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Sample records for corrosion inhibitors imidazolines

  1. A Review of CO2 Corrosion Inhibition by Imidazoline-based Inhibitor

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    Jaal Rafida Ahmad

    2014-07-01

    Full Text Available Carbon dioxide (CO2 corrosion is one of the most significant forms of attack in the oil and gas production and transportation systems. Corrosion inhibitors have been widely used in an effort to reduce the detrimental effect of the corrosion process. Different types of corrosion inhibitors have been applied for this purpose. The most frequent is the imidazoline-based inhibitors (IM, owing to their good adsorption characteristics and film-forming capability. Albeit their extensive use, their inhibition mechanism is not fully understood. This paper highlights the inhibition mechanism of IM and also the factors that contribute to its inhibition mechanism.

  2. The Synthesis of Imidazoline Derivative Compounds as Corrosion Inhibitor towards Carbon Steel in 1% NaCl Solution

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    Deana Wahyuningrum

    2008-03-01

    Full Text Available Oleic imidazoline is one of the nitrogen containing heterocyclic compounds that has been widely used as commercial corrosion inhibitor, especially in minimizing the carbon dioxide induced corrosion process in oilfield mining. In this present work, some imidazoline derivative compounds have been synthesized utilizing both conventional and microwave assisted organic synthesis (MAOS methods, in order to determine their corrosion inhibition properties on carbon steel surface. The MAOS method is more effective in synthesizing these compounds than the conventional method regarding to the higher chemical yields of products (91% to 94% and the shorter reaction times (7 to 10 minutes. The characterization of corrosion inhibition activities of the synthesized products towards carbon steel in 1% NaCl solution was determined by the Tafel plot method. The corrosion inhibition activities of compound 1b ((Z-2-(2-(heptadec-8-enyl-4,5-dihydroimidazol-1-ylethanamine, 2b ((Z-2-(2-(heptadec-8-enyl-4,5-dihydroimidazol-1-ylethanol and 3b (2-(2-heptadecyl-4,5-dihydroimidazol-1-ylethanamine at 8 ppm concentration in 1% NaCl solution are, respectively, 32.18%, 39.59% and 12.73%. The heptadec-8-enyl and hydroxyethyl substituents at C(2 and N(1 position of imidazoline ring, respectively, gave the most effective corrosion inhibition activity towards carbon steel compared to the presence of other substituents. The increase in concentrations of compound 1b, 2b and 3b in 1% NaCl solution tends to improve their corrosion inhibition activities. Based on the analysis of the free Gibbs adsorption energy (DG0ads values of compound 1b, 2b and 3b (-32.97, -34.34 and -31.27 kJ/mol, respectively, these compounds have the potential to interact with carbon steel through semi-physiosorption or semi-chemisorption.

  3. The influence of Desulfovibrio vulgaris on the efficiency of imidazoline as a corrosion inhibitor on low-carbon steel in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Rodriguez, Carlos A. [Facultad de Quimica UNAM, Ciudad Universitaria, C.P. 04510 Mexico, D.F. (Mexico)], E-mail: gorc74@yahoo.com; Rodriguez-Gomez, Francisco J.; Genesca-Llongueras, Joan [Facultad de Quimica UNAM, Ciudad Universitaria, C.P. 04510 Mexico, D.F. (Mexico)

    2008-12-01

    The action of Desulfovibrio vulgaris (Dv) during a corrosion process has been reported in literature, but the influence of imidazoline in the formation of biofilms is not clear, as well as the effect of bacteria on the efficiency of the corrosion inhibitors. The aim of this work is to determine the behavior of bacteria in the presence of imidazoline. Therefore, the growth of Dv, isolated and characterized from a morphological point of view, was monitored during 21 days, during which synthetic seawater was used as the culture medium, according to the ASTM D665-98 standard. Electrochemical noise (EN) was employed to establish the corrosion type generated by the microorganism on an AISI 1018 steel cylinder. The attack was observed using scanning electron microscopy (SEM). In order to evaluate the efficiency of the corrosion inhibitor, Tafel extrapolation was used; the optimum concentration of the inhibitor was used in the presence of sulphate-reducing bacteria (SRB). In general, two forms of corrosion were observed: localized corrosion (in the LAG phase) and mixed corrosion (in the LOG phase)

  4. Theoretical Research Progress in Inhibition Mechanism of Imidazoline Corrosion Inhibitor%咪唑啉型缓蚀剂缓蚀机理的理论研究进展

    Institute of Scientific and Technical Information of China (English)

    樊国栋; 崔梦雅

    2012-01-01

    Imidazoline and its derivatives are one of corrosion inhibitors which have been successfully used for metal corrosion control. The recent researches about the inhibition mechanism of corrosion inhibitors and the related molecular simulation are reviewed in this paper, including quantum chemical study on structure-activity relationship of molecular, molecular simulation of corrosion inhibitor/metal interface and inhibition mechanism of inhibitors in different corrosive media etc. Finally, development directions of imidazoline corrosion inhibitors are discussed.%咪唑啉及其衍生物是金属腐蚀缓蚀剂品种之一,相关研究十分活跃.本文从缓蚀剂分子构效关系的量子化学、缓蚀剂-金属界面体系的分子模拟和缓蚀剂分子在不同腐蚀介质中的缓蚀机理等方面的研究结果,综述了国内外有关咪唑啉型缓蚀剂的缓蚀作用机理及相关分子模拟的研究进展情况,探讨了其发展方向.

  5. 水溶性咪唑啉类缓蚀剂的合成及性能研究%Synthesis and performance of the water-soluble imidazoline corrosion inhibitor

    Institute of Scientific and Technical Information of China (English)

    邢占忠; 李永剑

    2011-01-01

    针对油田注水开发过程中存在的腐蚀问题,合成了水溶性的咪唑啉类缓蚀剂LRX,利用静态挂片法和极化曲线法考察了其缓蚀性能.结果表明,在苯甲酸与二乙烯三胺的摩尔比为1∶1.4,咪唑啉中间体与氯乙酸的摩尔比1∶ 1.5,季铵化温度控制在60℃,反应时间4h时,合成的咪唑啉类缓蚀剂LRX为阳极型缓蚀剂,对20#钢的缓蚀率达85%;合成的咪唑啉类缓蚀剂LRX与阻垢剂HEDP复配后,在缓蚀和阻CaCO3垢性能方面具有良好的协同效应.%One water-soluble imidazoline corrosion inhibitor LRX was synthesized aimimg at corrosion problems of injection waters system in oilfield. Corrosion performance of LRX was studied through the stat ic hanging experiments and the polarization curves. The results showed imidazoline corrosion inhibitor LRX was an anodic corrosion inhibitor and had good corrosion inhibition rate (85%) to 20# steel when the molar ratio of benzoic acids to diethylenetriamine was 1:1.4, the molar ratio of intermediate imidazoline to chloroacetic acid was 1:1.5, the quatemized temperature was 60 ℃ and the reaction time was 4 h. The mixture of LRX and HEDP had excellent synergy effect on the corrosion and the scales of CaCO3.

  6. Corrosion Inhibition of Imidazoline Derivates with Benzene Rings on Mild Steel in CO2-Saturated Brine Solution

    Institute of Scientific and Technical Information of China (English)

    CHEN Guo-hao; ZHAO Jing-mao

    2012-01-01

    Corrosion inhibition of three imidazoline derivates with different numbers of benzcne rings,namely 2-phenyl-1-ethylamino imidazoline(CI-1),2-phcnyl-1-ethylamino-1-methylbenzyl quaternary imidazoline(CI-12) and 2-phcnyl-1-bcnzoyl ethylamino imidazoline(CI-13),on mild steel in CO2-saturated brine solution was evaluated by mass-loss method and potentiodynamic polarization method.The results show that the three imidazoline derivates can inhibit CO2 corrosion effectively with CI-12 ranking the highest.They mainly restrain the anodic dissolution and act as anodic-type inhibitors.The adsorptions of these derivates on the mild steel surface follow the Langmuir adsorption isothermal equation and belong to chemical adsorption.

  7. Study on the Synthesis and Corrosion Inhibition Performance of Mannich-Modified Imidazoline

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    Xiangjun Kong

    2016-07-01

    Full Text Available A novel Mannich-modified imidazoline (MMI as cationic emulsifier was synthesised for corrosion harm reduction, through three steps — acylation, cyclization, and Mannich reaction. The surface activity was characterized by determination of surface tensions and critical micelle concentration (CMC. The corrosion inhibition performance of five types of steels in the simulated corrosion solution in the presence of the MMI was investigated by static weight loss tests. The results showed that the MMI had good surface activities, with CMC of 19.8 μg g−1 and surface tension of 36.4 mN m−1. The corrosion test results indicated that the corrosion rates of different materials were decreased significantly, and degrees of corrosion inhibition were always higher than 80.0 %. The main inhibition mechanism was most likely due to the adsorption of the corrosion inhibitor on the steel surface, leading to the prevention of corrosion medium from the metal surface.

  8. Carbon dioxide corrosion inhibition of N80 carbon steel in single liquid phase and liquid/particle two-phase flow by hydroxyethyl imidazoline derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Liu, X. [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang 110016, Liaoning Province (China); Department of Applied Chemistry, Shenyang Institute of Chemical Technology, Shenyang 110142 (China); Zheng, Y.G. [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang 110016, Liaoning Province (China); Okafor, P.C. [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang 110016, Liaoning Province (China); Department of Pure and Applied Chemistry, University of Calabar, Calabar (Nigeria)

    2009-07-15

    CO{sub 2} corrosion inhibition of N80 steel in liquid single-phase and liquid/particle two-phase flow by 2-undecyl-1-hydroxyethyl imidazoline (HEI-11) and 2-undecyl-1-hydroxyethyl-1-hydroxyethyl quaternary imidazoline (HQI-11) was investigated using weight loss, potentiodynamic polarization, EIS, and scanning electron microscope (SEM) techniques. The results show that the corrosion rate in the absence and presence of the imidazolines is strongly dependent on the flow condition and presence of entrained sand particles. The imidazolines function via a mixed-type corrosion inhibition mechanism. The inhibition efficiencies of the imidazolines followed the trend HQI-11 > HEI-11 in all the systems studied. Inhibition mechanism has been discussed in relation to the polycentric adsorption sites on the imidazoline molecules. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  9. Effect of an Imidazoline [IM–NH17] on the Corrosion Process of API5l–X52 Steel Exposed in Acidified Brines

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    A.G. Reynaud–Morales

    2009-10-01

    Full Text Available The inhibition effect of an aminoethyl oleic imidazoline [IM–NH17] on the corrosion of API5L–X52 steel in acidified 5% NaCl pH 3 solutions at 50°C was studied via electrochemical methods, i.e. potentiodynamic polarization tests and linear polarization resistance measurements. Polarization curves revealed that, under the test conditions, the inhibitor performs as a mixed type inhibitor. Linear Polarization Resistance measurements showed an increase in Rp values for inhibitor containing solutions as compared with the blank solution. The results revealed that the inhibitor efficiency increases with inhibitor concentration in the range from 12.5 ppm to 25ppm. From the electrochemical results, it was found that the adsorption mechanism that better fits the present system follows the Langmuir isotherm model.

  10. Corrosion Inhibitors for Reinforced Concrete

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    Steel corrosion in reinforced concrete structures has been a major problem across the U.S. Steel-reinforced concrete structures are continually subject to attack by corrosion brought on by naturally occurring environmental conditions. FerroGard, a corrosion inhibitor, developed by Sika Corporation, penetrates hardened concrete to dramatically reduce corrosion by 65% and extend the structure's service life.

  11. Corrosion inhibitors; Los inhibidores de corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Godinez, L. A.; Meas, Y.; Ortega-Borges, R.; Corona, A.

    2003-07-01

    In this paper, we briefly describe the characteristics, cost and electrochemical nature of the corrosion phenomena as well as some of the technologies that are currently employed to minimize its effect. The main subject of the paper however, deals with the description, classification and mechanism of protection of the so-called corrosion inhibitors. Examples of the use of these substances in different aggressive environments are also presented as means to show that these compounds, or their combination, can in fact be used as excellent and relatively cheap technologies to control the corrosion of some metals. In the last part of the paper, the most commonly used techniques to evaluate the efficiency and performance of corrosion inhibitors are presented as well as some criteria to make a careful and proper selection of a corrosion inhibitor technology in a given situation. (Author) 151 refs.

  12. Corrosion inhibitors from expired drugs.

    Science.gov (United States)

    Vaszilcsin, Nicolae; Ordodi, Valentin; Borza, Alexandra

    2012-07-15

    This paper presents a method of expired or unused drugs valorization as corrosion inhibitors for metals in various media. Cyclic voltammograms were drawn on platinum in order to assess the stability of pharmaceutically active substances from drugs at the metal-corrosive environment interface. Tafel slope method was used to determine corrosion rates of steel in the absence and presence of inhibitors. Expired Carbamazepine and Paracetamol tablets were used to obtain corrosion inhibitors. For the former, the corrosion inhibition of carbon steel in 0.1 mol L(-1) sulfuric acid solution was about 90%, whereas for the latter, the corrosion inhibition efficiency of the same material in the 0.25 mol L(-1) acetic acid-0.25 mol L(-1) sodium acetate buffer solution was about 85%.

  13. Corrosion Inhibitors for Aluminum.

    Science.gov (United States)

    Muller, Bodo

    1995-01-01

    Describes a simple and reliable test method used to investigate the corrosion-inhibiting effects of various chelating agents on aluminum pigments in aqueous alkaline media. The experiments that are presented require no complicated or expensive electronic equipment. (DDR)

  14. Quantum chemical analysis on molecular structures and inhibitive properties of imidazoline inhibitors%咪唑啉缓蚀剂分子结构与缓蚀性能的量子化学分析

    Institute of Scientific and Technical Information of China (English)

    胡松青; 贾晓林; 胡建春; 石鑫; 郭爱玲

    2011-01-01

    采用量子化学密度泛函理论,考察6种十一烷基咪唑啉缓蚀剂的缓蚀性能与分子结构的关系,通过前线轨道分布、Fukui指数、自然电荷分布以及分子中重原子对前线轨道贡献等分析缓蚀剂分子的反应活性位点.结果表明:咪唑啉类缓蚀剂分子与金属界面作用时,主要是咪唑环和亲水支链上的极性基团起作用,分子的活性位点主要分布在咪唑环及亲水取代基上的N、O、S等杂原子处;缓蚀剂的缓蚀效率与分子最高占有轨道能量(EHOMO)、最低空轨道能量(ELUMO)及分子负电荷总数(nTNC)都有较好的相关性;咪唑啉缓蚀剂与金属相互作用时,既能向金属原子的空轨道提供电子形成配位键,又可从金属中接受电子到缓蚀剂分子最低空轨道上形成反馈键,从而形成稳定的吸附.%The relationships between molecular structures of six undecyl imidazoline inhibitors and their inhibitive performance were investigated by using quantum chemical density functional theory (DFT). Via analysis of frontier orbital distribution, Fukui index, natural charge distribution and contribution to frontier orbital of heavy atoms, the reaction active sites of imidazoline molecules were obtained. The results indicate that imidazoline ring and its polar functional group on the hydrophilic chain play a significant role when inhibitors react with metal surface, and the reaction active sites mainly concentrate on the imidazoline ring and atoms of N,O,S located on hydrophilic substituent. The inhibition efficiency is closely related to some quantum chemical parameters of corrosion inhibitors such as the highest occupation orbital energy EHOMO, the lowest empty orbital energy ELUMO and total number of molecular negative charge nTNC. The imidazoline molecules could form coordinate bond and back-donating bond to metal surface when inhibitors react with metal, and stable adsorption could be formed.

  15. CORROSION INHIBITOR FOR CARBON STEELS

    African Journals Online (AJOL)

    corrosion inhibitor for carbon steel in 3% ac]neon.s' NaCl solution (pH 6) ... compared to stainless steels (Buchweishaija & Hagen 1997). Organic compounds are ... resistant dust for break and clutch linings, wood binders and mould (Gedam.

  16. Migrating corrosion inhibitor protection of concrete

    Energy Technology Data Exchange (ETDEWEB)

    Bjegovic, D.; Miksic, B.

    1999-11-01

    Migrating corrosion inhibitors (MCI) were developed to protect steel rebar from corrosion in concrete. They were designed to be incorporated as an admixture during concrete batching or used for surface impregnation of existing concrete structures. Two investigations are summarized. One studied the effectiveness of MCIs as a corrosion inhibitor for steel rebar when used as an admixture in fresh concrete mix. The other is a long-term study of MCI concrete impregnation that chronicles corrosion rates of rebar in concrete specimens. Based on data from each study, it was concluded that migrating corrosion inhibitors are compatible with concrete and effectively delay the onset of corrosion.

  17. 月桂基咪唑啉对银的缓蚀性能研究%Performance of lauryl imidazoline in the corrosion inhibition of silver

    Institute of Scientific and Technical Information of China (English)

    王菊琳; 栾莉; 李沫; 张治国; 马清林

    2012-01-01

    A lauryl imidazoline ( LM) has been synthesized and the structure was characterized by Fourier transform in frared (FT-IR) spectroscopy. The corrosion inhibition ability of LM was studied in Na2S corrosion medium for silver samples which based on composition of the Emperor Asoka Pagoda substrate by pre-filming, gravimetric method, potentiodynamic method and electrochemical impedance spectroscopy. In addition, the corrosion inhibition ability of LM was compared with those of benzotriazole ( BTA ) and l-phenyl-5-mercaptotetrazole( PMTA) , which were commonly used corrosion inhibitors in the field of silver heritage conservation. Compared with bare silver samples, the inhibition ratio of prefilmed silver samples by 1% LM was 59. 1% in 5 mg/L Na2S corrosion medium; the corrosion current density ic decreased by 0. 111 μA/cm and the electrical double-layer capacitance Cd decreased by 51. 39 μF/cm2 ; Meanwhile, the electrochemical impedance Rt increased by 73. 5 kΩ·cm2 ; Comparison of the corrosion inhibition effect for LM with those for BTA and PMTA, showed that the inhibition rate 77 for silver decreased in the order ηPMTA > ηLM > ηBTA, as confirmed by the results of gravimetric method, potentiodynamic method and electrochemical impedance spectroscopy.%合成了月桂基咪唑啉(LM),并采用FT-IR对LM进行结构表征.以南京长干寺遗址地宫出土的阿育王塔的银基体模拟样品为试样,通过预膜法、重量法、动电位扫描法、电化学交流阻抗法研究了LM对银试样在Na2S腐蚀介质中的缓蚀性能,并与银质文物上常用的含氮类缓蚀剂苯骈三氮唑(BTA)、含硫类缓蚀剂1-苯基-5-巯基四氮唑(PMTA)在Na2S腐蚀介质中的缓蚀效果进行了比较.结果表明,与裸银试样相比,经质量分数为1% LM预膜处理后的银试样在5mg/L Na2S溶液中的缓蚀率为59.1%;自腐蚀电流密度ic减小了0.111 μA/cm2,电化学体系的双电层电容Cd降低了51.39 μF/cm2,

  18. Quantum Chemical Studies on the Molecular Reactivity of Imidazoline Inhibitors%咪唑啉缓蚀剂分子反应活性的量子化学研究

    Institute of Scientific and Technical Information of China (English)

    郁金华; 史瑞莲

    2014-01-01

    In this article, 11 kinds of corrosion inhibitor molecules of imidazoline with the same alkyl long chain has been taken as the research objects. Using GGA /BLYP Method of DFT, reaction active sites of corrosion inhibitor molecule has been analyzed by calculating molecular quantitative parameters,such as frontier orbital distribution, charge distribution, orbital coefficient and Fukui index. The results indicated that the molecular reactivity area and active sites were mainly concentrated in the head of imidazoline molecules; the head of the imidazole ring and the heteroatom on hydrophilic substituent were the main active sites; S atoms had contributed enormously to HOMO and LUMO; at the same time S atoms was taken as nucleophilic and electrophilic active sites; with the number raising of S atoms, increased the reactivity sites and the corrosion efficiency; alkyl tail chain wasn’t affect the active distribution.%以11种同烷基链长咪唑啉类缓蚀剂分子为研究对象,采用DFT中的GGA/BLYP方法,通过计算分子的前线轨道分布、电荷分布、轨道系数、Fukui指数等,分析缓蚀剂分子位点的反应活性。结果表明,分子的反应活性区域和活性位点主要集中在咪唑啉分子头部的咪唑环和亲水取代基上的杂原子;S原子可同时作为亲核、亲电活性位,缓蚀效率随分子中S原子的增多而增加;烷基尾链对其活性分布基本不产生影响。

  19. Dissolution properties of cerium dibutylphosphate corrosion inhibitors

    NARCIS (Netherlands)

    Soestbergen, M. van; Erich, S.J.F.; Huinink, H.P.; Adan, O.C.G.

    2013-01-01

    The corrosion inhibitor cerium dibutylphosphate, Ce(dbp)3, prevents corrosion by cerium and dbp deposition at the alkaline cathode and acidic anode respectively. The pH dependent Ce(dbp)3 solubility seems to play an essential role in the inhibition degree. We found that Ce(dbp) 3 scarcely dissolves

  20. Corrosion inhibitors for intermediate cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Falk, I.; Suhr, L.

    1985-04-01

    The selected inhibitors were tested for heat and radiation stability and corrosion protection on the bench scale. Based on the results from these tests two of the products were selected, Bycoguard 81 and Bycoguard MP4S for continuing corrosion tests in an autoclave loop at 90 degrees C and 120 degrees C. Oxygen saturated deionized water with an addition of 1 ppm chloride was recirculated in the loop. Samples of copper and carbon steel were exposed to the water in the autoclave for periods up to 10 weeks. The purpose of this project was to find a substitute for hydrazine and chromates. Besides good corrosion protection qualities the toxic and environmental effect of the inhibitors should be minimal. The investigation has shown that the copper inhibitor BTA (benzotriazole) loses its corrosion protection qualities at a water temperature of 120 degrees C. The protection effects at 90 degrees C were satisfactory for both of the materials. The corrosion rates measured were 0.01 mm/y or less for the copper and carbon steel samples. The environment in the autoclave during the testing was more corrosive than is to be found in intermediate cooling systems. Due to the low corrosion rates measured the two inhibitors are to be recommended as alternatives to hydrazine and chromates.

  1. Corrosion protection with eco-friendly inhibitors

    Science.gov (United States)

    Shahid, Muhammad

    2011-12-01

    Corrosion occurs as a result of the interaction of a metal with its environment. The extent of corrosion depends on the type of metal, the existing conditions in the environment and the type of aggressive ions present in the medium. For example, CO3-2 and NO-3 produce an insoluble deposit on the surface of iron, resulting in the isolation of metal and consequent decrease of corrosion. On the other hand, halide ions are adsorbed selectively on the metal surface and prevent formation of the oxide phase on the metal surface, resulting in continuous corrosion. Iron, aluminum and their alloys are widely used, both domestically and industrially. Linear alkylbenzene and linear alkylbenzene sulfonate are commonly used as detergents. They have also been found together in waste water. It is claimed that these chemicals act as inhibitors for stainless steel and aluminum. Release of toxic gases as a result of corrosion in pipelines may lead in certain cases to air pollution and possible health hazards. Therefore, there are two ways to look at the relationship between corrosion and pollution: (i) corrosion of metals and alloys due to environmental pollution and (ii) environmental pollution as a result of corrosion protection. This paper encompasses the two scenarios and possible remedies for various cases, using 'green' inhibitors obtained either from plant extracts or from pharmaceutical compounds. In the present study, the effect of piperacillin sodium as a corrosion inhibitor for mild steel was investigated using a weight-loss method as well as a three-electrode dc electrochemical technique. It was found that the corrosion rate decreased as the concentration of the inhibitor increased up to 9×10-4 M 93% efficiency was exhibited at this concentration.

  2. Agricultural Polymers as Corrosion Inhibitors

    Science.gov (United States)

    Agricultural polymers were composed of extra-cellular polysaccharides secreted by Leuconostoc mesenteroides have been shown to inhibit corrosion on corrosion-sensitive metals. The substantially pure exopolysaccharide has a general structure consisting of alpha(1-6)-linked D-glucose backbone and appr...

  3. Diffusion Coatings as Corrosion Inhibitors

    Science.gov (United States)

    Ivanov, Radoslav; Ignatova-Ivanova, Tsveteslava

    2016-03-01

    Corrosion is the cause of irretrievable loss of huge amounts of metals and alloys. The harmful effects of corrosion can be reduced significantly by applying appropriate methods of corrosion protection. One method to protect metals against corrosion is the formation of diffusion coatings on them. High corrosion resistance is typical for the boride diffusion layers. Aluminothermy is one of the main methods for diffusion saturation of the surface of metal products with various elements, including boron, and under certain conditions with aluminum, too. Samples of steel 45 were put to aluminothermic diffusion saturation with boron in a pressurized steel container at a temperature of 1100K, for 6 hours in powdered aluminothermic mixtures. The content of B2O3 in the starting mixtures decreased from the optimum - 20% to 0%, and the content of Al and the activator - (NH4)2.4BF3 is constant, respectively 7% and 0.5%. Al2O3 was used as filler. The borided samples were tested for corrosion resistance in 10% HCl for 72 hours. The results show that their corrosion resistance depends on the composition of the starting saturating mixture (mainly on the content of B2O3), and respectively on the composition, structure, thickness and degree of adhesion of the layer to the metal base.

  4. Diffusion Coatings as Corrosion Inhibitors

    Directory of Open Access Journals (Sweden)

    Ivanov Radoslav

    2016-03-01

    Full Text Available Corrosion is the cause of irretrievable loss of huge amounts of metals and alloys. The harmful effects of corrosion can be reduced significantly by applying appropriate methods of corrosion protection. One method to protect metals against corrosion is the formation of diffusion coatings on them. High corrosion resistance is typical for the boride diffusion layers. Aluminothermy is one of the main methods for diffusion saturation of the surface of metal products with various elements, including boron, and under certain conditions with aluminum, too. Samples of steel 45 were put to aluminothermic diffusion saturation with boron in a pressurized steel container at a temperature of 1100K, for 6 hours in powdered aluminothermic mixtures. The content of В2О3 in the starting mixtures decreased from the optimum - 20% to 0%, and the content of Al and the activator - (NH42.4BF3 is constant, respectively 7% and 0.5%. Al2O3 was used as filler. The borided samples were tested for corrosion resistance in 10% HCl for 72 hours. The results show that their corrosion resistance depends on the composition of the starting saturating mixture (mainly on the content of В2О3, and respectively on the composition, structure, thickness and degree of adhesion of the layer to the metal base.

  5. Corrosion inhibitors performance for mild steel in CO{sub 2} containing solutions

    Energy Technology Data Exchange (ETDEWEB)

    Zavala Olivares, G.; Hernandez Gayosso, M.J.; Mora Mendoza, J.L. [Instituto Mexicano del Petroleo, Eje Central Lazaro Cardenas 152, Col. San Bartolo Atepehuacan, D.F. 07730 (Mexico)

    2007-06-15

    The Electrochemical Impedance Spectroscopy (EIS), was used to evaluate and compare the behavior of three different corrosion inhibitors: quaternary amine (QA), oleic imidazoline (OI) and amino coco propionic acid (ACP), on the corrosion of mild steel in 3% NaCl solutions, saturated with CO{sub 2} gas, under static conditions. Two pH values: 3.8 and 5.5 were considered. Under the conditions considered in this work, the results indicated film formation at the metal surface, probable due to the formation of iron carbonate. This condition modified the values of the resistance and double layer capacitance of the system. In general terms, the ACP inhibitor exhibited better performance, compared to the QA and OI. During the impedance measurements with OI and ACP, some deviations were observed at high frequencies, indicating probably that the inhibitors adsorption occurs in different way to the QA inhibitor and the amine adsorption is weaker than the other two inhibitors adsorption. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  6. Recent Natural Corrosion Inhibitors for Mild Steel: An Overview

    Directory of Open Access Journals (Sweden)

    Marko Chigondo

    2016-01-01

    Full Text Available Traditionally, reduction of corrosion has been managed by various methods including cathodic protection, process control, reduction of the metal impurity content, and application of surface treatment techniques, as well as incorporation of suitable alloys. However, the use of corrosion inhibitors has proven to be the easiest and cheapest method for corrosion protection and prevention in acidic media. These inhibitors slow down the corrosion rate and thus prevent monetary losses due to metallic corrosion on industrial vessels, equipment, or surfaces. Inorganic and organic inhibitors are toxic and costly and thus recent focus has been turned to develop environmentally benign methods for corrosion retardation. Many researchers have recently focused on corrosion prevention methods using green inhibitors for mild steel in acidic solutions to mimic industrial processes. This paper provides an overview of types of corrosion, corrosion process, and mainly recent work done on the application of natural plant extracts as corrosion inhibitors for mild steel.

  7. Progress of Corrosion Inhibitor for Oil Field Injection Water%油气田注水缓蚀剂研究进展

    Institute of Scientific and Technical Information of China (English)

    杨鹏辉; 张宇翔; 任香梅; 李霆; 杨江

    2014-01-01

    油气田注水缓蚀剂主要以有机吸附膜型缓蚀剂为主,介绍了油气田注水常用的吸附膜型缓蚀剂及其在油气田中的应用和研究进展,对咪唑啉类缓蚀剂的应用做了重点阐述,指出了吸附膜型缓蚀剂的发展方向。%The current state and progress of film -forming corrosion inhibitor for oil -gas field injection water was described.Research on the development of imidazoline corrosion inhibitor in oil -gas field was highlighted.Developing direction of corrosion inhibitor was pointed out.

  8. Evaluation of Encapsulated Inhibitor for Autonomous Corrosion Protection

    Science.gov (United States)

    Johnsey, M. N.; Li, W.; Buhrow, J. W.; Calle, L. M.; Pearman, B. P.; Zhang, X.

    2015-01-01

    This work concerns the development of smart coating technologies based on microencapsulation for the autonomous control of corrosion. Microencapsulation allows the incorporation of corrosion inhibitors into coating which provides protection through corrosion-controlled release of these inhibitors.One critical aspect of a corrosion protective smart coating is the selection of corrosion inhibitor for encapsulation and comparison of the inhibitor function before and after encapsulation. For this purpose, a systematic approach is being used to evaluate free and encapsulated corrosion inhibitors by salt immersion. Visual, optical microscope, and Scanning Electron Microscope (with low-angle backscatter electron detector) are used to evaluate these inhibitors. It has been found that the combination of different characterization tools provide an effective method for evaluation of early stage localized corrosion and the effectiveness of corrosion inhibitors.

  9. Waste of cleaning emulsion sewage as inhibitors of steel corrosion

    Science.gov (United States)

    Fazullin, D. D.; Mavrin, G. V.; Shaikhiev, I. G.

    2016-06-01

    The article describes the corrosion test of steel of the brand 20 in the stratal water. To increase corrosion resistance as a corrosion inhibitor the concentrate waste emulsion of the mark "Incam- 1" was provided. The article presents studies of the corrosion rate with different dosages of corrosion inhibitor in the stratal water. Based on these research results are revealed that the degree of protection of steel is 27% at a dosage of 3.8 g / dm3.

  10. Engineering Performance of a New Siloxane-Based Corrosion Inhibitor

    OpenAIRE

    Holmes, Niall; O'Brien, R.; Basheer, P. A.M.

    2013-01-01

    This paper presents an evaluation of a new non-toxic corrosion inhibitor on selected engineering properties of concrete mixes with different cementitious materials following a corrosion and durability study on concrete samples. Corrosion inhibitors consist of powders or solutions which are added to concrete when mixed to prevent or delay corrosion of steel by their reaction with ferrous ions to form a stable and passive ferric oxide film on the steel surface. The new inhibitor functions sligh...

  11. Corrosion-Inhibitor Efficiency Control: Comparison by Means of Different Portable Corrosion Rate Meters

    OpenAIRE

    Martinez Sierra, Isabel; Andrade Perdrix, Maria del Carmen; Rebolledo Ramos, Nuria; Luo, L; De Schutter, G

    2010-01-01

    Corrosion-inhibiting substances have been applied to suppress corrosion mainly on bare steel, but when corrosion is progressing, suppression can be achieved if anodic and cathodic reactions are avoided, which is not an easy objective, particularly if the bare metal is surrounded by concrete. In the present article, several corrosion inhibitors are studied to identify their inhibition efficiency in concrete. The percentage of reduction of the corrosion rate without and with inhibitor is named ...

  12. Recent Natural Corrosion Inhibitors for Mild Steel: An Overview

    OpenAIRE

    Marko Chigondo; Fidelis Chigondo

    2016-01-01

    Traditionally, reduction of corrosion has been managed by various methods including cathodic protection, process control, reduction of the metal impurity content, and application of surface treatment techniques, as well as incorporation of suitable alloys. However, the use of corrosion inhibitors has proven to be the easiest and cheapest method for corrosion protection and prevention in acidic media. These inhibitors slow down the corrosion rate and thus prevent monetary losses due to metalli...

  13. Accelerated corrosion testing results for specimens containing uncoated reinforcing steel and corrosion inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Kondratova, I. L.; Montes, P.; Bremner, T. W. [New Brunswick Univ., Dept, of Civil Engineering, Fredericton, NB (Canada)

    2000-07-01

    Concrete mixtures (water-cement ratios of 0.25, 0.40. or 0.60) containing uncoated reinforcing bars with a simulated crack, formed transverse to the axis of the bar, and with three commercial corrosion inhibitors added for corrosion protection (organic corrosion inhibitor,calcium nitrate-based corrosion inhibitor, and migratory corrosion inhibitor), were tested for corrosion damage. The objective was to evaluate the effectiveness of the different corrosion inhibitors in uncracked and cracked concrete slabs in a simulated marine environment. The specimens were placed in an accelerated exposure cabinet with four cycles of wetting and drying per day in simulated seawater, and corrosion rates measured using the linear polarization technique. Water-soluble chloride content in the rebars was analyzed at the end of the exposure period. The three corrosion inhibitors were found to show a wide variation in performance. There was a direct correlation between their effectiveness and addition rate. All three appeared to be more effective in reducing corrosion rate in a higher water-to-cement ratio concrete. Consistent performance was provided only by calcium nitrate at an addition rate of 25 litre/cu m of concrete, with water-to-cement ratios of 0.60 and 0.40. Pitting corrosion was observed in all pre-cracked high performance concrete specimens; the depth of the pit tended to be deeper when a corrosion inhibitor was used. 6 refs., 6 tabs., 6 figs.

