双苯并三唑Mannich碱在5% NaHCO_3溶液中对Cu的缓蚀作用

以苯并三唑(BTA)为母体合成了两种双苯并三唑Mannich碱1,2-双([1,2,3]苯并三唑)-1,2-二苯基氨基乙烷(BBTAP)和1,2-双([1,2,3]苯并三唑)-1,2-二甲基氨基乙烷(BBTAM)。采用静态失重法、极化曲线和电化学阻抗谱(EIS)研究了BBTAP、BBTAM和BTA在5 mass%NaHCO_3水溶液中的缓蚀性能和吸附行为。结果表明:在较高温度下,三种化合物在5%NaHCO_3溶液中对Cu均有较好的缓蚀作用。与BTA相比,BBTAP和BBTAM具有用量少,缓蚀效率高的特点。三种化合物在铜表面上的吸附过程均为放热过程,在铜表面上的吸附行为服从Langmuir吸附等温式,属于物理-化学混合吸附。     

AMT在碳钢-5%HCl体系中的缓蚀行为及其机理研究

用极化曲线、失重和EIS等方法研究了AMT(2-氨基-5-巯基-1,3,4-噻二唑)在碳钢/5%HCl体系中的缓蚀行为和机理.研究表明AMT在该体系中表现为混合型缓蚀剂,其缓蚀机理可归因于几何覆盖效应,在电极表面的吸附符合Langmuir吸附等温式,吸附热约为27.10kJ/mol左右,其EIS图谱在自腐蚀电位下与空白一样,只有一个时间常数,但一定程度阴极极化时出现低频吸附容抗     

3-氨基-5-巯基-1,2,4-三唑在除盐水中对Cu的缓蚀作用

用动电位极化法、电化学阻抗谱(EIS)和失重法研究了3-氨基-5-巯基-1,2,4-三唑（3-AMT）在除盐水中对Cu腐蚀行为的影响和吸附规律。研究表明,缓蚀效率随着缓蚀剂3-AMT浓度的上升而增大,当其浓度大于4× 10^-5 mol/L时,对Cu具有较好的缓蚀性能,3-AMT是一种混合型缓蚀剂。吸附过程为放热过程,属化学吸附,服从Langmuir吸附等温式。     

酸性介质中氮杂环类缓蚀剂在碳钢上的吸附行为

合成了一种新型含氮杂环有机物:2-(4-叔丁基-苯甲基硫)-5-(1,2,4-三氮唑)-甲基-(1,3,4-噁二唑)(TBTO),通过交流阻抗、动电位极化、失重实验研究了其在酸性介质中的缓蚀效率,并用扫描电镜方法分析了碳钢表面的腐蚀形貌变化.结果表明:TBTO在0.5mol/L H2SO4中对Q235钢的缓蚀作用高达96.2%,能同时抑制碳钢腐蚀的阴、阳极反应过程;化合物在碳钢表面上的吸附行为服从Langmuir吸附等温式.同时用量子化学中的从头算方法对缓蚀剂的分子结构与缓蚀性能的关系进行了研究.     

席夫碱基咪唑啉化合物对A3钢在盐酸介质中缓蚀性能研究

合成了BIA、BIOHA、BIMHA和BIMMA 4种席夫碱基咪唑啉化合物.用失重法和电化学方法研究了4种席夫碱基咪唑啉化合物对A3钢在盐酸介质中的缓蚀性能和吸附行为.结果表明,在1 mol/L HCl介质中4种化合物对A3钢均有缓蚀作用,它们的缓蚀能力大小为:BIA＞BIMMA＞BIOHA＞BIMHA.4种化合物均属于混合型缓蚀剂,但对阳极的缓蚀作用略大.4种化合物在A3钢表面上的吸附过程为放热过程,其吸附行为服从Langmuir吸附等温式,属于物理吸附.     

