Electrochemical Study on Corrosion Process of Steel Rebar/Concrete System

钢筋混凝土是当今世界最大量的工程材料。钢筋在混凝土中的腐蚀破坏是导致现代钢筋混凝土结构过早失效的最主要原因,已被公认为一个世界性难题。钢筋腐蚀对工程结构耐久性造成极大的威胁，给人民生命安全带来重大隐患，造成巨大经济损失，是关系国计民生的重大问题。钢筋混凝土的腐蚀是一个十分复杂、研究难度大的体系，由于钢筋在混凝土中的腐蚀破坏必然发生在钢筋/混凝土界面，钢筋/混凝土界面腐蚀破坏机理研究和钢筋腐蚀状态的无损检测是关键性的重要课题。 电化学阻抗谱（EIS）可以提供电化学反应机理和动力学方面的信息，给出反应的物理模型。EIS的测量结果表明，钢筋/混凝土体系的阻抗谱中包含两个时间常数，分别来自界面的双电...Corrosion of steel rebar in concrete becomes a main reason for the premature degradation of reinforced concrete, which is by far the most widely used construction material in the modern society. Due to the complexity of the steel/concrete system, great effort is still in need to explore the mechanism of the interfacial reaction and to develop non-destructive detection technique. Electrochemical...学位：理学博士院系专业：化学化工学院化学系_分析化学学号：B19982500

FABRICATION OF IrO_2-pH MICROELECTRODE AND ITS APPLICATION IN STUDY OF CHEMICAL MICRO-ENVIRONMENT AT STEEL/CONCRETE INTERFACE

采用电化学阳极氧化和高温碳酸盐氧化两种方法制备IrO2 - pH微电极 ,其特点是对氢离子响应快、线性范围宽、机械性能好、具有长期稳定性 .考察了该电极的 pH响应特性、化学成分、机械性能等 .结果表明 ,这种IrO2 -pH微电极适用于钢筋 /混凝土界面 pH值的原位测量The corrosion behavior of the reinforcing steel has a close dependence on the chemical micro-environment at the steel/concrete interface.In this paper,a kind of IrO 2-pH microelectrode was prepared by anodic electrochemical oxidation and thermal oxidation in carbonate.In the latter case,IrO 2 electrode showed fast linear response,wide linear range(pH 0～14),satisfying mechanical property and long-term stability.The formation of IrO 2 electrode was characterized and the potential response to H + was tested to explore the optimum condition of fabrication of the IrO 2 electrode.The IrO 2-pH electrode was applied for the in-situ measurement of pH at the steel/concrete interface.国家自然科学基金资助项目 (资助号 :5 98710 43

混凝土中钢筋腐蚀早期过程宏观腐蚀电池与微观腐蚀电池相互作用

建立一种阵列电极技术,通过测量不同时空的微电极腐蚀电位、电偶电流及其动态变化,研究了在腐蚀介质作用下,混凝土中钢筋腐蚀发生、发展早期过程阳极区和阴极区分布特征,探讨了钢筋腐蚀过程宏观腐蚀电池与微观腐蚀电池的相互作用机制.结果表明,伴随着点腐蚀的发生、发展过程,在钢筋/混凝土界面宏观腐蚀电池的作用明显,宏观腐蚀电池电流分布与腐蚀电位有密切的对应关系.混凝土中钢筋腐蚀过程总是存在着宏观腐蚀电池和微观腐蚀电池,二者密切相关、相互作用,对钢筋局部腐蚀的发生、发展过程有重要影响.国家自然科学基金重点项目(批准号:50731004);国家科技支撑计划项目(批准号:2007BAB27B04)资

不锈钢表面耐蚀处理新方法──荣获厦门市1994年度科技进步一等奖

不锈钢表面耐蚀处理新方法──荣获厦门市1994年度科技进步一等奖厦门大学化学化工学院林昌健，田昭武，穆纪千，胡融刚，谭建光一、不锈钢的腐蚀性随着科学和社会的发展，不锈钢的产量和用量正在大幅度增长，不锈钢被广泛地用于国防、化工、石油、运输、海洋、建筑、..