  14. Characterization of Encapsulated Corrosion Inhibitors for Environmentally Friendly Smart Coatings

    Science.gov (United States)

    Pearman, Benjamin Pieter; Li, Wenyan; Buhrow, Jerry; Zhang, Xuejun; Surma, Jan; Fitzpatrick, Lilly; Montgomery, Eliza; Calle, Luz Marina

    2014-01-01

    Research efforts are under way to replace current corrosion inhibitors with more environmentally friendly alternatives. However, problems with corrosion inhibition efficiency, coating compatibility and solubility have hindered the use of many of these materials as simple pigment additives.This paper will present technical details on how the Corrosion Technology Lab at NASAs Kennedy Space Center (KSC) has addressed these issues by encapsulating environmentally friendly inhibitors into organic and inorganic microparticles and microcapsules. The synthetic process for polymer particles was characterized and post-synthesis analysis was performed to determine the interactions between the inhibitors and the encapsulation material. The pH-controlled release of inhibitors from various particle formulations in aqueous base was monitored and compared to both electrochemical and salt immersion accelerated corrosion experiment. Furthermore, synergistic corrosion inhibition effects observed during the corrosion testing of several inhibitor combinations will be presented.

  15. Microorganisms as potential corrosion inhibitors of metallic materials

    Directory of Open Access Journals (Sweden)

    Tasić Žaklina Z.

    2016-01-01

    Full Text Available Corrosion presents the destruction of materials through chemical or electrochemical interactions with their environment. Interactions between the metal surface and bacterial cells or products of their metabolic activities can lead to microbially-influenced corrosion. Also, it is known that certain microorganisms can contribute to corrosion inhibition. In accordance to that, the literature dealing with the application of different microorganisms as a potentialy corrosion inhibitors of metals is investigated. Different bacterial strains as a corrosion inhibitor of a metalic materials are examined. Further, the role of extracellular polymeric substances in corrosion behavior of metals is emphasized. Based on the data presented in this work, it can be said that inhibition efficiency depends on microorganism as well as type of metal. Also, it is presented that some bacterial species can be used as a good corrosion inhibitor instead of toxic organic compounds.

  16. Migrating corrosion inhibitor blend for reinforced concrete: Part 1 -- Prevention of corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Elsener, B.; Buechler, M.; Stalder, F.; Boehni, H.

    1999-12-01

    The efficiency of a migrating corrosion inhibitor in preventing corrosion of mild steel was investigated in saturated calcium hydroxide (Ca[OH]{sub 2}) solutions and in mortar. The protective effect of the inhibitor against pitting corrosion caused by chloride attack and against uniform corrosion as a result of carbonation was determined. Results showed that high concentrations ({approx}10%) allowed the inhibition of pitting corrosion tritiation in solution containing 1 M/L sodium chloride (NaCl). However, inhibiting properties can be lost by evaporation of the volatile constituent of the inhibitor or by the precipitation of the nonvolatile fraction of the inhibitor in presence of calcium ions. Addition of the inhibitor blend to mortar yielded a retardation of the corrosion initiation in the case of chloride-induced corrosion, but o significant reduction in corrosion rate. No effect was found in carbonated samples, and no influence on the corrosion rate was detected. Additionally, the estimation of the extent of the retarding effect on corrosion initiation on real structures was difficult, as the inhibitor was found to evaporate from the mortar. This evaporation resulted in a loss of inhibiting properties. Hence, the long-term efficiency of the inhibitor could not be guaranteed.

  17. Corrosion inhibitor for aqueous ammonia absorption system

    Science.gov (United States)

    Phillips, Benjamin A.; Whitlow, Eugene P.

    1998-09-22

    A method of inhibiting corrosion and the formation of hydrogen and thus improving absorption in an ammonia/water absorption refrigeration, air conditioning or heat pump system by maintaining the hydroxyl ion concentration of the aqueous ammonia working fluid within a selected range under anaerobic conditions at temperatures up to 425.degree. F. This hydroxyl ion concentration is maintained by introducing to the aqueous ammonia working fluid an inhibitor in an amount effective to produce a hydroxyl ion concentration corresponding to a normality of the inhibitor relative to the water content ranging from about 0.015 N to about 0.2 N at 25.degree. C. Also, working fluids for inhibiting the corrosion of carbon steel and resulting hydrogen formation and improving absorption in an ammonia/water absorption system under anaerobic conditions at up to 425.degree. F. The working fluids may be aqueous solutions of ammonia and a strong base or aqueous solutions of ammonia, a strong base, and a specified buffer.

  18. Effect of Mixed Corrosion Inhibitors in Cooling Water System

    Directory of Open Access Journals (Sweden)

    Dina Raheem

    2011-01-01

    Full Text Available The effect of mixed corrosion inhibitors in cooling system was evaluated by using carbon steel specimens and weight loss analysis. The carbon steel specimens immersed in mixture of sodium phosphate (Na2 HPO4 used as corrosion inhibitor and sodium glocunate (C6 H11 NaO7 as a scale dispersant at different concentrations (20,40, 60, 80 ppm and at different temperature (25,50,75 and 100ºC for (1-5 days. The corrosion inhibitors efficiency was calculated by using uninhibited and inhibited water to give 98.1%. The result of these investigations indicate that the corrosion rate decreases with the increase the corrosion inhibitors concentration at 80 ppm and at 100ºC for 5 days, (i.e, corrosion rate= 0.014gmd.

  19. Corrosion Inhibition of a Green Scale Inhibitor Polyepoxysuccinic Acid

    Institute of Scientific and Technical Information of China (English)

    Rong Chun XIONG; Qing ZHOU; Gang WEI

    2003-01-01

    The corrosion inhibition of a green scale inhibitor, polyepoxysuccinic acid (PESA) wasstudied based on dynamic tests. It is found that when PESA is used alone, it had good corrosioninhibition. So, PESA should be included in the category of corrosion inhibitors. It is not only akind 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 higherthan 99%. Further study of corrosion inhibition mechanism reveals that corrosion inhibition ofPESA is not affected by carboxyl group, but by the oxygen atom inserted The existence ofoxygen atom in PESA molecular structure makes it easy to form stable chelate with pentacyclicstructure.

  20. Controlling internal corrosion of oil and gas pipelines : the corrosion inhibitor selection software (CISS) program

    Energy Technology Data Exchange (ETDEWEB)

    Doiron, A.; Papavinasam, S. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Materials Technology Laboratory

    2009-07-01

    The internal pitting corrosion of oil and gas pipelines can be effectively controlled through the addition of inhibitors. However, simulation of field operating conditions is necessary because the performance of corrosion inhibitors is influenced by several interacting parameters. This paper reviewed the Corrosion Inhibitor Selection Software (CISS) program. The materials transported in production pipelines are often multiphase, containing oil, aqueous (brine), and gas phases. The corrosion rate and inhibitor performance are influenced by composition, temperature, flow and pressure. Steel composition and structure also influence both the rate and type of corrosion. Improvements in corrosion test methodologies are aimed at simulating field corrosion conditions in the laboratory in a compressed time-scale. The parameters that influence the types of corrosion must be simulated in order for laboratory methodology to be relevant. The variables controlled should be quantifiable. There should also be a correlation between the influence of variables controlled in the laboratory and of the same variables in the field. The CISS program evaluates inhibitors in the following 4 steps: (1) pipeline operating conditions, (2) selection of laboratory methodology, (3) determination of operating conditions for the laboratory methodologies, and (4) selection of corrosion inhibitors. The 7 objectives of the CISS program are to optimize the strategies of inhibitor selection for pipeline applications; determine the hydrodynamic parameters of the pipe from field operating conditions; select appropriate laboratory methodologies for evaluating inhibitors; determine flow conditions for high-shear laboratory methodologies; develop a qualitative relationship between corrosion rates of non-shear laboratory methodologies and of pipelines; evaluate corrosion inhibitors based on results from different laboratory methodologies; and design cost-effective inhibitors for future applications. 47 refs

  1. Natural compounds as corrosion inhibitors for highly cycled systems

    Energy Technology Data Exchange (ETDEWEB)

    Quraishi, M.A.; Farooqi, I.H.; Saini, P.A. [Corrosion Research Lab., Aligarh (India)

    1999-11-01

    Strict environmental legislations have led to the development of green inhibitors in recent years. In continuation of the authors` research work on development of green inhibitors, they have investigated the aqueous extracts of three plants namely: Azadirachta indica, Punica Granatum and Momordica charantia as corrosion inhibitors for mild steel in 3% NaCl using weight loss and electrochemical methods. All the investigated compounds exhibited excellent corrosion inhibition properties comparable to that of HEDP. Azadirachta showed better scale inhibition effect than HEDP.

  2. Imidazoline receptors ligands

    Directory of Open Access Journals (Sweden)

    Agbaba Danica

    2012-01-01

    Full Text Available Extensive biochemical and pharmacological studies have determined three different subtypes of imidazoline receptors: I1-imidazoline receptors (I1-IR involved in central inhibition of sympathicus that produce hypotensive effect; I2-imidazoline receptors (I2-IR modulate monoamine oxidase B activity (MAO-B; I3-imidazoline receptors (I3-IR regulate insulin secretion from pancreatic β-cells. Therefore, the I1/I2/I3 imidazoline receptors are selected as new, interesting targets for drug design and discovery. Novel selective I1/I2/I3 agonists and antagonists have been recently developed. In the present review, we provide a brief update to the field of imidazoline research, highlighting some of the chemical diversity and progress made in the 2D-QSAR, 3D-QSAR and quantitative pharmacophore development studies of I1-IR and I2-IR imidazoline receptor ligands. Theoretical studies of I3-IR ligands are not yet performed because of insufficient number of synthesized I3-IR ligands.

  3. Characterization of Encapsulated Corrosion Inhibitors for Environmentally Friendly Smart Coatings

    Science.gov (United States)

    Pearman, B. P.; Calle, L. M.; Zhang, X.; Li, W.; Buhrow, J. W.; Johnsey, M. N.; Montgomery, E. L.; Fitzpatrick, L.; Surma, J. M.

    2015-01-01

    The NASA Kennedy Space Center's Corrosion Technology Lab at the Kennedy Space Center in Florida, U.S.A. has been developing multifunctional smart coatings based on the microencapsulation of environmentally friendly corrosion indicators, inhibitors and self-healing agents. This allows the incorporation of autonomous corrosion control functionalities, such as corrosion detection and inhibition as well as the self-healing of mechanical damage, into coatings. This paper presents technical details on the characterization of inhibitor-containing particles and their corrosion inhibitive effects using electrochemical and mass loss methods. Three organic environmentally friendly corrosion inhibitors were encapsulated in organic microparticles that are compatible with desired coatings. The release of the inhibitors from the microparticles in basic solution was studied. Fast release, for immediate corrosion protection, as well as long-term release for continued protection, was observed. The inhibition efficacy of the inhibitors, incorporated directly and in microparticles, on carbon steel was evaluated. Polarization curves and mass loss measurements showed that, in the case of 2MBT, its corrosion inhibition effectiveness was greater when it was delivered from microparticles.

  4. Hydroxyapatite microparticles as feedback-active reservoirs of corrosion inhibitors.

    Science.gov (United States)

    Snihirova, D; Lamaka, S V; Taryba, M; Salak, A N; Kallip, S; Zheludkevich, M L; Ferreira, M G S; Montemor, M F

    2010-11-01

    This work contributes to the development of new feedback-active anticorrosion systems. Inhibitor-doped hydroxyapatite microparticles (HAP) are used as reservoirs, storing corrosion inhibitor to be released on demand. Release of the entrapped inhibitor is triggered by redox reactions associated with the corrosion process. HAP were used as reservoirs for several inhibiting species: cerium(III), lanthanum(III), salicylaldoxime, and 8-hydroxyquinoline. These species are effective corrosion inhibitors for a 2024 aluminum alloy (AA2024), used here as a model metallic substrate. Dissolution of the microparticles and release of the inhibitor are triggered by local acidification resulting from the anodic half-reaction during corrosion of AA2024. Calculated values and experimentally measured local acidification over the aluminum anode (down to pH = 3.65) are presented. The anticorrosion properties of inhibitor-doped HAP were assessed using electrochemical impedance spectroscopy. The microparticles impregnated with the corrosion inhibitors were introduced into a hybrid silica-zirconia sol-gel film, acting as a thin protective coating for AA2024, an alloy used for aeronautical applications. The protective properties of the sol-gel films were improved by the addition of HAP, proving their applicability as submicrometer-sized reservoirs of corrosion inhibitors for active anticorrosion coatings.

  5. Corrosion inhibitor development for slightly sour environments with oxygen intrusion

    Energy Technology Data Exchange (ETDEWEB)

    Wylde, J.; Wang, H.; Li, J. [Clariant Oil Services North America, Calgary, AB (Canada)

    2009-07-01

    This presentation reported on a study that examined the effect of oxygen on the inhibition of carbon steel in slightly sour corrosion, and the initiation and propagation of localized attack. Oxygen can enter sour water injection systems through the vapor space in storage tanks and process system. Oxygen aggravates the corrosion attack by participating in the cathodic reaction under full or partial diffusion control. Laboratory testing results were reported in this presentation along with the development of corrosion inhibitors for such a slightly sour system. Bubble testing cells were used with continuous H{sub 2}/CO{sub 2} mixture gas sparging and occasional oxygen intrusion of 2 to 4 hours during a week long test. Linear polarization resistance (LPR) measurements and weight loss corrosion coupons were used to quantify the corrosion attack. The findings were presented in terms of the magnitude of localized attacks at different oxygen concentrations and intrusion periods, with and without the presence of corrosion inhibitors. tabs., figs.

  6. Effect of inhibitors and coatings on rebar corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Saricimen, H.; Ashiru, O.A.; Jarrah, N.R.; Quddus, A.; Shameem, M. [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia). Research Inst.

    1997-12-01

    Chloride-induced corrosion of reinforcing steel is a major cause of deterioration of concrete structures in the eastern province of Saudi Arabia. Two of the practical ways of preventing or retarding corrosion of reinforcing steel bars in concrete are by using (a) inhibitor in concrete mix, and (b) coating either on the rebars or on external surfaces of concrete structures. The objective of this study has been to evaluate the effect of two inhibitors, three concrete coatings, and two barrier coatings on corrosion of reinforcing steel bars. Reinforced concrete specimens were monitored by AC and DC electrochemical techniques while undergoing free and accelerated corrosion. Accelerated corrosion tests were performed under 4V impressed anodic potential. Corrosion of the steel bars were evaluated by measuring anodic current, time-to-cracking of concrete specimens, and corrosion rates of the steel bars. The results showed that the specimens with the concrete surface coatings did not perform better than the control specimens. Time-to-cracking was shorter and corrosion rate of steel bars was higher in specimens coated with concrete coatings. The inhibitors and rebar surface coatings reduced the corrosion rate of steel bars significantly and improved the time-to-cracking of the specimens in comparison to control specimens.

  7. 双子咪唑啉季铵盐的合成及其缓蚀与清蜡性能研究%Synthesis and Properties of Quaternaty Ammonium Bis-imidazoline as Inhibitor and Paraffin Remover

    Institute of Scientific and Technical Information of China (English)

    葛君; 樊国栋; 柴玲玲

    2011-01-01

    Bis-imidazoline quaternary ammonium salt, named as DTM, was synthesized by two-step reaction, where oleic acid and diethylenetriamine with hydrophilic/lipophilic groups was used as raw materials and 1,4-dibromobutane as coupling agent.The chemical structure of the obtained product was characterized by IR spectrum, the inhibitor efficiencies of DTM with different concentrations on Q235 steel in 8% hydrochloric acid was investigated using static weight loss test and polarization curve, and the paraffin removal rate( PRR) of the DTM was measured by a static wax-dissolving method.The results showed that the inhibitor DTM had a great corrosion inhibition effect for Q235 steel in 8% hydrochloric acid, the maximum inhibitor efficiency being up to 90.69%.In addition, the DTM possessed paraffin removal function; the PRR was 0.046 g/min when used singly, while the PRR was up to 0.115 g/min when used by combination with potassium bromide and isopropyl alcohol in volume ratio of 2∶ 1 ∶1.%以1,4-二溴丁烷为联接剂,油酸、二乙烯三胺为亲水亲油基团的初始原料合成了双子咪唑啉季铵盐DTM.利用红外光谱对产品的结构进行表征,用静态失重法、动电位扫描技术,测定了合成的双子咪唑啉季铵盐在不同加量下在8%盐酸介质中对Q235铜腐蚀的缓蚀效率,用静态溶蜡法测试了其清蜡速率.结果表明:该双子咪唑啉季铵盐在8%盐酸介质中对Q235钢具有较强的缓蚀性能,缓蚀效率可达90.69%,且具有一定的清蜡作用,单一使用DTM的清蜡速率为0.046 g/min,与KBr、异丙醇按体积比为2∶1∶1复配后清蜡速率可达0.115 g/min.

  8. Study on Synthesis and Corrosion Inhibitory Performance of Imidazoline Sulfuric Ester Salt(ISES)%咪唑啉硫酸酯盐ISES的合成及缓蚀性能研究

    Institute of Scientific and Technical Information of China (English)

    梅平; 邹华; 施汉荣; 艾俊哲

    2012-01-01

    1-Hydroxyethyl-2-oleic acid imidazoline(HEAI) was prepared by the reaction of oleic acid and N-(2-hydroxyethyl) ethylene diamine via amidation,cyclization. Then the end-product 1-hydroxyethyl-2-oleic acid imidazoline sulfuric ester salt(ISES) was obtained by the reaction of HEAI and aminosulfonic acid which was used as quaternization agent. The result of static weight-loss evaluation showed that ISES had better corrosion inhibition efficiency than HEAI. The corrosion inhibition rate reached 94. 88% when the temperature was 50 ℃ and the dosage of ISES was 200 mg · L-1 for steel N80 in 15% HCl.%以油酸、N-(2-羟乙基)乙二胺为原料,经酰胺化、环化合成了1-羟乙基-2-油酸基咪唑啉(HEAI),再采用氨基磺酸作为季铵化试剂与其反应得到目标产物1-羟乙基-2-油酸基咪唑啉硫酸酯盐(ISES).静态挂片失重法实验结果表明,ISES缓蚀效果显著优于HEAI;当温度为50℃、ISES用量为200mg·L-1时,对N80钢在15% HCl中的缓蚀率达到94.88%.

  9. Self-assembled monolayers of stearic imidazoline on copper electrodes detected using electrochemical measurements, XPS, molecular simulation and FTIR

    Institute of Scientific and Technical Information of China (English)

    LIU XiuYu; MA HouYi; MIAO Shuai; ZHOU Min

    2009-01-01

    A type of imidazoline inhibitor was synthesized using stearic acid and diethylenetriamine (DETA) as raw materials. Self-assembled monolayers (SAMs) of stearic imidazoline (IM) were prepared on copper surface. The copper electrode modified by IM was detected by electrochemical impedance spectros-copy (EIS), Tafel polarization curves, X-ray photoelectron spectroscopy (XPS) and Fourial transform reflection spectroscopy (FTIR). The biggest inhibition efficiency for copper corrosion of IM was 99% in NaCI solution according to EIS results. The XPS results provided evidence that the IM was adsorbed on copper surface. The theoretical calculations of molecular simulation supported the experimental re-sults and showed that the IM molecules were tilted at an angle to the copper surface.

  10. Effect of Wall Shear Stress on Corrosion Inhibitor Film Performance

    Science.gov (United States)

    Canto Maya, Christian M.

    In oil and gas production, internal corrosion of pipelines causes the highest incidence of recurring failures. Ensuring the integrity of ageing pipeline infrastructure is an increasingly important requirement. One of the most widely applied methods to reduce internal corrosion rates is the continuous injection of chemicals in very small quantities, called corrosion inhibitors. These chemical substances form thin films at the pipeline internal surface that reduce the magnitude of the cathodic and/or anodic reactions. However, the efficacy of such corrosion inhibitor films can be reduced by different factors such as multiphase flow, due to enhanced shear stress and mass transfer effects, loss of inhibitor due to adsorption on other interfaces such as solid particles, bubbles and droplets entrained by the bulk phase, and due to chemical interaction with other incompatible substances present in the stream. The first part of the present project investigated the electrochemical behavior of two organic corrosion inhibitors (a TOFA/DETA imidazolinium, and an alkylbenzyl dimethyl ammonium chloride), with and without an inorganic salt (sodium thiosulfate), and the resulting enhancement. The second part of the work explored the performance of corrosion inhibitor under multiphase (gas/liquid, solid/liquid) flow. The effect of gas/liquid multiphase flow was investigated using small and large scale apparatus. The small scale tests were conducted using a glass cell and a submersed jet impingement attachment with three different hydrodynamic patterns (water jet, CO 2 bubbles impact, and water vapor cavitation). The large scale experiments were conducted applying different flow loops (hilly terrain and standing slug systems). Measurements of weight loss, linear polarization resistance (LPR), and adsorption mass (using an electrochemical quartz crystal microbalance, EQCM) were used to quantify the effect of wall shear stress on the performance and integrity of corrosion inhibitor

  11. Changes of imidazoline receptors in spontaneously hypertensive rats

    Science.gov (United States)

    Mar, Guang-Yuan; Chou, Ming-Ting; Chung, Hsien-Hui; Chiu, Nien-Hua; Chen, Mei-Fen; Cheng, Juei-Tang

    2013-01-01

    The role of imidazoline receptors in the regulation of vascular function remains unclear. In this study, we evaluated the effect of agmatine, an imidazoline receptor agonist, on systolic blood pressure (SBP) in spontaneously hypertensive rats (SHRs) and investigated the expressions of imidazoline receptors by Western blot. The isometric tension of aortic rings isolated from male SHRs was also estimated. Agmatine decreased SBP in a dose-dependent manner in SHRs but not in the normal group [Wistar–Kyoto (WKY) rats]. This reduction in SBP in SHRs was abolished by BU224, a selective antagonist of imidazoline I2-receptors. Higher expression of imidazoline receptors in SHR was observed. Moreover, agmatine-induced relaxation in isolated aortic rings precontracted with phenylephrine or KCl. This relaxation was also abolished by BU224 but was not modified by efaroxan, an imidazoline I1-receptor antagonist. Agmatine-induced relaxation was also attenuated by PNU 37883, a selective blocker of vascular ATP-sensitive potassium (KATP) channels. Additionally, vasodilatation by agmatine was reduced by an inhibitor of protein kinase A (PKA). We suggest that agmatine can lower blood pressure in SHRs through activation of the peripheral imidazoline I2-receptor, which is expressed more highly in SHRs. PMID:23176371

  12. Inhibitor treatment program for chlorine dioxide corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Edmondson, J.G.; Holder, E.P.

    1991-11-12

    This patent describes a method of inhibiting corrosion by chlorine dioxide in oil field waterflood systems by adding a sufficient amount of a corrosion inhibiting composition. It comprises a phosphonate, a copolymer consisting of repeating units of acrylic acid/allyl hydroxy propyl sulfonate ether, and a permangante.

  13. Corrosion inhibitors for solar-heating and cooling

    Science.gov (United States)

    Humphries, T. S.

    1979-01-01

    Report describes results of tests conducted to evaluate abilities of 12 candidate corrosion inhibitors to protect aluminum, steel, copper, or stainless steel at typical conditions encountered in solar heating and cooling systems. Inhibitors are based on sodium salts including nitrates, borates, silicates, and phosphates.

  14. Polarized Neutron Reflectometry of Nickel Corrosion Inhibitors.

    Science.gov (United States)

    Wood, Mary H; Welbourn, Rebecca J L; Zarbakhsh, Ali; Gutfreund, Philipp; Clarke, Stuart M

    2015-06-30

    Polarized neutron reflectometry has been used to investigate the detailed adsorption behavior and corrosion inhibition mechanism of two surfactants on a nickel surface under acidic conditions. Both the corrosion of the nickel surface and the structure of the adsorbed surfactant layer could be monitored in situ by the use of different solvent contrasts. Layer thicknesses and roughnesses were evaluated over a range of pH values, showing distinctly the superior corrosion inhibition of one negatively charged surfactant (sodium dodecyl sulfate) compared to a positively charged example (dodecyl trimethylammonium bromide) due to its stronger binding interaction with the surface. It was found that adequate corrosion inhibition occurs at significantly less than full surface coverage.

  15. Corrosion inhibitor mechanisms on reinforcing steel in Portland cement pastes

    Science.gov (United States)

    Martin, Farrel James

    2001-07-01

    The mechanisms of corrosion inhibitor interaction with reinforcing steel are investigated in the present work, with particular emphasis on effects associated with corrosion inhibitors admixed into Portland cement paste. The principal objective in reinforcing steel corrosion inhibition for Portland cement concrete is observed to be preservation of the naturally passive steel surface condition established by the alkaline environment. Introduction of chloride ions to the steel surface accelerates damage to the passive film. Excessive damage to the passive film leads to loss of passivity and a destabilization of conditions that facilitate repair of the passive film. Passive film preservation in presence of chloride ions is achieved either through stabilization of the passive film or by modification of the chemical environment near the steel surface. Availability of inhibitors to the steel surface and their tendency to stabilize passive film defects are observed to be of critical importance. Availability of admixed corrosion inhibitors to the passive film is affected by binding of inhibitors during cement paste hydration. It is determined that pore solution concentrations of inorganic admixed inhibitors tend to be lower than the admixed concentration, while pore solution concentrations of organic admixed inhibitors tend to be higher than the admixed concentration. A fundamental difference of inhibitor function is observed between film-forming and defect stabilizing corrosion inhibitors. Experiments are conducted using coupons of reinforcing steel that are exposed to environments simulating chloride-contaminated Portland cement concrete. A study of the steel/cement paste interface is also performed, and compounds forming at this interface are identified using X-Ray diffraction.

  16. Selective imidazoline agonist moxonidine plus the ACE inhibitor ramipril in hypertensive patients with impaired insulin sensitivity: partners in a successful MARRIAGE?

    Science.gov (United States)

    Rayner, Brian

    2004-03-01

    Hypertension in combination with clinically overt diabetes mellitus is recognized as a particularly powerful combination of risk factors that greatly increases cardiovascular vulnerability. There is also evidence that presumed pre-diabetic conditions such as insulin resistance, hyperinsulinaemia and compensatory hyperglycaemia may amplify overall cardiovascular risk in patients with hypertension, especially when encountered as part of the condition known as metabolic syndrome X (Reaven's syndrome). The long-term benefits of antihypertensive therapy may be compromised if these drugs exert adverse effects on metabolic parameters such as insulin sensitivity, or if they promote a transition from pre-diabetes to overt diabetes. Class differences in the effects of antihypertensives on metabolic indices may therefore be an important consideration when choosing treatment for patients who exhibit these characteristics. Experience from clinical trials suggests that drugs that target the renin-angiotensin system may have metabolic advantages over drugs such as beta-blockers and diuretics, but this conclusion has not been proved definitively. Moxonidine, which selectively targets imidazoline type-1 receptors in the sympathetic vasomotor centres of the rostral-ventrolateral medulla, is an effective antihypertensive and has been reported to exert favourable metabolic effects in preclinical and clinical studies. The MARRIAGE study (Moxonidine And Ramipril Regarding Insulin And Glucose Evaluation) will extend these preliminary observations by comparing the effects of moxonidine and the ACE inhibitor ramipril--and the combination of both drugs--on metabolic and haemodynamic parameters in patients with hypertension and impaired fasting glycaemia. A description is provided of the design and conduct of MARRIAGE.

  17. Effect of flow on corrosion in catenary risers and its corrosion inhibitor performance

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Pedro Altoe; Magalhaes, Alvaro Augusto Oliveira; Silva, Jussara de Mello [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil); Kang, Cheolho; More, Parimal P. [Det Norske Veritas (DNV), Oslo (Norway)

    2009-07-01

    In oil and gas production, multiphase flow is often encountered and a range of different flow patterns can be experienced in pipelines. The flow regime transition and flow characteristics can be changed with the change of pipeline topography, which affects the corrosion and the performance of corrosion inhibitor in these multiphase pipelines. This paper outlines on the effect of inclination on the flow characteristics and their subsequent effect on corrosion rates. Also, this paper presents on the performance of three candidate corrosion inhibitors under severe slugging conditions at low water cut. For the simulation of offshore flow lines and risers, the experiments were carried out in a 44 m long, 10 cm diameter, three different pipeline inclinations of 0, 3 and 45 degrees. Light condensate oil with a viscosity of 2.5 cP at room temperature was used and water cut was 20%. The results indicated that the baseline corrosion rate in 45 degrees showed higher than other inclinations. Each corrosion inhibitor showed a different inhibitor performance. (author)

  18. Investigation of Corrosion Inhibitors by Nuclear Quadrupole Resonance Relaxometry Method

    Directory of Open Access Journals (Sweden)

    Nikolay Sinyavsky

    2015-12-01

    Full Text Available The changes taking place with the corrosion-resistant coating, but not the state of the surface subjected to corrosion are investigated in this paper in contrast to traditional approaches. We used the method of nitrogen relaxometry NQR and multi-exponential inversion of decay of longitudinal and transverse components of the nuclear magnetization is applied for the first time for this purpose. The results of experimental studies of changes in the distributions of spin-spin and spin-lattice relaxation of crystallite powder of sodium nitrite and urotropin, the mixture of which is used as a corrosion inhibitor of ferrous metals are considered.

  19. Influence of Organic Inhibitor on Corrosion Resistance of Steel in Simulated Concrete Pore Solution

    OpenAIRE

    Cai, Jingshun S.; C. C. CHEN; Liu, J. Z.; Liu, J. P.

    2014-01-01

    Organic corrosion inhibitor is one of lower cost technologies that limit the deterioration of concrete structures. The influence of a newly prepared organic corrosion inhibitor on the corrosion behavior of carbon steel in simulated concrete pore solution was investigated by polarization curves, electrochemical impedance spectroscopy, and so on. The effect of organic corrosion inhibitors on concrete working performance was also studied. The results show that the corrosion rate decreases with t...

  20. Modelling on corrosion inhibitor kinetics in carbon steel pipe used in oil industry

    Science.gov (United States)

    Hasmi, A. N.; Nuraini, N.; Wahyuningrum, D.; Sumarti, N.; Bunjali, B.

    2014-02-01

    A model to explain the kinetics of corrosion inhibitor is proposed here. The model is based on Transition State Theory. Our model has many similarities with Michelis-Menten Kinetics. The kinetics difference between uninhibited corrosion and inhibited corrosion is presented. Our model showed the inhibitor could suppress the corrosion rate.

  1. Release of cerium dibutylphosphate corrosion inhibitors from highly filled epoxy coating systems

    NARCIS (Netherlands)

    Soestbergen, M. van; Baukh, V.; Erich, S.J.F.; Huinink, H.P.; Adan, O.C.G.

    2014-01-01

    Carcinogenic chromates are phased out as corrosion inhibitors in organic coatings, and are replaced by benign alternatives. Cerium-based compounds are excellent corrosion inhibitors in an aqueous environment. However, whether they are effective as corrosion inhibitor in an organic coating also depen

  2. Potassium sorbate-A new aqueous copper corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Abelev, Esta [Department of Materials Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Starosvetsky, David [Department of Materials Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Ein-Eli, Yair [Department of Materials Engineering, Technion-Israel Institute of Technology, Haifa 32000 (Israel)]. E-mail: eineli@tx.technion.ac.il

    2007-01-01

    This work presents the novel nature of 2,4-hexadienoic acid potassium salt (potassium sorbate (KCH{sub 3}CH=CHCH=CHCO{sub 2})) as an effective copper aqueous corrosion inhibitor. The influence of pH and potassium sorbate concentration on copper corrosion in aerated sulfate and chloride solutions is reported. Degree of copper protection was found to increase with an increase in potassium sorbate concentration; an optimum concentration of this inhibitor in sulfate solutions was found to be 10 g/L. Copper is highly resistant to corrosion attacks by chloride ions in the presence of potassium sorbate. X-ray photoelectron spectroscopy (XPS) studies suggest that copper protection is achieved via the formation of a mixed layer of cuprous oxide, cupric hydroxide and copper(II)-sorbate at the metal surface.

  3. Composite corrosion inhibitors for secondary alkaline zinc anodes

    Institute of Scientific and Technical Information of China (English)

    JIA Zheng; ZHOU De-rui; ZHANG Cui-fen

    2005-01-01

    The corrosion inhibition property of PEG600 and In(OH)3 as composite corrosion inhibitors for secondary alkaline zinc electrodes was studied,and the inhibition efficiency was determined as 81.9%.The research focused on the mechanism by the methods of electrochemical impedance spectroscopy,polarization curves and IR spectroscopy.The results indicate that the corrosion inhibition effectiveness is attributed to the joint inhibition of anodic zinc dissolution and cathodic hydrogen evolution.And the anodic process is depressed to a greater extent than the cathodic process.The synergistic mechanism of the composite inhinbitors proves to be the enhancement of adsorption of PEG600 by In(OH)3.Potentiostatic experiment results and SEM images verify the inhibition of dendritic growth by the composite inhibitors.

