自组装席夫碱膜对铜的缓蚀行为

通过分子自组装技术在铜表面制备2-氨基-5-巯基-1,3,4-噻二唑缩对羟基苯甲醛（简称A）和2-氨基苯并咪唑缩对羟基苯甲醛（简称B）缓蚀膜。采用电化学测试方法研究了两种席夫碱自组装膜在质量分数为3%的NaCl溶液中对铜的缓蚀作用。结果表明,自组装分子膜能有效抑制铜片的腐蚀,对于席夫碱A,当溶液浓度为15 mmol·L^-1,组装时间为6 h时缓蚀效果最佳;对于席夫碱B,当溶液浓度为20 mmol·L^-1,组装时间为12 h时缓蚀效果最佳,A、B的缓蚀效率分别达到98.9%和96.73%。表面分析技术表明,席夫碱化合物在铜表面形成一层保护膜,有效阻挡了腐蚀粒子向金属基底的转移,从而抑制了腐蚀的发生。量化计算和分子动力学模拟分析了A、B两种缓蚀剂分子构型与缓蚀性能的关系以及在铜表面的吸附形态,结果表明,两种缓蚀剂具有很好的缓蚀性能,且缓蚀效果A>B,与实验结果一致。     

噁二唑缓蚀膜的制备及抗腐蚀性能研究

以二芳基酰肼为原料合成2,5-二苯基-1,3,4-噁二唑(PPD),在碳钢表面制备噁二唑自组装分子膜。采用表面分析技术、电化学测试等方法对PPD分子膜的制备条件及在3.5% NaCl溶液中的缓蚀性能进行了分析,通过量化计算对缓蚀机理进行了进一步的探讨。结果表明,PPD自组装膜的最佳组装条件为4 mmol•L-1组装液中组装12h,缓蚀效率达91.95%,XPS测试结果表明PPD分子在钢表面形成自组装膜,量化计算得到了缓蚀剂分子的活性位点。     

自组装席夫碱膜对铜的缓蚀行为

通过分子自组装技术在铜表面制备2-氨基-5-巯基-1,3,4-噻二唑缩对羟基苯甲醛(简称A)和2-氨基苯并咪唑缩对羟基苯甲醛(简称B)缓蚀膜。采用电化学测试方法研究了两种席夫碱自组装膜在质量分数为3%的NaCl溶液中对铜的缓蚀作用。结果表明,自组装分子膜能有效抑制铜片的腐蚀,对于席夫碱A,当溶液浓度为15 mmol?L-1,组装时间为6 h时缓蚀效果最佳;对于席夫碱B,当溶液浓度为20 mmol?L-1,组装时间为12 h时缓蚀效果最佳,A、B的缓蚀效率分别达到98.9%和96.73%。表面分析技术表明,席夫碱化合物在铜表面形成一层保护膜,有效阻挡了腐蚀粒子向金属基底的转移,从而抑制了腐蚀的发生。量化计算和分子动力学模拟分析了A、B两种缓蚀剂分子构型与缓蚀性能的关系以及在铜表面的吸附形态,结果表明,两种缓蚀剂具有很好的缓蚀性能,且缓蚀效果AB,与实验结果一致。     

氢键导向的Aza-BODIPY染料J-型聚集体

功能染料的J-型聚集体是一类重要的超分子材料并在诸多领域有广泛的应用。通过在氮杂氟硼二吡咯（Aza-BODIPY）染料核心结构的2，6-位引入尿嘧啶基团合成的Aza-BODIPY染料1，能够在双重氢键的作用下在甲基环己烷溶液中自组装形成J-型聚集体。该J-型聚集体的最大吸收波长位于768 nm，相比单体红移了47 nm。变温/变浓度紫外-可见吸收光谱研究表明，该J-型聚集体的形成符合协同自组装机理。利用透射电镜和激子耦合理论计算研究了J-型聚集体的形貌和分子排列结构。     

铜表面硬脂酸自组装膜的制备及耐腐蚀性能

应用自组装技术在Cu(OH)2纳米柱/CuO微花阶层结构表面制备硬脂酸自组装膜(SAM),运用电化学阻抗谱探讨了形成自组装膜的较佳浓度和自组装时间,通过极化曲线和循环伏安法考察了硬脂酸自组装膜在0.1 mol/L NaCl溶液中对铜电极的缓蚀性能.结果表明,当CuO/Cu(OH)2电极在8 mmol/L硬脂酸溶液中自组...     

