苯并三氮唑及其衍生物在NaCl溶液中对铜缓蚀作用的表面增强拉曼光谱

铜电极;苯并三氮唑及其衍生物在NaCl溶液中对铜缓蚀作用的表面增强拉曼光谱     

阿魏酸在玻碳电极上的电化学行为及其分析测定

阿魏酸在玻碳电极上的电化学行为及其分析测定;阿魏酸;溶出伏安法;循环伏安法;电化学分析     

硫酸溶液中聚天冬氨酸对碳钢的吸附缓蚀性能

应用电化学极化曲线和交流阻抗研究聚天冬氨酸(PASP)对碳钢的缓蚀性能,讨论了PASP浓度和温度对缓蚀效果的影响.结果表明:PASP是一种以抑制阳极为主的缓蚀剂.在实验温度范围内,PASP在0.5mol/L硫酸溶液中对碳钢的缓蚀效率随着温度升高而降低,并以10℃时的缓蚀效果最好.在给定温度下,缓蚀率均随PASP浓度的增加而迅速增加,但当PASP质量浓度达到2.5g/L时,缓蚀率的增加趋于平缓,10℃下,缓蚀率的最高值可达80.33%(PASP 6.0g/L),PASP在碳钢表面的吸附基本服从Freund lich吸附等温式,PASP的加入增大了碳钢的腐蚀反应表观活化能.     

Corrosion Inhibition of a Green Scale Inhibitor Polyepoxysuccinic Acid

The corrosion inhibition of a green scale inhibitor, polyepoxysuccinic acid (PESA) was studied based on dynamic tests. It is found that when PESA is used alone, it had good corrosion inhibition. So, PESA should be included in the category of corrosion inhibitors. It is not only a kind of green scale inhibitor, but also a green corrosion inhibitor. The synergistic effect betweenPESA and Zn2 or sodium gluconate is poor. However, the synergistic effect among PESA, Zn2 and sodium gluconate is excellent, and the corrosion inhibition efficiency for carbon steel is higher than 99%. Further study of corrosion inhibition mechanism reveals that corrosion inhibition of PESA is not affected by carboxyl group, but by the oxygen atom inserted. The existence of oxygen atom in PESA molecular structure makes it easy to form stable chelate with pentacyclic     

2-氨基嘧啶在盐酸介质中对钢的缓蚀性能

用失重法、动电位极化曲线和电化学阻抗谱（EIS）研究了2-氨基嘧啶(2-AP)在1.0~5.0 mol/L HCl溶液中（20~50 ℃）对冷轧钢的缓蚀作用。 结果表明,2-AP对冷轧钢在1.0 mol/L HCl中具有良好的缓蚀作用,且在钢表面的吸附符合校正的Langmuir吸附模型;缓蚀率随缓蚀剂浓度的增加而增大,但随温度的升高和HCl浓度的增加而降低。 2-AP为混合抑制型缓蚀剂;EIS谱呈半圆容抗弧,电荷转移电阻随缓蚀剂浓度的增加而增大。     

盐酸中La3+与NO3-离子对铝的缓蚀作用

用失重法和电化学方法研究了La^3 与NO3^-对铝的缓蚀作用。研究表明：铝在加有Lan的盐酸介质中，腐蚀受到轻微抑制，并且La^3 浓度对铝缓蚀的影响不显著。而若盐酸溶液中同时存在有La^3 与NO3^-，铝的腐蚀则大大地受到抑制，表面覆盖度与缓蚀剂浓度的关系符合Langmuir等温吸附方程，动电位极化实验表明La^3 与NO3^-主要抑制了铝腐蚀的阴极反应，La^3 与NO3^-的存在与否并没改变H^ 阴极放电的机理。不同浓度HCl介质中，La^3 与NO3^-在相同腐蚀时间下对铝的缓蚀率不同；在一定浓度HCl介质中，La^3 与NO3^-在不同腐蚀时间下对铝的缓蚀率亦不同。     

Adsorption and Corrosion Inhibition Behavior of Schiff Base-Based Cationic Gemini Surfactant on Mild Steel in Formic Acid

The adsorption and corrosion inhibition behavior of synthesized Schiff base-based cationic gemini surfactant bis[p-(N,N,N-tetradecyldimethylammonium bromide)benzylidene]thiourea (14-S-14) on mild steel in 20% formic acid in the temperature range of 30°C to 60°C was evaluated using weight loss measurements, solvent analysis of iron ions and potentiodynamic polarization measurements. The synthesized inhibitor was characterized using Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), and thin layer chromatography (TLC). The surface morphology of the corroded mild steel specimen was evaluated using scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDAX), and atomic force microscopy (AFM). Thermodynamic/kinetic parameters were calculated to elaborate the adsorption and corrosion inhibition mechanism of the inhibitor. The inhibition efficiency of the compound was found to vary with inhibitor concentration, immersion time, and temperature. The adsorption of the compound on the steel surface was found to obey Langmuir adsorption isotherm.      