  4. Benzotriazole a Corrosion Inhibitor for Antiques: Some Practical Surface Chemistry.

    Science.gov (United States)

    Walker, Robert

    1980-01-01

    Describes the structure and inhibitive properties of Benzotriazole. The chemical may be employed as an inhibitor to reduce corrosion of articles during storage or display. It may be applied to copper and copper-based antiques as well as to silver and other metals. (Author/JN)

  5. Effervescent Cationic Film Forming Corrosion Inhibitor Material and Process.

    Science.gov (United States)

    1991-10-15

    1000 ppm in the volume of aliminum surface of a weapon in a launch tube on a seawater that floods the weapon tube. submarine with a corrosion inhibitor film, comprising: 20 * * * * * 25 30 35 40 45 50 55 a. 60 65

  6. Effectiveness of inhibitors in increasing chloride threshold value for steel corrosion

    OpenAIRE

    Jin-xia XU; Jiang, Lin-Hua; Wei-lun WANG; TANG, Li; Cui, Li

    2013-01-01

    This investigation was aimed at evaluating the effectiveness of corrosion inhibitors in increasing the chloride threshold value for steel corrosion. Three types of corrosion inhibitors, calcium nitrite (Ca(NO2)2), zinc oxide (ZnO), and N,N'-dimethylaminoethanol (DMEA), which respectively represented the anodic inhibitor, cathodic inhibitor, and mixed inhibitor, were chosen. The experiment was carried out in a saturated calcium hydroxide (Ca(OH)2) solution to simulate the electrolytic environm...

  7. Electrochemical Evaluation of Corrosion Inhibitors to Austenistic Stainless Steel

    Directory of Open Access Journals (Sweden)

    Yosmari Adames Montero

    2014-03-01

    Full Text Available The use of corrosion inhibitors is one of the most universal methods, and diffused for the protection ofmetals, because they reduce substantially the corrosion losses when they are added in smallconcentrations. At the present work it was carried out the electrochemical tests evaluation of twoinhibitors, A and B, to be used in the chemical cleanings for trays of heat interchanger, which aresuffering thickness losses until its perforation. By the chemical composition analysis, it wasdemonstrated that the metal is an austenistic stainless steel and by electrochemical tests of linearpolarization resistance, electrochemical noise and cyclic sweep, were demonstrated the localizedcorrosion. The best efficiency of the inhibitor A was obtained with one and two percent concentration,while the inhibitor B shows values efficiency near 95% with two percent concentration.

  8. Polypeptide Inhibitors of Mineral Scaling and Corrosion

    Science.gov (United States)

    1989-06-01

    peptides are based on natural protein inhibitors of mineral formation and generally are enriched in aspartic acid and phosphoserine. Specifically, the...the protein inhibitors of mineral formation , we evaluated several methods of preparation of phosphopeptides. These included direct polymerization of 2...number of assays have been developed to measure the ability of the peptides to inhibit mineral formation . These include methods for assessing effects on

  9. Prediction aluminum corrosion inhibitor efficiency using artificial neural network (ANN)

    Science.gov (United States)

    Ebrahimi, Sh; Kalhor, E. G.; Nabavi, S. R.; Alamiparvin, L.; Pogaku, R.

    2016-06-01

    In this study, activity of some Schiff bases as aluminum corrosion inhibitor was investigated using artificial neural network (ANN). Hence, corrosion inhibition efficiency of Schiff bases (in any type) were gathered from different references. Then these molecules were drawn and optimized in Hyperchem software. Molecular descriptors generating and descriptors selection were fulfilled by Dragon software and principal component analysis (PCA) method, respectively. These structural descriptors along with environmental descriptors (ambient temperature, time of exposure, pH and the concentration of inhibitor) were used as input variables. Furthermore, aluminum corrosion inhibition efficiency was used as output variable. Experimental data were split into three sets: training set (for model building) and test set (for model validation) and simulation (for general model). Modeling was performed by Multiple linear regression (MLR) methods and artificial neural network (ANN). The results obtained in linear models showed poor correlation between experimental and theoretical data. However nonlinear model presented satisfactory results. Higher correlation coefficient of ANN (R > 0.9) revealed that ANN can be successfully applied for prediction of aluminum corrosion inhibitor efficiency of Schiff bases in different environmental conditions.

  10. Analysis of the Influence of Organic Corrosion Inhibitors on Corrosion of Reinforcement in Concrete Bridge Structure Under Simulated Field Service Environment

    OpenAIRE

    Shi, Liang; Ye, J.; C. C. CHEN; Wu, Y; Liu, J. Z.

    2014-01-01

    For concrete bridge projects in marine environments, attention must be paid to the reinforcement corrosion problems caused by chloride intrusion. As kinds of functional admixtures, which can reduce the reinforcement corrosion rate, corrosion inhibitors are becoming very popular in China in new bridge projects. Corrosion inhibitors cover both inorganic and organic inhibitors. Nitrite is representative of inorganic corrosion inhibitors, but its carcinogenicity has hindered its further developme...

  11. pH Sensitive Microcapsules for Delivery of Corrosion Inhibitors

    Science.gov (United States)

    Li, Wenyan; Calle, Luz M.

    2006-01-01

    A considerable number of corrosion problems can be solved by coatings. However, even the best protective coatings can fail by allowing the slow diffusion of oxygen and moisture to the metal surface. Corrosion accelerates when a coating delaminates. Often, the problems start when microscopic nicks or pits on the surface develop during manufacturing or through wear and tear. This problem can be solved by the incorporation of a self-healing function into the coating. Several new concepts are currently under development to incorporate this function into a coating. Conductive polymers, nanoparticles, and microcapsules are used to release corrosion-inhibiting ions at a defect site. The objective of this investigation is to develop a smart coating for the early detection and inhibition of corrosion. The dual function of this new smart coating system is performed by pH-triggered release microcapsules. The microcapsules can be used to deliver healing agents to terminate the corrosion process at its early stage or as corrosion indicators by releasing dyes at the localized corrosion sites. The dyes can be color dyes or fluorescent dyes, with or without pH sensitivity. Microcapsules were formed through the interfacial polymerization process. The average size of the microcapsules can be adjusted from 1 to 100 micron by adjusting the emulsion formula and the microcapsule forming conditions. A typical microcapsule size is around 10 microns with a narrow size distribution. The pH sensitivity of the microcapsule can also be controlled by adjusting the emulsion formula and the polymerization reaction time. Both corrosion indicator (pH indicator) and corrosion inhibitor containing microcapsules were formed and incorporated into paint systems. Test panels of selected steels and aluminum alloys were painted using these paints. Testing of compatibility between the microcapsule system and different paint systems are in progress. Initial experiments with the microcapsule containing paint

  12. Behavior of aspartic acid as a corrosion inhibitor for steel

    Energy Technology Data Exchange (ETDEWEB)

    Kalota, D.J.; Silverman, D.C. (Monsanto Co., St. Louis, MO (United States))

    1994-02-01

    Corrosion inhibition of steel by aspartic acid (C[sub 4]H[sub 7]NO[sub 4]), an amino acid of low molecular weight, was found to depend strongly on pH. At a pH less than the ionization constant at [approximately]9.5 to 10 (measured at 25 C), C[sub 4]H[sub 7]NO[sub 4] appeared to accelerate corrosion. Above the pH, it acted as a corrosion inhibitor for steel. A specially constructed potential-pH diagram for iron (Fe) that incorporated C[sub 4]H[sub 7]NO[sub 4] showed the change in behavior was accompanied by the most stable thermodynamic state changing from an iron aspartate complex to iron oxide. Polymerized C[sub 4]H[sub 7]NO[sub 4] (polyaspartic acid) behaved in a similar manner. Some other amino acids of low molecular weight behaved similarly.

  13. Chromenopyridin derivatives as environmentally benign corrosion inhibitors for N80

    Directory of Open Access Journals (Sweden)

    K.R. Ansari

    2017-02-01

    Full Text Available This research work was to investigate the corrosion inhibition performance of two newly synthesized chromenopyridine derivatives namely 2,4-diamino-5-(phenylthio-5H-chromeno[2,3-b]pyridine-3-carbonitrile (PPC-1 and 2,4-diamino-5-phenoxy-5H-chromeno[2,3-b]pyridine-3-carbonitrile (PPC-2 as potential environmentally friendly corrosion inhibitors for N80 steel in 15% hydrochloric acid (HCl. Various techniques like gravimetric, electrochemical impedance spectroscopy (EIS, Tafel polarizations, scanning electron microscope (SEM and atomic force microscopy (AFM have been used. The inhibition efficiencies given by PPC-1 and PPC-2 at 200 mg L−1 are 92.4% and 82.1% respectively. Tafel polarization revealed that both inhibitors are cathodic in nature. Langmuir adsorption isotherm was found to be the best fit. The experimental result was further supported by quantum chemical study.

  14. Green chemistry applied to corrosion and scale inhibitors

    Energy Technology Data Exchange (ETDEWEB)

    Darling, D.; Rakshpal, R. [Environmental Protection Agency, Washington, DC (United States)

    1998-12-31

    Numerous breakthroughs in environmental protection and pollution prevention have been realized in recent years by both industry and academia through the application of green chemistry principles. Green chemistry, or pollution prevention at the molecular level, is chemistry designed to reduce or eliminate the use or generation of hazardous materials associated with the manufacture and application of chemicals. The application of the green chemistry principles to the areas of corrosion and scale inhibitors has resulted in the reduction/elimination of many of the more toxic inhibitors and the development of newer, more environmentally friendly ones.

  15. Clays valorization as corrosion inhibitors for E400 reinforcing steel

    Directory of Open Access Journals (Sweden)

    Gassama Diadioly

    2016-06-01

    Full Text Available The behavior of E400 steel, a constructional steel widely used in Senegal, was studied in aqueous NaCl solution in the presence of two types of clay: volcanic tuffs, and sedimentary montmorillonite. The protection efficiency of these compounds were electrochemically assessed (corrosion potential variation curves, polarization curves and electrochemical impedance spectroscopy at various inhibitor contents. The results obtained showed that these inhibitors present an inhibitory efficacy of about 70% for an optimal concentration of 0.60% for the tuffs and 62% for a maximum content of 0.50% for montmorillonite.

  16. Azorhodanine derivatives as inhibitors for acidic corrosion of nickel.

    Science.gov (United States)

    Fouda, Abd El-Aziz S; Al-Sarawy, Ahmed A; Omar, Tark M

    2005-01-01

    Azorhodanine derivatives (HL1-HL5) were tested as corrosion inhibitors for nickel in 2M HNO3 solution using weight loss and galvanostatic polarization techniques. The results showed that these derivatives act as inhibitors for nickel in this medium. The inhibition was assumed to occur via adsorption of the inhibitor molecule on the metal surface. Polarization measurements indicated that these compounds act as mixed-type inhibitors, but the cathode is more polarized when an external current was applied. This means that these compounds retard the rate of hydrogen evolution and the rate of dissolution of the metal. Results showed that azorhodanine derivatives are adsorbed on the nickel surface following Temkin's adsorption isotherm. The activation energy and thermodynamic parameters were calculated and discussed at different temperatures (30-45 degrees C).

  17. Effectiveness of inhibitors in increasing chloride threshold value for steel corrosion

    Directory of Open Access Journals (Sweden)

    Jin-xia XU

    2013-07-01

    Full Text Available This investigation was aimed at evaluating the effectiveness of corrosion inhibitors in increasing the chloride threshold value for steel corrosion. Three types of corrosion inhibitors, calcium nitrite (Ca(NO22, zinc oxide (ZnO, and N,N'-dimethylaminoethanol (DMEA, which respectively represented the anodic inhibitor, cathodic inhibitor, and mixed inhibitor, were chosen. The experiment was carried out in a saturated calcium hydroxide (Ca(OH2 solution to simulate the electrolytic environment of concrete. The inhibitors were initially mixed at different levels, and then chloride ions were gradually added into the solution in several steps. The open-circuit potential (Ecorr and corrosion current density (Icorr determined by electrochemical impedance spectra (EIS were used to identify the initiation of active corrosion, thereby determining the chloride threshold value. It was found that although all the inhibitors were effective in decreasing the corrosion rate of steel reinforcement, they had a marginal effect on increasing the chloride threshold value.

  18. Characterization of the corrosion products formed on mild steel in acidic medium with N-octadecylpyridinium bromide as corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Nava, N., E-mail: tnava@imp.mx; Likhanova, N. V. [Direccion de Investigacion y Posgrado, Instituto Mexicano del Petroleo (Mexico); Olivares-Xometl, O. [Benemerita Universidad Autonoma de Puebla, Facultad de Ingenieria Quimica (Mexico); Flores, E. A. [Direccion de Investigacion y Posgrado, Instituto Mexicano del Petroleo (Mexico); Lijanova, I. V. [CIITEC, Instituto Politecnico Nacional (Mexico)

    2011-11-15

    The characterization of the corrosion products formed on mild steel SAE 1018 after 2 months exposure in aqueous sulfuric acid with and without corrosion inhibitor N-octadecylpyridinium bromide has been carried out by means of transmission {sup 57}Fe Moessbauer spectroscopy and X-ray powder diffraction (XRD). The major constituent of the rust formed in this environment without corrosion inhibitor is goethite ({alpha}-FeOOH). The samples with N-octadecylpyridinium bromide contain rozenite and large amounts of melanterite in the corrosion layers.

  19. Synergic Mechanism of an Organic Corrosion Inhibitor for Preventing Carbon Steel Corrosion in Chloride Solution

    Institute of Scientific and Technical Information of China (English)

    LIU Zhiyong; YU Lei; LI Qingzhong

    2015-01-01

    The inhibition effect of dimethylethanolamine (DMEA) and its composite with carboxylic acid was studied with the electrochemical tests. The experimental results indicate that DMEA is not a good inhibitor but the composite of DMEA with caprylic acid exhibits excellent inhibiting efficiency. The synergic mechanism of the organic corrosion inhibitors (OCIs) was studied with quantum chemical calculations. It is found that the DMEA forms a quaternary ammonium salt with the proton in carboxylic acid, and a cyclic complex formed between the salt and Fe may be responsible for the enhancement of inhibiting efficiency. The possible hydrogen bond formed between DMEA and carboxylic acid is not enough for the inhibiting effect. This work is helpful to proposing theoretical interpretation as well as developing a functional organic inhibitor to improve the durability of reinforced concrete contaminated with chloride.

  20. Characterization of Encapsulated Corrosion Inhibitors Containing Microparticles for Environmentally Friendly Smart Coatings

    Science.gov (United States)

    Pearman, Benjamin Pieter; Calle, Luz M.

    2015-01-01

    This poster presents the results obtained from experiments designed to evaluate the release properties, as well as the corrosion inhibition effectiveness, of several encapsulated corrosion inhibitors. Microencapsulation has been used in the development of environmentally friendly multifunctional smart coatings. This technique enables the incorporation of autonomous corrosion detection, inhibition and self-healing functionalities into many commercially available coating systems. Select environmentally friendly corrosion inhibitors were encapsulated in organic and inorganic pH-sensitive microparticles and their release in basic solutions was studied. The release rate results showed that the encapsulation can be tailored from fast, for immediate corrosion protection, to slow, which will provide continued long-term corrosion protection. The incorporation of several corrosion inhibitor release profiles into a coating provides effective corrosion protection properties. To investigate the corrosion inhibition efficiency of the encapsulated inhibitors, electrochemical techniques were used to obtain corrosion potential, polarization curve and polarization resistance data. These measurements were performed using the free as well as the encapsulated inhibitors singly or in combinations. Results from these electrochemical tests will be compared to those obtained from weight loss and other accelerated corrosion experiments.

  1. Benzotriazole as an inhibitor of brass corrosion in chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    Kosec, Tadeja [Jozef Stefan Institute, Department of Physical and Organic Chemistry, Jamova 39, 1000 Ljubljana (Slovenia); Milosev, Ingrid [Jozef Stefan Institute, Department of Physical and Organic Chemistry, Jamova 39, 1000 Ljubljana (Slovenia); Orthopaedic Hospital Valdoltra, Jadranska c. 31, 6280 Ankaran (Slovenia)], E-mail: ingrid.milosev@ijs.si; Pihlar, Boris [Faculty of Chemistry and Chemical Technology, University of Ljubljana, Askerceva 5, 1000 Ljubljana (Slovenia)

    2007-09-15

    The current research explores the formation of protective layers on copper, zinc and copper-zinc (Cu-10Zn and Cu-40Zn) alloys in chloride solution containing benzotriazole (BTAH), by use of electrochemical techniques, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Electrochemical reactions and surface products formed at the open circuit potential and as a function of the potential range are discussed. The addition of benzotriazole to aerated, near neutral 0.5 M NaCl solution affects the dissolution of copper, zinc, Cu-10Zn and Cu-40Zn alloys. The research also compares the inhibition efficiency and Gibbs adsorption energies of the investigated process. Benzotriazole, generally known as an inhibitor of copper corrosion is also shown to be an efficient inhibitor for copper-zinc alloys and zinc metal. The surface layer formed on alloys in BTAH-inhibited solution comprised both oxide and polymer components, namely Cu{sub 2}O and ZnO oxides, and Cu(I)-BTA and Zn(II)-BTA polymers. The formation of this mixed copper-zinc oxide polymer surface film provides an effective barrier against corrosion of both metal components in chloride solution.

  2. Effect of Incorporation of Inhibitor Loaded Mesoporous Silica on the Corrosion Behavior of Epoxy Coatings

    Directory of Open Access Journals (Sweden)

    Mahdi Yeganeh

    2013-12-01

    Full Text Available In this research, mesoporous silica was applied as the host of corrosion inhibitor (molybdate. The loaded mesoporous silica was dispersed in an epoxy matrix. The composite was then coated on the mild steel plate. Results showed that the corrosion resistance of the scratched epoxy/mesoporous silica loaded by molybdate was better than the one without molybdate or neat epoxy. On the other hand, EDX and FTIR studies showed the release of corrosion inhibitor in the scratched zone. It was due to pH-sensitive release of corrosion inhibitor in the aggressive media. Also, XRD data showed the presence of Mo compounds on the surface of steel.

  3. Improvement of the linear polarization resistance method for testing steel corrosion inhibitors

    Science.gov (United States)

    Faritov, A. T.; Rozhdestvenskii, Yu. G.; Yamshchikova, S. A.; Minnikhanova, E. R.; Tyusenkov, A. S.

    2016-11-01

    The linear polarization resistance method is used to improve the technique of corrosion control in liquid conducting according to GOST 9.514-99 (General Corrosion and Aging Protection System. Corrosion Inhibitors for Metals in Water Systems. Electrochemical Method of Determining the Protective Ability). Corrosion monitoring is shown to be performed by electronic devices with real-time data transfer to industrial controllers and SCADA systems.

  4. Testing Corrosion Inhibitors for the Conservation of Archaeological Copper and Copper Alloys

    Directory of Open Access Journals (Sweden)

    Robert B. Faltermeier

    1997-11-01

    Full Text Available This is a synopsis of the Ph.D. research undertaken at the Institute of Archaeology, University College London. The aim was to evaluate corrosion inhibitors for use in the conservation of copper and copper alloy archaeological artefacts. The objective of this work was to acquire an insight into the performance of copper corrosion inhibitors, when applied to archaeological copper.

  5. Performance of organic and inorganic substances as inhibitors for chloride-induced corrosion in concrete

    Energy Technology Data Exchange (ETDEWEB)

    Aydin, Oezlem [Gedik University Vocational High School, Istanbul (Turkey); Cizmeciglu, Zeki [Istanbul Commerce University, Istanbul (Turkey)

    2015-02-01

    Studies have been carried out to investigate the concrete corrosion inhibitor performance of silica fume admixture and an admixture of amino alcohols containing organic and inorganic substances. The concrete specimens with and without admixtures were subjected to accelerated corrosion tests to determine the time to corrosion initiation. The results showed that the specimens admixtured with nitrogen containing organic and inorganic inhibitors performed slightly better than concrete specimens with silica fume admixture.

  6. Green Inhibitors for Corrosion Protection of Metals and Alloys: An Overview

    Directory of Open Access Journals (Sweden)

    B. E. Amitha Rani

    2012-01-01

    Full Text Available Corrosion control of metals is of technical, economical, environmental, and aesthetical importance. The use of inhibitors is one of the best options of protecting metals and alloys against corrosion. The environmental toxicity of organic corrosion inhibitors has prompted the search for green corrosion inhibitors as they are biodegradable, do not contain heavy metals or other toxic compounds. As in addition to being environmentally friendly and ecologically acceptable, plant products are inexpensive, readily available and renewable. Investigations of corrosion inhibiting abilities of tannins, alkaloids, organic,amino acids, and organic dyes of plant origin are of interest. In recent years, sol-gel coatings doped with inhibitors show real promise. Although substantial research has been devoted to corrosion inhibition by plant extracts, reports on the detailed mechanisms of the adsorption process and identification of the active ingredient are still scarce. Development of computational modeling backed by wet experimental results would help to fill this void and help understand the mechanism of inhibitor action, their adsorption patterns, the inhibitor-metal surface interface and aid the development of designer inhibitors with an understanding of the time required for the release of self-healing inhibitors. The present paper consciously restricts itself mainly to plant materials as green corrosion inhibitors.

  7. Release Properties and Electrochemical Characterization of Encapsulated Corrosion Inhibitors for Environmentally Friendly Smart Coatings

    Science.gov (United States)

    Pearman, B. P.; Calle, L. M.; Zhang, X.; Li, W.; Buhrow, J. W.; Johnsey, M. N.; Montgomery, E. L.; Fitzpatrick, L.; Surma, J. M.

    2015-01-01

    The NASA Kennedy Space Center's Corrosion Technology Lab at the Kennedy Space Center in Florida, U.S.A. has been developing multifunctional smart coatings based on the microencapsulation of environmentally friendly corrosion indicators, inhibitors and self-healing agents. This allows for the incorporation of autonomous corrosion control functionalities, such as corrosion detection and inhibition as well as the self-healing of mechanical damage, into coatings. This paper presents technical details on the characterization of inhibitor-containing particles and their corrosion inhibitive effects using electrochemical and mass loss methods. Three organic environmentally friendly corrosion inhibitors were encapsulated in organic microparticles that are compatible with desired coatings. The total inhibitor content and the release of one of the inhibitors from the microparticles in basic solution was measured. Particles with inhibitor contents of up 60 wt% were synthesized. Fast release, for immediate corrosion protection, as well as long-term release for continued protection, was observed. The inhibition efficacy of the inhibitors, both as the pure materials and in microparticles, on carbon steel was evaluated. Polarization curves and mass loss measurements showed that, in the case of 2MBT, its corrosion inhibition effectiveness was greater when it was delivered from microparticles.

  8. Corrosion inhibitors: Correlation between chemical structure and efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Lukovits, I.; Koszto, T. [Hungarian Academy of Sciences (Hungary). Inst. of Chemistry

    1999-11-01

    Corrosion inhibition efficiencies of heterocyclic aromatic or partially saturated aromatic compounds (pyrimidines, benzothiazole derivatives, amino-acids containing an aromatic part, pyridines and quinolines) were correlated with quan chemical indices of the respective molecules. Inhibition efficiencies measured in acidic solutions containing 0.001 and 0.01 mol/L of the inhibitor, respectively, were collected. The quantum chemical calculations were done by using the simple Hueckel method. Comparison of inhibition efficiencies and the differences between energies of the highest occupied and the lowest unoccupied molecular orbitals {Delta} indicated that if {Delta} is lower than 1.3 (in beta units) then the compound will not be active, whereas if {Delta} > 1.3 beta, the compound may be efficient in 0.001 mole/L concentration. The critical value of {Delta} may be lower in solution with 0.01 mole/L inhibitor concentration. Although {Delta} alone is not sufficient to account for the variation in the experimental inhibition efficiencies, the present result indicates that compounds which may be easily excited will be inefficient inhibitors because they maybe altered or decomposed after the excitation takes place.

  9. Electrochemical and analytical characterization of three corrosion inhibitors of steel in simulated concrete pore solutions

    Science.gov (United States)

    Shi, Jin-Jie; Sun, Wei

    2012-01-01

    Corrosion inhibitors for steel, such as sodium phosphate (Na3PO4), sodium nitrite (NaNO2), and benzotriazole (BTA), in simulated concrete pore solutions (saturated Ca(OH)2) were investigated. Corrosion behaviors of steel in different solutions were studied by means of corrosion potential ( E corr), linear polarization resistance (LPR), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP). A field emission scanning electron microscope (FESEM) equipped with energy dispersive X-ray analysis (EDXA) was used for observing the microstructures and morphology of corrosion products of steel. The results indicate that, compared with the commonly used nitrite-based inhibitors, Na3PO4 is not a good inhibitor, while BTA may be a potentially effective inhibitor to prevent steel from corrosion in simulated concrete pore solutions.

  10. Corrosion inhibitors in concrete. Part II: Effect on chloride threshold values for corrosion of steel in synthetic pore solutions

    Energy Technology Data Exchange (ETDEWEB)

    Mammoliti, L.; Hansson, C.M.; Hope, B.B.

    1999-10-01

    The effectiveness of four commercially available corrosion inhibitors for use in cement-based materials was assessed in synthetic concrete pore solution containing chlorides. The effect of the surface topography of the sample and the composition of the pore solution was also assessed. Although in a parallel study the inhibitors were observed to delay the onset of corrosion, in these tests in pore solution they were found to be ineffective in increasing the chloride threshold value of reinforcing steel exposed to chlorides and had little influence on the progression of corrosion once initiated. This suggests that chemical reactions within the cement phase are responsible for the observed results. Metallographically polished samples proved the most resistant to corrosion regardless of electrolyte composition and samples with all surface finishes exhibited lower resistance in solutions containing only calcium hydroxide than in the higher pH synthetic concrete pore solutions.

  11. Study of Plant Cordia Dichotoma as Green Corrosion Inhibitor for Mild Steel in Different Acid Media

    Directory of Open Access Journals (Sweden)

    R. Khandelwal

    2011-01-01

    Full Text Available The corrosion inhibition of mild steel using extracts of Cordia dichotoma in different acid media was investigated by mass loss and thermometric methods. The experiments were carried out at 299±0.2 K in presence of different concentrations of dry fruit, leaves and stem extracts of Cordia dichotoma. The results reveal that the alcoholic extracts of Cordia dichotoma is a better corrosion inhibitor than that of toxic chemicals. The fruit extract is more potent than leaves and stem extracts to inhibit the corrosion rate. The study seeks to investigate the possibility of using extracts of Cordia dichotoma as a green corrosion inhibitor for mild steel.

  12. The effect of corrosion inhibitors on microbial communities associated with corrosion in a model flow cell system.

    Science.gov (United States)

    Duncan, Kathleen E; Perez-Ibarra, Beatriz Monica; Jenneman, Gary; Harris, Jennifer Busch; Webb, Robert; Sublette, Kerry

    2014-01-01

    A model flow cell system was designed to investigate pitting corrosion in pipelines associated with microbial communities. A microbial inoculum producing copious amounts of H₂S was enriched from an oil pipeline biofilm sample. Reservoirs containing a nutrient solution and the microbial inoculum were pumped continuously through six flow cells containing mild steel corrosion coupons. Two cells received corrosion inhibitor "A", two received corrosion inhibitor "B", and two ("untreated") received no additional chemicals. Coupons were removed after 1 month and analyzed for corrosion profiles and biofilm microbial communities. Coupons from replicate cells showed a high degree of similarity in pitting parameters and in microbial community profiles, as determined by 16S rRNA gene sequence libraries but differed with treatment regimen, suggesting that the corrosion inhibitors differentially affected microbial species. Viable microbial biomass values were more than 10-fold higher for coupons from flow cells treated with corrosion inhibitors than for coupons from untreated flow cells. The total number of pits >10 mils diameter and maximum pitting rate were significantly correlated with each other and the total number of pits with the estimated abundance of sequences classified as Desulfomicrobium. The maximum pitting rate was significantly correlated with the sum of the estimated abundance of Desulfomicrobium plus Clostridiales, and with the sum of the estimated abundance of Desulfomicrobium plus Betaproteobacteria. The lack of significant correlation with the estimated abundance of Deltaproteobacteria suggests not all Deltaproteobacteria species contribute equally to microbiologically influenced corrosion (MIC) and that it is not sufficient to target one bacterial group when monitoring for MIC.

  13. Adsorption and performance of the 2-mercaptobenzimidazole as a carbon steel corrosion inhibitor in EDTA solutions

    Energy Technology Data Exchange (ETDEWEB)

    Calderón, J.A., E-mail: andres.calderon@udea.edu.co [Centro de Investigación, Innovación y Desarrollo de Materiales –CIDEMAT, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Vásquez, F.A. [Centro de Investigación, Innovación y Desarrollo de Materiales –CIDEMAT, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Carreño, J.A. [Laboratório de H2S, CO2 e Corrosividade, Instituto Nacional De Tecnologia (INT), Av. Venezuela, 82 – Térreo, Anexo 01, Sala 101A, Saúde, Rio de Janeiro, RJ (Brazil)

    2017-01-01

    This study presents a thermodynamic analysis of the adsorption and anti-corrosion performance of 2-mercaptobenzimidazole (2-MBI) on carbon steel in EDTA-Na2 solutions. The adsorption of the inhibitor on the metal surface was studied as a function of the concentration of the inhibiting species and the temperature of the system. The corrosion inhibition efficiency was studied by electrochemical impedance spectroscopy and mass loss tests. The results show that the adsorption of the inhibitor onto the metal surface behaves according to the Langmuir model, following an endothermic process. The inhibitor is chemically adsorbed onto the carbon steel surface. The efficiency of corrosion inhibition was above 93%, which was confirmed by both mass loss tests and the electrochemical impedance technique. The good performance of the corrosion inhibitor was maintained up to 24 h after the inhibitor was added to the corrosive EDTA-Na2 solutions. When the ratio of the volume of solution/exposed area was reduced, a decrease in the area covered by the inhibitor was observed. The best cost/benefit ratio for the corrosion protection of carbon steel was obtained when the number of moles of the inhibitor per surface area was maintained at 2.68 mmol cm{sup −2}. - Highlights: • Adsorption of the inhibitor on the metal surface is confirmed by thermodynamic data. • Adsorption of the inhibitor onto the metal behaves according to the Langmuir model. • Endothermic adsorption process indicates that the inhibitor is chemically adsorbed. • The efficiency of corrosion inhibition was above 93%. • The good performance of the corrosion inhibitor was maintained up to 24 h.

  14. An electrochemical and microstructural characterization of steel-mortar admixed with corrosion inhibitors

    Institute of Scientific and Technical Information of China (English)

    Tuan; Anh; Nguyen; Recep; AVCI

    2009-01-01

    The present research brings new insights on the role of admixed corrosion inhibitors in the processes of cement hydration and rebar corrosion. The admixing of NaCl and the corrosion inhibitors in fresh mortar was found to alter the morphology and microstructure of the hardened mortar at the steel-mortar interfacial region. The admixing of the inhibitors increased the risk of carbonation of cement hydrates at the steel-mortar interfacial region, but partially displaced chloride ions. Chloride and the admixed inhibitors facilitated the formation of different cement hydrates and affected chloride binding at the steel-mortar interfacial region. The admixing of all three inhibitors was found to increase the polarization resistance of steel, indicating reduced corrosion rate of the steel over 48-day exposures to salt ponding.

  15. An electrochemical and microstructural characterization of steel-mortar admixed with corrosion inhibitors

    Institute of Scientific and Technical Information of China (English)

    SHI XianMing; YANG ZhengXian; Tuan Anh Nguyen; SUO ZhiYong; Recep AVCI; SONG ShiZhe

    2009-01-01

    The present research brings new insights on the role of admixed corrosion inhibitors in the processes of cement hydration and rebar corrosion. The admixing of NaCI and the corrosion inhibitors in fresh mortar was found to alter the morphology and microstructure of the hardened mortar at the steel-mor-tar interfacial region. The admixing of the inhibitors increased the risk of carbonation of cement hy-drates at the steel-mortar interracial region, but partially displaced chloride ions. Chloride and the ad-mixed inhibitors facilitated the formation of different cement hydrates and affected chloride binding at the steel-mortar interfacial region. The admixing of all three inhibitors was found to increase the po-larization resistance of steel, indicating reduced corrosion rate of the steel over 48-day exposures to salt ponding.

  16. Laboratory and field tests of corrosion inhibitors for an offshore application

    Energy Technology Data Exchange (ETDEWEB)

    Skjerve, Sofie; Fuhr, Geir Gundersen; Haldogaard, Geir

    2006-03-15

    Statoil started a R and D-project in 2002 where the goal was to implement environmental friendly corrosion control at a Statoil operated oil producing field. In this project the following tasks have been addressed: 1) Reduction of the chemical consumption. 2) Documentation of the discharge level of the corrosion inhibitor. 3) Documentation of the environmental impact. 4) Development of new environmentally friendly acceptable corrosion inhibitors. 5) Laboratory and field testing of new corrosion inhibitors. This paper describes laboratory and field tests of corrosion inhibitors for this project. The field tests were carried out on an offshore oil producing installation in the North Sea. Five corrosion inhibitor suppliers with totally eleven products were taking part in this test. All the products were tested in the laboratory. The four most promising products from the laboratory tests were tested in the field during a fourteen days offshore test. Only one of the tested products gave satisfactory results from the corrosion field test. Corrosion measurements were performed both with a Zero Resistance Ammetry (ZRA) probe installed directly into a flow line and with two side streams units. One side stream unit was connected upstream the test separator and the other unit was connected downstream the test separator. (author) (tk)

  17. New corrosion inhibitor acrylamide methyl ether for mild steel in 1 M HCl

    Science.gov (United States)

    Ma, Xinyu; Jiang, Xiaohui; Xia, Shuwei; Shan, Mingli; Li, Xia; Yu, Liangmin; Tang, Qunwei

    2016-05-01

    Pursuit of good inhibition performance has been a persistent objective for advanced inhibitor industry. Here we demonstrate the experimental realization of a new corrosion inhibitor acrylamide methyl ether (AAME) from N-Methylol acrylamide (N-MAM) for mild steel in 1 M HCl. The resultant adsorption films have inhibition efficiency as high as 96.2%. Moreover, a theoretical investigation is also launched to demonstrate the potential mechanism behind the promising corrosion behaviors. This work represents a significant step forward, as it demonstrates how to make scalable AAME inhibitors as well as to enhance inhibition performances for high-efficiency and cost-effective corrosion inhibition platforms.