2-氨基-5-巯基-1,3,4-噻二唑缓蚀剂结构的密度泛函计算

采用密度泛函量子化学计算方法,获得了在B3LYP/6-311 G(2d)(5D,7F)理论水平上2-氨基-5-巯基-1,3,4-噻二唑(简称AMT)4种互变异构体的平衡几何构型、能量和电荷分布,证实了4种互变异构体的所有原子处于同一平面,且有一种异构体最稳定.研究结果表明:AMT4种异构体中的环骨架具有芳香性,AMTc与Cu形成的缓蚀膜层是Cu(Ⅰ)与AMTc中的7N和2S原子分别形成共价键和配位键相互交错而成.计算了AMT4种异构体的谐振频率和红外光谱强度.     

硫酸介质中2-氨基-5-苯基-1,3,4-噻二唑对碳钢的缓蚀作用

采用动电位极化曲线和电化学阻抗谱研究了2-氨基-5-苯基-1,3,4-噻二唑(APT)在0.5mol/L硫酸中对碳钢的腐蚀抑制作用.结果表明,APT为混合型缓蚀剂,其在碳钢表面的吸附为化学吸附,阻抗参数的变化表明APT吸附在碳钢表面,形成保护膜,其吸附方式遵循Langmuir吸附等温式,并且吸附自发进行.     

古代青铜文物保护研究现状及AMT的应用

介绍了古代青铜文物腐蚀的主要产物、青铜病的起因 及危害,概述了国内外青铜文物保护现状,在作者前期研究结果基础上,总结了2-氨基-5- 巯基-1,3,4-噻二唑(AMT)作为青铜文物缓蚀保护剂的缓蚀性能和保护机制,指出了AMT用于青 铜文物保护的优势和未来的研究方向.     

三唑化合物在0.5 mol/L硫酸中对Q235钢的缓蚀作用

合成了一种新型三氮唑化合物:1-苯次乙亚氨基-2-巯基-5-[1-(1,3,4-三氮唑)亚甲基]-1,3,4-三氮唑(PMT),并通过失重试验、动电位极化、电化学阻抗谱及扫描电镜方法研究了其在0.5mol/L硫酸溶液中对Q235碳钢的缓蚀作用。结果表明,该三唑化合物在硫酸中对Q235碳钢有较好的缓蚀效果,是混合型缓蚀剂。     

双苯并咪唑化合物对碳钢在H2SO4溶液中的缓蚀作用

通过腐蚀失重法、电化学法和扫描电镜等方法研究了双苯并咪唑化合物(BBB)对碳钢在0.25 mol/LH2SO4溶液中的缓蚀行为.结果表明,双苯并咪唑化合物缓蚀性能优异,缓蚀效率随缓蚀剂浓度增大而升高,且为同时抑制碳钢腐蚀阴阳极过程的混合型缓蚀剂.在碳钢表面的吸附符合Langmuir等温吸附规律.     

用量子化学密度泛函理论研究环状含氮化合物分子结构与缓蚀性能的关系

用量子化学计算泛函密度理论(DFT)中的B3LYP方法，在6-31G基组水平上，对5种环状含氮化合物：3-氨基-1,2，4-三唑、2-氨基-1，3，4-二氢噻唑、5-对甲苯基-1，3，4-三唑、3-氨基-5-甲硫基-1，2，4-三唑和2-氨基苯咪唑的缓蚀性能与分子结构及电子结构的关系进行了研究，用Fukui指效分析了分子中原子的反应性．结果表明文中涉及到的分子均为存在共轭体系的平面分子，缓蚀效率与分子的最高占据轨道的能量EHOMO、最低空轨道与最高占据轨道的能量差△E(ELUMO-EHOMO)有较好的相关性．可以认为缓蚀剂分子在金属表面通过亲核作用与金属作用而形成吸附膜。该类缓蚀剂分子是通过吡啶氮原子提供电子与金属发生作用的．     

