PGSTAT101电化学工作站

PGSTAT204电化学工作站

PGSTAT204是Autolab系列中新的一员，是一款研究级的紧凑型电化学工作站。PGSTAT204的槽压为20V，最大输出电流为400mA。PGSTAT204预留一个扩展插槽，可用于一个功能模块的扩展。PGSTAT204可用于与外部设备的模拟/数字信号的输入/输出。PGSTAT204内置模拟积分器，用于电量的实时采集和积分电流的测量。

NOVA软件控制的自动样品处理

对于样品量大的情况，自动样品处理和分析是非常方便的。同时还减少了出错，污染等风险..............

腐蚀研究——氢渗透实验

Hydrogen permeation is a phenomenon that limits the practical use of high tensile strength steel alloys by introducing cracking hazards due to hydrogen penetration and hydrogen accumulation in the bulk of the alloy.

腐蚀研究——缓蚀剂

A corrosion inhibitor is a substance when added in a small concentration to an environment reduces the corrosion rate of a metal exposed to that environment. Inhibitors often play an important role in the oil extraction and processing industries where they have always been considered to be the first line of defence against corrosion.

腐蚀研究——PX1000测定临界点蚀温度

Critical pitting temperature (CPT) is the lowest temperature on the test surface at which stable propagating pitting occurs under specified test conditions indicated by a rapid increase beyond a set limit of the measured anodic current density of the specimen.

腐蚀研究——腐蚀的基础理论

Corrosion refers to a process that involves deterioration or degradation of metal. The most common example of corrosion is the formation of rust on steel. Most corrosion phenomena are of electrochemical nature and consist of at least two reactions on the surface of the corroding metal. One of the reactions is the oxidation (e.g., dissolution of iron) also referred to as the anodic partial reaction.other is a reduction reaction (e.g., reduction of oxygen), and is referred to as the cathodic partial reaction. The products of the electrochemical reactions can react with each other non-electrochemically to form the final product (e.g., rust). For example, the corrosion of iron to form rust proceeds according to the overall reaction:

腐蚀研究——腐蚀速率的测量

Electrochemical methods provide an alternative to traditional methods used to determine the rate of corrosion. Direct and quantitative determination of corrosion rates can be determined from simple electrochemical measurement like a linear sweep voltammetry (LSV).

腐蚀研究——测量极化电阻

In the previous application note, the procedure for estimating corrosion rates was outlined. The calculations were valid under the assumption that the corrosion reactions were under charge transfer control and that the mechanisms of the reactions were known. In real life, often, corrosion is a result of several reactions and it is not possible to a priori determine the reaction mechanism. In such cases Polarization Resistance, Rp, can be used to determine the resistance of the metal under investigation against corrosion.

腐蚀研究——等效电路模型

In recent years Electrochemical Impedance Spectroscopy or EIS has been successfully applied to the study of corrosion systems. EIS has been used effectively to measure the polarization resistance for corrosion systems and for the determination of corrosion mechanisms for systems where DC electrochemical methods have failed.

瑞士万通Autolab302N电化学工作站评估铜槽添加剂电镀效果

应用领域： 电镀 关键词： 铜槽，恒电流电镀，电化学工作站 样品： 电镀槽液 设备和附件： AUT302N+RDE

The influence of cement type and admixture on life span of reinforced concrete utility poles subjected to the high salinity environment of Northeastern Brazil, studied by corrosion potential testing

Reinforced concrete structures installed in coastal zones have constantly been threatened by environmental damaging elements. The chloride ion is known as one of the most aggressive of these elements, causing, among other damages, corrosion of the steel reinforcement and then degradation of the concrete matrix. The goal of this work was to determine the influence of cement type on the resistance and durability of reinforced concrete samples with 25 mm cover thickness, when submitted to aging in a 3.4% sodium chloride aqueous solution and in a high salinity marine environment. Reinforced concrete light poles were cast following the same batching procedures, and after the curing period, they were exposed to atmosphere in a corrosion station near Aracaju, Sergipe State, Northeastern Brazil’s coast. Two concrete mixtures were made using CPII-F 32 (filler-modified Portland cement): a mix with no admixture and a mix with addition of 8% silica fume swapping fine aggregates. Another mixture was batched with CPV-ARI RS (high-early-strength Portland cement, with sulfur resistance). All the three mixture were designed with cement content of about 350 kg/m3. The performance of the structures was evaluated from the results of physicochemical, mechanical and electrochemical testing, after over a year of natural aging. Corrosion potentials of the reinforced concrete samples and of the cast utility poles were measured in terms of the aging time at the natural environment and under chloride ion accelerated aging at laboratory. The half-cell potential measurements showed that the best results were obtained from the mixture containing CPII-F 32 cement and silica fume, followed by the concrete made with CPV-ARI RS cement. The mixture batched with CPII-F 32 cement without admixture presented the worst durability performance.