  18. Low Toxicity Corrosion Inhibitors for Smart Coatings Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Kennedy Space Center (KSC) is located near one of the most corrosive natural environments in the world. Corrosion of KSC ground assets is exacerbated by the...

  19. Development of Ecofriendly Corrosion Inhibitors for Application in Acidization of Petroleum Oil Well

    Directory of Open Access Journals (Sweden)

    M. Yadav

    2013-01-01

    Full Text Available In the present investigation the protective ability of 1-(2-aminoethyl-2-octadecylimidazoline (AEODI and 1-(2-octadecylamidoethyl-2-octadecylimidazoline (ODAEODI as corrosion inhibitors for N80 steel in 15% hydrochloric acid has been studied, which may find application as ecofriendly corrosion inhibitors in acidizing processes in petroleum industry. Different concentration of synthesized inhibitors AEODI and ODAEODI was added to test solution (15% HCl, and corrosion inhibition of N80 steel was tested by weight loss, potentiodynamic polarization, and AC impedance measurements. Influence of temperature (298 to 323 K on the inhibition behaviour was studied. Surface studies were performed by using SEM. It was found that both the inhibitors were effective inhibitors, and their inhibition efficiency was significantly increased with increasing their concentration. Polarization curves revealed that the used inhibitors represent mixed-type inhibitors. The adsorption of used inhibitors led to a reduction in the double-layer capacitance and an increase in the charge transfer resistance. The adsorption of used compounds was found to obey Langmuir isotherm. The adsorption of the corrosion inhibitors at the surface of N80 steel is the root cause of corrosion inhibition.

  20. What determines the inhibition effectiveness of ATA, BTAH, and BTAOH corrosion inhibitors on copper?

    Science.gov (United States)

    Kokalj, Anton; Peljhan, Sebastijan; Finsgar, Matjaz; Milosev, Ingrid

    2010-11-24

    Three corrosion inhibitors for copper-3-amino-1,2,4-triazole (ATA), benzotriazole (BTAH), and 1-hydroxybenzotriazole (BTAOH)-were investigated by corrosion experiments and atomistic computer simulations. The trend of corrosion inhibition effectiveness of the three inhibitors on copper in near-neutral chloride solution is determined experimentally as BTAH ≳ ATA ≫ BTAOH. A careful analysis of the results of computer simulations based on density functional theory allowed to pinpoint the superior inhibiting action of BTAH and ATA as a result of their ability to form strong N-Cu chemical bonds in deprotonated form. While these bonds are not as strong as the Cl-Cu bonds, the presence of solvent favors the adsorption of inhibitor molecules onto the surface due to stronger solvation of the Cl(-) anions. Moreover, benzotriazole displays the largest affinity among the three inhibitors to form intermolecular aggregates, such as [BTA-Cu](n) polymeric complex. This is another factor contributing to the stability of the protective inhibitor film on the surface, thus making benzotriazole an outstanding corrosion inhibitor for copper. These findings cannot be anticipated on the basis of inhibitors' molecular electronic properties alone, thus emphasizing the importance of a rigorous modeling of the interactions between the components of the corrosion system in corrosion inhibition studies.

  1. Introduction of Lubricants Corrosive Inhibitors in Brief%润滑油腐蚀抑制剂简介

    Institute of Scientific and Technical Information of China (English)

    朱建军; 王立

    2015-01-01

    It was outlined the cause of metals corrosion and the mechanism of lubricants corrosive inhibitors. Several commonly used corrosive inhibitors were introduced.%简述了金属腐蚀的原因和润滑油腐蚀抑制剂的作用机理。介绍了几种常用的腐蚀抑制剂。

  2. Tannin bark Melalauca cajuputi powell (gelam) as green corrosion inhibitor of mild steel

    Science.gov (United States)

    Talib, Nur Atiqah Abu; Zakaria, Sarani; Hua, Chia Chin; Othman, Norinsan Kamil

    2014-09-01

    Tannin was extracted from gelam bark and used to produce corrosion inhibitor for mild steel. Tannin was extracted from gelam bark using 70% aqueous acetone for 6 hour. Tannin powder was characterization using fourier transform infrared spectroscopy to analyse chemical component in tannin and Scanning electron microscope (SEM) for tannin physical structure. The tannin effect on the corrosion inhibition of mild steel has been investigated in 1Mol HCl solution for 6 hour followed ASTM. The weight loss method were applied to study the mild steel corrosion behavior in the present and absend of different concentration of tannin (250, 300, 350)ppm. Tannin act good inhibitor as corrosion inhibitor for mild steel in acid medium. Surface morphology of carbon steel with and without inhibitor was investigated by scanning electron microscopy.

  3. Tannin bark Melalauca cajuputi powell (gelam) as green corrosion inhibitor of mild steel

    Energy Technology Data Exchange (ETDEWEB)

    Talib, Nur Atiqah Abu; Zakaria, Sarani; Hua, Chia Chin; Othman, Norinsan Kamil [School of Applied Physic, Faculty Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2014-09-03

    Tannin was extracted from gelam bark and used to produce corrosion inhibitor for mild steel. Tannin was extracted from gelam bark using 70% aqueous acetone for 6 hour. Tannin powder was characterization using fourier transform infrared spectroscopy to analyse chemical component in tannin and Scanning electron microscope (SEM) for tannin physical structure. The tannin effect on the corrosion inhibition of mild steel has been investigated in 1Mol HCl solution for 6 hour followed ASTM. The weight loss method were applied to study the mild steel corrosion behavior in the present and absend of different concentration of tannin (250, 300, 350)ppm. Tannin act good inhibitor as corrosion inhibitor for mild steel in acid medium. Surface morphology of carbon steel with and without inhibitor was investigated by scanning electron microscopy.

  4. Estimating the gas permeability of commercial volatile corrosion inhibitors at elevated temperatures with thermo-gravimetry

    CSIR Research Space (South Africa)

    Pieterse, N

    2006-08-01

    Full Text Available permeability of commercial volatile corrosion inhibitors at elevated temperatures with thermo-gravimetry Niel Pieterse a, Walter W. Focke a,*, Eino Vuorinen b, Ilona Racz c a Department of Chemical Engineering, Institute of Applied Materials, University...

  5. Protection of bronze artefacts through polymeric coatings based on nanocarriers filled with corrosion inhibitors

    Science.gov (United States)

    de Luna, Martina Salzano; Buonocore, Giovanna; Di Carlo, Gabriella; Giuliani, Chiara; Ingo, Gabriel M.; Lavorgna, Marino

    2016-05-01

    Protective coatings based on polymers synthesized from renewable sources (chitosan or an amorphous vinyl alcohol based polymer) have been prepared for the protection of bronze artifacts from corrosion. Besides acting as an effective barrier against corrosive species present in the environment, the efficiency of the coatings has been improved by adding corrosion inhibitor compounds (benzotriazole or mercaptobenzothiazole) to the formulations. The liquid medium of the formulations has been carefully selected looking at maximizing the wettability on the bronze substrate and optimizing the solvent evaporation rate. The minimum amount of inhibitor compounds has been optimized by performing accelerated corrosion tests on coated bronze substrates. The inhibitors have been directly dissolved in the coating-forming solutions and/or introduced by means of nanocarriers, which allow to control the release kinetics. The free dissolved inhibitor molecules immediately provide a sufficient protection against corrosion. On the other hand, the inhibitor molecules contained in the nanocarriers serve as long-term reservoir, which can be activated by external corrosion-related stimuli in case of particularly severe conditions. Particular attention has been paid to other features which affect the coating performances. Specifically, the adhesion of the protective polymer layer to the bronze substrate has been assessed, as well as its permeability properties and transparency, the latter being a fundamental feature of protective coating for cultural heritages. Finally, the protective efficiency of the produced smart coatings has been assessed through accelerated corrosion tests.

  6. Layered double hydroxides as containers of inhibitors in organic coatings for corrosion protection of carbon steel

    OpenAIRE

    Hang, To Thi Xuan; Truc, Trinh Anh; Duong, Nguyen Thuy; Pébère, Nadine; Olivier, Marie-Georges

    2012-01-01

    International audience; The present work focuses on the use of layered double hydroxides (LDH) as containers for corrosion inhibitors in an epoxy coating. 2-Benzothiazolylthio-succinic acid (BTSA), used as corrosion inhibitor, was intercalated by co-precipitation in magnesium-aluminum layered double hydroxides. The obtained LDH-BTSA was characterized by infrared spectroscopy, X-ray diffraction and scanning electron microscopy. BTSA release from LDH-BTSA in NaCl solutions was investigated by U...

  7. Vapour phase corrosion inhibitors from South African renewable resources and their evaluation

    CSIR Research Space (South Africa)

    Vuorinen, E

    2006-02-01

    Full Text Available ) in an environment depends on the vapour pressure of the compounds. Suitable chemicals from the petroleum industry are used as corrosion inhibitors but often chemicals from renewable resources have been overlooked. Furfural is produced from bagasse (a by... of amines proved to be excellent VCIs for mild steel. Screening of potential VCIs from furfural and furfural derivatives will be done using thermogravimetry. Vapour Phase Corrosion Inhibitors from South African Renewable Resources and their Evaluation...

  8. Development of effective combined kinetic hydrate inhibitor/corrosion inhibitor (KHI/CI) products

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Len. W.; Anderson, Joh.

    2006-03-15

    Low Dosage Hydrate Inhibitors (LDHIs) are gaining worldwide acceptance as a viable alternative to the more conventional methods of hydrate flow assurance control. Use of this LDHI technology in combination with Corrosion Inhibitors (CI) in production systems such as sub sea developments enables operating companies to further significantly reduce capital costs. CI can have a significant impact of the efficacy of Kinetic Hydrate Inhibitors (KHI). This paper will review the experience of developing combined KHI and CI products (KHI/CI) with the aim of producing effective products whilst also incorporating the goal of the use of more environmentally friendly CI. Relevant KHI/CI product case histories will be considered. The development of KHI to be used in the presence of CI will also be considered in different production scenarios. This relates to the typical situation of continuous CI usage with the seasonal application of KHI. Experience is also shown of how the incorporation of Thermodynamic Hydrate Inhibitors (THI) to KHI/CI products, in order to enable the combined product to control hydrates in higher subcooling systems, can also have a role to play in the influence that the CI has on the efficiency of the KHI. (author) (tk)

  9. Investigation of ginkgo biloba leave extracts as corrosion and Oil field microorganism inhibitors.

    Science.gov (United States)

    Chen, Gang; Zhang, Min; Zhao, Jingrui; Zhou, Rui; Meng, Zuchao; Zhang, Jie

    2013-05-07

    Ginkgo biloba (Ginkgoaceae), originating from China, now distributes all over the world. Wide application of Ginkgo biloba extracts is determined by the main active substances, flavonoids and terpenoids, which indicates its extracts suitable to be used as an effective corrosion inhibitor. The extracts of Ginkgo biloba leave have been investigated on the corrosion inhibition of Q235A steel with weight loss and potentiodynamic polarisation techniques. The inhibition efficiency of the extracts varies with extract concentration. The extracts inhibit corrosion mainly by adsorption mechanism. Potentiodynamic polarisation studies show that extracts are mixed type inhibitors. The antibacterial activity of the extracts against oil field microorganism (SRB, IB and TGB) was also investigated.

  10. A Novel Hydrazinecarbothioamide as a Potential Corrosion Inhibitor for Mild Steel in HCl

    Directory of Open Access Journals (Sweden)

    Abu Bakar Mohamad

    2013-04-01

    Full Text Available 2-(1-methyl-4-((E-(2-methylbenzylideneamino-2-phenyl-1H-pyrazol-3(2H-ylidene-hydrazineecarbothioamide (HCB was synthesized as a corrosion inhibitor from the reaction of 4-aminoantipyrine, thiosemicarbazide and 2-methylbenzaldehyde. The corrosion inhibitory effects of HCB on mild steel in 1.0 M HCl were investigated using potentiodynamic polarization (PDP and electrochemical impedance spectroscopy (EIS. The results showed that HCB inhibited mild steel corrosion in acidic solution and inhibition efficiency increased with an increase in the concentration of the inhibitor. The inhibition efficiency was up to 96.5% at 5.0 mM. Changes in the impedance parameters suggested that HCB adsorbed on the surface of mild steel, leading to the formation of a protective film. The novel corrosion inhibitor synthesized in the present study was characterized using Fourier transform infrared spectroscopy (FTIR and nuclear magnetic resonance (NMR spectral data.

  11. Interfacial modification of clay nanotubes for the sustained release of corrosion inhibitors.

    Science.gov (United States)

    Joshi, Anupam; Abdullayev, Elshad; Vasiliev, Alexandre; Volkova, Olga; Lvov, Yuri

    2013-06-18

    Long-lasting anticorrosive coatings for steel have been developed on the basis of halloysite nanotubes loaded with three corrosion inhibitors: benzotriazole, mercaptobenzothiazole, and mercaptobenzimidazole. The inhibitors' loaded tubes were admixed at 5-10 wt % to oil-based alkyd paint providing sustained agent release and corrosion healing in the coating defects. The slow 20-30 h release of the inhibitors at defect points caused a remarkable improvement in the anticorrosion efficiency of the coatings. Further time expansion of anticorrosion agent release has been achieved by the formation of release stoppers at nanotube ends with urea-formaldehyde copolymer and copper-inhibitor complexation. The corrosion protection efficiency was tested on ASTM A366 steel plates in a 0.5 M NaCl solution with the microscanning of corrosion current development by microscopy inspection and studying paint adhesion. The best protection was found using halloysite/mercaptobenzimidazole and benzotriazole inhibitors. Stopper formation with urea-formaldehyde copolymer provided an additional increase in corrosion efficiency as a result of the longer release of inhibitors.

  12. Some organic compounds as inhibitors for the corrosion of aluminum alloy 6063 in deaerated carbonate solution

    Energy Technology Data Exchange (ETDEWEB)

    Bazzi, L.; Hamdani, M. [Lab. de Chimie Physique, Agadir (Morocco); Kertit, S. [Ecole Normale Superieure de Takaddoum, Rabat (Morocco). Lab. de Physico-Chimie des Materiaux

    1995-11-01

    Some organic compounds were tested as corrosion inhibitors for aluminum alloy 6063 (Al 6063, UNS A96063) in a deaerated carbonate solution using the electrochemical polarization method. The compounds studied were thiourea (TOR), diorthoaminodiphenyldisulfane (DOAPD), and benzotriazole (BTA). Results showed DOAPD was the best inhibitor. Its inhibition efficiency reaches a maximum value of 95.8% at 10{sup {minus}2} M. Polarization measurements indicated DOAPD acted as a cathodic and anodic (mixed) inhibitor without changing the mechanism of the water evolution reaction. DOAPD was adsorbed on the aluminum surface according to a Langmuir isotherm model. The other compounds tested had no effect on pitting corrosion of Al 6063.

  13. Environmentally Compatible Vapor-Phase Corrosion Inhibitor for Space Shuttle Hardware

    Science.gov (United States)

    Novak, Howard L.; Hall, Phillip B.

    2003-01-01

    USA-SRB Element is responsible for the assembly and refurbishment of the non-motor components of the SRB as part of Space Shuttle. Thrust Vector Control (TVC) frames structurally support components of the TVC system located in the aft skirt of the SRB. TVC frames are exposed to the seacoast environment after refurbishment and, also, to seawater immersion after splashdown, and during tow-back to CCAFS-Hangar AF refurbishment facilities. During refurbishment operations it was found that numerous TVC frames were experiencing internal corrosion and coating failures, both from salt air and seawater intrusions. Inspectors using borescopes would visually examine the internal cavities of the complicated aluminum alloy welded tubular structure. It was very difficult for inspectors to examine cavity corners and tubing intersections and particularly, to determine the extent of the corrosion and coating anomalies. Physical access to TVC frame internal cavities for corrosion removal and coating repair was virtually impossible, and an improved method using a Liquid (water based) Vapor-phase Corrosion Inhibitor (LVCI) for preventing initiation of new corrosion, and mitigating and/or stopping existing corrosion growth was recommended in lieu of hazardous paint solvents and high VOC / solvent based corrosion inhibitors. In addition, the borescopic inspection method used to detect corrosion, and/or coating anomalies had severe limitations because of part geometry, and an improved non-destructive inspection (NDI) method using Neutron Radiography (N-Ray) was also recommended.

  14. Corrosion Effects on the Strength Properties of Steel Fibre Reinforced Concrete Containing Slag and Corrosion Inhibitor

    OpenAIRE

    Sivakumar Anandan; Sounthararajan Vallarasu Manoharan; Thirumurugan Sengottian

    2014-01-01

    Corrosion in steel can be detrimental in any steel rebar reinforced concrete as well as in the case of steel fibre reinforced concrete. The process of corrosion occurring in steel fibre incorporated concrete subjected to corrosive environment was systematically evaluated in this study. Concrete specimens were prepared with steel fibre inclusions at 1.5% Vf (volume fraction) of concrete and were added in slag based concrete (containing manufactured sand) and replaced with cement at 20%, 40%, ...

  15. The Effect of Adding Corrosion Inhibitors into an Electroless Nickel Plating Bath for Magnesium Alloys

    Science.gov (United States)

    Hu, Rong; Su, Yongyao; Liu, Hongdong; Cheng, Jiang; Yang, Xin; Shao, Zhongcai

    2016-10-01

    In this work, corrosion inhibitors were added into an electroless nickel plating bath to realize nickel-phosphorus (Ni-P) coating deposition on magnesium alloy directly. The performance of five corrosion inhibitors was evaluated by inhibition efficiency. The results showed that only ammonium hydrogen fluoride (NH4HF2) and ammonium molybdate ((NH4)2MoO4) could be used as corrosion inhibitors for magnesium alloy in the bath. Moreover, compounding NH4HF2 and (NH4)2MoO4, the optimal concentrations were both at 1.5 ~ 2%. The deposition process of Ni-P coating was observed by using a scanning electron microscope (SEM). It showed corrosion inhibitors inhibited undesired dissolution of magnesium substrate during the electroless plating process. In addition, SEM observation indicated that the corrosion inhibition reaction and the Ni2+ replacement reaction were competitive at the initial deposition time. Both electrochemical analysis and thermal shock test revealed that the Ni-P coating exhibited excellent corrosion resistance and adhesion properties in protecting the magnesium alloy.

  16. Analysis of corrosion resistance behavior of inhibitors in concrete using electrochemical techniques

    Science.gov (United States)

    Song, Ha-Won; Saraswathy, Velu

    2006-08-01

    Reinforced concrete is one of the most durable and cost effective construction materials. However, in high chloride environments, it can suffer from corrosion due to chloride induced breakdown of the normal passive layer protecting the reinforcing steel bars inside concrete. One means of protecting embedded steel reinforcement from chloride induced corrosion is the addition of corrosion inhibiting admixtures. In the present investigation, various inhibitors such as sodium nitrite, zinc oxide, mono ethanol amine, diethanolamine, and triethanol amine have been used in concrete in different percentages. Their effectiveness was then studied using various electrochemical techniques such as rapid chloride ion penetration test, open circuit potential measurement, electrochemical impedance measurement, potentiodynamic polarization measurement, and gravimetric weight loss measurement. The results thus obtained indicate that the addition of inhibitors enhances the corrosion resistance properties.

  17. Study on an Eco-Friendly Corrosion and Scale Inhibitor in Simulated cooling water

    Directory of Open Access Journals (Sweden)

    Defang Zeng1

    2013-01-01

    Full Text Available In this study, a composite eco-friendly phosphate-free corrosion and scale inhibitor used in simulated cooling water has been developed by sodium polyacrylate, zinc sulfate, sodium tungstate, sodium gluconate and triethanolamine . The corrosion and scale inhibition rate were respectively evaluated by weight loss experiment , the static scale inhibition test and electrochemical test. The results indicated that the corrosion and scale inhibitor was consisted of polyacrylate 14ppm,zinc sulfate 3ppm,sodium tungstate 7ppm,sodium gluconate 2ppm and triethanolamine12ppm.The corrosion inhibition rate could reached 92.79%, and anti-scaling inhibition rate could reached 96.01%. The formula was efficient , phosphate-free and environmental, it would be widely used

  18. Electrophoretic deposition of graphene oxide as a corrosion inhibitor for sintered NdFeB

    Science.gov (United States)

    He, Wenting; Zhu, Liqun; Chen, Haining; Nan, Haiyang; Li, Weiping; Liu, Huicong; Wang, Yan

    2013-08-01

    Graphene oxide (GO) was deposited uniformly on the surface of permanent magnet material NdFeB by electrophoretic deposition (EPD). Electrophoretic deposited graphene oxide (EPD-GO) coating was reduced partially after EPD process, owing to the removal of oxygen functional groups. And EPD-GO coating showed excellent adhesion to the NdFeB matrix. According to the results of electrochemical tests, the decrease in corrosion current density and the positive shift in corrosion potential have both demonstrated that EPD-GO coating served as a corrosion inhibitor, protecting NdFeB from NaCl aqueous solution.

  19. Benzotriazole (BTA), A Promising Corrosion Inhibitor for WC-Co Hardmetal

    Energy Technology Data Exchange (ETDEWEB)

    Schnyder, B.; Stoessel-Sittig, C.; Koetz, R.; Hochstrasser-Kurz, S. [ETH Zuerich (Switzerland); Virtanen, S. [ETH Zuerich (Switzerland); Jaeggi, Ch. [University of Bern (Switzerland); Eichenberger, N. [University of Bern (Switzerland); Szoecs, E. [University of Bern (Switzerland); Siegenthaler, H. [University of Bern (Switzerland); Ziegler, P. [AGIE SA (Switzerland); Beltrami, I. [AGIE SA (Switzerland)

    2004-03-01

    Wire Electro-Discharge Machining (W-EDM) of tungsten carbide with Co-binder may lead to corrosion and discolouration at the surface. The corrosion behaviour of WC-Co based hardmetal was investigated in different aqueous solutions (acidic, neutral, and alkaline solutions). At open-circuit potential WC-Co based hardmetals show rather high dissolution rates in all types of electrolyte. An efficient corrosion inhibitor (benzotriazole, C{sub 6}H{sub 5}N{sub 3}) could be found for a borate buffer solution, pH = 8.4. (author)

  20. Synthesis of Oxide Nanoparticles in Hybrid Nanocomposite Coatings as Nanoreservoirs of Corrosion Inhibitors

    Science.gov (United States)

    Pirhady Tavandashti, Nahid; Sanjabi, Sohrab

    Nanostructured hybrid silica/epoxy films containing boehmite nanoparticles were investigated in the present work as pretreatments for AA2024 alloy. To produce the nanocomposite sol-gel films, boehmite nanoparticles prepared from hydrolysis/condensation of aluminum isopropoxide (AlI) were doped into another hybrid organosiloxane sol. The produced oxide nanoparticles have the capability to act as nanoreservoirs of corrosion inhibitors, releasing them controllably to protect the metallic substrate from corrosion. For this purpose the corrosion inhibitor, cerium nitrate, was introduced into the sol-gel system via loading the nanoparticles. The morphology and the structure of the hybrid sol-gel films were studied by Scanning Electron Microscopy (SEM). The corrosion protection properties of the films were investigated by Potentiodynamic Scanning (PDS) and Electrochemical Impedance Spectroscopy (EIS). The results show that the presence of boehmite nanoparticles highly improved the corrosion protection performance of the silica/epoxy coatings. Moreover, they can act as nanoreservoirs of corrosion inhibitors and provide prolonged release of cerium ions, offering a self-healing property to the film.

  1. Antibacterial drugs as corrosion inhibitors for bronze surfaces in acidic solutions

    Energy Technology Data Exchange (ETDEWEB)

    Rotaru, Ileana [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania); Varvara, Simona, E-mail: svarvara@uab.ro [Department of Exact Sciences and Engineering, “1 Decembrie 1918” University, 11-13 Nicolae Iorga St., 510009 Alba Iulia (Romania); Gaina, Luiza [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania); Muresan, Liana Maria, E-mail: limur@chem.ubbcluj.ro [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania)

    2014-12-01

    Graphical abstract: - Highlights: • All four investigated antibacterial drugs act as corrosion inhibitors for bronze surface. • In the presence of antibiotics, a 3RC electric circuit simulates the corrosion system. • The electrochemical results indicate as best inhibitors Doxy, followed by Strepto. • HOMO–LUMO energy gap increases in the order: Doxy > Strepto > Cipro > Amoxi. • The thin protective film on bronze is reinforced by the presence of the antibiotics. - Abstract: The present study is aiming to investigate the effect of four antibiotics (amoxicillin, ciprofloxacin, doxycycline and streptomycin,) belonging to different classes of antibacterial drugs on bronze corrosion in a solution simulating an acid rain (pH 4). Due to their ability to form protective films on the metal surface, the tested antibiotics act as corrosion inhibitors for bronze. The antibiotics were tested at various concentrations in order to determine the optimal concentration range for the best corrosion inhibiting effect. In evaluating the inhibition efficiency, polarization curves, electrochemical impedance spectroscopy, SEM and XPS measurements were used. Moreover, a correlation between the inhibition efficiency of some antibacterial drugs and certain molecular parameters was determined by quantum chemical computations. Parameters like energies E{sub HOMO} and E{sub LUMO} and HOMO–LUMO energy gap were used for correlation with the corrosion data.

  2. ALOE-VERA GEL AS POTENTIAL CORROSION INHIBITOR FOR CONCRETE STEEL REINFORCEMENT

    Directory of Open Access Journals (Sweden)

    Héctor Herrera-Hernández

    2015-09-01

    Full Text Available In this work a GEL extracted from ALOE VERA leaves has been electrochemically studied as a possible corrosion inhibitor for concrete steel rebar. The corrosion resistance was evaluated by Electrochemical Impedance Spectroscopy (EIS measurements in hydrochloric acid solution (1M HCl as a function of GEL-inhibitor addition, uninhibited measurements were also discussed. The impedance results revealed that after addition of different GEL-extract proportion, the corrosion process of the steel exposed to acidic solution is remarkably inhibited, and it was also determined that the molecules of the GEL-extract follow a physisorption mechanism on the metal surface according to the Langmuir isotherm model with and adsorption standard free energy of about G°ads 14.17 kJ/mol. In this sense, the GEL extracted from ALOE-VERA leaves behaved as a mixed-type inhibitor.

  3. Experimental study on the influence of the hydrate inhibitor on the scaling tendency and corrosive nature of oilfield wastewater%水合物抑制剂对油田水结垢腐蚀性影响的试验研究

    Institute of Scientific and Technical Information of China (English)

    靳晓霞; 侯洋; 程艳; 滕厚开; 黄泾; 呼文财

    2011-01-01

    The low dose hydrate inhibitor has effects in various degrees on oil-gas-water treatment process and treatment effectiveness, with the multi-phase mixed transportation system getting into the oil-gas-water treatment system. The effects of five different types of low dose hydrate inhibitors on the scaling tendency and corrosive nature, after they have got into the wastewater treatment systems, are studied. The study shows that the effect of low dose hydrate inhibitor on the scaling tendency of oilfield wastewater is not much, but the effect on the compatibility with scale inhibitor and dispersion agent is not satisfactory. For the oilfield wastewater which does not have H2S acidic corrosion, the low dose hydrate inhibitor has inhibiting effect on its corrosion nature, and has good compatibility with imidazoline derivatives corrosion inhibitors.%低剂量水合物抑制剂随多相混输体系进入到油气水处理系统后,对油气水处理工艺和处理效果有着不同程度的影响.研究了5种不同类型的低剂量水合物抑制剂进入污水处理系统后对污水结垢性和腐蚀性的影响.研究表明,低剂量水合物抑制剂对油田污水的结垢性影响不大,但是与阻垢分散剂配伍不理想;对于存在H2S酸性腐蚀的油田污水,低剂量水合物抑制剂对其腐蚀性有抑制作用,且与咪唑啉衍生物类缓蚀剂配伍性良好.

  4. Exopolysaccharides from lactic acid bacteria as corrosion inhibitors

    Directory of Open Access Journals (Sweden)

    Ignatova-Ivanova Tsveteslava

    2016-03-01

    Full Text Available Bacterial EPSs (exopolysaccharides are believed to play an important role in the environment by promoting survival strategies such as bacterial attachment to surfaces and nutrient trapping, which facilitate processes of biofilm formation and development. These microbial biofilms have been implicated in corrosion of metals, bacterial attachment to prosthetic devices, fouling of heat exchange surfaces, toxicant immobilization, and fouling of ship hulls. In this paper, data on EPS production and the effect of EPS on corrosion of steel produced by Lactobacillus sp. are presented and discussed. Lactobacillus delbrueckii K27, Lactobacillus delbrueckii B8, Lactobacillus delbrueckii KO43, Lactobacillus delbrueckii K3, Lactobacillus delbrueckii K15 and Lactobacillus delbrueckii K17 was obtained from Collection of Department of General and Applied Microbiology, Sofia University. It was tested for its ability to produce exopolysaccharides when cultivated in a media containing 10% sucrose, 10% lacose and 10% maltose. The study of the corrosive stability of steel samples was conducted on the gravimetrique method. The rate of corrosion, the degree of protection, and coefficient of protection have been calculated. The structure of layer over steel plates was analysed by SEM (scanning electron microscopy JSM 5510. It could be underlined that 10% sucrose, 10% lactose and 10% maltose in the media stimulated the process of protection of corrosion.

  5. Exopolysaccharides from lactic acid bacteria as corrosion inhibitors

    Science.gov (United States)

    Ignatova-Ivanova, Tsveteslava; Ivanov, Radoslav

    2016-03-01

    Bacterial EPSs (exopolysaccharides) are believed to play an important role in the environment by promoting survival strategies such as bacterial attachment to surfaces and nutrient trapping, which facilitate processes of biofilm formation and development. These microbial biofilms have been implicated in corrosion of metals, bacterial attachment to prosthetic devices, fouling of heat exchange surfaces, toxicant immobilization, and fouling of ship hulls. In this paper, data on EPS production and the effect of EPS on corrosion of steel produced by Lactobacillus sp. are presented and discussed. Lactobacillus delbrueckii K27, Lactobacillus delbrueckii B8, Lactobacillus delbrueckii KO43, Lactobacillus delbrueckii K3, Lactobacillus delbrueckii K15 and Lactobacillus delbrueckii K17 was obtained from Collection of Department of General and Applied Microbiology, Sofia University. It was tested for its ability to produce exopolysaccharides when cultivated in a media containing 10% sucrose, 10% lacose and 10% maltose. The study of the corrosive stability of steel samples was conducted on the gravimetrique method. The rate of corrosion, the degree of protection, and coefficient of protection have been calculated. The structure of layer over steel plates was analysed by SEM (scanning electron microscopy) JSM 5510. It could be underlined that 10% sucrose, 10% lactose and 10% maltose in the media stimulated the process of protection of corrosion.

  6. Chemistry of the interaction between azole type corrosion inhibitor molecules and metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kovacevic, Natasa [Department of Physical and Organic Chemistry, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Kokalj, Anton, E-mail: tone.kokalj@ijs.si [Department of Physical and Organic Chemistry, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia)

    2012-11-15

    By means of density functional theory calculations, it has been shown how typical organic corrosion inhibitors-molecules that have the ability to remarkably slow down the corrosion of metals and alloys-interact with bare surfaces of various types of metals. As representative model systems, benzimidazole and benzotriazole inhibitors on iron, copper, and aluminum surfaces are considered. It is found that bonding depends sensitively on the type of metal. On transition metals with open d-band the inhibitor molecules can chemisorb strongly either parallel to the surface with a pronounced {pi}-d hybridization or perpendicularly with unsaturated N atom(s) through {sigma}-molecular orbitals, whereas on transition metals with fully occupied d-band and on sp-metals the molecules weakly chemisorb only with the latter mode. In addition to neutral inhibitor molecules also inhibitors in deprotonated (anionic) and protonated (cationic) forms are considered, because many corrosion inhibitors possess acidic hydrogens as well as basic heteroatoms. It is shown that the chemisorptive bonding is far the strongest for deprotonated inhibitors and, moreover, that even protonated inhibitors may chemisorb, although such bonding is characteristic of more reactive metals. However adsorbed protonated inhibitors are likely to deprotonate on all considered metals, whereas further deprotonation from neutral to deprotonated form is more likely on more reactive metals. Highlights: Black-Right-Pointing-Pointer Bonding of azole corrosion inhibitors onto metal surfaces characterized by DFT calculations. Black-Right-Pointing-Pointer Adsorption bonding depends sensitively on the type of metal. Black-Right-Pointing-Pointer Azoles bond with either {pi}-system or {sigma}-orbitals to transition metals with open d-band. Black-Right-Pointing-Pointer Azoles bond with {sigma}-orbitals to transition metals with fully occupied d-band and to sp-metals. Black-Right-Pointing-Pointer Among various molecular forms

  7. New Naturally Occurring Product Extract as Corrosion Inhibitor for 316 Stainless Steel in 5% HCl

    Institute of Scientific and Technical Information of China (English)

    T.Y.Soror

    2004-01-01

    Medipolymorphol, a new sterol isolated from the whole plant of Medicago polymorpha Roxb was used as corrosion inhibitor for 316 stainless steel in 5% HCl at room temperature. Electrochemical techniques have been found to be reliable in evaluating corrosion characteristics of the system. Several techniques have been used including Tafel, linear polarization, potentiodynamic polarization, and open circuit potential (OCP) studies. The additives simultaneously deaccelerated the anodic process, intensified the cathodic process and provided a stable passive state, giving good inhibition efficiencies to stainless steel electrodes. In addition, adsorption isotherm have been fitted for the inhibitor under investigation.