Influence of Molecular Weight on Mild Steel Corrosion Inhibition Effect by Polyvinyl Alcohol in Hydrochloric Acid Solution

The corrosion inhibition of mild steel in hydrochloric acid solution in the presence of three different molecular weights of polyvinyl alcohol (PVA) designated as PVA-I, PVA-II, and PVA-III corresponding to 14,000, 72,000, and 125,000 g mol^?1, respectively, was investigated using electrochemical impedance spectroscopy, linear polarization resistance (LPR), and potentiodynamic polarization techniques at 25°C. It was found that PVA of different molecular weights inhibited the corrosion of mild steel in the acid environment. Inhibition efficiency (η%) increases with increase in concentration of the polymers. LPR measurements clearly show that inhibition efficiency increases with increasing molecular weight in the order PVA-III > PVA-II > PVA-I. Polarization curves indicate that PVA functions as a mixed inhibitor affecting both the anodic metal dissolution and cathodic hydrogen evolution partial reactions of the corrosion process. The experimental data obtained fitted well into Langmuir adsorption isotherm model. Physical adsorption mechanism is proposed from the thermodynamic (free energy of adsorption) parameters obtained.     

盐酸溶液中氯代十六烷基吡啶在锌表面上的吸附及其缓蚀作用

盐酸溶液中氯代十六烷基吡啶在锌表面上的吸附及其缓蚀作用杨春芬，白宇新（云南大学化学系昆明６５００９１）关键词锌，氯代十六烷基吡啶，吸附，缓蚀作用在抑制金属腐蚀的方法中，缓蚀剂的应用是最受重视的一种，因为它具有用量少，不需附加设备和不改变金属制品本性等...     

Synthesis and Effect of Some 5-Alkyl-1,3,4-Triazole-2-Thione Derivatives on Corrosion Behavior of Molybdenum Electrode in Hydrochloric Acid

A novel series of self-assembled surfactants derived from 5-alkyl-1,3,4-triazole-2-thione have been synthesized. The purity of surfactants synthesized was checked by rutinary methodologies (FTIR spectroscopy, ¹H-NMR, MS and elemental analysis). Their surface active properties at equilibrium in water at 25°C were determined. Also, the inhibitive effect of these compounds, in the case of molybdenum in acid medium, was investigated thoursough galvanostatic and galvanodynamic techniques. Galvanodynamic polarization data indicates that these surfactants act as very good inhibitors of molybdenum in hydrochloric acid both for cathode and anode. Galvanostatic measurement has the same trend of inhibitive effect as that of the galvanodynamic polarization data, which indicate the formation of a protective layer on the metal surface by the adsorption of surfactants molecules.     

磷酸溶液中DDA在锌表面的吸附及其缓蚀作用

采用失重法及电化学法研究了锌在含或不含十二烷基胺（DDA）的磷酸溶液中的腐蚀作用，得出相应的动力学方程，求得有关的动力学及热力学参数.用光电子能谱（XPS）检测发现，在40～70 ℃区间，锌在磷酸溶液中生成Zn(OH)x覆盖层，表现出较强的自缓蚀效果，而在30～40 ℃区间，因DDA以及, 等微粒同时吸附在锌表面，DDA在磷酸溶液中表现出较强的缓蚀作用.用吸附理论讨论了这种缓蚀作用产生的原因.     

Corrosion of Copper in Presence of Acetic Acid Derivatives

The anodic corrosion of copper in presence of acetic acid derivatives were determined by measuring the limiting current. It is found that the rate of corrosion increased by decreasing H₃PO₄ concentration and electrode height. The experimental results showed that the inhibition efficiency increased with increasing concentration of the investigated compounds at a fixed temperature, but decreases with increasing temperature. Values of activation energy indicate that the reaction is diffusion controlled. The isotherm Langmuir, Temkin, and Flory Huggins are applied. The values of free energy of adsorption (ΔG_ads) obtained indicate the spontaneous adsorption of the inhibitor. The overall mass transfer correlations under the present conditions have been obtained using dimensional analysis method. The results agreed with the previous studies of mass transfer to rotating cylinder in turbulent flow.At the end of the corrosion process the morphology of the specimens after experiment is monitored using scanning electron microscope (SEM). SEM examination of the copper surface revealed that these compounds inhibited copper from corrosion by adsorption on its surface to form protective film. The presence of these organic compounds adsorbed on the electrode surface was confirmed by SEM investigations.