SIMULTANEOUS ELECTRODEPOSITION OF LEAD AND LEAD DIOXIDE FROM BATTERY EFFLUENTS

Results are reported of experiments and modelling of cathodic Pb and anodic PbO2 electrodeposition, aimed at developing a process using both reactions simultaneously for treating aqueous effluents from lead-acid battery plants. Pb(II) solubilities and equilibrium potentials were calculated as functions of pH and sulfate activities. Using kinetic parameters from the literature or determined experimentally, (illustrative) models were developed for current density-potential and current efficiency-potential relationships, together with the current density dependence of specific electrical energy consumptions for Pb(II) recovery. Experimental current density-potential and charge efficiency-potential relationships were in broad agreement with model predictions, with near unity current efficiencies for mass transport controlled PbO2 deposition from electrolytes containing 1 mol Pb(II) m-3 at pH 0.7 or 12. However, charge efficiencies for cathodic deposition of lead were typically 0.2 for 1 mol Pb(II) m-3 + 1 mol O2 (aq) m-3; removal of dissolved oxygen was predicted and determined to increase current efficiencies to near unity. Simultaneous cathodic Pb and anodic PbO2 electrodeposition was predicted to be feasible, with tight control of current densities being required to minimise specific electrical energy consumptions.

Potentiodynamically Deposited Polyaniline on Stainless Steel Inexpensive, High-Performance Electrodes for Electrochemical Supercapacitors

Polyaniline ~PANI! has been studied as an active material for electrochemical capacitors. Polymerization of aniline to PANI has been carried out potentiodynamically on a stainless steel ~SS! substrate, instead of Pt-based substrates generally employed for this application. The PANI/SS electrodes have been evaluated by assembling symmetrical capacitors in NaClO4 1 HClO4 mixed electrolyte and subjecting them to galvanostatic charge/discharge cycles between 0 and 0.75 V. The effect of substrate has been assessed by comparing the capacitance of PANI/SS and PANI/Pt electrodes. The capacitance of PANI/SS electrode is higher than that of PANI/Pt electrode by several times. The effect of sweep rate of potentiodynamic deposition of PANI/SS on capacitance has been investigated. At a power density of 0.5 kW kg21, a capacitance value of 815 F g21 of PANI is obtained for the deposition sweep rate of 200 mV s21. Increase in thickness of PANI on the SS substrate results in an increase in capacitance of PANI. This value of capacitance is the highest ever reported for any electrochemical capacitor material. Thus, in addition to a favorable economic aspect involved in using SS instead of Pt or Pt-based substrate, the advantage of higher capacitance of PANI has also been achieved.

RED MUD AS A CORROSION INHIBITOR FOR REINFORCED CONCRETE

The effectiveness of red mud as corrosion inhibitor of carbon steel embedded in concrete was evaluated using cyclic voltammetry and electrochemical impedance spectroscopy. The testing media were red mud solutions (pH=12), alkaline solutions having the same pH (NaOH 0.08M and Ca(OH)2 0.04M), and reinforced mortar. In all cases chloride additions were used for evaluating the inhibition effectiveness. The results show that red muds are able to maintain steel passivity in presence of high chloride concentration, i.e., in mortar 3% CaCl2 by weight of cement, and in solution a ratio Cl-/OH- equal to 5 (maximum tested values).

Performance characteristics of a gelled-electrolyte valve-regulated lead-acid battery

12 V/25 AH gelled-electrolyte valve-regulated lead-acid batteries have been assembled in-house and their performance studied in relation to the absorptive glass-microfibre valve-regulated and floodedelectrolyte counterparts at various discharge rates and temperatures between – 40°C and 40°C. Although the performance of the gelled-electrolyte valve-regulated battery is similar to both the absorptive glass-microfibre valve-regulated and flooded-electrolyte lead-acid batteries at temperatures above 0°C, it is superior to both the flooded-electrolyte and absorptive glass-microfibre valve-regulated lead-acid batteries at temperatures between 0°C and – 40°C. The latter characteristic is attractive for expanding the application regime of valveregulated lead-acid batteries. The corrosion rate for the positive grids in the gelled-electrolyte is also lower than both the flooded-electrolyte and absorptive glass-microfibre configurations.

