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1.
Omar Abdullah Hazzazi 《Journal of Applied Electrochemistry》2007,37(8):933-940
The influence of the concentration of sodium succinate (SS) on the corrosion and spontaneous dissolution of copper in aerated
non-stirred highly concentrated (5.0 M) NaCl solutions was studied at different temperatures (10–60 °C). The investigations
involved weight loss as well as potentiodynamic polarization and impedance measurements. The inhibition efficiency increases
with increase in the concentration of SS and decreases with temperature. The inhibition mechanism involves adsorption of SS
on the copper surface. An adherent layer of inhibitor is postulated to account for the protective effect. Energy dispersion
X-ray (EDX) examinations of the electrode surface confirmed the existence of such an adsorbed film. The potential of zero
charge (pzc) of copper was studied by the ac impedance technique and the mechanism of adsorption is discussed. 相似文献
2.
This paper reports results of potentiodynamic polarization, electrochemical impedance measurements and erosion-corrosion of mild steel in aerated sulfide containing 3.5% NaCl solutions at room temperature. The pitting corrosion behavior was studied in NaCl solution containing 0.001, 0.005 and 0.010 M Na2S, using potentiodynamic polarization and electrochemical impedance spectroscopy. The erosion-corrosion resistance was evaluated after rotating the samples in sulfide polluted NaCl solution for 24 h at a velocity of 300, 600 and 900 ppm using a rotating disc electrode. Results showed that the presence of sulfide ions in NaCl solution resulted in a significant increase in the corrosion attack due to the local acidification caused by iron sulfide formation. The localized replacement of the protective Fe-oxide film by a non-protective iron sulfide film is responsible for the pitting and erosion-corrosion attack. The study concluded that the higher the concentration of sulfide in NaCl solution, the lower the resistance to pitting and erosion-corrosion. Moreover, increasing the solution rotating velocity affects negatively the erosion-corrosion resistance. 相似文献
3.
Inhibition of copper corrosion in aerated hydrochloric acid solution by amino-acid compounds 总被引:2,自引:0,他引:2
The effect of two amino-acid compounds, dl-alanine and dl-cysteine, on copper corrosion in an aerated 0.5 mol l−1 HCl solution was studied by weight-loss measurements, potentiodynamic polarisation curves, and electrochemical impedance
spectroscopy. A conventional benzotriazole (BTA) inhibitor was also tested for comparison. dl-cysteine was shown to be the most effective inhibitor among those tested inhibitors. Potentiodynamic polarisation results
revealed that both the dl-alanine and dl-cysteine acted as an anodic inhibitor; however, dl-cysteine, in particular, was more effective, as it strongly suppressed anodic current densities. The improved inhibition
efficiency of dl-cysteine in the 0.5 mol l−1 HCl solution was due to its adsorption on the copper surface via the mercapto group in its molecular structure. 相似文献
4.
5.
通过多步法合成了离子型含双苯并三氮唑环的目标分子,4,4’-{苯-1,3-二基二[(1E)-3-羰基丙-1-烯-1,3-二基]}二[2-(2H-苯并三唑-2-基)苯醇酸]二钾。在室温条件下,目标分子在3.5%(质量) NaCl/DMSO(二甲基亚枫)混合溶液(体积比:40/60)中能够发生分子自组装产生纳-微米级的自聚集体。通过傅里叶变换红外光谱(FT-IR)、拉曼光谱和X射线光电子能谱(XPS)的表征,证实了所形成的目标分子自聚集体能够对铜表面产生强烈的化学吸附作用,在铜表面形成自组装膜。利用电化学方法测定了目标分子自聚集体吸附在铜表面形成自组装膜后,在3.5%(质量) NaCl溶液中的缓蚀性能。结果表明目标分子自聚集体在NaCl溶液中能高效地抑制铜腐蚀。 相似文献
6.
Study on highly efficient corrosion inhibition of copper by regular self-aggregates of organic molecule
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Xue LUO Chuan JING Haijun HUANG Hongru LI Zhiyong WANG Zhenqiang WANG Fang GAO Shengtao ZHANG 《化工学报》1951,71(10):4733-4749
This study presents synthesis of target ionic bistriazole rings-based molecule, 4,4'-{benzene-1,3-diylbis[(1E)-3-oxoprop-1-ene-1,3-diyl]}bis[2-(2H-benzotriazol-2-yl)phenolate] dipotassium (BDBD), through multi-step preparation route. At room temperature, the target molecule can self-assemble to produce nano-micron self-aggregates in a 3.5%(mass) NaCl / DMSO (dimethyl maple) mixed solution (volume ratio, 40/60). It is shown that the predominantly strong chemical adsorption of the formed molecular self-aggregates on the studied copper specimen leads to the yield of self-assembly film on copper surface, which is characterized by FT-IR, Raman and XPS spectroscopy. The corrosion inhibition performance of the stable self-aggregates adsorbed-copper specimens in 3.5%(mass) brine solution based on electrochemical method is surveyed. The results show that the target molecular self-aggregates can effectively inhibit copper corrosion in NaCl solution. 相似文献
7.