Electrochemical Behavior of Zinc-Bismuth Alloy Electrodes in Gelled Electrolytes

锌电极的自腐蚀速率,持续放电下的阳极溶解速率和电极钝化的难易程度是碱性电池性能的重要电化学参数.本文应用线性极化、恒流放电等电化学实验方法研究了电解液中添加CArbOPOl树脂以及电极中添加bI对锌电极电化学行为的影响.并应用金相显微镜和环境扫描电子显微镜(ESEM)对锌电极和锌铋合金电极浸蚀及放电后的形貌进行了表征.结果表明:电解液中添加适量的CArbOPOl树脂可明显提高电极的极化电阻,显著降低电极的自腐蚀速率;阳极的溶解电位出现不同程度的正移,阳极过电位显著增大且大电流密度放电时较明显促进电极钝化.锌电极中添加一定量的bI对改善电极表面氧化物膜的沉积形貌和电极表面固液界面的传质条件,减小电极的自腐蚀速率,抑制电极自腐蚀等方面具有显著作用.The self-corrosion rate, anodic dissolution rate, and passivating tendency of a zinc anode are important parameters that affect the performance of alkaline batteries.Effects of the addition of Carbopol resin to the electrolyte and the addition of passivation Bi passivation to the electrodes on the electrochemical behavior of Zn electrodes were investigated by linear polarization and chronopotentiometry.Surface morphologies of Zn electrodes and Zn-Bi alloy electrodes after etched and constant current dissolution were examined using a metallographic microscope and environmental scanning electron microscope (ESEM).Results showed that the addition of Carbopol resin significantly enhanced the polarization resistance, decreased the self-corrosion current, led to a positive shift in anodic dissolution potential, remarkably increased the anodic overpotential and promoted the passivation of alloy electrodes.The addition of Bi markedly improved the oxide film morphology and mass transfer between solid-liquid interfaces, decreased the self-corrosion rate of Zn electrodes and inhibited the self-corrosion process in Zn electrodes.国家自然科学基金(50731004);国家科技支撑计划(2007BAB27B04-N43CTT)资助项目---

Electrochemical Behavior of Zinc-Bismuth Alloy Electrodes in Gelled Electrolytes

The self-corrosion rate, anodic dissolution rate, and passivating tendency of a zinc anode are important parameters that affect the performance of alkaline batteries. Effects of the addition of Carbopol resin to the electrolyte and the addition of passivation Bi passivation to the electrodes on the electrochemical behavior of Zn electrodes were investigated by linear polarization and chronopotentiometry. Surface morphologies of Zn electrodes and Zn-Bi alloy electrodes after etched and constant current dissolution were examined using a metallographic microscope and environmental scanning electron microscope (ESEM). Results showed that the addition of Carbopol resin significantly enhanced the polarization resistance, decreased the self-corrosion current, led to a positive shift in anodic dissolution potential, remarkably increased the anodic overpotential and promoted the passivation of alloy electrodes. The addition of Bi markedly improved the oxide film morphology and mass transfer between solid-liquid interfaces, decreased the self-corrosion rate of Zn electrodes and inhibited the self-corrosion process in Zn electrodes.National Natural Science Foundation of China [50731004]; National Sci-Tech Supporting Program of China [2007BAB27B04-N43CTT