Interaction Mechanism of a Novel Polymer Electrolyte Composed of Poly(acrylonitrile), Lithium Triflate, and Mineral Clay

The addition of optimumcetyl pyridiumchloride (CPC)–modified montmorillonite (CM) increases the ionic conductivity of poly(acrylonitrile)-based electrolytes by roughly two orders of magnitude. Specific interactions between the silicate layer, the nitrile group, and the lithium cation were investigated by FTIR, solid-state NMR, dielectric analyzer, and alternating current impedance. IR and NMR spectra confirm that the negative charges in the silicate layers alter the ionic charge environment of the PAN-based electrolyte composites, which have the same function as the polar group in PAN. The optimum CM content to achieve the maximum ionic conductivity is 6 phr. However, untreated montmorillonite leads to insignificant polymer intercalation, the negative charges in the silicate layers fail to appreciably disturb the attractive force of the lithium salt, and the resulting conductivity improvement is also less than that of the CM additives.

Evaluation of environmentally friendly paints over weathering galvanised steel: the influence of the surface roughness

A comparative study between a high solid paint (P1) and a traditional coat (P2) was made using EIS technique, both paints were applied over weathering galvanised steel. The results indicated that the high solid paint had the better behaviour and so, it represents a good environmentally friendly alternative. Previously, the optimum weathering degree was assessed based on the impedance modulus evolution and the surface roughness profiles. In the last part of this work, the macroscopic behaviour of a new paint system, based on P1 priming coat and a water-borne resin as a topcoat, was evaluated by submitting to different accelerated tests. The influence of weathering galvanised degree was analysed, as well. Regardless of the test, the increase of such parameter was corresponded to an behaviour improvement.

Electrochemical techniques for corrosion assessment of reinforced concrete structures

This paper reviews the results of ?ve di?erent electrochemical techniques which have been investigated for use in evaluating corrosion rates of steel re- inforcement in concrete structures. Linear polarization resistance, harmonic analy- sis, AC impedance and galvanostatic pulse transient analysis are all techniques which were found to give consistent rates of corrosion. Electrochemical-noise measure- ments were found to be less suitable for this application. Electrical equivalent- circuit models are derived for corroding and passive steel bars in concrete, and these are used to interpret and understand the results obtained from each technique. The practical use of each technique is discussed, and optimum measurement parameters for practical application have been derived from the experimental studies.

Electrochemical Noise Evaluation of Cathodically Protected Steel Embedded Structures

Impressed current cathodic protection, (CP) is a useful method to control corrosion of steel embedded in concrete structures. Less common is the sacrificial anode system, since concrete is a high resistive path for the structure current demand.

Electrochemical Chloride Extraction from Concrete Bridge Components

Electrochemical techniques for concrete bridge protection and rehabilitation was one of the research areas of the SHRP concrete and structures technical program. Four reports document the work under SHRP contract C-102A, Electrochemical Chloride Removal and Protection of Concrete Bridge Components.

Electroanalysis of Glutathione and Cephalexin Using the Boron- Doped Diamond Thin-Film Electrode Applied to Flow Injection Analysis

Electroanalysis of glutathione and cephalexin was studied in 0.1 M carbonate buffer pH 9.2 with boron-doped diamond thin-film electrodes by cyclic voltammetry. It was found that a well resolved and irreversible oxidation voltamogram was obtained for glutathione and cephalexin showed a discernible response. The linear dynamic range for glutathione was 0.1-5.0 mM with a detection limit of 10 μM (S/B = 3). For cephalexin, the detection limit was 5.0 mM. In addition, glutathione was studied by hydrodynamic voltammetry and flow injection analysis with amperometric detection. The Hydrodynamic voltammogram exhibited the maximum signal-to-background ratio (S/B) at 0.75 V. The amperometric results for glutathione provided a linear dynamic range of 0.5-100 μM with a detection limit of 0.5 μM.