The inhibitive action of three Schiff bases, N,N
-o-phenylen-bis(3-methoxysalicylidenimine) (V–o-Ph–V), N,N
-p-phenylen-bis (3-methoxysalicylidenimine) (V–p-Ph–V) and N-[(2-hydroxy-3-methoxyphenyl)methylene]-histidine (V-His), on copper corrosion in aerated 0.5 mol dm–3 NaCl and NaBr solutions was investigated using EIS and steady-state polarization techniques. The inhibitor effectiveness depended strongly on the geometric structure of the Schiff bases. Among the three kinds of Schiff base used, the inhibition efficiency of V–o-Ph–V on copper corrosion was the highest, V–p-Ph–V the next and V-His the lowest. The Schiff bases inhibited the cathodic current more significantly than the anodic current. The different influences of V–o-Ph–V or V–p-Ph–V on the anodic and cathodic reactions led to the appearance of a low frequency capacitive loop in the impedance spectra. The inhibition action of the Schiff bases was due to their adsorption on the copper surface followed by complexation with Cu(I) or Cu(II) ions, forming a blocking barrier to copper corrosion. 相似文献
8.
Mohammed A. Amin Sayed S. Abd El-Rehim E.E.F. El-Sherbini Rady S. Bayoumi 《Electrochimica acta》2007,52(11):3588-3600
The effect of succinic acid (SA) on the corrosion inhibition of a low carbon steel (LCS) electrode has been investigated in aerated non-stirred 1.0 M HCl solutions in the pH range (2-8) at 25 °C. Weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were applied to study the metal corrosion behaviour in the absence and presence of different concentrations of SA under the influence of various experimental conditions. Measurements of open circuit potential (OCP) as a function of time till steady-state potentials (Est) were also established. Surface analysis using energy dispersive X-ray (EDX) and scanning electron microscope (SEM) allowed us to clarify the mechanistic aspects and evaluate the relative inhibition efficiency. Results obtained showed that SA is a good “green” inhibitor for LCS in HCl solutions. The polarization curves showed that SA behaves mainly as an anodic-type inhibitor. EDX and SEM observations of the electrode surface confirmed existence of a protective adsorbed film of the inhibitor on the electrode surface. The inhibition efficiency increases with increase in SA concentration, pH of solution and time of immersion. Maximum inhibition efficiency (≈97.5%) is obtained at SA concentrations >0.01 M at pH 8. The effect of SA concentration and pH on the potential of zero charge (PZC) of the LCS electrode in 1.0 M HCl solutions has been studied and the mechanism of adsorption is discussed. Results obtained from weight loss, polarization and impedance measurements are in good agreements. 相似文献
9.
Synergistic effect of 2-mercapto benzimidazole and KI on copper corrosion inhibition in aerated sulfuric acid solution 总被引:4,自引:0,他引:4
2-Mercapto benzimidazole (MBI) was used as a copper corrosion inhibitor in aerated 0.5 mol L–1 H2SO4 solutions. The inhibition efficiency (IE) increased with increasing MBI concentration to 74.2% at the 1 mM level. A synergistic effect existed when MBI and iodide ions were used together to prevent copper corrosion in sulfuric acid. It was found that IE reached 95.3% in 0.5 mol L–1 H2SO4 solutions containing 0.75 mmol L–1 MBI and 0.25 mmol L–1 KI. X-ray photoelectron spectroscopy (XPS) analysis of the copper samples showed that a (Cu+MBI) complex film formed on the surface to inhibit the copper corrosion and the iodide ions did not participate in the formation of the inhibitor film. The synergistic effect was attributed to the adsorption of iodide anions on the copper surface, which then facilitated the adsorption of protonated MBI and the formation of an inhibitive film. 相似文献
10.
The corrosion behavior of pure Fe and pure Cr at 600 °C under a deposit of solid NaCl, with and without the presence of water vapor, was studied by using electrochemical impedance spectroscopy (EIS) and mass gain measurements. The mass gain of both metals sharply increased when water vapor was introduced into the system. In EIS measurement, only one capacitive loop obtained on the pure Fe and Cr coated with solid NaCl and gave the information of oxide layer on them. For the oxide in air, there is a good relationship between the Rox and the reaction rate for both pure Fe and Cr with different oxide time. The lower the Rox is, the higher the reaction rate is. Although no good relationship can be set up between the Rox and the reaction rate when water vapor presented, its trend with oxide time for both metals is generally in accordance with that of the corrosion rate measured by the mass gain curves. The electrochemical technique is an effective method for studying corrosion performance at high temperature. 相似文献
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12.