噁二唑缓蚀膜的制备及抗腐蚀性能

以二芳基酰肼为原料,合成2,5-二苯基-1,3,4-噁二唑(PPD),在碳钢表面制备噁二唑自组装分子膜。采用电化学测试、表面分析等方法对PPD分子膜的制备条件及其在质量分数3.5%NaCl溶液中的缓蚀性能进行了分析,通过量化计算对缓蚀机理进行了进一步探讨。结果表明,PPD自组装膜的最佳组装条件是:在4 mmol/L PPD组装液中组装12 h,缓蚀效率达91.95%。XPS测试结果表明,PPD分子在钢表面形成了自组装膜。量化计算得到了缓蚀剂分子的活性位点,PPD的N原子同时具有较大的Fukui(-)(0.076)和Fukui(+)(0.058)数值,说明它们既可以提供电子形成配位键,也可以接受电子形成反馈键。     

二层组装四磺酸酞菁铜修饰电极的制备、表征与应用

四磺酸酞菁铜在1，3-二环己基碳二亚胺（DCC）的活化下与自组装膜上的氨基发生表面化学反应，制得了二层组装半胱胺．四磺酸酞菁铜／金电极，将四磺酸酞菁铜固定在金电极表面。利用循环伏安、扫描电镜进行了组装电极的表征。这种二层组装的电极对半胱胺酸具有催化作用。     

4-(9-蒽基)-6-十六烷氧基-2-氨基-1,3,5-三嗪的合成及光谱行为的研究

从三氯均三嗪出发通过三步反应合成了4-(9-蒽基)-6-十六烷氧基-2-氨基-1,3,5-三嗪(AHTA),并通过红外、核磁、质谱、高分辨质谱对目标产物进行了表征.研究表明AHTA分子在基态下分子的蒽环与三嗪环不共平面,激发态下表现为ICT的荧光发射.由于分子间氢键作用的存在,AHTA在自组装膜和LB膜中均形成H-聚集体.     

表面活性剂自组装的计算机模拟及在新材料中的应用进展

从热力学和动力学角度对近年表面活性剂自组装特性的计算机模拟研究进行了综述,计算机模拟是研究表面活性剂自组装特性、超分子聚集体结构和特性的有效方法;叙述了表面活性剂在新材料中的应用情况,表面活性剂分子在溶液中和界面上可以自组装形成有序的超分子聚集体,从而在材料制备中发挥重要的作用;提出了存在的一些问题并对发展前景进行了展望。     

对羟基苯甲酸自组装膜对铜的缓蚀作用

利用自组装技术将对羟基苯甲酸在铜表面形成自组装单分子膜,利用电化学阻抗谱和极化曲线研究了自组装膜对铜的缓蚀作用及其吸附行为。结果表明,对羟基苯甲酸分子易在铜表面形成稳定的自组装单分子膜,该膜抑制了铜的阳极氧化过程,改变了电极表面的双电层结构,固/液界面双电层电容明显降低,有良好的缓蚀效果。研究结果还表明,对羟基苯甲酸在铜表面的吸附行为符合Langmuir吸附等温式,吸附机理是典型的物理吸附。     

Study on highly efficient corrosion inhibition of copper by regular self-aggregates of organic molecule

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.     

Development of a galvanic sensor system for detecting the corrosion damage of the steel embedded in concrete structures: Part 1. Laboratory tests to correlate galvanic current with actual damage

The correlation between sensor output and corrosion rate of reinforcing steel was evaluated by laboratory electrochemical tests in saturated Ca(OH)₂ with 3.5 wt.% NaCl. In this paper, two types of electrochemical probes were developed: galvanic cells containing of steel/copper and steel/stainless steel couples. The corrosion behavior in saturated Ca(OH)₂ solution with and without 3.5 wt.% NaCl addition for the different electrodes was investigated by potentiodynamic test. Weight loss measurement and galvanic corrosion test were conducted to obtain the corrosion rate of reinforcing steel and the charge of sensor in saturated Ca(OH)₂ solution with 3.5 wt.% NaCl addition, respectively.

The results of the potentiodynamic test indicated the possibility of detecting an ingress point of chlorides by measuring the galvanic current. In galvanic corrosion tests, the galvanic current of steel/copper couple was higher than that of steel/stainless steel couple, i.e., the steel/copper sensor is more suitable for high resistance environment. The steel/stainless sensor showed a better linear correlation than the steel/copper sensor. Through the relationship between the sensor system output and the weight loss (mg/cm²) of steel, real corrosion damage of the steel embedded in concrete can be detected.     

Inhibition of corrosion processes on copper in aerated sodium chloride solutions by 5-(3-aminophenyl)-tetrazole

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.     