Electrochemical impedance spectroscopy study of strained titanium in fluoride media

The aim of this study was to investigate the electrochemical behavior of strained commercially pure (CP) titanium in slightly acidic fluoride-containing media by electrochemical impedance spectroscopy (EIS) measurement. The electrolyte chosen in this study was 1% NaCl solution with different NaF concentrations ranging from 0 to 1%, at pH 6 and 37 8C. Different tensile strains, including 0, 1, 2, 4, 5 and 10%, were applied to the test specimens with a tensile testing machine during the EIS measurements. Surface chemical analyses were performed with electron spectroscopy for chemical analysis (ESCA) and Auger electron spectroscopy (AES). The results showed that the impedance decreased with increasing the NaF concentration and the tensile strain. When the NaF concentration was higher than 0.1%, the protectiveness of TiO2 formed on CP titanium was destroyed by fluoride ions, resulting in the formation of a complex compound of Na2TiF6, regardless of the tensile strain applied. According to the surface chemical analyses, the equivalent circuits simulating the electrochemical behavior of strained CP titanium in slightly acidic media with different NaF concentrations were proposed.

Effects of fungal laccase immobilization procedures for the development of a biosensor for phenol compounds

Fungal laccase was immobilized on carbon-fiber electrodes using classical methods: physical adsorption, glutaraldehyde, carbodiimide and carbodiimide/glutaraldehyde. The highest biosensor response was obtained using carbodiimide/ glutaraldehyde for coupling laccase to carboxyl groups on the carbon fibers. In this method, different percentages of glutaraldehyde had important effects on the sensitivity of the biosensor, the best percentage of glutaraldehyde being 10% (m/v). The behavior of the obtained biosensor was investigated in terms of sensitivity, operational range, pH and applied potential. The developed biosensor showed an optimum response at pH 5.0 and at an applied potential of ?100 mV. The immobilized laccase retained a good activity for over 2 months. ? 2001 Elsevier Science B.V. All rights reserved.

Effect of Partial Substitution of Nickel by Tin, Aluminum, Manganese and Palladium on the Properties of LaNi5-Type Metal Hydride Alloys

Neste trabalho é feito um estudo do comportamento eletroquímico de eletrodos formados por pó de ligas de hidreto metálico do tipo AB5 com formula??es LaNi(5-x)Zx, onde Z é um elemento metálico que substitui parcialmente o Ni, que inclui Sn, Al, Mn e Pd. No caso do Mn, algumas estruturas do tipo AB6 s?o também consideradas. A substitui??o de uma pequena fra??o do Ni pelo Al, Sn e Mn (x ? 0.3) promove um aumento da capacidade de armazenamento de hidrogênio (CAH), enquanto que o Pd leva à um decréscimo desta propriedade. Em geral todas as ligas apresentam alta CAH inicial, mas exibem baixa estabilidade. Foi observado que a diminui??o da press?o de equilíbrio de hidrogênio em fun??o do teor de Mn, nas ligas AB5, relaciona-se diretamente com o aumento do volume da cela cristalina unitária. Através de experimentos de impedancia eletroquímica nota-se um aumento significativo da cinética de rea??o de hidreta??o/desidreta??o com o aumento do número de ciclos de carga/descarga do eletrodo, devido ao aumento da área ativa. Também foi observado que, no geral, as ligas que apresentam maior CAH s?o aquelas que possuem menor energia de ativa??o para a rea??o de oxida??o de hidrogênio.

Effect of Hexacyanoferrate(II/III) on Self-Assembled Monolayers of Thioctic Acid and 11-Mercaptoundecanethiol on Gold

Hexacyanoferrate (II/III) is a redox probe commonly applied in the characterization of SAMs. However, it has been reported that the redox probe influences the characteristics of the SAM. Since the stability of the SAM is of paramount importance in sensitive detection of unlabeled peptides and proteins with impedimetric immunosensors, the effect of this redox probe has been further investigated.

Effect of Fluoride Ions on Ti6Al4V Alloy Passivation in Lactated Ringer’s Serum

The corrosive behavior of Ti and its alloys in fluoride media is well known. Based on electrochemical studies, this paper describes the effect of fluoride ions on the passive behavior of Ti6Al4V alloy in lactated Ringer’s serum. The open circuit potential of the alloy in the serum, which lies in the passive region of TiO2, shifts to more negative values as fluoride ions are added. The voltammogram obtained in the serum presents an active-passive behavior close to -0.2 V (SCE) that changes with the presence of fluoride ions, evidencing higher anodic currents. Electrochemical impedance spectroscopy plots obtained at OCP after varying immersion times in the serum display an almost capacitive behavior and the polarization resistance becomes enhanced after 7 days. With the addition of fluoride ions, the film’s resistance decreases, but a stable protective layer develops after 7 days of immersion time, indicating the film’s repair.