A comparative study of benzotriazole and 2-amino-5-mercapto-1,3,4-thiadiazole as Copper corrosion inhibitors in acid media

In this paper the corrosion behaviour of copper in 5% (by weight) citric, sulphuric and hydrochloric acids is studied. The efficiency of 2-amino-5-mercapto-1,3,4-thiadiazole (AMT) as a corrosion inhibitor is compared with the use of benzotriazole (BTA). The experimental techniques were weight loss, polarization curves, polarization resistance and electrochemical impedance spectroscopy. AMT showed greater inhibition efficiency than BTA in sulphuric and hydrochloric acids. In citric acid AMT and BTA show a similar behaviour.     

A preliminary investigation of corrosion inhibition of mild steel in 0.5 M H2SO4 by 2-amino-5-(n-pyridyl)-1,3,4-thiadiazole: Polarization, EIS and molecular dynamics simulations

The efficiency, as steel corrosion inhibitors in 0.5 M H₂SO₄, of two thiadiazole derivatives, 2-amino-5-(3-pyridyl)-1,3,4-thiadiazole (3-APTD) and 2-amino-5-(4-pyridyl)-1,3,4-thiadiazole (4-APTD), was investigated by polarization and electrochemical impedance spectroscopy. The protection efficiency increases with increasing inhibitors concentration, but the temperature has hardly effect on the inhibition efficiency of APTD. The adsorption of APTD on iron surface obeys the Langmuir isotherm. The experimental results show that the inhibition efficiency of 4-APTD is higher than that of 3-APTD, and the molecular dynamics (MD) simulations show that the adsorption of 4-APTD on iron surface has the higher binding energy than that of 3-APTD.     

2-Amino-5-(4-pyridinyl)-1,3,4-thiadiazole monolayers on copper surface: Observation of the relationship between its corrosion inhibition and adsorption structure

Corrosion inhibition behavior of 2-amino-5-(4-pyridinyl)-1,3,4-thiadiazole (4-APTD) monolayers on copper surface were investigated by electrochemical impedance spectroscopy (EIS), electrochemical polarization measurement and surface-enhanced Raman scattering (SERS) experiment. The EIS mechanism of the copper surface with 4-APTD monolayers fitted to the mode of R(Q(R(QR))). The electrochemical polarization measurements indicated high inhibition efficiency of about 90.4%. SERS results suggested that 4-APTD molecules anchored at copper surface in a tilted orientation directly via N³ and N¹² atoms. The transition adsorption states of 4-APTD on the copper surface were observed as the potential applied from 0 to −1.6 V vs. SCE.     

Quantum chemical study of some cyclic nitrogen compounds as corrosion inhibitors of steel in NaCl media

Corrosion inhibition efficiencies of 3-amino-1,2,4-triazole (3-ATA), 2-amino-1,3,4-thiadiazole (2-ATDA), 5-(p-tolyl)-1,3,4-triazole (TTA), 3-amino-5-methylmercapto-1,2,4-triazole (3-AMTA) and 2-aminobenzimidazole (2-ABA) as corrosion inhibitors on steel in sodium chloride media were investigated by using semiempirical PM3 and density functional theory (DFT) methods. Quantum chemical parameters such as highest occupied molecular orbital energy (E_HOMO), lowest unoccupied molecular orbital energy (E_LUMO), energy gap (ΔE) and dipole moment (μ) have been calculated for these compounds by using semiempirical PM3 and 6-31G(d), 6-311G(d,p) DFT methods. It was found that theoretical data support the experimental results.     