G. Petkova E. Sokolova S. Raicheva P. Ivanov 《Journal of Applied Electrochemistry》1998,28(10):1067-1071
The inhibition effect of gamma-pyrodiphenone (PD) on copper corrosion in near neutral sulphate solutions was investigated. Weight loss and polarization measurements show a high inhibition efficiency (>96%) of PD on copper corrosion at extremely low concentrations. PD suppresses active copper dissolution and oxygen reduction. The potentiodynamic cathodic reduction measurements showed an inhibition of oxide formation and stabilization of the Cu2O oxide in the presence of PD. XPS measurements suggested that the high inhibition effect of PD on copper corrosion is due to the adsorption of PD molecules, as a first stage, and the formation of a film with a polymer-like structure by coordination of PD with Cu2O on prolonged exposure. 相似文献
13.
Da-quan Zhang Li-xin Gao Guo-ding Zhou Kang Yong Lee 《Journal of Applied Electrochemistry》2008,38(1):71-76
Inhibition of copper corrosion by imidazole (IM) and 1-n-undecyl-imidazole (UDIM) in 0.5 M HCl was investigated by weight-loss
measurements, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). 1-n-undecyl-imidazole
showed the better inhibitive effect compared with IM. Potentiodynamic polarization results revealed that both IM and UDIM
acted as anodic inhibitors, in particular UDIM suppressed anodic current densities significantly. Molecular structure parameters
of IM and UDIM were obtained by using an MM2 forcefield program and AM1 quantum chemical calculation. It was found that UDIM
has higher levels of HOMO and LUMO energy and a larger electron density in its imidazoly ring.
Presented as paper No.13-07 at 14th APCC conference, October 2006, Shanghai, China 相似文献
14.
The corrosion of single crystal pure iron in 3.5% NaCl solutions and its inhibition by 3-amino-5-mercapto-1,2,4-triazole (AMTA) have been studied using in situ and ex situ Raman spectroscopy, cyclic voltammetry (CV), open-circuit potential (OCP), potentiodynamic polarization (PDP), chronoamperometry (CA), and electrochemical impedance spectroscopy (EIS) measurements. CV experiments indicated that the iron electrode in the chloride solution alone showed an anodic peak at ∼−650 mV after the 5th cycle shifted to ∼−610 mV after the 20th cycle; another cathodic peak appeared at ∼−990 mV. In the presence of 1.0 mM AMTA, these two peaks shifted to ∼550 and −1050 mV, respectively. OCP, PDP, CA and EIS revealed that the presence of AMTA and the increase of its concentration move the corrosion potential to more positive values and decrease both the corrosion current and corrosion rate. This effect also increases with increasing the immersion time of iron electrode to 24 h in the test electrolyte. In situ and ex situ Raman investigations confirmed that the addition of AMTA molecules to the chloride solution strongly inhibits the iron corrosion through their adsorption onto the surface blocking its active sites and preventing its corrosion. 相似文献
15.
E. Szocs Gy. Vastag A. Shaban G. Konczos E. Kálmán 《Journal of Applied Electrochemistry》1999,29(11):1339-1345
The mechanism of copper corrosion and its inhibition were studied using electrochemical techniques, in situ scanning tunneling microscopy (STM) and electrochemical quartz crystal microbalance (EQCM) methods. The morphological changes of Cu (111) were followed in 0.1 M Na2SO4 solution at pH 2.95. The adsorption of 5-mercapto-1-phenyl-tetrazole (5-McPhTT) at different concentrations was studied. The anodic dissolution of copper in 0.1 M Na2SO4 was clearly modified and hindered by the addition of 5-McPhTT. The anodic current density was reduced sharply due to the adsorption of the inhibitor on the metal surface thus providing protection. EQCM data revealed that the addition of the inhibitor to the aggressive solution did not cause a continuous increase in the electrode mass. This fact indicates that the inhibitor effect in hindering copper corrosion was due to the adsorption of a monolayer or even a submonolayer. 相似文献
16.