Covalently coupling the antibody on an amine-self-assembled gold surface to probe hyaluronan-binding protein with capacitance measurement

Hyaluronan-binding proteins (HABPs), the important structural components of extracellular matrices, served important structural and regulatory functions during development and in maintaining adult tissue homestats. A sensitive, specific and rapid-responsing immunosensor to probe hyaluronan-binding cartilage protein was presented in this work. The novel immunosensor supplied a label-free detection method for HABP, which was based on measuring the capacitance change in-between the unlabeled HABP (antigen) and rabbit-anti-HABP (Ra-HABP, antibody). The HABP immunosensor was prepared by covalently coupling Ra-HABP on an amine-self-assembled gold surface with glutaraldehyde. The capacitance change corresponding to the concentration of HABP, the target antigen, was evaluated by an electrochemical approach called potentiostatic-step in microseconds. The immunosensor showed a specific response to HABP in the range 10/1000 ng/ml. The presented work supplied a promising clinical screening method.

Corrosion Behavior of Electroplated Silver Coatings

The functional silver coatings were electrodeposited at various current densities from the borate-phosphate-carbonate (BPC) bath on copper and nickel substrates. The morphology of obtained coatings was studied by SEM and STM. Corrosion properties in 0.5 M H2SO4 solution was determined by methods of impedance spectroscopy and voltammetry. Corrosion products were determined by EDX analysis. The corrosion behavior of silver coatings was strongly related to their morphology. A higher corrosion resistance (15.4 kOhm cm2) was found for silver coatings obtained at lower current density 0.5 A dm–2. These coatings were fine-crystalline, smooth and compact. Upon these data, the operational range of current density (0.4 – 0.6 A dm–2) was established. The studied silver coatings are intended for microelectronics applications.

APPLICATION OF PERCOLATION THEORY FOR DESCRIPTION OF ELECTRICAL PROPERTIES OF CONDUCTING COATINGS

In this paper electrical and electrochemical measurements of the organic coatings conducting electric current and able to work as anodes in cathodic protection of reinforced concrete have been presented. Evaluation of coating resistance as a function of graphite content was performed with the use of impedance measurements. On this basis a threshold of percolation of epoxide coating modified with electrographite was assessed. A current loading of conductive coatings was evaluated by potentiodynamic measurements. Basing on the performed measurements it has been stated that the minimum graphite content in the coating cannot be lower than 35%.

Water-swollen cation-exchange membranes prepared using poly(vinyl alcohol) (PVA)/poly(styrene sulfonic acid-co-maleic acid) (PSSA-MA)

Awater-swollen type of poly(vinyl alcohol) (PVA)/poly(styrene sulfonic acid-co-maleic acid) (PSSA-MA) cation-exchange membrane was prepared and characterized in terms of its electrochemical properties including ion-exchange capacity (IEC), electrical resistance, and transport number, etc. PVA/PSSA-MA membranes exhibited low electrical resistance and highly swelling property. In spite of 2–4 times higher water swelling ratio (WSR) than that of CMX (Tokuyama Corp., Japan), the transport number of the prepared membrane was comparable to that of the commercial membrane (tn > 0.93). Moreover, the electric resistance of PVA/PSSA-MA membrane was measured as low as 1.0–1.5cm2. Further, in this study, interrelation between the membrane characteristics and crosslinking was investigated, and the result exhibited that the crosslinking degree is one of major factors affecting the ion transport through a water-swollen ion-exchange membrane (IEM). ? 2002 Elsevier Science B.V. All rights reserved.