  8. A theoretical study of carbohydrates as corrosion inhibitors of iron

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, Salim M.; Ali, Nozha M. [Libyan Academy for Graduate Studies, Tripoli (Libyan Arab Jamahiriya). Chemistry Dept.; Ali-Shattle, Elbashir E. [Tripoli Univ. (Libyan Arab Jamahiriya). Chemistry Dept.

    2013-08-15

    The inhibitive effect of fructose, glucose, lactose, maltose, and sucrose against the iron corrosion is investigated using density functional theory at the B3LYP/6-31 G level (d) to search the relation between the molecular structure and corrosion inhibition. The electronic properties such as the energy of the highest occupied molecular orbital (HOMO), the energy of lowest unoccupied orbital (LUMO), the energy gap (LUMO-HOMO), quantum chemical parameters such as hardness, softness, the fraction of the electron transferred, and the electrophilicity index are reported. The inhibition efficiency of the investigated carbohydrates follows the trend: maltose < sucrose < lactose < fructose < glucose. (orig.)

  9. Corrosion

    Science.gov (United States)

    Slabaugh, W. H.

    1974-01-01

    Presents some materials for use in demonstration and experimentation of corrosion processes, including corrosion stimulation and inhibition. Indicates that basic concepts of electrochemistry, crystal structure, and kinetics can be extended to practical chemistry through corrosion explanation. (CC)

  10. Corrosion

    Science.gov (United States)

    Slabaugh, W. H.

    1974-01-01

    Presents some materials for use in demonstration and experimentation of corrosion processes, including corrosion stimulation and inhibition. Indicates that basic concepts of electrochemistry, crystal structure, and kinetics can be extended to practical chemistry through corrosion explanation. (CC)

  11. Predicting the adsorption properties of carbon dioxide corrosion inhibitors using a structure-activity relationship

    Energy Technology Data Exchange (ETDEWEB)

    Kinsella, B.; De Marco, R.; Jefferson, A.; Pejcic, B. [Western Australian Corrosion Research Group, Department of Applied Chemistry, Curtin University of Technology, GPO Box U1987, Perth, 6845, WA (Australia); Durnie, W. [Nalco/Exxon Energy Chemicals Ltd, Hardley, Hythe, Southampton (Australia)

    2004-07-01

    This paper presents a study of the influence of various chemical inhibitors on the corrosion rate of mild steel in brine electrolyte under carbon dioxide conditions. The performances as corrosion inhibitors were fitted to a Temkin adsorption isotherm, and various constants of adsorption (i.e., adsorption equilibrium constants and molecular interaction constants) have been obtained. The inhibitor adsorption mechanism has been discussed in terms of thermodynamics (i.e., {delta}H, {delta}G and {delta}S) and this revealed that some compounds chemisorbed onto the steel electrode. In addition, molecular modelling was undertaken using PCSPARTAN Plus and HyperChem Professional, and the various molecular parameters have been correlated with the thermodynamic adsorption properties of the inhibitors. A four-parameter fit for both negative and positive charged molecules is discussed. (authors)

  12. Standard guide for evaluating and qualifying oilfield and refinery corrosion inhibitors in the laboratory

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This guide covers some generally accepted laboratory methodologies that are used for evaluating corrosion inhibitors for oilfield and refinery applications in well defined flow conditions. 1.2 This guide does not cover detailed calculations and methods, but rather covers a range of approaches which have found application in inhibitor evaluation. 1.3 Only those methodologies that have found wide acceptance in inhibitor evaluation are considered in this guide. 1.4 This guide is intended to assist in the selection of methodologies that can be used for evaluating corrosion inhibitors. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory requirements prior to use.

  13. Theoretical study of inhibition efficiencies of some amino acids on corrosion of carbon steel in acidic media: green corrosion inhibitors.

    Science.gov (United States)

    Dehdab, Maryam; Shahraki, Mehdi; Habibi-Khorassani, Sayyed Mostafa

    2016-01-01

    Inhibition efficiencies of three amino acids [tryptophan (B), tyrosine (c), and serine (A)] have been studied as green corrosion inhibitors on corrosion of carbon steel using density functional theory (DFT) method in gas and aqueous phases. Quantum chemical parameters such as EH OMO (highest occupied molecular orbital energy), E LUMO (lowest unoccupied molecular orbital energy), hardness (η), polarizability ([Formula: see text]), total negative charges on atoms (TNC), molecular volume (MV) and total energy (TE) have been calculated at the B3LYP level of theory with 6-311++G** basis set. Consistent with experimental data, theoretical results showed that the order of inhibition efficiency is tryptophan (B) > tyrosine (C) > serine (A). In order to determine the possible sites of nucleophilic and electrophilic attacks, local reactivity has been evaluated through Fukui indices.

  14. Quantitative structure activity relationships of some pyridine derivatives as corrosion inhibitors of steel in acidic medium.

    Science.gov (United States)

    El Ashry, El Sayed H; El Nemr, Ahmed; Ragab, Safaa

    2012-03-01

    Quantum chemical calculations using the density functional theory (B3LYP/6-31G DFT) and semi-empirical AM1 methods were performed on ten pyridine derivatives used as corrosion inhibitors for mild steel in acidic medium to determine the relationship between molecular structure and their inhibition efficiencies. Quantum chemical parameters such as total negative charge (TNC) on the molecule, energy of highest occupied molecular orbital (E (HOMO)), energy of lowest unoccupied molecular orbital (E (LUMO)) and dipole moment (μ) as well as linear solvation energy terms, molecular volume (Vi) and dipolar-polarization (π) were correlated to corrosion inhibition efficiency of ten pyridine derivatives. A possible correlation between corrosion inhibition efficiencies and structural properties was searched to reduce the number of compounds to be selected for testing from a library of compounds. It was found that theoretical data support the experimental results. The results were used to predict the corrosion inhibition of 24 related pyridine derivatives.

  15. Decyl glucoside as a corrosion inhibitor for magnesium-air battery

    Science.gov (United States)

    Deyab, M. A.

    2016-09-01

    In this research, the effects of decyl glucoside (DG) on the corrosion inhibition and battery performance of Mg-air battery have been investigated. Chemical and electrochemical techniques have been used to evaluate the corrosion rate and inhibitor efficiency. Mg surface has been characterized with scanning electron microscopy (SEM) and infrared spectroscopy (FTIR). A significant reduction in the corrosion rate of Mg in battery electrolyte (3.5% NaCl solution) has been observed in the presence of DG surfactant. Maximum inhibition efficiency (>94%) is achieved at critical micelle concentration of DG surfactant (CMC = 2.5 mM). The presence of DG surfactant increases the activation energy of the corrosion reaction. Physisorption mechanism has been suggested for the inhibition action of DG surfactant. The Mg-air battery containing DG surfactant offers higher operating voltage, discharge capacity and anodic utilization than in its absence.

  16. Study of a Triazole Derivative as Corrosion Inhibitor for Mild Steel in Phosphoric Acid Solution

    Directory of Open Access Journals (Sweden)

    Lin Wang

    2012-01-01

    Full Text Available The corrosion inhibition by a triazole derivative (PAMT on mild steel in phosphoric acid (H3PO4 solution has been investigated by weight loss and polarization methods. The experimental results reveal that the compound has a significant inhibiting effect on the corrosion of steel in H3PO4 solution. It also shows good corrosion inhibition at higher concentration of H3PO4. Potentiodynamic polarization studies have shown that the compound acts as a mixed-type inhibitor retarding the anodic and cathodic corrosion reactions with predominant effect on the cathodic reaction. The values of inhibition efficiency obtained from weight loss and polarization measurements are in good agreement. The adsorption of this compound is found to obey the Langmuir adsorption isotherm. Some kinetic and thermodynamic parameters such as apparent activation energy, frequency factor, and adsorption free energy have been calculated and discussed.

  17. 一种新型抗高温酸化缓蚀剂的制备与性能评价%Development and performance evaluation of a neW type of resistance to high temperature acidifying corrosion inhibitor

    Institute of Scientific and Technical Information of China (English)

    李小可; 熊颖; 陈大钧

    2014-01-01

    The quality ratio of thiourea,ethylene polyamine and oleic acid are 0. 2: 1: 2,synthesizing a kind of oleic acid thiourea imidazoline by condensation dehydration reaction. Mixing with surfactant,pyri-dine,aldehyde,alkynol to get a new type of resistance to high temperature acidifying corrosion inhibitor LX-1. Evaluating corrosion inhibition effect of inhibitor,compatibility,resistance to temperature perform-ance. Results show that the corrosion inhibitor performance is good:with 0. 6% of LX-1,carbon steel cor-rosion rate is 0. 015 mm/ a and the inhibiting efficiency of LX-1 against the liquid-phase of carbon steel can be as high as 95% ;having good compatibility with formation ion and various chemical agents;resist-ant to high temperature;when the concentration of hydrochloric acid is 20% and the temperature is 90 ℃,carbon steel corrosion rate 0. 023 mm/ a,the inhibiting efficiency 89. 0% .%硫脲、多乙烯多胺、油酸按照质量比0.2:1:2,通过缩合脱水反应合成出了一种油酸硫脲基咪唑啉,并复配表面活性剂、吡啶、醛、炔醇等,得到一种新型抗高温酸化缓蚀剂 LX-1,对缓蚀剂的缓蚀性能、相容性、抗温性能进行评价。结果表明,缓蚀剂的缓蚀性能良好,LX-1加量为0.6%时,缓蚀率达到95%,腐蚀速率达0.015 mm/ a;与地层离子及各种化学剂相容性好;能抗高温90℃,盐酸浓度20%时,腐蚀速率0.023 mm/ a,缓蚀率89.0%。

  18. Punica granatum leave extract as green corrosion inhibitor for mild steel in Hydrochloric acid

    Directory of Open Access Journals (Sweden)

    Abboud Y.

    2013-09-01

    Full Text Available Leave of Punica granatum extract (LPGE as green inhibitor for the corrosion of mild steel in 1M HCl solution was studied using weight-loss and potentiodynamic polarization measurements. The results obtained revealed that LPGE has fairly good inhibiting properties for mild steel corrosion in 1M HCl solution, with efficiency of around 94 % at a concentration of 1 g/l. The inhibition was of a mixed anodic–cathodic nature. The film which is formed over the metal surface was analysed by FT-IR spectroscopy. Further examination using X-ray diffraction confirms the role of LPGE as an effective corrosion inhibitor for mild steel in acid media.

  19. Aromatic quinoxaline as corrosion inhibitor for bronze in aqueous chloride solution

    Indian Academy of Sciences (India)

    N Saoudi; A Bellaouchou; A Guenbour; A Ben Bachir; E M Essassi; M El Achouri

    2010-06-01

    A new corrosion inhibitor, viz. 3-ethyl-6-méthyl-quinoxalin-2-one, 1-benzyl-6-methyl-quinoxalin- 2-one, 2-benzyloxy-3,6-dimethyl-quinoxaline, 1-benzyl-3-methyl-quinoxalin-2-one, were synthesized in the laboratory. Their influence on the inhibition on corrosion of bronze in aqueous chloride solution (3% NaCl) was studied by electrochemical polarization methods and weight-loss measurements. The impact of temperature on the effectiveness of the substances mentioned above has been determined between 20 and 60°C. The results showed that the corrosion resistance was greatly enhanced in the presence of inhibitor and that the effectiveness depends on some physicochemical properties of the molecule, related to its functional groups. These compounds act through the formation of a protective film on the surface of the alloy.

  20. Molecular Structure of Phenylthiourea as a Corrosion Inhibitor for Mild Steel in Hydrochloric Acid

    Institute of Scientific and Technical Information of China (English)

    Anees A, Khadom

    2011-01-01

    The application of statistical analysis and quantum chemical models on the corrosion inhibition of mild steel in hydrochloric acid in presence of phenylthiourea (PTU) as corrosion inhibitor have been investigated. Two mathematical models were used, second order polynomial model and Arrhenius type equation model. STATISTICA software based on Levenberg-Marquardt estimation method was used to evaluate the coefficients of two Models. It follows that the two models were suitable to represent the corrosion rate data at different conditions. The correlation coefficient of second order polynomial model was 0.973, while for the Arrhenius type model was 0.919. The structure of inhibitor was optimized by ArgusLab 4.0.1 package. The quantum chemical parameters (EHoMO, ELUMO, AE, and dipole moment μ) were estimated by PM3-SCF method.

  1. DEVELOPMENT OF AN ENVIRONMENTALLY BENIGN MICROBIAL INHIBITOR TO CONTROL INTERNAL PIPELINE CORROSION

    Energy Technology Data Exchange (ETDEWEB)

    Bill W. Bogan; Brigid M. Lamb; Gemma Husmillo; Kristine Lowe; J. Robert Paterek; John J. Kilbane II

    2004-12-01

    The overall program objective is to develop and evaluate environmentally benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is to develop one or more environmentally benign (a.k.a. ''green'') products that can be applied to maintain the structure and dependability of the natural gas infrastructure. Various chemicals that inhibit the growth and/or the metabolism of corrosion-associated microbes such as sulfate reducing bacteria, denitrifying bacteria, and methanogenic bacteria were evaluated to determine their ability to inhibit corrosion in experiments utilizing pure and mixed bacterial cultures, and planktonic cultures as well as mature biofilms. Planktonic cultures are easier to inhibit than mature biofilms but several compounds were shown to be effective in decreasing the amount of metal corrosion. Of the compounds tested hexane extracts of Capsicum pepper plants and molybdate were the most effective inhibitors of sulfate reducing bacteria, bismuth nitrate was the most effective inhibitor of nitrate reducing bacteria, and 4-((pyridine-2-yl)methylamino)benzoic acid (PMBA) was the most effective inhibitor of methanogenic bacteria. All of these compounds were demonstrated to minimize corrosion due to MIC, at least in some circumstances. The results obtained in this project are consistent with the hypothesis that any compound that disrupts the metabolism of any of the major microbial groups present in corrosion-associated biofilms shows promise in limiting the amount/rate of corrosion. This approach of controlling MIC by controlling the metabolism of biofilms is more environmentally benign than the current approach involving the use of potent biocides, and warrants further investigation.

  2. Multiphysics modelling, quantum chemistry and risk analysis for corrosion inhibitor design and lifetime prediction.

    Science.gov (United States)

    Taylor, C D; Chandra, A; Vera, J; Sridhar, N

    2015-01-01

    Organic corrosion inhibitors can provide an effective means to extend the life of equipment in aggressive environments, decrease the environmental, economic, health and safety risks associated with corrosion failures and enable the use of low cost steels in place of corrosion resistant alloys. To guide the construction of advanced models for the design and optimization of the chemical composition of organic inhibitors, and to develop predictive tools for inhibitor performance as a function of alloy and environment, a multiphysics model has been constructed following Staehle's principles of "domains and microprocesses". The multiphysics framework provides a way for science-based modelling of the various phenomena that impact inhibitor efficiency, including chemical thermodynamics and speciation, oil/water partitioning, effect of the inhibitor on multiphase flow, surface adsorption and self-assembled monolayer formation, and the effect of the inhibitor on cathodic and anodic reaction pathways. The fundamental tools required to solve the resulting modelling from a first-principles perspective are also described. Quantification of uncertainty is significant to the development of lifetime prediction models, due to their application for risk management. We therefore also discuss how uncertainty analysis can be coupled with the first-principles approach laid out in this paper.

  3. Safe corrosion inhibitor for treating cooling water on heat power engineering plants

    Science.gov (United States)

    Nikolaeva, L. A.; Khasanova, D. I.; Mukhutdinova, E. R.; Safin, D. Kh.; Sharifullin, I. G.

    2017-08-01

    Heat power engineering (HPE) consumes significant volumes of water. There are, therefore, problems associated with corrosion, biological fouling, salt deposits, and sludge formation on functional surfaces of heat power equipment. One of the effective ways to solve these problems is the use of inhibitory protection. The development of new Russian import-substituting environmentally friendly inhibitors is very relevant. This work describes experimental results on the OPC-800 inhibitor (TU 2415-092-00206 457-2013), which was produced at Karpov Chemical Plant and designed to remove mineral deposits, scale, and biological fouling from the surfaces of water-rotation node systems on HPE objects. This reagent is successfully used as an effective corrosion inhibitor in the water recycling systems of Tatarstan petrochemical enterprises. To save fresh make-up water, the circulating system is operated in a no-blow mode, which is characterized by high evaporation and salt content coefficients. It was experimentally found that corrosion rate upon treatment of recycled water with the OPC-800 inhibitor is 0.08-0.10 mm/year. HPE mainly uses inhibitors based on oxyethylidene diphosphonic (OEDPA) and nitrilotrimethylphosphonic (NTMPA) acids. The comparative characteristic of inhibition efficiency for OPC-800 and OEDF-Zn-U2 is given. The results obtained indicate that OPC-800 can be used as an inhibitor for treatment of cooling water in HPE plants. In this case, it is necessary to take into account the features of water rotation of a thermal power plant.

  4. 21 CFR 178.3300 - Corrosion inhibitors used for steel or tinplate.

    Science.gov (United States)

    2010-04-01

    .... 178.3300 Section 178.3300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... technical effect: (1) Corrosion inhibitors (active ingredients) used in packaging materials for the... Dicyclohexylamine and its salts of fatty acids derived from animal or vegetable oil Dicyclohexylamine...

  5. Application of carbohydrate polymers as corrosion inhibitors for metal substrates in different media: A review.

    Science.gov (United States)

    Umoren, Saviour A; Eduok, Ubong M

    2016-04-20

    Naturally occurring polysaccharides are biopolymers existing as products of biochemical processes in living systems. A wide variety of them have been employed for various material applications; as binders, coatings, drug delivery, corrosion inhibitors etc. This review describes the application of some green and benign carbohydrate biopolymers and their derivatives for inhibition of metal corrosion. Their modes and mechanisms of protection have also been described as directly related to their macromolecular weights, chemical composition and their unique molecular and electronic structures. For instance, cellulose and chitosan possess free amine and hydroxyl groups capable of metal ion chelation and their lone pairs of electrons are readily utilized for coordinate bonding at the metal/solution interface. Some of the carbohydrate polymers reviewed in this work are either pure or modified forms; their grafted systems and nanoparticle composites with multitude potentials for metal protection applications have also been highlighted. Few inhibitors grafted to introduce more compact structures with polar groups capable of increasing the total energy of the surface have also been mentioned. Exudate gums, carboxymethyl and hydroxyethyl cellulose, starch, pectin and pectates, substituted/modified chitosans, carrageenan, dextrin/cyclodextrins and alginates have been elaborately reviewed, including the effects of halide additives on their anticorrosion performances. Aspects of computational/theoretical approach to corrosion monitoring have been recommended for future studies. This non-experimental approach to corrosion could foster a better understanding of the corrosion inhibition processes by correlating actual inhibition mechanisms with molecular structures of these carbohydrate polymers.

  6. Ab initio modeling of the bonding of benzotriazole corrosion inhibitor to reduced and oxidized copper surfaces.

    Science.gov (United States)

    Kokalj, Anton

    2015-01-01

    The bonding of benzotriazole-an outstanding corrosion inhibitor for copper-on reduced and oxidized copper surfaces is discussed on the basis of density functional theory (DFT) calculations. Calculations reveal that benzotriazole is able to bond with oxide-free and oxidized copper surfaces and on both of them it bonds significantly stronger to coordinatively unsaturated Cu sites. This suggests that benzotriazole is able to passivate the reactive under-coordinated surface sites that are plausible microscopic sites for corrosion attack. Benzotriazole can adsorb in a variety of different forms, yet it forms a strong molecule-surface bond only in deprotonated form. The bonding is even stronger when the deprotonated form is incorporated into organometallic adcomplexes. This is consistent with existing experimental evidence that benzotriazole inhibits corrosion by forming protective organometallic complexes. It is further shown that adsorption of benzotriazole considerably reduces the metal work function, which is a consequence of a large permanent molecular dipole and a properly oriented adsorption structure. It is argued that such a pronounced effect on the work function might be relevant for corrosion inhibition, because it should diminish the anodic corrosion reaction, which is consistent with existing experimental evidence that benzotriazole, although a mixed type inhibitor, predominantly affects the anodic reaction.

  7. Organic substances as inhibitors for chloride-induced corrosion in reinforced concrete

    Energy Technology Data Exchange (ETDEWEB)

    Ormellese, M.; Bolzoni, F.; Lazzari, L.; Brenna, A.; Pedeferri, M. [Department Chemistry, Material and Chemical Engineering, Politecnico di Milano (Italy)

    2011-02-15

    Corrosion inhibitors are used to prevent chloride-induced corrosion in reinforced concrete structures. Since performance of commercial organic inhibitors is only partially satisfactory, a 7-year long research has been carried out in order to set-up a new organic inhibitive mixture, able to prevent chlorides-induced corrosion. A first screening, by means of potentiodynamic polarisation test in alkaline synthetic pore solution, was performed on 80 organic compounds, mainly primary and tertiary amines, aminoalcohols, carboxylates compounds and aminoacids, in order to select the best inhibiting substances. The nine best inhibitive organic substances were selected for long-term tests: 2 amines (dimethylethanolamine and triethylentetramine), 4 aminoacids (aspartate, asparagine, glutamate and glutamine) and 3 carboxylates compounds (tartrate, benzoate and EDTA). Potentiostatic polarisation and free corrosion tests in synthetic pore solution were performed, as well as tests in concrete exposed to accelerated chlorides penetration. Five years of tests allow estimating the efficiency of the substances in preventing chlorides-induced corrosion, in term of influence on chlorides penetration and on critical chlorides threshold. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Antifungal drugs as corrosion inhibitors for aluminium in 0.1 M HCl

    Energy Technology Data Exchange (ETDEWEB)

    Obot, I.B. [Department of Chemistry, Faculty of Science, University of Uyo, Uyo (Nigeria)], E-mail: proffoime@yahoo.com; Obi-Egbedi, N.O. [Department of Chemistry, University of Ibadan, Ibadan (Nigeria); Umoren, S.A. [Department of Chemistry, Faculty of Science, University of Uyo, Uyo (Nigeria)

    2009-08-15

    The inhibitive capabilities of Clotrimazole (CTM) and Fluconazole (FLC), two antifungal drugs, on the electrochemical corrosion of aluminium in 0.1 M HCl solution has been studied using weight loss measurements at 30 and 50 deg. C. The results indicate that both compound act as inhibitors in the acidic corrodent. At constant acid concentration, the inhibition efficiency (%I) increased with increase in the concentration of the inhibitors. Increase in temperature increased the corrosion rate in the absence and presence of the inhibitors but decreased the inhibition efficiency. CTM and FLC adsorbed on the surface of aluminium according to the Langmuir adsorption isotherm model at all the concentrations and temperatures studied. Phenomenon of physical adsorption is proposed from the activation parameter obtained. Thermodynamic parameters reveal that the adsorption process is spontaneous. The reactivity of these compounds was analyzed through theoretical calculations based on AM1 semi-empirical method to explain the different efficiencies of these compounds as corrosion inhibitors. CTM was found to be a better inhibitor than FLC.

  9. Apricot juice as green corrosion inhibitor of mild steel in phosphoric acid

    Directory of Open Access Journals (Sweden)

    Aprael S. Yaro

    2013-03-01

    Full Text Available The corrosion protection of mild steel in 1 M H3PO4 solution by apricot juice was studied at different temperatures by weight loss technique. Adsorption, activation and statistical studies were addressed in this work. Adsorption studies showed that inhibitor adsorbed on metal surface according to Langmuir isotherm. Average value of heat of adsorption was −14.93 kJ/mol indicates a spontaneous physical adsorption on metal surface. Activation parameters did not changed with addition of inhibitor indicates that there is no change in reaction mechanism. Analysis of variance (ANOVA was also applied. This analysis showed that the corrosion rate influenced by temperature, inhibitor concentration and combined interaction of them.

  10. Allium Sativum (Garlic Extract as Nontoxic Corrosion Inhibitor

    Directory of Open Access Journals (Sweden)

    K. Rajam

    2013-01-01

    Full Text Available The inhibition efficiency (IE of an aqueous extract of garlic in controlling corrosion of carbon steel in well water in the absence and presence of Zn2+ has been evaluated by mass-loss method. The formulation consisting of 2 mL of garlic extract and 25 ppm Zn2+ offers 70% inhibition efficiency to carbon steel immersed in well water. Polarization study reveals that this formulation controls the anodic reaction predominantly. FTIR spectra reveal that the protective film consists of Fe2+-allicin complex and Zn(OH2.

  11. Punica granatum leave extract as green corrosion inhibitor for mild steel in Hydrochloric acid

    OpenAIRE

    Abboud Y.; Chagraoui A.; Tanane O.; El Bouari A.; Hannache H.

    2013-01-01

    Leave of Punica granatum extract (LPGE) as green inhibitor for the corrosion of mild steel in 1M HCl solution was studied using weight-loss and potentiodynamic polarization measurements. The results obtained revealed that LPGE has fairly good inhibiting properties for mild steel corrosion in 1M HCl solution, with efficiency of around 94 % at a concentration of 1 g/l. The inhibition was of a mixed anodic–cathodic nature. The film which is formed over the metal surface was analysed by FT-IR spe...

  12. On Statues of Volatile Corrosion Inhibitor Paper%气相防锈纸研究现状

    Institute of Scientific and Technical Information of China (English)

    李丹希; 刘全校; 许文才; 尹彦娜

    2014-01-01

    The definition, core components, application, corrosion inhibition mechanism and production processes of volatile corrosion inhibitor paper are introduced. On this basis, the research status of volatile corrosion inhibitor paper are explained from three directions. It is the study of core components of volatile corrosion inhibitor paper, the new universal volatile corrosion inhibitor paper studies and other relevant research. The foreign research about volatile corrosion inhibitor paper is exhaustivenesser than domestic. It's mainly about impregnated or coated with high efficiency or low toxicity volpor phase inhibitor on paper to made volatile corrosion inhibitor paper. The domestic research of environmental toxicity vapor corrosion inhibitor paper are lagging behind other countries, but in the research areas of plant-based non-toxic and multi-component universal vapor corrosion inhibitor paper is more prominent. To sum up, the future developing trends of volatile corrosion inhibitor paper are the study of new non-toxic volatile corrosion inhibitor paper and universal volatile corrosion inhibitor paper. At the same time, trying to improve the relevant laws and regulations are also necessary.%对气相防锈纸的定义、核心成分、应用、缓蚀机理和生产工艺进行了介绍。在此基础上,从气相防锈纸核心成分的研究、新型通用气相防锈纸的研究和多组分气相防锈纸3方面对国内外气相防锈纸的研究现状进行了阐述。国外关于气相防锈纸的研究较国内详尽,且以纸张浸渍或涂覆高效、低毒型缓蚀剂制成气相防锈纸为主。我国在环保低毒型气相防锈纸上的研究虽落后于国外,但在植物型水性无毒气相缓蚀剂、多组分通用型环保气相防锈纸的研究领域较为突出。研究指出,无毒新型、通用型为我国气相防锈纸的未来发展趋势。

  13. Comparative Study of Elaeis Guiniensis Exudates (Palm Wine as a Corrosion Inhibitor for Mild Steel in Acidic and Basic Solutions

    Directory of Open Access Journals (Sweden)

    S.C. Nwigbo

    2012-01-01

    Full Text Available This study has explored the possibility of using a typical plant extract other than the use of conventional materials as corrosion inhibitor. Elaeis guinensis exudates (Palm wine, which contains carbonyl groups, double bonds and triple bonds as shown by the FTIR, Gas chromatography-mass spectrometry and phytochemical tests is a one of good natural materials as corrosion inhibitor. This paper was focused on the behaviour of palm wine as corrosion inhibitor for mild steel in (0.1 and 0.5 M H2SO4 and NaOH solutions at 303 and 333 K temperatures and inhibitor concentrations using weight loss measurement. Results showed that weight loss decreases as concentration of both solutions studied increase. The inhibitor performs better under the basic solution compared to the acidic solution. The kinetics results showed that activation energy increases as temperature and inhibitors concentration increase. Palm wine inhibitor adsorbed on the surface of mild steel through physical adsorption.

  14. Performance evaluation of pectin as ecofriendly corrosion inhibitor for X60 pipeline steel in acid medium: experimental and theoretical approaches.

    Science.gov (United States)

    Umoren, Saviour A; Obot, Ime B; Madhankumar, A; Gasem, Zuhair M

    2015-06-25

    The corrosion inhibition effect of pectin (a biopolymer) for X60 pipeline steel in HCl medium was investigated using weight loss, electrochemical, water contact angle measurements, and scanning electron microscopy techniques. The results obtained show that pectin acts as a good corrosion inhibitor for X60 steel. Inhibition efficiency increased with increase in pectin concentration and temperature. Potentiodynamic polarization results reveal that pectin could be classified as a mixed-type corrosion inhibitor with predominant control of the cathodic reaction. The effective corrosion inhibition potential of pectin could be related to the adsorption of pectin molecules at the metal/solution interface which is found to accord with the Langmuir adsorption isotherm model and a protective film formation. Quantum chemical calculations provided insights into the active sites and reactivity parameters governing pectin activity as a good corrosion inhibitor for X60 steel.

  15. Study on Surface Adsorption and Inhibition Behavior of Corrosion Inhibitors Contained in Copper Foil Rolling Oil

    Institute of Scientific and Technical Information of China (English)

    Xiong Sang; Sun Jianlin; Jiang Wei; Xu Yang; Zeng Yingfeng; Xia Lei

    2015-01-01

    Adsorption and inhibition behavior of 2,5-bis(ethyldisulfanyl)-1,3,4-thiadiazole (DMTDA) andN-((6-methyl-1H -benzo[d][1,2,3]triazol-1-yl)methyl)-N-octyloctan-1-amine (EAMBA) as corrosion inhibitors contained in copper foil roll-ing oil have been investigated using gravimetric and electrochemical techniques. Meanwhile, scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) have been employed to observe the surface topography and analyze the components on copper foil. The results show that the rolling oil containing DMTDA and EAMBA can signiifcantly decrease the dissolution rate and increase the inhibition efifciency of samples, especially in the case of best compounded rolling oil system. The SEM and EDS investigations also conifrmed that the protection of the copper foil surface is achieved by strong adsorption of the molecules which can prevent copper from being corroded easily. Reactivity descriptors of the corrosion inhibitors have been calculated by the density functional theory (DFT) and the reactivity has been analyzed through the molecular orbital and Fukui indices. Active sites of inhibitor are mainly concentrated on the ring and the polar functional groups, and in the meanwhile, the distribution is helpful to form coordination and backbonding among molecules and then to form stable adsorption on the metal surface. And this work provides theoretical evidence for the selection of corrosion inhibitors contained in copper foil rolling oil.

  16. Seed Extract of Psidium guajava as Ecofriendly Corrosion Inhibitor for Carbon Steel in Hydrochloric Acid Medium

    Institute of Scientific and Technical Information of China (English)

    K.P.Vinod Kumar; M. Sankara Narayana Pillai; G. Rexin Thusnavis

    2011-01-01

    The anticorrosion characteristics of the seeds of Psidium guajava (P. Guajava) fruits on carbon steel in acid medium were examined with weight loss data and subsequently thermodynamic factors such as heat of adsorption of the inhibitor on the metal surface (Q), change in entropy (△S), change in free energy of the reaction (△G), corrosion rate (CR) and energy of activation for corrosion reaction of carbon steel (E) were also evaluated. Adsorption isotherm was plotted to study the adsorption of the inhibitor on the metal surface with increasing concentration of the inhibitor. The functional groups responsible for inhibition were investigated using Fourier transform infrared (FT-IR) spectra. Electrochemical parameters were evaluated through the potentiodynamic Tafel polarization and impedance spectral studies. Scanning electron microscopy (SEM) micrographs were recorded to investigate the change in surface morphology. The complete study reveals the efficiency of seed extract of P. Guajava as a safe, ecofriendly and alternate corrosion inhibitor for carbon steel in acid medium.

  17. Synergistic effects of additives to benzotriazole solutions applied as corrosion inhibitors to archaeological copper and copper alloy artefacts.

    OpenAIRE

    Golfomitsou, S.

    2006-01-01

    Benzotriazole (BTA) is a corrosion inhibitor extensively used for the stabilisation of active corrosion of archaeological copper and copper alloys. However, BTA often fails to effectively retard corrosion when applied on heavily corroded artefacts. Although there are numerous studies about its mode of action on clean copper, there is no comprehensive understanding about the way it is bonded to corroded copper. This thesis aimed to understand and compare BTA and its mode of action on clean and...

  18. Gallic acid as a corrosion inhibitor of carbon steel in chemical decontamination formulation

    Energy Technology Data Exchange (ETDEWEB)

    Keny, S.J.; Kumbhar, A.G. [Reactor Water Chemistry Section, Water and Steam Chemistry Division, Bhabha Atomic Research Center, Mumbai 400 085 (India); Thinaharan, C. [Technical Physics and Prototype Engineering Division, Bhabha Atomic Research Center, Mumbai 400 085 (India); Venkateswaran, G. [Reactor Water Chemistry Section, Water and Steam Chemistry Division, Bhabha Atomic Research Center, Mumbai 400 085 (India)], E-mail: gvenk@magnum.barc.ernet.in

    2008-02-15

    Gallic acid (GA) was found to provide corrosion inhibition to carbon steel (CS) at 4.25 mM concentration. Inherent stability to radiation degradation as compared to other reductant and coupled with its anionic nature with respect to removal using ion exchange column makes it suitable for using as both reductant as well as corrosion inhibitor in dilute decontamination formulations operating in the regenerative mode. A formulation containing CA (1.4 mM), EDTA/NTA (1.4 mM), AA (1.0-2.0 mM) and GA (4.25 mM) was found to be more efficient in dissolving hematite and providing 31% corrosion inhibition (passivation) to the CS.

