重法、电化学法、表面分析等方法对其缓蚀性能进行分析,展望了在不同介质中对低碳钢有机缓蚀剂的研究方向。

杂环砌块构筑的有机分子对钢和铜的缓蚀性能研究进展

现代工业中,钢和铜易遭受无机酸侵蚀,特别是工业生产会加剧酸雨的发生,使这些金属受到酸腐蚀,从而影响其各项性能并造成巨大的经济损失及安全隐患,因此防止酸介质对钢和铜等金属的腐蚀具有非常重要的意义。在防止金属钢和铜被酸侵蚀的策略上,有机缓蚀剂方法因表现出低毒性、低成本、高效率、环境友好等许多独特的优点而引起人们的重点关注。杂原子能够增强有机分子在钢和铜表面上的吸附性能,促进有机化合物在这些金属表面形成保护屏障,进而有效提高金属在酸环境中的缓蚀效率。因此,可以利用有机缓蚀分子的极性杂环砌块基团在钢和铜表面具有吸附效应以及非极性的长链可在这些金属表面形成稳定的定向排列等特性,有效隔离侵略性腐蚀介质和金属表面直接接触以实现缓蚀作用。针对钢和铜在无机酸溶液中的缓蚀研究现状,本文重点总结了近年来基于杂环砌块构筑的有机缓蚀剂分子在酸介质中抑制钢和铜等金属腐蚀的研究进展,对腐蚀及缓蚀机理进行简要描述,并基于实验研究、量化计算和材料模拟分析讨论了含杂环有机缓蚀剂的化学结构与缓蚀性能之间的依赖关系,展望了未来该领域可能的研究重点与目标。