金属氢化物电极中氢扩散系数的电化学测试方法

Ni／MH电池中，金属氢化物电极的充放电性能是由电极／溶液界面的电化学过程和合金内部氢的扩散过程共同决定的，而且在多数情况下是由氢的扩散过程控制的。扩散系数是表征扩散速度的一个重要的动力学参数，扩散系数越大表明扩散速度越快，电极性能越好。因此，要研究金属氢化物电极就必须测试其中氢的扩散系数。这不仅具有理论意义，而且对于筛选贮氢合金或优化合金的组成具有现实的指导意义。 近年来，国内外学者已经对各种贮氢合金及其金属氢化物电极中氢的扩散行为进行了大量的研究。所用的方法可以分为核磁共振(NMR)法、准弹性中子散射(QNS)法和电化学方法。其中，电化学方法主要包括：恒电位阶跃法、恒电流放电法、循环伏安法、电化学阻抗法、脉冲电流法和电化学渗氢法。但是，在已经报道的对同一体系中氢扩散系数的电化学测试中，不同的作者用同一种方法或者同一作者用不同的方法得出的结果都不相同，而且有些规律甚至完全相反。为了考察各种方法在实际应用中的切实可行性及其测试结果的准确度和可比性，本文综述了国内外电化学工作者用于测定贮氢合金和金属氢化物电极中氢扩散系数的各种电化学方法，并从理论和实验的角度对这些方法进行了比较和讨论。

不锈钢钝化膜耐蚀性与半导体特性的关联研究

不锈钢由于其优越的耐蚀性被广泛应用于现代社会的各个领域。 然而，在许多腐蚀性环境介质中，不锈钢的腐蚀仍经常发生，尤其易发生危害较大的局部腐蚀. 深入研究不锈钢耐蚀机理，对于指导发展超高耐蚀性的不锈钢新材料及表面改性新技术具有重要意义。不锈钢表面钝化膜的形成、破裂以及点蚀的发生过程包含了电子与离子的传输。电荷的传输是在电场驱动下发生的，而电场受钝化膜电子结构的影响，因此，钝化膜耐蚀性与其半导体电子特性密切相关。有研究表明，不锈钢的耐蚀性很大程度上依赖于其表面钝化膜的组成、结构及厚度等， 已发展了不少先进的表面处理技术，如离子束、电子束、激光束等物理技术，对不锈钢钝化膜进行改性处理，试图提高不锈钢的耐蚀性能。林昌健等人提出了一种可大幅度提高不锈钢耐蚀性的电化学表面处理技术，初步解释不锈钢改性钝化膜具有优异耐蚀性的原因。本文主要侧重应用极化曲线、交流阻抗和电容测量电化学方法，研究电化学改性不锈钢钝化膜的耐蚀机理，试图从钝化膜半导体特性探明改性不锈钢钝化膜的超高耐蚀性与电子特性的关系，进一步阐明改性钝化膜高耐蚀性的本质原因。

三种有机缓蚀剂对钢筋阻锈作用的电化学研究

一般情况下，钢筋混凝土的孔溶液是高碱性的，从而使钢筋表面生成一层致密的、具有良好耐蚀性的钝化膜。氯离子的侵入和混凝土的碳化(中性化)是导致钢筋腐蚀的主要原因。当侵蚀性介质(如Cl一和CO )进入到钢筋／混凝土界面时，钢筋 表面可能去钝化而发生腐蚀，造成钢筋混凝土结构的破坏。 电化学阴极保护、混凝土再碱化、施加保护性涂层、添加缓蚀剂等多种方法已广泛应用于钢筋混凝土结构的保护。其中，使用缓蚀剂是一种相对简单、经济和有效的方法。亚硝酸盐是传统的缓蚀剂，具有良好的缓蚀效果，但由于毒性等原因限制了它的使用。因此，发展环境友好的、适合钢筋混凝土结构的高效缓蚀剂具有重要的实际意义， 电化学噪音(EN)是近年来发展起来评价缓蚀剂的电化学的新方法一。EN技术测量简单，对仪器要求不高，测量过程不需外加激励信号，适合腐蚀全过程的连续、现场监测。 N-月桂酰肌氨酸钠(N-lauroyl sarcosinate)、D．葡萄糖酸钠(D—sodium gluconate)和?-甘油磷酸钠(?-sodium glycerophosphate)都含有多元环，与铁有较强的络合作用，能吸附在钢铁表面，阻止钢铁的腐蚀。虽然有文献报道，?-甘油磷酸钠对钢筋混凝土中的钢筋有较好的缓蚀效果，而葡萄糖酸盐可有效阻止钢筋在含氯离子的水溶液中的腐蚀，并可能在碱性条件下对钢铁有较好的缓蚀作用。但有关这3种缓蚀剂对钢筋的缓蚀作用研究还是不多。本文主要应用线性极化法、电化学噪音、电化学阻抗谱等电化学方法研究在含Cl一的环境中以上三者对钢筋电化学腐蚀行为的影响及其阻锈作用。