XPS/SERS STUDY OF ELECTROCHEMICALLY MODIFIED PASSIVE FILM ON STAINLESS STEEL

应用X射线光电子能谱 (XPS)和表面增强拉曼光谱 (SERS)考察 1 8 8不锈钢表面电化学改性钝化膜各层次的化学组成。XPS的结果表明电化学改性处理可使钝化膜老化。膜层中含大量的CrO3,但未检测到CrO2 4。在膜的各个层次均发生铬的富集 ,而在最外层铬的含量并非最大。表明在改性处理过程中 ,铬优先溶解 ,部分物种可进入溶液。铁在膜的外层存在Fe(Ⅱ )和Fe(Ⅲ )两种氧化态 ,同样有利于非晶态结构的形成。原位SERS测试的结果指明CrO 24 主要存在于膜的最表层 ,进一步探明不锈钢表面电化学改性钝化膜的离子选择特性In order to make further insight into the nature of passivity, the combination of XPS and SERS was employed to ex situ and in situ characterize the chemical composition and structure of electrochemically modified passive film of 18/8 stainless steel. It was evidenced that the electrochemical modification gave rise to dehydration of the passive film. There existed an abundance of CrO 3 in the outer layer of passive film, but no CrO 2 4 was sensed by XPS measurements. The enrichment of Cr appeared throughout the passive film, and the maximum of it did not locate at the outmost layer. It implied that the preferential solvating happened during the electrochemical modification. Like the coexistence of Cr 2O 3 and CrO 3 in the barrier layer, the oxides of Fe(Ⅱ) and Fe(Ⅲ) species at the outer layer played a beneficial role in the formation of non crystalline passive film. It was revealed that from in situ SERS and ion selective screen of CrO 2 4 may be formed on the surface, which repulsed the attack of the aggressive ions and strengthened the stability of the electrochemically modified passive film of 18/8 stainless steel.国家自然科学基

Microelectrodes for in Situ Chemical Measurements in Sediments

微电极技术在测量不稳定沉积物化学中具有不可替代的作用,日益受到重视。综合论述了目前实际应用于定量沉积物化学的三大电化学类型的微电极,覆盖了pH微电极、pCO2微电极、硫化物微电极、溶解氧膜微电极、汞金伏安微电极的工作原理、制作方法和应用文献。特别介绍了实验室制作氧化铱pH微电极的方法和性能,描述了制作汞金伏安微电极的详细步骤及其在测量沉积物氧化还原化学成分的具体实验装置和技术方法,认为微电极技术的引入对深化沉积物生物地球化学过程研究具有重要作用。Microelectrodes for in situ chemical measurements in sediments are powerful techniques that cannot be substituted by alternative methods and are receiving increasing attentions from scientific community.This paper introduces three major electrochemical categories of microelectrodes that have practical applications in quantifying sediment chemistry,and cover the working principles,construction procedures,and applications of pH microelectrode,pCO_(2) microelectrode,sulfide selective microelectrode,oxygen membrane microelectrode,and Hg-Au voltammetric microelectrode in sediments.In particular,this paper describes the electrochemical properties of Iridium oxides pH microelectrodes and Hg-Au microelectrodes constructed in the laboratory and provides in details technicalities for measuring redox chemical species in sediments by voltammetry.It is believed that microelectrode applications have deepened biogeochemical study in sediments.国家自然科学基金项目“应用多种微电极技术研究近岸沉积物化学”(编号:40476035);; 教育部留学回国基金项目资