脉冲电沉积纳米镍-碳化硅复合镀层的性能

分别采用直流(DC)和换向脉冲电流(PRC)电沉积法制得纳米Ni-SiC复合镀层。采用X射线衍射仪、扫描电镜、能谱仪对比研究了纯Ni镀层和Ni-SiC复合镀层的微观结构、宏观残余应力、表面形貌及成分。用浸泡法研究了不同镀层在3.5%(质量分数)NaCl和10%(体积分数)H2SO4溶液中的腐蚀行为。结果表明,脉冲电沉积能改变镀层的微观结构,有效提高镀层硬度,降低宏观残余应力。脉冲电沉积所得到的纯Ni镀层和纳米Ni-SiC复合镀层在3.5%NaCl及10%H2SO4溶液中的耐蚀性均优于直流镀层。脉冲镀层在3.5%NaCl溶液中受腐蚀很轻,主要腐蚀形态为点蚀,而在10%H2SO4溶液中,SiC粒子作为增强相使镀层的耐腐蚀性进一步提高。     

Plant derived cationic dye as an effective corrosion inhibitor for 7075 aluminum alloy in 3.5% NaCl solution

The inhibition of the corrosion of 7075 aluminum alloy in 3.5 wt.% NaCl solution by 5,6-dihydro-9,10-dimethoxybenzo[g]-1,3-benzodioxolo[5,6-a]quinolizinium (berberine) has been studied using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, scanning electrochemical microscopy (SECM) and scanning electron microscopy (SEM). Inhibition efficiency was found to increase with increasing concentration of berberine. The adsorption of the berberine on the 7075 aluminum alloy surface obeyed the Langmuir adsorption isotherm. The adsorbed film on 7075 aluminum alloy surface containing inhibitor was confirmed by the SEM, and SECM. The results obtained showed that the berberine could serve as an effective inhibitor of the corrosion of 7075 aluminum alloy in 3.5% NaCl.     

Surface analysis and adsorption behavior of caffeine as an environmentally friendly corrosion inhibitor at the copper/aqueous chloride solution interface

Abstract

Corrosion inhibitors based on environmentally friendly and harmless products are currently being studied and developed. The corrosion inhibition properties of caffeine (1,3,7-trimethylxanthine) on copper corrosion in aqueous chloride solution (3.5?wt.% NaCl) are analysed here using stationary and transient electrochemical methods, and a theoretical study based on density functional theory is carried out. Caffeine is a very competitive compared to the chemical inhibitors that are often used for copper protection. Electrochemical and impedance experiments reveal that the protective efficiency of caffeine reaches a value of 96% at a concentration of 10^?2?mol L^?1. Based on these results, the Langmuir model appears to be the best representation of the adsorption of caffeine onto the copper surface. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and X-ray diffraction (XRD) were used to determine the surface morphology and the chemical composition of the copper surface in chloride media, in the absence and presence of caffeine. The results show the development of a mechanism of corrosion inhibition. In order to confirm the correlation between the inhibitory effect and the molecular structure of caffeine, quantum chemical parameters are used to calculate its electronic properties.     

Electrodeposition of homogeneous and adherent polypyrrole on copper for corrosion protection

Electrochemical synthesis of polypyrrole (PPy) on copper electrodes is researched using different techniques. The synthesised films are found to be very adherent and homogeneous. The corrosion behaviour of Cu/PPy is assessed in a 3.5% NaCl solution using polarisation curves and open circuit potential-time. The relationship between porosity and anticorrosive properties is demonstrated. The chronopotentiometry technique is seen to be the best to produce a good coating that yields good protection against copper corrosion for long immersion times.     

钢的环保型防锈抑断颜料的研制

概述了研制的钢的环保型防锈颜料(替代铬酸盐)的防锈抑断性能。在3．5％(质量分数)NaCl的中性和酸性水溶液中，对5种常用钢的防锈性能比铬酸盐好；在3．5％NaCl的碱性水溶液中的防锈性比铬酸盐略低；在3．5％NaCl的中性水溶液中，抑制两种常用钢应力腐蚀的能力比铬酸盐高，而抑制腐蚀疲劳断裂(CF)的能力与研制颜料的配方有关。     

Effect of benzotriazole (BTA) addition on Polypyrrole film formation on copper and its corrosion protection

Benzotriazole (BTA) was added in a conducting Polypyrrole (PPy) film prepared on copper in oxalic acid aqueous solution containing pyrrole monomer to improve corrosion protection by the PPy film and reduce copper corrosion. When BTA was added in the preparation solution, the copper surface was covered by a BTA–Cu complex layer before the anodic polymerization of PPy was started. On the copper surface with the BTA layer, the initial dissolution of copper was inhibited and the PPy polymerization-deposition was started immediately after the anodic current was imposed. The PPy film thus formed was doped with oxalic ions and ionized BTA and was homogeneous in thickness and strongly adhesive. The PPy film containing BTA protected the copper from corrosion in 3.5 wt.% NaCl solution. In 400 h of immersion, copper dissolution was inhibited with 80% protection efficiency relative to that of bare copper.