Corrosion Mitigation of Copper in Acidic Chloride Pickling Solutions by 2-Amino-5-ethyl-1,3,4-thiadiazole

Corrosion of copper in acidic chloride pickling solutions of 0.5 M HCl and its mitigation by 2-amino-5-ethyl-1,3,4-thiadiazole (AETDA) have been investigated using potentiodynamic polarization, chronoamperometry, electrochemical impedance spectroscopy (EIS), and weight-loss measurements. The study was also complemented by scanning electron microscopy (SEM), energy dispersive x-ray (EDX), and UV-Visible absorption spectroscopy investigations. The presence of AETDA and the increase of its concentration in the chloride solutions greatly decreased the corrosion rate and increased the surface and polarization resistances of copper as indicated by the electrochemical measurements. Weight-loss data also indicated that AETDA decreases the dissolution of copper coupons in the studied chloride solution. SEM/EDX investigations showed that AETDA molecules are strongly adsorbed onto copper surface. The UV-Visible absorption spectra confirmed that AETDA molecules suppress the corrosion of copper via their interactions with the copper surface via their adsorption then formation of AETDA-Cu complex.     

3%NaCl溶液中铜的表面膜及BTA膜的光电化学研究

３％ＮａＣｌ溶液中铜的表面膜及ＢＴＡ膜的光电化学研究任聚杰，杨迈之，童汝亭，蔡生民（河北医学院石家庄０５００１７）（北京大学北京１００８７１）（河北师范大学石家庄０５００１６）１引言人们已经注意到Ｃｌ－对Ｃｕ有腐蚀作用［１，２］，关于ＢＴＡ对Ｃｕ的缓...     

Evaluation of some non-toxic thiadiazole derivatives as bronze corrosion inhibitors in aqueous solution

The inhibiting effect of four innoxious thiadiazole derivatives (2-mercapto-5-amino-1,3,4-thiadiazole (MAT), 2-mercapto-5-acetylamino-1,3,4-thiadiazole (MAcAT), 2-mercapto-5-methyl-1,3,4-thiadiazole (MMeT) and 2-mercapto-5-phenylamino-1,3,4-thiadiazole (MPhAT)) on bronze corrosion in an aerated solution of 0.2 g L⁻¹ Na₂SO₄ + 0.2 g L⁻¹ NaHCO₃ at pH 5 was studied by potentiodynamic voltammetry and electrochemical impedance spectroscopy.The corrosion parameters determined from the polarisation curves indicate that the addition of the investigated thiadiazole derivatives decreases both cathodic and anodic current densities, due to an inhibition of the corrosion process, through the adsorption of thiadiazoles on the bronze surface. The inhibiting effect of the investigated organic compounds appears to be more pronounced on the anodic process than on the cathodic one and, except for the case MPhAT, it is enhanced by the increases of the inhibitors’ concentration.The adsorption of the thiadiazole derivatives on bronze was confirmed by the presence of the nitrogen atoms in the EDX spectra of the bronze exposed to inhibitor-containing solutions.The magnitude of polarisation resistance values and, consequently, the inhibition efficiencies are influenced by the molecular structure of thiadiazole derivatives. The strongest inhibition was noticed in the presence of compounds with phenyl amino- or amino-functionalities in their molecules. The maximum protection efficiencies were obtained by addition of: 5 mM MAT (95.9%), 1 mM MAcAT (95.7%), 5 mM MMeT (92.6%) and 0.1 mM MPhAT (97%). EIS measurements also revealed that the inhibitor effectiveness of the optimal concentrations of thiadiazole is time-dependent.     

Corrosion inhibition of copper in neutral chloride media by a novel derivative of 1,2,4-triazole

The efficiency of a new corrosion inhibitor, the bis-(4-amino-5-mercapto-1,2,4-triazol-3-yl)-butane (BAMTB), on copper was investigated in an aerated 3% NaCl solution using various techniques. Voltammetry, chronopotentiometry and electrochemical impedance spectroscopy (EIS) were performed to evaluate the inhibition efficiency of BAMTB. The surface layers were also characterized by Raman micro-spectroscopy and by scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX). Potentiodynamic polarization curves showed that BAMTB is a mixed-type inhibitor for copper in neutral chloride solution and is even more efficient than the reference compound benzotriazole.