Laura Earnden Joshua Van Der Zalm Aicheng Chen Alejandro G. Marangoni Roy van Lier Erica Pensini 《Journal of surfactants and detergents》2022,25(3):399-411
Corrosion in carbon steel units of chemical, petrochemical and oil and gas plants poses safety and economic concerns. The goal of our study is to investigate the corrosion inhibition effectiveness of an environmentally benign surfactant, namely sodium lauroyl lactylate (SLL), in comparison to sodium cocoyl glutamate (SCG) and sodium dodecyl sulfate (SDS). The corrosion of carbon steel in 1 M HCl was markedly inhibited by 0.05 and 0.1 M of the anionic surfactant SLL, as determined from weight loss over 96 h, at ambient conditions. X-ray photoelectron spectroscopy (XPS) showed that SLL adsorbed at the carbon steel surface, forming a protective film that decreased corrosion. Scanning electron microscopy (SEM) showed that carbon steel surfaces immersed in 1 M HCl for 96 h had an etched appearance without SLL, whereas they retained their smoothness with 0.1 M SLL. Electrochemical impedance spectroscopy (EIS) measurements confirmed that SLL passivated carbon steel surfaces, markedly increasing the polarization resistance Rp from ≈95 to ≈20,694 Ω cm2 over a 12 h period. In contrast, without SLL, Rp decreased from ≈92 to ≈12 Ω cm2. These results demonstrate for the first time that the environmentally friendly surfactant SLL is an efficient corrosion inhibitor in extreme environments such as 1 M HCl solutions. Dissimilar to SLL, SCG and SDS were not effective in inhibiting corrosion. 相似文献
17.
Inhibition of corrosion processes of copper in aerated 3.5% NaCl solutions by 5-(3-aminophenyl)-tetrazole (APT) has been investigated
using open-circuit potential, potentiodynamic polarization, potentiostatic current–time, electrochemical impedance spectroscopy,
and weight loss measurements together with pH and Raman spectroscopy. Increasing concentrations of APT greatly decreased the
corrosion rate and increased the surface and polarization resistance. It was concluded that the adsorption of APT blocks the
active sites on the copper surface leading to the formation of cuprous chloride and oxychloride complexes. This was supported
by the Raman spectrum obtained from the copper surface after 24 days of immersion in a 3.5% NaCl solution containing 5.0 mM
APT. The results collectively are in good agreement and show clearly that APT is a good corrosion inhibitor for copper under
the conditions studied.
El-Sayed M. Sherif is on leave from Physical Chemistry Department, National Research Centre, Dokki, Cairo, Egypt. 相似文献
18.
The passivation and pitting corrosion of tin-nickel alloy (34% Ni-66% Sn) in NaCl solution was studied using potentiodynamic, cyclic voltammetry and electrochemical impedance spectroscopy (EIS) techniques complemented by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of concentration of the chloride ion, the switching potential, scans rate and pH on the electrochemical behavior of Sn-Ni alloy is discussed. The data indicate that the corrosion rate and the pitting corrosion of Sn-Ni alloy increases by the increasing of chloride ion concentration. The observed corrosion resistance of electrodeposited Sn-Ni alloy is due to the formation of a thin passive film from tin and nickel oxides. 相似文献
19.
Due to rain events historical monuments exposed to the atmosphere are frequently submitted to wet and dry cycles. During drying periods wetness is maintained in some confined regions and the corrosion product layer, generally denominated patinas, builds up and gets thicker. The aim of this study is to use electrochemical impedance spectroscopy (EIS) to investigate the electrochemical behaviour of pure copper coated with two artificial patina layers and submitted either to continuous or to intermittent immersion tests, this latter aiming to simulate wet and dry cycles. The experiments were performed in 0.1 mol dm−3 NaCl solution and in artificial rainwater containing the most significant pollutants of the city of São Paulo. The results of the continuous immersion tests in the NaCl solution have shown that the coated samples behave like a porous electrode with finite pore length. On the other hand, in the intermittent tests a porous electrode response with semi-infinite pore length can be developed. The results were interpreted based on the model of de Levie and a critical comparison with previous interpretations reported in the literature for similar systems is presented. 相似文献
20.
Application of the electrochemical quartz crystal microbalance (EQCM) to the study of metal corrosion and its inhibition is rather recent. Among the advantages of this technique are its very high sensitivity and the possibility of simultaneous mass variations and voltammogram recording. These characteristics suggest the use of the EQCM for research in very low corrosion rate conditions. This paper reports the results of EQCM measurements on the corrosion inhibition rates of Ni in 0.1m HClO4, in the absence and presence of different inhibitors in free corrosion conditions, for following inhibitors: acridine (A), benzyl quinolinium chloride (BQCl), dodecyl quinolinium bromide (DDQBr), tributylbenzyl ammonium iodide (TBNI) and potassium iodide (KI). The corrosion rate was reduced considerably by KI and TBNI. DDQBr showed a good inhibitive efficiency, while BQCl had only a small effect, and A stimulated corrosion of the Ni. Voltammograms at different scanning rates and the mass variation in the same solutions were recorded. Comparison of the current density and the mass changes provided the basis for a qualitative interpretation of the passivation of Ni and the mechanism of action of the different inhibitors. 相似文献