氯离子对模拟混凝土孔隙液中钢筋腐蚀行为的影响

钢筋腐蚀是导致钢筋混凝土结构过早破坏的主要原因，已成为世界普遍关注并日益突出的一大灾害。混凝土中钢筋的腐蚀是因为其表面钝化膜遭到破坏，而造成这种破坏的主要因素是混凝土的碳化和氯离子的侵蚀。氯离子是极强的阳极活化剂，但只有当钢筋表面附近溶液的氯离子浓度达到一定的临界值后，钢筋才会发生腐蚀。因此，探明氯离子对钢筋腐蚀电化学行为的影响及其引起腐蚀的浓度临界值，对钢筋腐蚀与防护的研究有重要意义。影响钢筋耐蚀性的最主要参数是钢筋所处介质的pH值和氯离子浓度。由于混凝土体系的复杂性，故在探索混凝土中钢筋腐蚀机理时，常采用模拟体系，本文应用动电位扫描法测试钢筋阳极极化曲线，研究钢筋在给定pH值和氯离子浓度的模拟混凝土孔隙液中的腐蚀电化学行为，从极化曲线的形状和击穿电位的变化判断该pH值下钢筋表面钝化膜的破裂和击穿电位突降的氯离子浓度临界值，进而阐明钢筋在模拟混凝土孔隙液中的腐蚀电化学行为。

二茂铁及其与DNA复合物的电化学行为

二茂铁(Fc)是一类富电子化合物, 由于二茂铁基团具有芳香性、氧化还原活性、稳定性及低毒性,目前已得到广泛的应用[1鄄3].二茂铁良好的氧化还原活性可为考察复杂电化学动力学过程提供理想的模型体系. 关于二茂铁在铂、金、玻碳电极上的伏安行为已有报道[4鄄6], 然而应用碳纳米管(CNT)修饰电极进行二茂铁的电化学行为的研究很少见报道. 碳纳米管是1991 年发现的一种具有奇特的电学性能、明显的量子效应、大比表面积、高稳定性和强吸附性的材料, 将它应用于二茂铁的电化学行为的研究具有重要的实际意义. 脱氧核糖核酸(DNA)是生物体重要的遗传物质,近年来, 以金属配合物作为指示剂的DNA 电化学传感器的研究已引起人们的广泛关注. 该类传感器的指示剂是一类与DNA 以不同作用模式结合的电活性化合物,其作用模式通常有3种：插入作用、沟面结合和静电作用. 二茂铁由于具有2 个可以自由旋转的环戊二烯环与DNA 碱基产生疏水、堆积作用而发生沟面结合, 因此可以作为DNA 电化学传感器的指示剂. 我们应用循环伏安法、微分脉冲伏安法、旋转圆盘电极实验、交流阻抗法等技术研究了二茂铁在旋转CNT 修饰电极上的电化学行为,进而讨论了其在扩散控制下和电化学控制下与小牛胸腺DNA 的相互作用.

MnO2 超级电容器材料在中性电解质中的电化学特性

电化学超级电容器以其优良的脉冲充放电性能以及传统物理电容器所不具备的大容量储能优势已引起人们的广泛兴趣。这种新型能源储备装置应用前景十分广泛。国外对超级电容器电极材料研究十分活跃。Zheng 和Jow 等人制备的无定形水合α- RuO2 ?χH2O ,以硫酸为电解质,比电容达720 FPg ,工作电位114 V (vs. SHE) ,是目前发现的较为理想的高性能超级电容器材料。但钌属稀贵金属,价格昂贵,从而限制了它的实用化。因此,寻找廉价材料替代贵金属成为近几年来的研究热点。MnO2 是碱性锌—锰电池常见的电极材料,资源广泛、价格便宜、对环境无污染,但在超级电容器的应用报道很少。硫酸属腐蚀性强酸,对金属集电体材料有腐蚀,包括MnO2 在内的许多电极活性物质在强酸介质下均不能稳定存在。一旦电容器受到挤压、撞击等破坏,易导致硫酸泄露,造成更大的危害。因此,研究可适用于中性电解质的MnO2 超级电容器材料既具理论意义又有应用前景。本文通过常温液相氧化法合成了MnO2 超级电极器材料,并研究了该材料在中性电解质的电化学特性。