  19. Polysaccharide from Plantago as a green corrosion inhibitor for carbon steel in 1M HCl solution.

    Science.gov (United States)

    Mobin, Mohammad; Rizvi, Marziya

    2017-03-15

    Polysaccharide from Plantago ovata was investigated for its inhibition characteristics for carbon steel corrosion in 1M HCl. The mucilage of the Plantago is comprised of a highly branched polysaccharide, arabinosyl (galaturonic acid) rhamnosylxylan (AX), which is mainly responsible for the corrosion inhibition of the carbon steel. The techniques that were used to assess the inhibition and adsorption properties of the AX in the acid solution are gravimetric method, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), atomic force microscopy (AFM), UV-vis spectroscopy and FTIR. Thermodynamic and activation parameters revealed that the spontaneous adsorption of AX on carbon steel was mixed type and predominantly chemical in nature. Quantum chemical analysis supports the proposed mechanism of inhibition. AX from Plantago could serve as a green corrosion inhibitor for the carbon steel in hydrochloric medium with good inhibition efficiency but low risk of environmental pollution.

  20. Development of an environmentally friendly combined scale/corrosion inhibitor for subsea application

    Energy Technology Data Exchange (ETDEWEB)

    Jenkins, Alyn [M-I SWACO, Houston, TX (United States)

    2009-07-01

    In many offshore oil and gas fields, production chemicals are required to be applied subsea to mitigate the common flow assurance problems that are present either in the well or subsea gathering and flow lines. Common flow assurance issues include scale, hydrate formation, corrosion and also wax deposition. For subsea systems, production chemicals are applied either at the subsea wellhead, flow lines or downhole. However, for many fields there are an inadequate number of chemical umbilicals, chemical injection pumps or chemical storage tanks. Consequently, there is a strong requirement for combination or multifunctional products that help to minimize the amount of chemical injection equipment needed. This paper describes the work involved in developing an environmentally acceptable combined scale/corrosion inhibitor for deployment in subsea pipelines in a UK North Sea oil field. The paper details the laboratory testing performed and includes corrosion field data that has been used to confirm product performance. (author)

  1. Investigation of some green compounds as corrosion and scale inhibitors for cooling systems

    Energy Technology Data Exchange (ETDEWEB)

    Quraishi, M.A.; Farooqi, I.H.; Saini, P.A. (Aligarh Muslim Univ. (India))

    1999-05-01

    The performance of an open-recirculating cooling system, an important component in most industries, is affected by corrosion and scale formation. Numerous additives have been used in the past for the control of corrosion and scale formation. Effects of the naturally occurring compounds azadirachta indica (leaves), punica granatum (shell), and momordica charantia (fruits), on corrosion of mild steel in 3% sodium chloride (NaCl) were assessed using weight loss, electrochemical polarization, and impedance techniques. Extracts of the compounds exhibited excellent inhibition efficiencies comparable to that of hydroxyethylidine diphosphonic acid (HEDP), the most preferred cooling water inhibitor. The compounds were found effective under static and flowing conditions. Extracts were quite effective in retarding formation of scales, and the maximum antiscaling efficiency was exhibited by the extract of azadirachta indica (98%). The blowdown of the cooling system possessed color and chemical oxygen demand (COD). Concentrations of these parameters were reduced by an adsorption process using activated carbon as an adsorbent.

  2. 缓蚀剂及其在飞机上的应用%Corrosion Inhibitors and Their Application in Aircraft

    Institute of Scientific and Technical Information of China (English)

    朱辰; 邱实

    2013-01-01

    Corrosion of aircraft structures is not only a serious hazard to flight safety, but also causes huge economic losses. Corrosion inhibitors as an effective approach for controlling corrosion had already been widely used in aircraft maintenance. We summarized the classification and scope of corrosion inhibitors in U.S. military, introduced the application of corrosion inhibitor of domestic and foreign military as well as civilian aviation, analyzed the prosperous application of corrosion inhibitor in domestic, and proposed the recommendations of exploiting corrosion inhibitor of autonomous intellectual property.%飞机结构的腐蚀不但严重危害飞行安全,而且会造成巨大的经济损失。为了让缓蚀剂作为控制腐蚀产生及其扩展的一种有效手段,在飞机维护中得到更广泛的使用,总结了美国军方对缓蚀剂的分类及使用要求和范围,介绍了目前国内外军用和民用飞机中缓蚀剂的应用情况,分析了缓蚀剂在国内的应用前景,提出了开发自主知识产权缓蚀剂产品的建议。

  3. Use of Extracted Green Inhibitors as a Friendly Choice in Corrosion Protection of Low Alloy Carbon Steel

    Directory of Open Access Journals (Sweden)

    Jano, A.

    2012-11-01

    Full Text Available Mitigation of corrosion impact on environment is an important step in environmental protection. Use of environmentally friendly corrosion protection methods is very important. It is smart to choose cheap and safe to handle compounds as corrosion inhibitors. The use of green inhibitors (extracted inexpensively, from the seed endosperm of some Leguminosae plants, and investigation of their efficiency in corrosion protection is the aim of this study. As green inhibitor one kind of polysaccharides (galactomannan from locust bean gum (also known as carob gum, carob bean gum extracted from the seed of carob tree is used. Corrosion protection efficiency of these extracted green inhibitors was tested for carbon steel marked as: steel 39, steel 44, and iron B 500 (usually applied as reinforcing bars to concrete. Sulfuric acid solution in the presence of chloride ions was used as corrosion media. The composition of corrosion acid media used was 1 mol L-1 H2SO4 and 10-3 mol L-1 Cl- (in the form of NaCl. Electrochemical techniques such as potentiodynamic polarization methods were used for inhibitor efficiency testing.

  4. Enhancement of active corrosion protection via combination of inhibitor-loaded nanocontainers.

    Science.gov (United States)

    Tedim, J; Poznyak, S K; Kuznetsova, A; Raps, D; Hack, T; Zheludkevich, M L; Ferreira, M G S

    2010-05-01

    The present work reports the synthesis of layered double hydroxides (LDHs) nanocontainers loaded with different corrosion inhibitors (vanadate, phosphate, and 2-mercaptobenzothiazolate) and the characterization of the resulting pigments by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The anticorrosion activity of these nanocontainers with respect to aluminum alloy AA2024 was investigated by electrochemical impedance spectroscopy (EIS). The bare metallic substrates were immersed in dispersions of nanocontainers in sodium chloride solution and tested to understand the inhibition mechanisms and efficiency. The nanocontainers were also incorporated into commercial coatings used for aeronautical applications to study the active corrosion protection properties in systems of industrial relevance. The results show that an enhancement of the active protection effect can be reached when nanocontainers loaded with different inhibitors are combined in the same protective coating system.

  5. Mangrove tannins and their flavanoid monomers as alternative steel corrosion inhibitors in acidic medium

    Energy Technology Data Exchange (ETDEWEB)

    Rahim, Afidah A. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia)]. E-mail: afidah@usm.my; Rocca, E. [Laboratoire de Chimie du Solide Mineral, Universite Henri Poincare, Nancy I BP 239, 54506 Vandoeuvre Les Nancy (France); Steinmetz, J. [Laboratoire de Chimie du Solide Mineral, Universite Henri Poincare, Nancy I BP 239, 54506 Vandoeuvre Les Nancy (France); Kassim, M.J. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia); Adnan, R. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia); Sani Ibrahim, M. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia)

    2007-02-15

    The inhibitive behaviour on steel of flavanoid monomers that constitute mangrove tannins namely catechin, epicatechin, epigallocatechin and epicatechingallate was investigated in an aerated HCl solution via electrochemical methods. The monomers were found to be mainly cathodic inhibitors and the inhibition efficiency was dependent on concentration. To explain the adsorptive behaviour of the molecules on the steel surface, a semiempirical approach involving quantum chemical calculations using HyperChem 6.0 was undertaken. The HOMO electronic density of the molecule was used to explain the inhibiting mechanism. The most probable adsorption centers were found in the vicinity of the phenolic groups. In a second part, the use of mangrove tannin, extracted from the mangrove barks as steel corrosion inhibitors in acidic media was investigated and its inhibitive efficiency was compared with that of commercial mimosa, quebracho and chestnut tannins. The inhibitive performance of mangrove tannins was comparable to the other tannins investigated, indicating their potential in corrosion protection.

  6. Electrochemical Study on Newly Synthesized Chlorocurcumin as an Inhibitor for Mild Steel Corrosion in Hydrochloric Acid

    Directory of Open Access Journals (Sweden)

    Ahmed A. Al-Amiery

    2013-11-01

    Full Text Available A new curcumin derivative, i.e., (1E,4Z,6E-5-chloro-1,7-bis(4-hydroxy-3-methoxyphenylhepta-1,4,6-trien-3-one (chlorocurcumin, was prepared starting with the natural compound curcumin. The newly synthesized compound was characterized by elemental analysis and spectral studies (IR, 1H-NMR and 13C-NMR. The corrosion inhibition of mild steel in 1 M HCl by chlorocurcumin has been studied using potentiodynamic polarization (PDP measurements and electrochemical impedance spectroscopy (EIS. The inhibition efficiency increases with the concentration of the inhibitor but decreases with increases in temperature. The potentiodynamic polarization reveals that chlorocurcumin is a mixed-type inhibitor. The kinetic parameters for mild steel corrosion were determined and discussed.

  7. Polyethelene Glycol-Anthranilic Acid Composite as Corrosion Inhibitor for Mild Steel in Acid Medium

    Directory of Open Access Journals (Sweden)

    N. Banumathi

    2010-01-01

    Full Text Available The polymer PGA composite was prepared by chemical oxidative method of polyethylene glycol, anthranilic acid with ammonium persulphate in oxalic acid medium. The resulted polymer was characterized by FTIR spectroscopy. The performance of the polymer polyglycol anthranilic acid composite (PGA as corrosion inhibitor for mild steel in 1 M HCl has been studied by weight loss, potentiodynamic and impedance spectroscopy methods. The maximum IE was found to be 97%. Experimental results were fitted to Langmuir adsorption isotherm. Electrochemical studies confirmed the inhibitive nature of the PGA composite and also the mixed nature of the inhibitor. The polymer is found to be highly efficient non-toxic and environmentally safe.

  8. Two pyrazine derivatives as inhibitors of the cold rolled steel corrosion in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Deng Shuduan, E-mail: dengshuduan@163.co [Faculty of Wood Science and Decoration Technology, Southwest Forestry University, Kunming 650224 (China); Li Xianghong; Fu Hui [Department of Fundamental Courses, Southwest Forestry University, Kunming 650224 (China)

    2011-02-15

    Research highlights: Two pyrazine derivatives of 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP) are good inhibitors for the corrosion of steel in 1.0 M HCl solution. The inhibition efficiency follows the order: ABP > AP. The substitution Br of ABP is the additional centre of adsorption and increases the electron density of pyrazine ring, which can facilitate its adsorption on the metal surface. For either ABP or AP, the adsorption obeys Langmuir adsorption isotherm. Both ABP and AP act as mixed-type inhibitors. - Abstract: The inhibition effect of two pyrazine derivatives of 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP) on the corrosion of cold rolled steel (CRS) in 1.0 M hydrochloric acid (HCl) was studied by weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. The results show that both AP and ABP are good inhibitors, and inhibition efficiency follows the order: ABP > AP. The adsorption of each inhibitor on CRS surface obeys Langmuir adsorption isotherm. Potentiodynamic polarization curves show that two pyrazine derivatives act as mixed-type inhibitors. EIS spectra exhibit one capacitive loop and confirm the inhibitive ability.

  9. Indole and Its Derivatives as Corrosion Inhibitors forC-Steel during Pickling

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The corrosion of three types of C-steel in 10% hydrochloric acid solution has been investigated in the absence and the presence of the inhibitors, indole (A), indole acetic acid (B), indole butyric acid (C), and 3-acetyl indole (D), by weight-loss measurements at different temperatures (30~70℃). The results showed that inhibiting efficiency depended upon the presence of the substituted groups in the pyrrole ring. The inhibiting efficiency of the inhibitors increased in the order: Inh. C<lnh. B<lnh. A<lnh. D. Linear Arrhenius plots were obtained in the absence and the presence of inhibitors. Results elucidated the effect of temperatures and molecular structure on the inhibition efficiency. The activation energy, Ea, of the three alloys was calculated and it was found that it depended on the type of steel and inhibitor.

  10. Inhibiting properties and adsorption of an amine based fatty acid corrosion inhibitor on carbon steel in aqueous carbon dioxide solutions

    Energy Technology Data Exchange (ETDEWEB)

    Buchweishaija, Joseph

    1997-12-31

    Carbon dioxide corrosion is a major corrosion problem in oil and gas production systems and many organic inhibitors have been tested and used to protect the substrate from corrosion. This thesis studies the mechanism of interaction of the inhibitor molecule with the metallic substrate and how this affects the dissolution rate of the metal. The performance of a commercial amine based fatty acid corrosion inhibitor has been investigated using rotating cylinder electrodes and carbon steel electrodes in CO{sub 2} saturated formation water in the temperature range between 35 to 80{sup o}C. The corrosion process was monitored by electrochemical impedance measurements, and at the end of each experiment full polarization curves were recorded. When the inhibitor was applied on noncorroded electrodes, high inhibitor performance, over 99.7%, was observed independent of temperature. On precorroded electrodes inhibitor performance was found to depend on temperature and time of precorrosion. Above 60{sup o}C, the inhibitor performance decreased with increasing time of precorrosion, presumably because of the formation of a corrosion film of either iron carbonate or a combination of iron carbonate and iron carbide which prevent the inhibitor from reaching the surface. The inhibitor protection efficiency was assumed to be associated with the degree of inhibitor coverage at the material surface, and adsorption isotherms have been calculated in the concentration range between 0.1 ppm and 100 ppm. A Langmuir isotherm was found to give the best fit. The inhibitor performance on a 2 days precorroded rotating electrode was investigated at different solution pH ranging between 4.5 and 6.5 at 35{sup o}C. 130 refs., 80 figs., 22 tabs.

  11. Emblica Officinalis (Indian Gooseberry Leaves Extract as Corrosion Inhibitor for Mild Steel in 1N HCl Medium

    Directory of Open Access Journals (Sweden)

    R. Saratha

    2010-01-01

    Full Text Available Corrosion inhibition efficiency of acid extract of dry Emblica officinalis leaves for mild steel in 1N HCl medium is investigated in the present study. Experimental methods include weight loss, potentiodynamic polarization and impedance studies. The results indicate Emblica officinalis leaves to be a good corrosion inhibitor of a mixed type and having efficiency of 87.9% at 2% v/v inhibitor concentration. Corrosion inhibition may be due to the spontaneous physical adsorption of the plant constituents on the mild steel surface. Experimental data fitted the Langmuir, Temkin, Freundlich and Flory-Huggins adsorption isotherms.

  12. Study of caffeine as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    Science.gov (United States)

    Solehudin, Agus; Berman, Ega Taqwali; Nurdin, Isdiriayani

    2015-09-01

    The corrosion behaviour of steel surface in the absence and presence of caffeine in 3.5% NaCl solution containing dissolved H2S gas is studied using electrochemical impedance spectroscopy (EIS). The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H2S at different caffeine concentrations showed that corrosion rate of carbon steel decreases with increasing of caffeine concentrations from 0 to 0,1 mmol/l. Whereas, the corrosion rate increase with increasing of caffeine concentrations from 1 to 10 mmol/l. It is clear that no inhibition efficiency increases with increasing inhibitor concentration. The optimum value of inhibition efficiency was 90% at a caffeine concentration of 0.1 mmol/l. This suggests that caffeine's performance as a corrosion inhibitor is more effective at a concentration of 0.1 mmol/l.

  13. Screening and Quantification of Aliphatic Primary Alkyl Corrosion Inhibitor Amines in Water Samples by Paper Spray Mass Spectrometry.

    Science.gov (United States)

    Jjunju, Fred P M; Maher, Simon; Damon, Deidre E; Barrett, Richard M; Syed, S U; Heeren, Ron M A; Taylor, Stephen; Badu-Tawiah, Abraham K

    2016-01-19

    Direct analysis and identification of long chain aliphatic primary diamine Duomeen O (n-oleyl-1,3-diaminopropane), corrosion inhibitor in raw water samples taken from a large medium pressure water tube boiler plant water samples at low LODs (corrosion inhibitors in an industrial water boiler plant and other related samples in the water treatment industry. This approach was applied for the analysis of three complex water samples including feedwater, condensate water, and boiler water, all collected from large medium pressure (MP) water tube boiler plants, known to be dosed with varying amounts of polyamine and amine corrosion inhibitor components. Polyamine chemistry is widely used for example in large high pressure (HP) boilers operating in municipal waste and recycling facilities to prevent corrosion of metals. The samples used in this study are from such a facility in Coventry waste treatment facility, U.K., which has 3 × 40 tonne/hour boilers operating at 17.5 bar.

  14. Preparation and characterization of a chitosan-based low-pH-sensitive intelligent corrosion inhibitor

    Institute of Scientific and Technical Information of China (English)

    Yu-ning Wang; Chao-fang Dong; Da-wei Zhang; Pan-pan Ren; Li Li; Xiao-gang Li

    2015-01-01

    A chitosan (CS)-based low-pH-sensitive intelligent corrosion inhibitor was prepared by loading a pH-sensitive hydrogel with benzotriazole (BTA); the pH-sensitive hydrogel was synthetized by crosslinking CS with glutaraldehyde (GTA). Analysis by Fou-rier-transform infrared (FT–IR) spectroscopy showed that Schiff reactions occurred between amino and aldehyde groups. The swelling abil-ity of the hydrogel was investigated using a mass method, and it was observed to swell more in an acidic environment than in an alkaline en-vironment. The hydrogel’s loading capacity of BTA was approximately 0.377 g·g−1, and its release speed was faster in an acidic environment than in an alkaline environment because of its swelling behavior. The corrosion inhibition ability of the intelligent inhibitor was tested by immersion and electrochemical methods. The results showed that after 4 h of immersion, the polarization resistance (Rp) value of copper with the intelligent inhibitor was approximately twice of that of copper with BTA, indicating that the intelligent inhibitor could effectively prevent copper from corroding.

  15. Anti-corrosion Performance of a New Corrosion Inhibitor for Rebar%一种新型钢筋阻锈剂的阻锈性能

    Institute of Scientific and Technical Information of China (English)

    阚欣荣; 封孝信; 王晓燕

    2011-01-01

    The anti-corrosion performance of a new rebar inhibitor containing amino group and carboxylic group was evaluated by means of hardened mortar test and half cell potential method. The adsorption of corrosion inhibitor on rebar in concrete was analyzed. The results show that the corrosion inhibitor could delay the corrosion and reduce the corrosion rate of the rebar.%采用硬化砂浆和半电池电位法评价了一种自制的含有氨基和羧基的新型钢筋阻锈剂IH2的阻锈性能,并采用标准工作曲线法分析了混凝土中钢筋对阻锈剂的吸附性能。结果表明,IH2钢筋阻锈剂可以延长钢筋发生锈蚀的时间,降低钢筋的腐蚀速率,具有良好的阻锈性能。

  16. Evaluation of proposed natural corrosion inhibitors for X-52 carbon steel in ethanol media

    Science.gov (United States)

    Oliveira, Rafael F.

    This work describes the testing performed for corrosion control actions for X-52 carbon steel in ethanol media by using inhibitors, the following compounds were included: linalyl formate, linalyl acetate, linalyl butyrate, citronellyl acetate and 1-pentylallyl acetate. The experiments were performed in an electrochemical 3 electrode system with an X-52 steel rotating cylinder electrode (RCE) with rotational speed adjusted to 130 RPM. The system was deaerated by bubbling nitrogen gas into the ethanol solution. The Electrochemical Impedance Spectroscopy (EIS) technique was used to characterize the metal/electrolyte interface. Experimental testing was performed in anhydrous ethanol solution with 5 mM or 10 mM of one inhibitor. Surface analyses for the corroded surfaces were obtained by scanning electron microscopy (SEM) and White light interferometry (WLI). The results suggest that linalyl formate promotes the highest corrosion inhibition efficiency at 10 mM, followed by citronellyl acetate and linalyl butyrate. At this concentration, 1-pentylallyl acetate and linalyl acetate have not promoted corrosion inhibition. At a concentration of 5 mM, linalyl formate, linalyl acetate and linalyl butyrate promoted high inhibition efficiencies during the first hours but none was able to promote a longer protection than one day, possibly due to chemical degradation, chemical reactions and/or reduced surface coverage. The linalyl formate is considered the best chemical for inhibition purposes, especially at the concentration of 10 mM.

  17. Effects of Organic Corrosion Inhibitor and Chloride Ion Concentration on Steel Depassivation and Repassivation in Solution

    Institute of Scientific and Technical Information of China (English)

    WANG Zixiao; YU Lei; LIU Zhiyong; SONG Ning

    2015-01-01

    Effect of an organic corrosion inhibitor (OCI) named PCI-2014 added in chloride solution on the critical chlo-ride concentration of mild steel depassivation and the critical OCI concentrations for repairing the steel in different chlo-ride solution were investigated. The results show that the critical chloride concentration increases exponentially with raises of PCI-2014 concentration in the solution. Within a certain chloride ion concentration range, the critical PCI-2014 concentration for repairing the corroded steel is also increases exponentially with enhancement of chloride content in the solution. Atomic force microscopy images display the molecular particles of inhibitor are adsorbed on the steel surface and formed a protective layer. Analysis of X-ray photoelectron spectroscopy shows the chloride ions at the surface of steel are displaced by atoms or molecules of the inhibitor in chloride condition.

  18. Effects of Organic Corrosion Inhibitor and Chloride Ion Concentration on Steel Depassivation and Repassivation in Solution

    Institute of Scientific and Technical Information of China (English)

    WANG; Zixiao; YU; Lei; LIU; Zhiyong; SONG; Ning

    2015-01-01

    Effect of an organic corrosion inhibitor(OCI) named PCI-2014 added in chloride solution on the critical chloride concentration of mild steel depassivation and the critical OCI concentrations for repairing the steel in different chloride solution were investigated.The results show that the critical chloride concentration increases exponentially with raises of PCI-2014 concentration in the solution.Within a certain chloride ion concentration range,the critical PCI-2014 concentration for repairing the corroded steel is also increases exponentially with enhancement of chloride content in the solution.Atomic force microscopy images display the molecular particles of inhibitor are adsorbed on the steel surface and formed a protective layer.Analysis of X-ray photoelectron spectroscopy shows the chloride ions at the surface of steel are displaced by atoms or molecules of the inhibitor in chloride condition.

  19. Contribution of acoustic emission to monitor the effect of phosphate based inhibitor on the corrosion behavior of steel reinforcement

    Energy Technology Data Exchange (ETDEWEB)

    Nahali, Haifa [Laboratoire MATEIS CNRS UMR5511 (Equipe CorrIS), INSA-Lyon, Villeurbanne (France); Univ. de Tunis El Manar, Belvedere (Tunisia). Unite de Recherche ' ' Mecanique-Energetique' ' ; Dhouibi, Leila [Univ. de Tunis El Manar, Belvedere (Tunisia). Unite de Recherche ' ' Mecanique-Energetique' ' ; Idrissi, Hassane [Laboratoire MATEIS CNRS UMR5511 (Equipe CorrIS), INSA-Lyon, Villeurbanne (France)

    2014-11-01

    One of the most important causes of reinforced concrete structures deterioration is the corrosion of the reinforcement steel. This corrosion depends on the presence of aggressive agents such as chlorides in the surrounding medium. Numerous protection techniques have been employed to mitigate this corrosion. Among them, the use of corrosion inhibitors has been considered as one of the most effective solutions. In the present work, the influence of phosphate based inhibitor on the corrosion of reinforcing steels embedded in mortar, and immersed in sodium chloride solution, was investigated by acoustic emission technique. The monitoring of specimens shows that the phosphate based inhibitor addition in the mortar increase the threshold of chloride concentrations, causing the breakdown of steel passivation layer. Thus, the acoustic signatures of concrete fracture and of structure degradation during the corrosion of these specimens have been highlighted. Similarly, the mechanism of phosphate action in terms of preventing steel from corrosion in mortar specimens was analysed by characterization methods (SEM, XRD) of the steel-mortar interface.

  20. Semiempirical Theoretical Studies of 1,3-Benzodioxole Derivatives as Corrosion Inhibitors

    Directory of Open Access Journals (Sweden)

    Omnia A. A. El-Shamy

    2017-01-01

    Full Text Available The efficiency of 1,3-benzodioxole derivatives as corrosion inhibitors is theoretically studied using quantum chemical calculation and Quantitative Structure Activity Relationship (QSAR. Different semiempirical methods (AM1, PM3, MNDO, MINDO/3, and INDO are applied in order to determine the relationship between molecular structure and their corrosion protection efficiencies. Different quantum parameters are obtained as the energy of highest occupied molecular orbital EHOMO, the energy of the lowest unoccupied molecular orbital ELUMO, energy gap ΔEg, dipole moment μ, and Mulliken charge on the atom. QSAR approach is applied to elucidate some important parameters as the hydrophobicity (Log P, surface area (S.A, polarization (P, and hydration energy (EHyd.

  1. Corrosion inhibitors for mild steel; stannous tin (SnII) in ordinary portland cement

    Energy Technology Data Exchange (ETDEWEB)

    Sagoe-Crentsil, K.K.; Glasser, F.P.; Yilmaz, V.T. (Univ. of Aberdeen (United Kingdom). Dept. of Chemistry)

    1994-01-01

    Salts containing divalent tin (SnII) are shown to give a measure of corrosion protection to mild steel embedded in cement paste. Results of linear polarization measurements are shown for samples cured at 40[degree] for up to 240 days in pastes containing initially 0-1628mM/l chloride: Sn[sup 2+], but not Sn[sup 4+], is an effective inhibitor at an initial concentration of 200mM/l. However tin solubility in pore fluid is very low: less than 0.01mM/l at 60d. It is speculated that tin stabilizes the passivating layers although no direct evidence for the incorporation of tin in corrosion product was found by analytical electron microscopy. Other theories of inhibition are discussed.

  2. New and Green Multi-component Scaling and Corrosion Inhibitor for the Cooling Water of Central Air Conditioners

    Science.gov (United States)

    Li, Maodong; Dai, Chenlin; Yang, Bo; Qiao, Yue; Zhu, Zhiping

    2016-12-01

    A green multi-component inhibitor was developed in this study to obtain suitable scale and corrosion inhibitor for the cooling water treatment of central air conditioners. The inhibitor formulation consisted of hydrolyzed polymaleic anhydride/Tween-80/sodium N-lauroyl sarcosinate/tolyltriazole (named 4-HTSA). Weight loss test and electrochemical method were used to investigate the corrosion inhibition performance of 4-HTSA on A3 carbon steel and T2 red copper in synthetic cooling water, and the scale inhibition performance of 4-HTSA was studied by the calcium carbonate precipitation method. The influence of parameters, such as pH, temperature, scaling and corrosive ion, on 4-HTSA was researched. Scanning electron microscopy (SEM) and x-ray diffraction were used for examination of the scale, and corrosion coupons were analyzed by SEM/energy-dispersive x-ray spectroscopy. Results showed that 4-HTSA had excellent scale and corrosion inhibition performance and wide tolerance to pH, temperature and the concentration of scaling and corrosive ion. Polarization curves indicated that 4-HTSA was anodic inhibitor.

  3. A Revisit to the Corrosion Inhibition of Aluminum in Aqueous Alkaline Solutions by Water-Soluble Alginates and Pectates as Anionic Polyelectrolyte Inhibitors

    Directory of Open Access Journals (Sweden)

    Refat Hassan

    2013-01-01

    Full Text Available The corrosion behavior of aluminum (Al in alkaline media in presence of some natural polymer inhibitors has been reinvestigated. The inhibition action of the tested inhibitors was found to obey both Langmuir and Freundlich isotherms models. The inhibition efficiency was found to increase with increasing the inhibitors concentration and decrease with increasing the temperature, suggesting physical adsorption mechanism. Factors such as the concentration and geometrical structure of the inhibitor, concentration of the corrosive medium, and temperature affecting the corrosion rates were examined. The kinetic parameters were evaluated, and a suitable corrosion mechanism consistent with the kinetic results obtained is suggested and discussed.

  4. Olive pomace extract (OPE as corrosion inhibitor for steel in HCl medium

    Directory of Open Access Journals (Sweden)

    Driss Bouknana

    2014-09-01

    Full Text Available Objective: To explore the possibility of reuse olive pomace extract as a corrosion inhibition of steel in an acidic medium (HCL, 1 mol/L, and to compare the inhibitory effect of olive pomace (OP samples collected from three extraction process of olive oil: press process, continuous process three-phase and continuous process two-phase and olive pomace continuous process two-phase without stone and stone of olive (both fractions were separated by mill in the eastern region of Morocco. Methods: The electrochemical behavior of the C38 steel in HCl medium in the absence and presence olive pomace was studied by gravimetric and electrochemical techniques such as potentiodynamic polarization, linear polarization and impedance spectroscopy. The effect of temperature was also studied. The experimental data with several adsorption isotherms at different temperatures were tested to determine the standard free energy of adsorption process and the adsorption mode of inhibitor on the surface of the steel were studied. Results: The samples of the olive pomace tested in the corrosion experiment have a very complex and heterogeneous physicochemical composition. They contain a variety of organic and inorganic compounds of very different nature and concentration, allowing the olive pomace play a very important role in anti-corrosion activity. The inhibition efficiency increased with increased olive pomace concentration to attain a maximum value of 92.1% at 1.4伊10-5 with small differences among the other samples of olive pomace. Conclusions: The use of solid waste (pomace of crushing olives (oil mills as green inhibitors in the fight of corrosion plays a dual function, firstly, destituting the pollution of the receiving environments (soil, water, etc. and on the other hand, a recovery of components (bioactive such as phenolic compounds.

  5. 合水油田注水管网缓蚀剂 XD的开发优化与应用研究%Research on development and application of corrosion inhibitor XD for water injection pipe networks in Heshui Oilfield

    Institute of Scientific and Technical Information of China (English)

    吴大康; 范峥; 李稳宏; 马文军; 赵欢娟

    2016-01-01

    为了解决合水油田注水管网严重腐蚀这一问题,首先利用K‐均值聚类分析对在役586条注水管线进行研究,找出最具代表性的庄一注、庄二注、庄三注作为新型复配缓蚀剂XD的试验对象,然后通过对试片腐蚀形貌以及腐蚀产物组成、含量的检测来确定注水管网的腐蚀成因。最后,针对此问题合成了一种多位点吸附型咪唑啉季铵盐MIQAS ,以MIQAS为缓蚀剂,聚环氧琥珀酸钠(PEAS)为阻垢剂,1,2苯并异噻唑啉‐3‐酮(BIT)为杀菌剂进行复配,并借助单因素和多指标正交试验设计对MIQAS、PESA和BIT含量进行优化。结果表明,溶解氧、侵蚀性CO2、Cl-引起的吸氧腐蚀、CO2腐蚀和点蚀是导致注水管网腐蚀的主要原因,C a2+、细菌造成的结垢腐蚀和细菌腐蚀对其也有一定影响。当该复配缓蚀剂ρ(MIQAS)∶ρ(PESA)∶ρ(BIT)=120 mg/L∶65 mg/L∶50 mg/L时,XD对庄一注、庄二注和庄三注的缓蚀率分别高达98.24%、98.63%、99.17%,取得了良好的防腐效果。%In order to solve the severe corrosion of water injection pipe networks in Heshui Oilfield ,586 water injection pipelines in service were studied using K‐means clustering analysis . Zhuangyizhu ,Zhuangerzhu and Zhuangsanzhu were selected as representative experimental objects of new compound inhibitor XD .Micro‐morphology of steel sheet ,composition and content of corrosion products were determined and analyzed to find out the corrosion reason .A kind of multi‐adsorbed‐sites imidazoline quaternary ammonium salt MIQAS was synthesized aiming at above problems . Then ,single factor and multi‐target orthogonal design experiments were employed to optimize MIQAS ,PESA and BIT content . The results show that the main reasons of corrosion including oxygen absorption ,acid and pitting induced by dissolved oxygen ,erosive carbon dioxide and chloride . The fouling

  6. Indole Alkaloids of Alstonia angustifolia var. latifolia as Green Inhibitor for Mild Steel Corrosion in 1 M HCl Media

    Science.gov (United States)

    Raja, Pandian Bothi; Qureshi, Ahmad Kaleem; Rahim, Afidah Abdul; Awang, Khalijah; Mukhtar, Mat Ropi; Osman, Hasnah

    2013-04-01

    The inhibition effect of mild steel (MS) corrosion in 1 M HCl was studied by the addition of indole alkaloids (crude) isolated from Alstonia angustifolia var. latifolia ( A. latifolia) leaves at 303 K. Potentiodynamic polarization, impedance spectroscopy, scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) analyses were used for this study. Results show that the isolated alkaloid extract of A. latifolia is a good inhibitor and exhibited maximum inhibition efficiency (above 80%) at concentrations between 3 and 5 mg/L. Polarization measurements indicated that the inhibitor does not alter the mechanism of either anodic or cathodic reactions and acted as mixed-type inhibitor. The inhibition efficiencies of both electrochemical techniques are found to be in good agreement and adsorption of inhibitor follows Langmuir isotherm. Adsorption of inhibitor over metal surface was well supported by the SEM studies, while FTIR studies evidenced the presence of indole alkaloids as green inhibitor that reduces the rate of corrosion.