IN SITU ECSTM INVESTIGATION ON FORMATION AND BREAKDOWN OF PASSIVE FILM FOR POLYCRYSTALLINE STAINLESS STEEL

利用电化学扫描隧道显微镜（ＥＣＳＴＭ），原位研究不同电位下不锈钢在 ０．５Ｍ Ｈ２ＳＯ４十 ０．０２Ｍ ＮａＣｌ溶液中表面形貌的动态行为，并讨论电位对不锈钢电化学阻抗谱（ＥＩＳ）的影响 结果表明：不锈钢在活化－钝化过渡区电位表面粗糙度最大；进入钝化区后，在钝化膜完整处，电位越高，表面粗糙度越小，钝化膜呈有序生长， 在钝化膜薄弱处．电位控制在０．２Ｖ时，钝化膜最为完整 在０．５Ｖ时，表面微点蚀坑开始萌生，电位为０．８Ｖ时，已有的微点蚀坑有所生长，不锈钢表面ＥＣＳＴＭ形貌与电化学阻抗谱测量呈对应关系：电位为 ０．２Ｖ时，表面钝化膜最为完整，阻抗最大；电位为 ０．５Ｖ时，在钝化膜薄弱处萌生点蚀坑，钝化膜阻抗有所下降；电位为０．８Ｖ时，钝化膜完整处得到明显的整平，阻抗相比０．５Ｖ时明显提高，但由于已萌生的微点蚀坑开始生长，阻抗相比 ０．２ Ｖ时仍有所降低。The dynamic behavior of surface topography for the stainless steel in 0.5M H2SO4+ 0.02M NaCl was traced in situ by electrochemical scanning tunneling microscope (ECSTM). The results showed a different response for the integrated passivated domain and pit-prone location on the surface when a given potentials was applied to the sample. The roughness parameter Sa for both domains appeared a maximum when controlled potential in the transition passivation region. In the potential region of passivation, passivated grains began to grow orderly on the integrated domain, and Sa decreased with increasing potential. While on the pit-prone domain, metastable micro-pits were observed when a passive potential was controlled at 0.5 V and 0.8 V. The impedance behaviors for steel sample in the different potential regions of passivation were examined by electrochemical impedance spectroscopy (EIS) and discussed based on the ECSTM results. At 0.2 V potential, the flawless surface showed the greatest impedance, and at 0.5 V, the impedance droped due to the initiation of metastable micro-pit. When controlled potential at 0.8 V, the surface roughness decreased considerably on the integrated domain, but the total impedance showed smaller resulted from the development of micro-pit in the preference location.国家自然科学基金 59525102，59871043资助项

Corrosion Behavior of Reinforcing Steel in Concrete Subjected to Chloride Contamination By EIS

通讯联系人, Tel: ( 86_592) _2189354, E_mial: cjlin@ xmu. edu. cn[中文文摘]应用电化学阻抗谱(EIS)研究环境介质中氯离子对混凝土中钢筋腐蚀行为的影响.结果表明,在测量的频率范围内,钢筋混凝土体系的阻抗谱图包含两个时间常数,分别对应于界面的双电层和钢筋表面的混凝土保护层.其低频段的半圆有些压扁,表明界面双电层的充放电行为偏离理想电容器,可归因于钢筋表面的不均一性.在浸泡后期,低频段出现拖尾,同时电荷转移电阻Rct减小了近两个数量级,这是由于钢筋表面的钝化膜已经破裂,发生活性腐蚀,况且氯离子浓度的增大加速了腐蚀发展过程.讨论了混凝土中在钢筋腐蚀发生,发展的过程中,其腐蚀电位Ecorr以及等效电路中的Rct和Warburg阻抗等元件的变化特征.[英文文摘]Electrochemical impedance spectroscopy(EIS) was employed to study the influence of chloride on the corrosion behavior of reinforcing steel in concrete.In Nyquist plot,the spectrum consists of two semicircles,indicating that the reinforced concrete system contained two time constants,one derived from electrical double layer of reinforcing steel and the other from the deposition film of concrete layer.The depressed semicircle in lower frequency featured the non_faradic behavior of the electrical double layer (EDL) deviated from idea capacitor due to dif fusive effect which was att ributed to the surface roughness of rebar and the inhomogenity of concrete layer.Then the EDL was denoted by a constant phase element (CPE) other than a capacitor in the equivalent circuit . At the late stage of immersion, a new element , Warburg resistance Wevolved along with dramatic decrease in the value of polarization resistance, R p, convincing the break down of the passive film and the init iation of active corrosion. The increase of [ Cl- ] in external solution prominently accelerated this trend.福建省自然科学基金 (E0 2 1 0 0 0 6)资