  7. Adsorption behavior of caffeine as a green corrosion inhibitor for copper

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Fernando Silvio de [Grupo de Estudos de Processos Eletroquimicos e Eletroanaliticos, Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Giacomelli, Cristiano [Departamento de Quimica, Universidade Federal de Santa Maria, Av. Roraima 1000, 97119-900, Santa Maria, RS (Brazil); Goncalves, Reinaldo Simoes [Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501-970, Porto Alegre, RS (Brazil); Spinelli, Almir, E-mail: almir.spinelli@ufsc.br [Grupo de Estudos de Processos Eletroquimicos e Eletroanaliticos, Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil)

    2012-12-01

    Electrochemical and impedance experiments were carried out to evaluate the corrosion behavior of copper in aerated 0.1 mol L{sup -1} H{sub 2}SO{sub 4} solutions in the presence of three xanthine derivatives with similar chemical structures. The corrosion rate of copper was found to increase in the presence of theophylline and theobromine and decrease in the presence of caffeine. The adsorption and inhibitory effect of caffeine on copper surfaces in aerated 0.1 mol L{sup -1} H{sub 2}SO{sub 4} solutions were then investigated in detail by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), contact angle measurements, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and fluorescence experiments. The data obtained indicate that caffeine behaves as a cathodic-type inhibitor adsorbing onto the copper surface according to the Temkin isotherm, with the negative Increment G Degree-Sign {sub ads} value of - 31.1 kJ mol{sup -1} signifying a spontaneous adsorption process. The corrosion inhibition efficiency increased with caffeine concentration in the range of 1.0-10.0 mmol L{sup -1}. Furthermore, the EIS results obtained at the open-circuit potential and surface analysis (SEM, EDS and fluorescence) clearly demonstrated the adsorption of the organic compound onto the copper electrode. The contact angle measurements revealed the formation of a hydrophobic protective film. This film covers up to 72% of the total active surface, acts as a protective barrier and prevents interaction between the metal, water and oxygen molecules. - Highlights: Black-Right-Pointing-Pointer We have investigated the adsorption and corrosion inhibition of caffeine on copper surfaces. Black-Right-Pointing-Pointer Caffeine behaves as a cathodic-type inhibitor. Black-Right-Pointing-Pointer Caffeine adsorbs onto copper surface according to Temkin isotherm. Black-Right-Pointing-Pointer There exists the formation of a hydrophobic film that acts as a

  8. Study on the Effects of Corrosion Inhibitor According to the Functional Groups for Cu Chemical Mechanical Polishing in Neutral Environment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Won; Kim, Jae Jeong [Institute of Chemical Process, Seoul National University, Seoul (Korea, Republic of)

    2015-08-15

    As the aluminum (Al) metallization process was replaced with copper (Cu), the damascene process was introduced, which required the planarization step to eliminate over-deposited Cu with Chemical Mechanical Polishing (CMP) process. In this study, the verification of the corrosion inhibitors, one of the Cu CMP slurry components, was conducted to find out the tendency regarding the carboxyl and amino functional group in neutral environment. Through the results of etch rate, removal rate, and chemical ability of corrosion inhibitors based on 1H-1,2,4-triazole as the base corrosion inhibitor, while the amine functional group presents high Cu etching ability, carboxyl functional group shows lower Cu etching ability than base-corrosion inhibitor which means that it increases passivation effect by making strong passivation layer. It implies that the corrosion inhibitor with amine functional group was proper to apply for 1st Cu CMP slurry owing to the high etch rate and with carboxyl functional group was favorable for the 2nd Cu CMP slurry due to the high Cu removal rate/dissolution rate ratio.

  9. The use of Euphorbia falcata extract as eco-friendly corrosion inhibitor of carbon steel in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    El Bribri, A. [Laboratoire de Chimie Organique, Bioorganique et Environnement, Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Tabyaoui, M., E-mail: hamidtabyaoui@yahoo.fr [Laboratoire de Chimie Organique, Bioorganique et Environnement, Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Laboratoire des Matériaux, Nanoparticules et Environnement, Université Mohamed V Agdal, Faculté des Sciences, 4 Av. Ibn Battouta, B.P. 1014 RP, M-10000 Rabat (Morocco); Tabyaoui, B. [Laboratoire de Chimie Organique, Bioorganique et Environnement, Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); El Attari, H.; Bentiss, F. [Laboratoire de Catalyse et de Corrosion des Matériaux (LCCM), Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco)

    2013-08-15

    Euphorbia falcata L. extract (EFE) was investigated as eco-friendly corrosion inhibitor of carbon steel in 1 M HCl using gravimetric, ac impedance, polarization and scanning electron microscopy (SEM) techniques. The experimental results show that EFE is good corrosion inhibitor and the protection efficiency is increased with the EEF concentration. The results obtained from weight loss and ac impedance studies were in reasonable agreement. Impedance experimental data revealed a frequency distribution of the capacitance, simulated as constant phase element. Polarization curves indicated that EFE is a mixed inhibitor. The corrosion inhibition was assumed to occur via adsorption of EFE molecules on the metal surface. The adsorption of the E. falcata extract was well described by the Langmuir adsorption isotherm. The calculated ΔG{sub ads}{sup o} value showed that the corrosion inhibition of the carbon steel in 1 M HCl is mainly controlled by a physisorption process. - Graphical abstract: Display Omitted - Highlights: • EFE is a good eco-friendly inhibitor for the corrosion of carbon steel in 1 M HCl. • EFE acts as mixed-type inhibitor in 1 M HCl medium. • Weight loss, ac impedance and polarization methods are in reasonable agreement. • The adsorption of EFE is well described by the Langmuir adsorption isotherm.

  10. Research on anti-corrosion property of rare earth inhibitor for X70 steel

    Institute of Scientific and Technical Information of China (English)

    ZHU Yanhua; ZHUANG Jia; YU Yongsheng; ZENG Xianguang

    2013-01-01

    Three kinds of rare earth nitrates were adopted to sodium molybdate to get three kinds of LnN-M compounded inhibitors (La(NO3)3+Na2MoO4(LaN-M),Ce(NO3)3+Na2MoO4(CeN-M),Pr(NO3)3+Na2MoO4(PrN-M)).The combination of weight-loss method and the electrochemical test,was used to evaluate and analyze the corrosion inhibition efficiency of these LnN-M inhibitors to make the research on their corrosion inhibition performance,and the sequential order of their performance was found as follows:CeN-M> LaN-M>PrN-M,among which,the inhibition efficiency of CeN-M for the X70 steel could reach 98.21%.The synergism parameters were calculated by weight-loss method,these computational data indicated that the synergistic effect between rare earth nitrates and sodium molybdate was obvious and significant.Surface morphology,chemical composition and phase components of the precipitation films were tested for discussing the mechanism of LnN-M inhibitors.The outer electronic configuration of the lanthanide was found to have an important influence on the inhibition efficiency.The CeN-M inhibitor was discovered to have the best inhibition effect with the amorphous cerium oxides.The results of this research revealed that the precipitation films formed on the surface of the steel samples had a crucial influence on the inhibition efficiencies after adding LnN-M inhibitors.

  11. Kinetics of Corrosion Inhibition of Aluminum in Acidic Media by Water-Soluble Natural Polymeric Pectates as Anionic Polyelectrolyte Inhibitors

    Directory of Open Access Journals (Sweden)

    Refat M. Hassan

    2013-06-01

    Full Text Available Corrosion inhibition of aluminum (Al in hydrochloric acid by anionic polyeletrolyte pectates (PEC as a water-soluble natural polymer polysaccharide has been studied using both gasometric and weight loss techniques. The results drawn from these two techniques are comparable and exhibit negligible differences. The inhibition efficiency was found to increase with increasing inhibitor concentration and decrease with increasing temperature. The inhibition action of PEC on Al metal surface was found to obey the Freundlich isotherm. Factors such as the concentration and geometrical structure of the inhibitor, concentration of the corrosive medium, and temperature affecting the corrosion rates were examined. The kinetic parameters were evaluated and a suitable corrosion mechanism consistent with the kinetic results is discussed in the paper.

  12. THE STUDY OF HENNA LEAVES EXTRACT AS GREEN CORROSION INHIBITOR FOR MILD STEEL IN ACETIC ACID.

    Directory of Open Access Journals (Sweden)

    H. G. Chaudhari

    2016-05-01

    Full Text Available The inhibitive action of henna leaves extract on mild steel in acetic acid solution have been investigated by weight-loss, A C impedence and potentiodynamic polarization measurements. The study indicates that as acid concentration increases corrosion rate increases. The corrosion inhibition efficiency increases with increase in concentration of extract. The result obtained revealed that henna leaves extract act as efficient inhibitor. The adsorption of the henna leaves extract obeyed Langmuir adsorption isotherm. The calculated thermodynamic parameters indicated that the adsorption was a spontaneous, exothermic process accompanied by an increase in entropy. Cathodic and anodic polarization curves show that henna leaves extract is a mixed-type inhibitor. Normal 0 false false false EN-IN X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin-top:0cm; mso-para-margin-right:0cm; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0cm; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}   ABSTRACT:    The inhibitive action of henna leaves extract on mild steel in acetic acid solution have been investigated by weight-loss, A C impedence and potentiodynamic polarization measurements. The study indicates that as acid concentration increases corrosion rate increases. The corrosion inhibition efficiency increases with increase in concentration of extract. The result obtained revealed that henna leaves extract act as efficient inhibitor. The adsorption of the henna leaves

  13. Bee Wax Propolis Extract as Eco-Friendly Corrosion Inhibitors for 304SS in Sulfuric Acid

    OpenAIRE

    Femiana Gapsari; Rudy Soenoko; Agus Suprapto; Wahyono Suprapto

    2015-01-01

    The inhibition properties of bee wax propolis (BWP) extract on the 304SS in 0.5 M sulfuric acid were conducted using potentiodynamic polarization, EIS, and XRD. Quercetin (2-(3.4-dihydroxy phenyl)-3.5.7-trihydroxy-4H-chromen-4-one) was identified as the main compound in the BWP extract based on FTIR and HPLC analysis. The results showed that the inhibitor could retard the corrosion rate of 304SS in 0.5 M sulfuric acid which reached 97.29% and 91.42% at 2000 ppm based on potentiodynamic polari...

  14. Standard practice for evaluating and qualifying oil field and refinery corrosion inhibitors using rotating cage

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This practice covers a generally accepted procedure to use the rotating cage (RC) for evaluating corrosion inhibitors for oil field and refinery applications. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  15. Cysteine as a non toxic corrosion inhibitor for copper alloys in conservation

    DEFF Research Database (Denmark)

    Gravgaard, Mari; van Lanschot, Jettie

    2012-01-01

    The aim of this work is to examine cysteine as an alternative to benzotriazole (BTA) for the conservation of archaeological objects with bronze disease. Investigation of the two inhibitors involved the use of electrochemical techniques, measurements of weight change in high humidity and comparative...... studies of colour changes in the corrosion products. The results obtained in this article demonstrate that cysteine could be a non-toxic alternative to BTA. Cysteine performed as well as BTA on pre-corroded coupons with bronze disease in high humidity and showed acceptable results during testing...

  16. Density functional theory and molecular dynamics simulation study on corrosion inhibition performance of mild steel by mercapto-quinoline Schiff base corrosion inhibitor

    Science.gov (United States)

    Saha, Sourav Kr.; Ghosh, Pritam; Hens, Abhiram; Murmu, Naresh Chandra; Banerjee, Priyabrata

    2015-02-01

    Corrosion inhibition mechanism of two mercapto-quinoline Schiff bases, eg., 3-((phenylimino)methyl)quinoline-2-thiol (PMQ) and 3-((5-methylthiazol-2-ylimino)methyl) quinoline-2-thiol (MMQT) on mild steel surface is investigated by quantum chemical calculation and molecular dynamics simulation. Quantum chemical parameters such as EHOMO, ELUMO, energy gap (ΔE), dipolemoment (μ), electronegativity (χ), global hardness (η) and fraction of electron transfers from the inhibitor molecule to the metallic atom surface (ΔN) have been studied to investigate their relative corrosion inhibition performance. Parameters like local reactive sites of the present molecule have been analyzed through Fukui indices. Moreover, adsorption behavior of the inhibitor molecules on Fe (1 1 0) surface have been analyzed using molecular dynamics simulation. The binding strength of the concerned inhibitor molecules on mild steel surface follows the order MMQT>PMQ, which is in good agreement with the experimentally determined inhibition efficiencies. In view of the above, our approach will be helpful for quick prediction of a potential inhibitor from a lot of similar inhibitors and subsequently in their rational designed synthesis for corrosion inhibition application following a wet chemical synthetic route.

  17. Sucrose fatty esters from underutilized seed oil of Terminalia catappa as potential steel corrosion inhibitor in acidic medium

    Directory of Open Access Journals (Sweden)

    Adewale Adewuyi

    2016-12-01

    Full Text Available Corrosion of metals is a common problem which requires definite attention. In response to this, the oil was extracted from the seed of Terminalia catappa and used to synthesize sucrose fatty esters via simple reaction mechanism which was considered eco-friendly and sustainable. The corrosion inhibition capacity of sucrose fatty esters for mild steel in 1 M HCl was studied using the weight loss method. It was shown that sucrose fatty ester inhibited corrosion process of mild steel and obeyed Langmuir isotherm. Corrosion rate and inhibition efficiency of sucrose fatty esters were found to reduce with increase of immersion time. The study presented sucrose fatty ester as a promising inhibitor of mild steel corrosion in acidic medium.

  18. Ceria nanoparticles vis-à-vis cerium nitrate as corrosion inhibitors for silica-alumina hybrid sol-gel coating

    Science.gov (United States)

    Lakshmi, R. V.; Aruna, S. T.; Sampath, S.

    2017-01-01

    The present work provides a comparative study on the corrosion protection efficiency of defect free sol-gel hybrid coating containing ceria nanoparticles and cerium nitrate ions as corrosion inhibitors. Less explored organically modified alumina-silica hybrid sol-gel coatings are synthesized from 3-glycidoxypropyltrimethoxysilane and aluminium-tri-sec-butoxide. The microemulsion derived nanoparticles and the hybrid coatings are characterized and compared with coatings containing cerium nitrate. Corrosion inhibiting capability is assessed using electrochemical impedance spectroscopy. Scanning Kelvin probe measurements are also conducted on the coatings for identifying the apparent corrosion prone regions. Detailed X-ray photoelectron spectroscopy (XPS) analysis is carried out to comprehend the bonding and corrosion protection rendered by the hybrid coatings.

  19. Investigation of some Schiff base compounds containing disulfide bond as HCl corrosion inhibitors for mild steel

    Energy Technology Data Exchange (ETDEWEB)

    Behpour, M., E-mail: m.behpour@kashanu.ac.i [Department of Chemistry, Faculty of Science, University of Kashan, Kashan (Iran, Islamic Republic of); Ghoreishi, S.M.; Mohammadi, N. [Department of Chemistry, Faculty of Science, University of Kashan, Kashan (Iran, Islamic Republic of); Soltani, N. [Payame Noor University (PNU), Shahin Shahr Branch, Isfahan (Iran, Islamic Republic of); Salavati-Niasari, M. [Department of Chemistry, Faculty of Science, University of Kashan, Kashan (Iran, Islamic Republic of)

    2010-12-15

    Research highlights: {yields} All studied Schiff bases are effective inhibitors for mild steel in 2.0 M HCl. {yields} The inhibition is accomplished by adsorption of molecules on the steel surface. {yields} Examined Schiff bases behave as mixed type inhibitor. {yields} Feed back bonds form between the Schiff bases and steel surface. {yields} Quantum chemical calculations were applied to explain the experimental results. - Abstract: The inhibition performance of three Schiff bases containing disulfide bond as corrosion inhibitors for mild steel in 2.0 M HCl has been investigated by weight loss measurements, potentiodynamic polarization measurements and electrochemical impedance spectroscopy (EIS). Potentiodynamic polarization study showed that all the inhibitors are mixed type. The adsorption of inhibitors on mild steel surface was found to follow Langmuir adsorption isotherm and the adsorption isotherm parameters (K{sub ads}, {Delta}G{sub ads}) were determined. Quantum chemical calculations were further applied to reveal the adsorption structure and explain the experimental results. Some samples of mild steel were examined by SEM.

  20. THE EXTRACT OF PANDAN LEAF (Pandanus amaryllifous Roxb AS CORROSION INHIBITORS OF SS-304 IN H2SO4 SOLUTION

    Directory of Open Access Journals (Sweden)

    Victor Kayadoe

    2015-11-01

    Full Text Available This study aims to determine the efficiency of inhibition and corrosion rate of SS-304 in H2SO4 solution using the extract of pandan leaf (Pandanus amaryllifous Roxb by gravimetric method. The extract of pandan leaf was obtained by maceration extraction using ethanol. Based on phytochemical test, it is found that there are several compounds of secondary metabolites of flavonoids, steroids, alkaloids, anthraquinonoid, and tannins in the exract of pandan leaf. In the corrosion inhibition test, it was performed various concentration toward the extract of pandan leaf and temperature to determine its effect on corrosion inhibition efficiency of SS-304 in H2SO4 1 M solution for 3 hours. The results showed that the inhibition efficiency significantly increases with the increasing of inhibitor concentration, which means the reduction in the corrosion rate. The optimum inhibition efficiency was obtained at inhibitor concentration of 0.8%, which was 89.06% with a corrosion rate of 5.15 mm/year. Conversely, the increasing of temperatures caused the reduction of inhibition efficiency, which means the increasing of corrosion rate. The lowest efficiency was obtained at a temperature of 50 °C, which was 11.56% with corrosion rate of 74.33% mm/year

  1. A modified method for evaluation of materials containing volatile corrosion inhibitor

    Institute of Scientific and Technical Information of China (English)

    WAN Hong-jing; HUANG Hong-jun; ZHANG Min; LI Zhi-guang

    2005-01-01

    A systematic research on a modified method that was developed to evaluate the effectiveness of volatile corrosion inhibitor(VCI) materials was carried out. The metal specimen in size of 50 mm×25 mm×2 mm was level mounted on the top of a beaker by transparent adhesive tape and the assembly was placed in a constant temperature water bath and kept at approximately 40 ℃ to accelerate the vaporization of VCI and distilled water, which was placed at the bottom of the beaker at the same time. The experimental results show that the reproducibility of rust appearance and corrosion rate calculated by specimen's mass loss is perfect. The outstanding characteristic of the rust appearance based on different VCI formula is discovered that is very important in studying the mechanism of VCI and the synergism of chemical reagent. The accelerated ratio is increased greatly as compared with the traditional method and the value is approximately 15 as compared with Shijiazhuang atmospheric environment corrosion test. The modified method is suitable for formula screening test and quick effectiveness evaluation of VCI materials.

  2. Experimental and computational studies of Nicotiana tabacum leaves extract as green corrosion inhibitor for mild steel in acidic medium

    Directory of Open Access Journals (Sweden)

    Jeetendra Bhawsar

    2015-09-01

    Full Text Available In the present work corrosion inhibition of mild steel in 2 M H2SO4 solution by Nicotiana tabacum extract was studied by weight loss method. It has been found that the extract acts as an effective corrosion inhibitor for mild steel in Sulfuric acid medium. The inhibition process is attributed to the formation of an adsorbed film of inhibitor on the metal surface which protects the metal against corrosion. The inhibition efficiency (%IE and surface coverage (θ of N. tabacum extract increased with increase in inhibitor concentration but decreased with increasing the temperature. The adsorption of extract on the mild steel surface was found to obey Langmuir’s adsorption isotherm. The free energy value (ΔGads indicated that the adsorption of inhibitor molecules was typical of physisorption. The results obtained show that N. tabacum Extract could serve as an excellent eco-friendly green corrosion inhibitor. Quantum chemical parameters such as highest occupied molecular orbital energy (EHOMO, lowest unoccupied molecular orbital energy (ELUMO, energy gap (ΔE, dipole moment (μ and Mulliken charges were calculated. Quantum chemical calculations also supported experimental data and the adsorption of inhibitor molecules onto the metal surface.

  3. Effect of tannin from Rhizophora apiculate as corrosion inhibitor for epoxy paint on mild steel

    Science.gov (United States)

    Idora, M. S. Noor; Quen, L. K.; Kang, H. S.

    2017-09-01

    There is a great concern to protect the steel surfaces from corrosion phenomenon in seawater environment. Several approaches have been proposed to introduce alternative new compounds in the paint which are green sources that can reduce environmental risks. The aim of this investigation was to enhance the protection properties of epoxy paint by providing an anticorrosive inhibitor for the paint. In this approach, the abilities of mangrove tannins, extracted from Rhizophora apiculata bark were studied. The inhibitive properties of mangrove tannins were evaluated by weight loss measurement, electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM). Results shows the addition of mangrove tannin in the coating boosted the anticorrosive properties of the paint and represents valuable environmentally friendly of inhibitor.

  4. Is the analysis of molecular electronic structure of corrosion inhibitors sufficient to predict the trend of their inhibition performance

    Energy Technology Data Exchange (ETDEWEB)

    Kokalj, Anton, E-mail: tone.kokalj@ijs.s [Department of Physical and Organic Chemistry, Jozef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia)

    2010-12-30

    The often used approach in the corrosion inhibition studies employing quantum chemical calculations that relies on the correlation between molecular electronic structure parameters and inhibition effectiveness is critically examined. It is shown that the inhibition performance of three selected triazole-based corrosion inhibitors for copper - 3-amino-1,2,4-triazole (ATA), benzotriazole (BTAH), and 1-hydroxybenzotriazole (BTAOH) - cannot be explained on this basis in a sound manner. As the effectiveness of inhibitors is due to several phenomena, the outcome depends on the interplay between them and although molecular electronic parameters may provide many necessary elements, the involved effects can be estimated only approximately which may not always suffice. This supports the proposition that in general molecular electronic properties cannot be directly related to inhibition effectiveness - the actual relation is more involved - thus emphasizing the importance of a rigorous modeling of the inhibitor-surface interaction in the corrosion inhibition studies.

  5. Opuntia ficus-indica Extract as Green Corrosion Inhibitor for Carbon Steel in 1 M HCl Solution

    Directory of Open Access Journals (Sweden)

    J. P. Flores-De los Ríos

    2015-01-01

    Full Text Available The effect of Opuntia ficus-indica (Nopal as green corrosion inhibitor for carbon steel in 1 M HCl solution has been investigated by using weight loss tests, potentiodynamic polarization curves, and electrochemical impedance spectroscopy measurements. Also, scanning electron microscopy (SEM and Fourier transform infrared spectroscopy (FT-IR analysis were performed. The inhibitor concentrations used ranged from 0 to 300 ppm at 25, 40, and 60°C. Results indicated the inhibition efficiency increases with increasing extract concentration and decreases with the temperature, and the inhibitor acted as a cathodic-type inhibitor which is physically absorbed onto the steel surface. In fact, the adsorption of the inhibitor on the steel surface follows the Langmuir adsorption isotherm, indicating monolayer adsorption. The presence of heteroatoms such as C, N, and O and OH groups were responsible for the corrosion inhibition.

  6. Extraction of oleuropein from olive leaves, in order to use as inhibitor against the corrosion of metals

    Directory of Open Access Journals (Sweden)

    EFROSINI KOKALARI (TELI

    2014-06-01

    Full Text Available Oleuropein is the most abundant phenolic compound in olive leaves. This compound has been extensively studied for human health benefits. In recent years oleuropein, is proved to be an efficient inhibitor against the corrosion of metals and alloys. The use of chemical inhibitors has been limited, because of the environmental threat. The increasing ecological awareness among scientists have led to the development of “green” alternatives to mitigate corrosion. It is very important to choose cheap and safety handled compounds to be used as corrosion inhibitors.The extract of oleuropein from olive leaves, represent a great inhibitive action about 93%, against the corrosion of carbon steel in acidic media. Oleuropein, a natural product of the secoiridoid group, is a heterosidic ester of elenolic deteracid and 3,4-dihydroxyphenylethanol, containing a molecule of glucose, the hydrolysis of which yields elenolic acid glucoside and hydroxytyrosol. Oleuropein from the olive leaves was obtained by alcoholic extraction in room temperature using microwave irradiation. The extract was stored at 4oC and in the dark. The product of extraction was analyzed with HPLC, and infrared (IR spectroscopy, in order to define it’s chemical structure. Also we defined the yield, density and molecular weight of the product. The product of extraction was oleuropein and we propose to use it as corrosion inhibitor.

  7. Amino acids as corrosion inhibitors for copper in acidic medium: Experimental and theoretical study

    Directory of Open Access Journals (Sweden)

    Milošev Ingrid

    2013-01-01

    Full Text Available Experimental electrochemical methods combined with quantum chemical calculations and molecular dynamics simulations were used to investigate the possibility of use various amino acids as “green” corrosion inhibitors for copper in 0.5 M HCl solution. Among eleven amino acids studied, cysteine achieved the highest inhibitor effectiveness reaching 52% at 10 mM concentration. Other amino acids reached achieved effectiveness less than 25%, some of them even acted as corrosion accelerators. Based on the experimental results, theoretical calculations and simulations were focused on cysteine and alanine. The electronic and reactivity parameters of their protonated forms in electrical double layer were evaluated by density functional calculations. In addition, molecular dynamic simulations were introduced to follow the adsorption behaviour of these two amino acids at the Cu(111 surface in the electrolyte solution. The results indicate that the orientation of both molecules is nearly parallel to the surface except of ammonium group which is directed away from the surface. Therefore, as the orientation of the cysteine and alanine molecules at the surface is similar, thiol functional group is responsible for superior inhibition efficiency of cysteine.

  8. Synthesis and Application of Phenyl Nitrone Derivatives as Acidic and Microbial Corrosion Inhibitors

    Directory of Open Access Journals (Sweden)

    Shijun Chen

    2015-01-01

    Full Text Available Nitrone has drawn great attention due to its wide applications as a 1,3-dipole in heterocyclic compounds synthesis and the bioactivities. With the special structure, nitrone can also be used as ligand in inorganic chemistry. Based on the current research, the nitrones are anticipated to be effective inhibitors against acidic and microbial corrosion. The aim of this work is to investigate the inhibitory action of nitrones. In this work, a series of phenyl nitrone derivatives (PN was synthesized and used as acidic and microbial corrosion inhibitors. The results indicate that several compounds show moderate to high inhibition efficiency (IE in 3% HCl. Accompanied with HMTA or BOZ, the IEs greatly increase, and the highest efficiency of 98.5% was obtained by using PN4 + BOZ. Investigation of the antibacterial activity against oilfield microorganism shows that the nitrone derivatives can inhibit SRB, IB, and TGB with moderate to high efficiency under 1,000 mg/L, which makes them potential to be used as bifunctional oilfield chemicals.

  9. Eclipta Alba as Corrosion Pickling Inhibitor on Mild Steel in Hydrochloric Acid

    Institute of Scientific and Technical Information of China (English)

    M. Shyamala; A. Arulanantham

    2009-01-01

    Due to ease of application, cost effectiveness and environmentally safe, in this study, the corrosion inhibition effect of aqueous extract of Eclipta alba in 1 N hydrochloric acid has been investigated by weight loss, potentiodynamic polarization and impedance methods and the extracts of Eclipta alba were found to be effective corrosion pickling inhibitor. The effect of immersion time and temperature revealed that the extracts of Eclipta alba with an optimum concentration of 8.0% v/v showed maximum inhibition efficiency of 99.6% at 3 h immersion time and 30℃. Arrhenius plots for mild steel immersed in 1 N HCI solution in the absence and presence of optimum concentration (8.0% in v/v) of Eclipta alba extract showed the effect of temperature. Polarization studies indicate that this plant extract acts as a mixed type inhibitor. The adsorption of Eclipta alba follows Langmuir adsorption isotherm. The inhibition action may be due to the presence of the Wedelactone and also the alkaloid Ecliptine present in the leaves of Eclipta alba.

  10. Anaerobic digestion of aircraft deicing fluid wastes: interactions and toxicity of corrosion inhibitors and surfactants.

    Science.gov (United States)

    Gruden, Cyndee L; Hernandez, Mark

    2002-01-01

    Corrosion inhibitors and surfactants are present in aircraft deicing fluids (ADFs) at significant concentrations (> 1% w/w). The purpose of this research was to study the interactions of a common nonionic surfactant with the commercially significant corrosion inhibitors used in modern ADF (4- and 5-methylbenzotriazole [MeBT]), and to determine the effects of their mixture on the conventional anaerobic digestion process. In mesophilic anaerobic microcosms codigesting wastewater solids, propylene glycol, and MeBT, increasing surfactant levels resulted in enhanced MeBT sorption on digester solids. As judged by anaerobic toxicity assays, responses from digesters containing surfactant concentrations below their critical micelle concentration (CMC) suggested that low nonionic surfactant concentrations could facilitate a reduction in the apparent toxicity of MeBT. In microcosms exposed to surfactant concentrations above their CMC, no increase in MeBT solubility was observed, and the anaerobic toxicity response corresponded to control systems not containing surfactant. Direct microscopic measurements of digesting biomass using fluorescent phylogenetic probes (fluorescent in situ hybridization) revealed that members of the domain Bacteria were more sensitive to MeBT in the presence of surfactant than were members of the domain Archaea.

  11. Multicomponent click synthesis of new 1,2,3-triazole derivatives of pyrimidine nucleobases: promising acidic corrosion inhibitors for steel.

    Science.gov (United States)

    González-Olvera, Rodrigo; Espinoza-Vázquez, Araceli; Negrón-Silva, Guillermo E; Palomar-Pardavé, Manuel E; Romero-Romo, Mario A; Santillan, Rosa

    2013-12-06

    A series of new mono-1,2,3-triazole derivatives of pyrimidine nucleobases were synthesized by one-pot copper(I)-catalyzed 1,3-dipolar cycloaddition reactions between N-1-propargyluracil and thymine, sodium azide and several benzyl halides. The desired heterocyclic compounds were obtained in good yields and characterized by NMR, IR, and high resolution mass spectrometry. These compounds were investigated as corrosion inhibitors for steel in 1 M HCl solution, using electrochemical impedance spectroscopy (EIS) technique. The results indicate that these heterocyclic compounds are promising acidic corrosion inhibitors for steel.

  12. Multicomponent Click Synthesis of New 1,2,3-Triazole Derivatives of Pyrimidine Nucleobases: Promising Acidic Corrosion Inhibitors for Steel

    Directory of Open Access Journals (Sweden)

    Rodrigo González-Olvera

    2013-12-01

    Full Text Available A series of new mono-1,2,3-triazole derivatives of pyrimidine nucleobases were synthesized by one-pot copper(I-catalyzed 1,3-dipolar cycloaddition reactions between N-1-propargyluracil and thymine, sodium azide and several benzyl halides. The desired heterocyclic compounds were obtained in good yields and characterized by NMR, IR, and high resolution mass spectrometry. These compounds were investigated as corrosion inhibitors for steel in 1 M HCl solution, using electrochemical impedance spectroscopy (EIS technique. The results indicate that these heterocyclic compounds are promising acidic corrosion inhibitors for steel.

  13. The reduction ring-opening reaction of imidazoline

    Institute of Scientific and Technical Information of China (English)

    史真; 李诤; 白银娟

    2000-01-01

    A new reduction ring-opening reaction of 2-imidazoline with sodium borohydride is reported, and the effect of reaction condition on the yield, reaction mechanism and the use of the new reaction in synthesis of ethylenediamine derivatives are discussed. A new method for the preparation of unsymmetrical substituted ethylenediamine via the reduction ring-opening reaction of imidazoline is provided.

  14. Preparation of ferrocenyl imidazolines using bis(triphenyl)oxodiphosphonium trifluoromethanesulfonate

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    An efficient synthesis of ferrocenyl imidazolines starting from ferrocenyl carboxylic acids has been developed. Bis(triphenyl)oxodiphosphonium trifluoromethanesulfonate was used to convert smoothly ferrocenyl carboxylic amides bearing an amine side chain, derived from ferrocenyl carboxylic acids and 1,2-diamines, to their corresponding ferrocenyl imidazolines.

  15. Preparation of ferrocenyl imidazolines using bis(triphenyl)oxodiphosphonium trifluoromethanesulfonate

    Institute of Scientific and Technical Information of China (English)

    WANG XueQiang; XIA JiBao; DAI XiaoYang; YOU ShuLi

    2009-01-01

    An efficient synthesis of ferrocenyl imidazolines starting from ferrocenyl carboxylic acids has been developed.Bis(triphenyl)oxodiphosphonium trifluoromethanesulfonate was used to convert smoothly ferrocenyl carboxylic amides bearing an amine side chain,derived from ferrocenyl carboxylic acids and 1,2-diamines,to their corresponding ferrocenyl imidazolines.

  16. Synthesis, spectral and structural properties of bis-imidazoline selones

    Indian Academy of Sciences (India)

    Arruri Sathyanarayana; Katam Srinivas; Anindita Mandal; Saswati Gharami; Ganesan Prabusankar

    2014-09-01

    New biphenyl derivatives of bis-imidazoline selones were synthesized in good yield and characterized by multinuclear (1D and 2D) NMR and UV-vis studies. The solid state structures of bis-imidazoline selones were further confirmed by single crystal X ray diffraction technique.

  17. The Efficient Synthesis of 2-Arylamino-2-imidazolines, 2-Heteroaryl ...

    African Journals Online (AJOL)

    2-Arylamino-2-imidazolines were prepared by heating dimethyl aryldithioimidocarbonates and ethylenediamine under reflux. ... proaches entails a three-step protocol involving the conversion ..... 2-arylamino-2-imidazoline 3a,b or 6b (0.01 mol) in methanol ... (C–N stretching), 1110 (cyclic ether C–O–C stretching), 741.

  18. 缓蚀剂分子结构与抗硫性能及其缓蚀机理研究%RELATIONSHIP BETWEEN CHEMICAL MOLECULAR STRUCTURE AND ANTI-SULFUR PROPERTIES AND INHIBITION MECHANISM OF CORROSION INHIBITORS

    Institute of Scientific and Technical Information of China (English)

    刘月学; 刘烈炜; 董猛; 张大同

    2012-01-01

    用饱和H_2S/CO_2失重法、高压H_2S/CO_2动态失重法、原子力显微镜(AFM)、环境扫描电镜(SEM)和X射线能量色散光谱(EDX)研究了咪唑啉衍生物、曼尼希碱、吡啶季铵盐、喹啉季铵盐和新稠杂环季铵盐5种不同分子结构缓蚀剂对N80钢的抗硫性能。结果表明5种缓蚀剂对N80钢的抗硫性能均随缓蚀剂浓度的增加而增强,各缓蚀剂的抗硫性能优劣顺序为:新稠杂环季铵盐〉喹啉季铵盐〉吡啶季铵盐〉咪唑啉衍生物〉曼尼希碱。静电吸附作用较强、空间位阻效应较小且中心吸附原子的电子云密度较大的缓蚀剂抗硫效果更好,其缓蚀机理主要是有效抑制CO_2/Cl~-腐蚀且促使试片表面生成致密的硫化物保护膜。%The inhibitive properties of five kinds of corrosion inhibitors,which contain imidazoline derivative, mannich base,pyridine quaternary ammonium salt,quinoline quaternary ammonium salt and a new fused heterocycle quaternary ammonium salt were studied by means of mass loss of saturated H_2S/CO_2 and dynamic rotating with high-pressure of H_2S/CO_2,atomic force microscopy(AFM),environmental scanning electron microscope (SEM) and energy dispersive X-ray(EDX) analysis on N80 steel.The results showed that inhibitive properties of five kinds of inhibitors enhanced with the increase of their concentration.The excellent order of the inhibitors was as followed:the new fused heterocycle quaternary ammonium saltquinoline quaternary ammonium saltpyridine quaternary ammonium saltimidazoline derivativemannich base.Corrosion inhibitor which had stronger electrostatic adsorption,smaller steric hindrance effect and larger electron density of the adatom had the better anti-sulfur properties.The inhibition mechanism of corrosion inhibitor was to inhibit the corrosion of CO_2/C1~- and spur the formation of the compact sulfide film.

  19. In-situ contact electrical resistance technique for investigating corrosion inhibitor adsorption on copper electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Moretti, G.; Quartarone, G.; Zingales, A. [Univ. of Venice (Italy). Dept. of Chemistry; Molokanov, V.V. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Physical Chemistry

    1998-02-01

    Traditional electrochemical tests and the contact electrical resistance technique (CER) were used to investigate the effect on corrosion of pure copper (99.999 wt%) of adding benzotriazole (BTA) and 1-hydroxybenzotriazone (1-OH-BTA) to acidic solutions (sulfuric acid [H{sub 2}SO{sub 4}], pH = 1.7, and sodium sulfate [Na{sub 2}SO{sub 4}] until total sulfate [SO{sub 4}{sup 2{minus}}] concentration = 0.1 M). This technique permitted growth of oxide and/or salt films as well as adsorption of the organic inhibitors on the copper surface to be evaluated. Formation of copper oxide ([Cu{sub 2}O]{sub 2})., sulfate (CuSo{sub 4}{center_dot}5H{sub 2}O), thiocyanate (CuSCN), and halogenyde (CuI, CuBr, and CuCl) films on copper electrodes was followed in situ in sulfate solutions at various pH values under low overpotentials. Effects of pH, solution anion content, and/or the amount of BTA or 1-OH-BTA on electrical resistance (R) of the surface films formed on pure copper electrodes were treated. BTA acted as a more efficient corrosion inhibitor than 1-OH-BTA, reaching inhibition percentages (IP) of {approximately}90% compared to those of 1-OH-BTA, which reached a maximum of {approximately}76% in 2 {times} 10{sup {minus}3} M solutions. It was possible to distinguish between maximum R of the surface film, found in solutions containing BTA, associated with the adsorption of neutral inhibitor molecules, and the sharp rise in R attributable to [Cu(BTA)]{sub n} complex formation.

  20. Organic compounds as corrosion inhibitors for mild steel in acidic media: correlation between inhibition efficiency and chemical structure

    Energy Technology Data Exchange (ETDEWEB)

    Elias, Elizandra C.S.; Chrisman, Erika C.A.N. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Escola de Quimica

    2009-12-19

    The use of inhibitors for mild steels corrosion control which are in contact with aggressive environment is an accepted practice in acid treatment of oil-wells. Organic compounds have been studied to evaluate their corrosion inhibition potential. Film-forming corrosion inhibitors, commonly used to protect oil-field equipment, can be absorbed on the steel surface to give structurally ordered layers. Therefore, the electrons should act as an important role for this adsorption. Studies reveal that organic compounds show significant inhibition efficiency. For this purpose, their molecules should contain N, O and S heteroatoms in various functional groups, long hydrocarbon linear or branched radical and anion and cation active components. However, most of these compounds are not only expensive but also toxic to living beings. According to the 'Green Chemistry' rules, corrosion inhibitors based on organic compounds should be cheap, with low toxicity and have high inhibition efficiency. In this study, the effects of some organic compounds with different groups such as amide, ether, phenyldiamine, anime and aminophenol on the corrosion behavior of mild steel in acidic media have been investigated. The experimental data were obtained by gravimetric measurements. The results show that these compounds reveal a promising corrosion inhibition where phenyldiamine is the most efficient. The effect of molecular structure on the corrosion inhibition efficiency was investigated by semi-empirical quantum chemical calculations. The electronic properties such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy levels, and LUMO-HOMO energy gap orbital density were calculated. The relations between the inhibition efficiency and some quantum parameters are discussed and correlations are proposed. The highest values for the HOMO densities were found in the vicinity nitrogen atom, indicating that it is the most probable adsorption center

  1. Electrochemical evaluation of antibacterial drugs as environment-friendly inhibitors for corrosion of carbon steel in HCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Golestani, Gh.; Shahidi, M., E-mail: shahidi1965@gmail.com; Ghazanfari, D.

    2014-07-01

    The effect of penicillin G, ampicillin and amoxicillin drugs on the corrosion behavior of carbon steel (ASTM 1015) in 1.0 mol L⁻¹ hydrochloric acid solution was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) techniques. The inhibition efficiency was found to increase with increasing inhibitor concentration. The effect of temperature on the rate of corrosion in the absence and presence of these drugs was also studied. Some thermodynamic parameters were computed from the effect of temperature on corrosion and inhibition processes. Adsorption of these inhibitors was found to obey Langmuir adsorption isotherm. There was a case of mixed mode of adsorption here but while penicillin was adsorbed mainly through chemisorption, two other drugs were adsorbed mainly through physisorption. Potentiodynamic polarization measurements indicated that the inhibitors were of mixed type. In addition, this paper suggests that the electrochemical noise (EN) technique under open circuit conditions as the truly noninvasive electrochemical method can be employed for the quantitative evaluation of corrosion inhibition. This was done by using the standard deviation of partial signal (SDPS) for calculation of the amount of noise charges at the particular interval of frequency, thereby obtaining the inhibition efficiency (IE) of an inhibitor. These IE values showed a reasonable agreement with those obtained from potentiodynamic polarization and EIS measurements.

  2. A new dioxime corrosion inhibitor for the protection and conservation of copper: synthesis, characterization and evaluation in acidic chloride solution

    Science.gov (United States)

    Abu-Baker, Ahmad N.; Al-Qudah, Mahmoud A.

    2016-08-01

    This study aimed to investigate a new dioxime compound as a corrosion inhibitor for copper. The compound (4,6-dihydroxy benzene-1,3-dicarbaldehyde dioxime) was synthesized and characterized by nuclear magnetic resonance spectroscopy. Electrochemical impedance spectroscopy and potentiodynamic polarization measurements were used to compare the dioxime compound with benzotriazole for their effectiveness as corrosion inhibitors for copper in 0.1 M HCl solution. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were used to investigate the bonding mechanisms and morphological changes of the two inhibitors on the copper surface. The electrochemical techniques showed that the new dioxime compound was more effective than benzotriazole in inhibiting copper corrosion in the acidic chloride medium. The FTIR and SEM results indicated that the dioxime compound was able to coordinate with copper ions and formed a protective film on the copper surface. It was concluded that the new dioxime compound proved effectiveness to be used as a corrosion inhibitor for the protection and conservation of copper.

  3. Effects of Corrosion Inhibitors on Lubrication Performance of Rolling Oil for Copper Foil

    Institute of Scientific and Technical Information of China (English)

    Xiong Sang; Sun Jianlin; Zeng Yingfeng; Xu Yang

    2014-01-01

    The 2,5-bis(ethyldisulfanyl)-1,3,4-thiadiazole (T561), benzotriazole (BTA), 1-N, N-bis (2-ethylhexyl) amino-methyl-4-methyl-1h-benzotriazole (IRGAMET39) and 1-[N, N-bis (2-ethylhexyl) aminomethyl] methyl benzotriazole (TT-LX) have been evaluated as corrosion inhibitors used in rolling oil for cold rolling of copper foil. The MRS-10A four-ball friction and wear tests have been carried out to compare their tribological properties, and the lubricating performance of rolling oils has been studied through rolling experiments. The oil sample containing IRGAMET 39 has the same PB value as that one containing T561, with the coefifcient of friction increased by 35.6%and wear scar diameter decreased by 4%. The minimum rolling gauge has been studied after rolling lubrication, but the results show that inhibitors have no effect on it. Scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) analyses have indicated that the inhibitor is adsorbed on the copper surface to prevent copper from being corroded easily. In addition, the LEXT OLS4000 laser confo-cal microscopy has been used to observe the foil surface which shows that the streaks of foil surface are clear, the scratches are shallow and the surface failure is improved effectively.

  4. DETERMINATION OF CORROSION INHIBITOR CRITERIA FOR TYPE III/IIIA TANKS DURING SALT DISSOLUTION OPERATIONS SUMMARY DOCUMENT

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J.; Wiersma, B.; Garcia-Diaz, B.

    2009-10-01

    Dissolution of salt from Type III/IIIA waste tanks at the Savannah River Site may create solutions with inhibitor concentrations below those currently required (0.6M OH{sup -} and 1.1M OH{sup -} + NO{sub 2}{sup -}) per the Corrosion Control Program for high nitrate salt solutions (5.5 to 8.5M NO{sub 3}{sup -}). An experimental program was conducted to evaluate the corrosion susceptibility of grade A537 carbon steel for waste simulants containing 4.5-8.5M NaNO{sub 3} with maximum inhibitor concentrations of 0.6M NaOH and 0.2M NaNO{sub 2}. These maximum inhibitor concentrations used in this program are at a reduced level from those currently required. Current requirements were initially established for the Types I, II and IV tanks made of A285 carbon steel. The experimental program involved corrosion testing to evaluate the pitting and stress corrosion stress corrosion cracking (SCC) susceptibility of the Type III/IIIA waste tank materials. The program was conducted in two phases; the results of the first phase were reported previously (WSRC-STI-2006-00029). In this second phase, the corrosion specimens were modified to represent the 'as-fabricated' condition of the tank wall, and included specimens with mill scale, ground welds and stress-relief heat treatments. The complete description of the corrosion testing and the results are reported herein. The collective corrosion test results for A537 carbon steel in high nitrate waste simulants (4.5 - 8.5M) with the maximum inhibitor concentrations of 0.6M NaOH and 0.2M NaNO{sub 2} were as follows: (1) In long-term non-polarized U-bend testing, heat treatment, similar to the waste tank stress relief regime, reduced the incidence of cracking over the 18-month test period. Vapor space SCC was found to initiate on non-heat treated U-bend coupons. (2) In polarized U-bend testing, cracking occurred on U-bend coupons that had welds prepared similar to those in the waste tanks, i.e. ground and heat treated. (3) In

  5. Localized dealloying corrosion mediated by self-assembled monolayers used as an inhibitor system.

    Science.gov (United States)

    Shrestha, B R; Bashir, A; Ankah, G N; Valtiner, M; Renner, F U

    2015-01-01

    The structure and chemistry of thiol or selenol self-assembled organic monolayers have been frequently addressed due to the unique opportunities in functionalization of materials. Such organic films can also act as effective inhibition layers to mitigate oxidation or corrosion. Cu-Au alloy substrates covered by self-assembled monolayers show a different dealloying mechanism compared to bare surfaces. The organic surface layer inhibits dealloying of noble metal alloys by a suppression of surface diffusion at lower potentials but at higher applied potentials dealloying proceeds in localized regions due to passivity breakdown. We present an in situ atomic force microscopy study of a patterned thiol layer applied on Cu-Au alloy surfaces and further explore approaches to change the local composition of the surface layers by exchange of molecules. The pattern for the in situ experiment has been applied by micro-contact printing. This allows the study of corrosion protection with its dependence on different molecule densities at different sites. Low-density thiol areas surrounding the high-density patterns are completely protected and initiation of dealloying proceeds only along the areas with the lowest inhibitor concentration. Dealloying patterns are highly influenced and controlled by molecular thiol to selenol exchange and are also affected by introducing structural defects such as scratches or polishing defects.

  6. Bee Wax Propolis Extract as Eco-Friendly Corrosion Inhibitors for 304SS in Sulfuric Acid

    Directory of Open Access Journals (Sweden)

    Femiana Gapsari

    2015-01-01

    Full Text Available The inhibition properties of bee wax propolis (BWP extract on the 304SS in 0.5 M sulfuric acid were conducted using potentiodynamic polarization, EIS, and XRD. Quercetin (2-(3.4-dihydroxy phenyl-3.5.7-trihydroxy-4H-chromen-4-one was identified as the main compound in the BWP extract based on FTIR and HPLC analysis. The results showed that the inhibitor could retard the corrosion rate of 304SS in 0.5 M sulfuric acid which reached 97.29% and 91.42% at 2000 ppm based on potentiodynamic polarization and EIS measurement, respectively. The inhibition efficiency decreased with increasing temperature. The inhibition mechanism of BWP extract on the 304SS was physisorption and obeyed Temkin adsorption isotherm equation. The thin protective layer on the 304SS surface was confirmed by XRD.

  7. Herbs as new type of green inhibitors for acidic corrosion of steel

    Energy Technology Data Exchange (ETDEWEB)

    Khamis, E. [Faculty of Science, Chemistry Department, Alexandria University, P.O. Box 426 Ibrahimia Alexandria 21321 (Egypt); AlAndis, N. [College of Science, Chemistry Department, King Saud University (Saudi Arabia)

    2002-09-01

    Corrosion inhibition of steel in sulphuric acid by six different herb plants has been studied using a.c and d.c electrochemical techniques. The environmentally friendly investigated compounds are namely: thyme, coriander, hibiscus, anis, black cumin and Garden cress. Electrochemical impedance spectroscopy has been successfully used to evaluate the performance of these compounds. The ac measurements showed that the dissolution process is activation controlled. Bode and theta diagrams show only one time constant ({tau}). Potentiodynamic polarization curves indicate that the studied compounds are mixed-type inhibitors. The order of increasing inhibition efficiency was correlated with the change of the constituent active materials of the compounds. Thyme, which contains the powerful antiseptic thymol as the active ingredient, offers excellent protection for steel surface. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

  8. An assessment to evaluate the validity of different methods for the description of some corrosion inhibitors.

    Science.gov (United States)

    Aboelnga, M M; Awad, M K; Gauld, J W; Mustafa, M R

    2014-09-01

    New research and development efforts using computational chemistry in studying an assessment of the validity of different quantum chemical methods to describe the molecular and electronic structures of some corrosion inhibitors were introduced. The standard and the highly accurate CCSD method with 6-311++G(d,p), ab initio calculations using the HF/6-31G++(d,p) and MP2 with 6-311G(d,p), 6-31++G(d,p), and 6-311++G(2df,p) methods as well as DFT method at the B3LYP, BP86, B3LYP*, M06L, and M062x/6-31G++(d,p) basis set level were performed on some triazole derivatives and sulfur containing compounds used as corrosion inhibitors. Quantum chemical parameters, such as the energy of the highest occupied molecular orbital energy (E(HOMO)), the energy of the lowest unoccupied molecular orbital energy (E(LUMO)), energy gap (ΔE), dipole moment (μ), sum of total negative charges (TNC), chemical potential (Pi), electronegativity (χ), hardness (η), softness (σ), local softness (s), Fukui functions (f (+),f (-)), electrophilicity (ω), the total energy change (∆E(T)) and the solvation energy (S.E), were calculated. Furthermore, the accuracy and the applicability of these methods were estimated relative to the highest accuracy and standard CCSD with 6-311++G(d,p) method. Good correlations between the quantum chemical parameters and the corresponding inhibition efficiency (IE%) were found.

  9. Assessment of multi-phase movements in a gas-gathering pipeline and the relevance to on-line, real-time corrosion monitoring and inhibitor injection

    Energy Technology Data Exchange (ETDEWEB)

    Baker, M.A.; Asperger, R.G.

    1988-01-01

    A study was conducted to determine the time required for aqueous fluid to travel 100 miles (160 km) from an offshore platform in the Gulf of Mexico to landfill. If this time is short, the corrosivity of the water at landfall may be used as the basis for setting the offshore corrosion inhibitor injection rates. But, for this particular system, the traveling time was found to be long, greater than 65 days. Therefore, the corrosivity as measured on-shore can not be used for online, real-time adjustments of the offshore, corrosion inhibitor chemical pumps.

  10. Aluminum corrosion mitigation in alkaline electrolytes containing hybrid inorganic/organic inhibitor system for power sources applications

    Science.gov (United States)

    Gelman, Danny; Lasman, Itay; Elfimchev, Sergey; Starosvetsky, David; Ein-Eli, Yair

    2015-07-01

    The severe corrosion accompanied with hydrogen evolution process is the main obstacle preventing the implementation of Al as an anode in alkaline batteries. It impairs the functionality of alkaline battery, due to a drastic capacity loss and a short shelf life. The possibility to reduce Al corrosion rate in alkaline solution with the use of hybrid organic∖inorganic inhibitor based on poly (ethylene glycol) di-acid (PEG di-acid) and zinc oxide (ZnO) was examined in this work. A correlation between an Al corrosion rates and the concentrations of both PEG di-acid and ZnO in alkaline is shown. Selecting 5000 ppm PEG di-acid and 16 gr/l ZnO provides substantial corrosion protection of Al, reducing the corrosion rate in a strong alkaline solution by more than one order of magnitude. Moreover, utilizing the same formulation results in increase in Al-air battery discharge capacity, from 44.5 (for a battery utilizing only KOH in the electrolyte) to 70 mhA/cm2 (for a battery utilizing ZnO/PEG di-acid hybrid inhibitor in the electrolyte). The morphology and composition of the Al electrode surface (studied by SEM, EDS, and XRD) depend on PEG di-acid and ZnO concentrations.

  11. Development and Application of Green Corrosion Inhibitors Extracted from Natural Plants%天然植物绿色缓蚀剂的发展与应用

    Institute of Scientific and Technical Information of China (English)

    陈洪祥; 蒋林华; 任利剑; 吴宇研; 郭万里; 陈虹霖

    2012-01-01

    综述了国内外从天然植物中提取绿色缓蚀剂的研究历程,并展望了其发展趋势:从天然植物中提取、分离、加工新型绿色缓蚀剂的有效成分,进一步研究植物型绿色缓蚀剂作用机理,绿色缓蚀剂的复配以及高新科技在植物缓蚀剂研发时的应用是未来植物型缓蚀剂发展的重要方向。%The development process of green corrosion inhibitors extracted from natural plants was summarized, and the development trends of the natural environmental friendly corrosion inhibitors were discussed. It was showed that the new environmental friendly corrosion inhibitors extracted and separated from natural plants, further research on mechanism of green corrosion inhibitors, the compound formula of various green corrosion inhibitors and application of high technology in development of green corrosion inhibitors were valuable direction of development of green corrosion inhibitors extracted from natural plants in the future.

  12. Some aromatic hydrazone derivatives as inhibitors for the corrosion of C-steel in phosphoric acid solution.

    Science.gov (United States)

    Fouda, Abd El-Aziz S; Al-Sarawy, Ahmed A; Radwan, Mohamed S

    2006-01-01

    The effect of furfural benzoylhydrazone and its derivatives (I-VII) as corrosion inhibitors for C-steel in 1M phosphoric acid solution has been studied by weight-loss and galvanostatic polarization techniques. A significant decrease in the corrosion rate of C-steel was observed in the presence of the investigated inhibitors. This study revealed that, the inhibition efficiency increases with increasing the inhibitor concentration, and the addition of iodide ions enhances it to a considerable extent. The effect of temperature on the inhibition efficiency of these compounds was studied using weight-loss method. Activation energy (E(a)*) and other thermodynamic parameters for the corrosion process were calculated and discussed. The galvanostatic polarization data indicated that, the inhibitors were of mixed-type, but the cathode is more polarized than the anode. The adsorption of these compounds on C-steel surface has been found to obey Frumkin's adsorption isotherm. The mechanism of inhibition was discussed in the light of the chemical structure of the undertaken inhibitors.

  13. Corrosion inhibition by inorganic cationic inhibitors on the high strength alumunium alloy, 2024-T3

    Science.gov (United States)

    Chilukuri, Anusha

    The toxicity and carcinogenic nature of chromates has led to the investigation of environmentally friendly compounds that offer good corrosion resistance to AA 2024-T3. Among the candidate inhibitors are rare earth metal cationic (REM) and zinc compounds, which have received much of attention over the past two decades. A comparative study on the corrosion inhibition caused by rare earth metal cations, Ce3+, Pr3+, La3+ and Zn2+ cations on the alloy was done. Cathodic polarization showed that these inhibitor ions suppress the oxygen reduction reaction (ORR) to varying extents with Zn2+ providing the best inhibition. Pr3+ exhibited windows of concentration (100-300 ppm) in which the corrosion rate is minimum; similar to the Ce3+ cation. Scanning Electron Microscopy (SEM) studies showed that the mechanism of inhibition of the Pr3+ ion is also similar to that of the Ce3+ ion. Potentiodynamic polarization experiments after 30 min immersion time showed greatest suppression of oxygen reduction reaction in neutral chloride solutions (pH 7), which reached a maximum at a Zn2+ ion concentration of 5 mM. Anodic polarization experiments after 30 min immersion time, showed no anodic inhibition by the inhibitor in any concentration (0.1 mM - 10 mM) and at any pH. However, anodic polarization of samples immersed after longer immersion times (upto 4 days) in mildly acidic Zn2+ (pH 4) solutions showed significant reduction in anodic kinetics indicating that zinc also acts as a “slow anodic inhibitor”. In contrast to the polarization experiments, coupons exposed to inhibited acidic solutions at pH 4 showed complete suppression of dissolution of Al2CuMg particles compared to zinc-free solutions in the SEM studies. Samples exposed in pH 4 Zn2+-bearing solution exhibited highest polarization resistance which was also observed to increase with time. In deaerated solutions, the inhibition by Zn2+ at pH 4 is not observed as strongly. The ability to make the interfacial electrolyte

  14. Inhibiting Properties of Morpholine as Corrosion Inhibitor for Mild Steel in 2N Sulphuric Acid and Phosphoric Acid Medium

    Directory of Open Access Journals (Sweden)

    K. Jayanthi

    2012-01-01

    Full Text Available The inhibition effect of morpholine on the corrosion of mild steel in 2N sulphuric acid and phosphoric acid has been studied by mass loss and polarization techniques between 302K and 333K. The inhibition efficiency increased with increase in concentration. The corrosion rate increased with increase in temperature and decreased with increase in concentration of inhibitor compared to blank. The adsorption of inhibitor on the mild steel surface has been found to obey Temkin's adsorption isotherm. Potentiostatic polarization results reveal that morpholine act as mixed type inhibitor. The values of activation energy (Ea, free energy of adsorption (∆Gads, enthalpy of adsorption (∆H, and entropy of adsorption (∆S were also calculated.

  15. Synthesis of some novel non ionic surfactants based on tolyltriazole and evaluation their performance as corrosion inhibitors for carbon steel

    Directory of Open Access Journals (Sweden)

    M.A. Migahed

    2013-06-01

    Full Text Available Five new synthesized non ionic surfactants (I–V were synthesized and characterized using FTIR and NMR spectroscopic methods. Performance of the synthesized compounds as corrosion inhibitors for X- 65 type carbon steel in oil wells formation water was investigated by various techniques such as weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS. It was found that the percentage inhibition efficiency (η% increases by increasing the inhibitor concentration until the critical micelle concentration (CMC is reached. Also, the results showed enhancement in inhibition efficiencies with increasing both molecular size of the surfactant and the degree of ethoxylation. Potentiodynamic polarization curves indicated that the inhibitors under investigation act as mixed type. The data obtained from electrochemical impedance spectroscopy (EIS were analyzed to model the corrosion inhibition process through equivalent circuit. Finally, the nature of the protective film formed on carbon steel surface was analyzed by SEM and EDX techniques.

  16. DETERMINATION OF CORROSION INHIBITOR CRITERIA FOR TYPE III/IIIA TANKS DURING SALT DISSOLUTION OPERATIONS INTERIM REPORT

    Energy Technology Data Exchange (ETDEWEB)

    Counts, K; Bruce Wiersma, B; John Mickalonis, J

    2007-12-31

    Preparation of high level waste for vitrification involves in part the dissolution of salt cake from the carbon steel storage tanks. During dissolution, a point is reached in which the corrosion inhibitors, hydroxide and nitrite, are diluted below established guidelines, and nitrate stress corrosion cracking (SCC) is possible. Because the addition of inhibitors may be counterproductive to process efficiency and waste minimization, corrosion testing was initiated to revisit and possibly revise the guidelines for inhibitor limits. The bases for the work summarized in this status report are results from previously-completed phases of study. In the first two phases of study, several reduced-inhibitor levels were tested in HLW simulants with nitrate concentrations ranging from 4.5 M to 8.5 M. The first two phases of work determined, among other things, the reduced-inhibitor levels and solution chemistries in which heat-treated and non-heat-treated A537 carbon steel is susceptible to SCC, crevice corrosion, and pitting. The work covered in this current task both builds on and verifies the conclusions of the previous work. The current work involves testing of low levels of inhibitors in HLW simulants with 5.5 M to 8.5 M nitrate concentrations. Stressed U-bend specimens, both polarized and non-polarized, were tested. Non-polarized U-bend testing is ongoing, with the U-bends currently in test for 100 days. The purpose of the testing is to determine SCC susceptibility in the vapor space (VS) and liquid air interface (LAI) regions of the HLW tanks under conditions expected during salt dissolution, and also to verify previous accelerated testing. The simulated wastes being tested have nitrate concentrations of 5.5 M and 8.5 M and inhibitor levels of 0.01 M/0.01 M hydroxide/nitrite and 0.1 M/ 0.1 M hydroxide/nitrite. The open circuit potential measurements being monitored and the corrosion morphology of the U-bends are in agreement with results and observations of previous

  17. Study of benzotriazole as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    Energy Technology Data Exchange (ETDEWEB)

    Solehudin, Agus, E-mail: asolehudin@upi.edu [Department of Mechanical Engineering Education, Indonesia University of Education (UPI), Bandung, West Java (Indonesia); Nurdin, Isdiriayani [Department of Chemical Engineering, Bandung Institute of Technology, Bandung, West Java (Indonesia)

    2014-03-24

    Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H{sub 2}S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH.

  18. Study of benzotriazole as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

    Science.gov (United States)

    Solehudin, Agus; Nurdin, Isdiriayani

    2014-03-01

    Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H2S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH.

  19. The use of morinda citrifolia as a green corrosion inhibitor for low carbon steel in 3.5% NaCl solution

    Science.gov (United States)

    Kusumastuti, Rahayu; Pramana, Rakhmad Indra; Soedarsono, Johny W.

    2017-03-01

    The effect and mechanism of green corrosion inhibitor of Morinda Citrifolia (Noni) toward low carbon steel material has been researched. The general background is to develop the cheap and eco-friendly corrosion inhibitor based on components taken from tropical plants that grow +in Indonesia. This research aims to determine the effectiveness of the use of the extracts of noni as green corrosion inhibitor of carbon steel material in aggressive environment. The medium applied for this experiment is 3.5% natrium chloride solution. The variation of the concentration and immersion time duration has been applied as the experimental parameters. All the work was done at room temperature. The corrosion rate was measured by electrochemical polarization method with CMS 600-Gamry instruments and weight loss. The adsorption of inhibitor into the metal surface, which induced bonding formation after immersion was observed by using FTIR method. Inhibition mechanism was observed by polarization curves and fitted by the Langmuir adsorption models. The experimental results show that the higher concentration of inhibitor increasing the inhibition effect. The optimum inhibition is obtained at 3 ppm noni fruit extract, after immersion for about 288 hours. The corrosion rates obtained was 1.385 mpy, with the inhibitor efficiency of 76.92%. The monolayer film is formed coating the surface material as a result of mixed type corrosion inhibitor behavior of Noni. It can be concluded that this green inhibitor is effective to be used for low carbon steel material.

  20. In situ monitoring of corrosion mechanisms and phosphate inhibitor surface deposition during corrosion of zinc-magnesium-aluminium (ZMA) alloys using novel time-lapse microscopy.

    Science.gov (United States)

    Sullivan, James; Cooze, Nathan; Gallagher, Callum; Lewis, Tom; Prosek, Tomas; Thierry, Dominique

    2015-01-01

    In situ time-lapse optical microscopy was used to examine the microstructural corrosion mechanisms in three zinc-magnesium-aluminium (ZMA) alloy coated steels immersed in 1% NaCl pH 7. Preferential corrosion of MgZn(2) lamellae within the eutectic phases was observed in all the ZMA alloys followed by subsequent dissolution of Zn rich phases. The total extent and rate of corrosion, measured using time-lapse image analysis and scanning vibrating electrode technique (SVET) estimated mass loss, decreased as Mg and Al alloying additions were increased up to a level of 3 wt% Mg and 3.7 wt% Al. This was probably due to the increased presence of MgO and Al(2)O(3) at the alloy surface retarding the kinetics of cathodic oxygen reduction. The addition of 1 × 10(-2) mol dm(-3) Na(3)PO(4) to 1% NaCl pH 7 had a dramatic influence on the corrosion mechanism for a ZMA with passivation of anodic sites through phosphate precipitation observed using time-lapse image analysis. Intriguing rapid precipitation of filamentous phosphate was also observed and it is postulated that these filaments nucleate and grow due to super saturation effects. Polarisation experiments showed that the addition of 1 × 10(-2) mol dm(-3) Na(3)PO(4) to the 1% NaCl electrolyte promoted an anodic shift of 50 mV in open circuit potential for the ZMA alloy with a reduction in anodic current of 2.5 orders of magnitude suggesting that it was acting primarily as an anodic inhibitor supporting the inferences from the time-lapse investigations. These phosphate additions resulted in a 98% reduction in estimated mass loss as measured by SVET demonstrating the effectiveness of phosphate inhibitors for this alloy system.

  1. Investigation of Synthesized Sulfonated Melamine Formaldehyde as a Novel Corrosion Inhibitor for Mild Steel in Saline Environment

    Science.gov (United States)

    Sharifi, Zahra; Pakshir, Mahmoud; Mohamadi, Somayeh

    2015-02-01

    A water soluble compound named sulfonated melamine formaldehyde (SMF) was synthesized and its corrosion inhibition behavior was studied for carbon steel in 3.5% NaCl solution by polarization measurements and electrochemical impedance spectroscopy (EIS). SMF was characterized with hydrogen nuclear magnetic resonance spectroscopy and then its physical properties and corrosion prevention efficiencies were investigated. The corrosion behavior of SMF was found to be dependent strongly on the electric nature of functional groups which are present in its structure. The decrease in ( i corr) and the increase in inhibition efficiency (% IE) with increasing the SMF concentrations proves that it protects C-steel in 3.5% NaCl solution from being corroded and Nyquist diagrams indicate that increasing charge transfer resistance is associated with a decrease in the capacitance and increase in the percentage inhibition efficiency. The decrease in capacitance values could be attributed to the adsorption of the inhibitor molecules at the metal surface by increasing the concentration of inhibitor in the solution the inhibition efficiency increased and the best inhibition was obtained at 1000 ppm inhibitor concentration. The scanning electron microscope was used to investigate the surface morphology of specimens in the absence and presence of inhibitor compound.

  2. Static secondary ion mass spectrometry investigation of corrosion inhibitor Irgamet®39 on copper surfaces treated in power transformer insulating oil

    OpenAIRE

    Facciotti, Marco; Amaro, Pedro S.; Brown, Richard C. D.; Paul L. Lewin; Pilgrim, James A.; Wilson, Gordon; Jarman, Paul N.; Fletcher, Ian W.

    2015-01-01

    Static secondary ion mass spectrometry was used to study the corrosion inhibitor Irgamet®39 on the surface of copper treated in insulating oils and the effect of temperature changes, by means of temperature programmed desorption experiments under vacuum, on metal coverage. Four commercial oils, both corrosive and non-corrosive, showed no significant influence on the stability of the tolyltriazole layer and the energy of its main desorption event from copper was calculated around 100 kJ mol?1....

  3. Hydrazino-methoxy-1,3,5-triazine Derivatives' Excellent Corrosion Organic Inhibitors of Steel in Acidic Chloride Solution.

    Science.gov (United States)

    El-Faham, Ayman; Osman, Sameh M; Al-Lohedan, Hamad A; El-Mahdy, Gamal A

    2016-06-01

    The corrosion inhibition performance of 2-hydrazino-4,6-dimethoxy-1,3,5-tirazine (DMeHT), 2,4-dihydrazino-6-methoxy-1,3,5-triaizine (DHMeT), and 2,4,6-tridydrazino-1,3,5-triaizne (TH₃) on steel corrosion in acidic media was examined using electrochemical techniques. The results showed 2,4-Ddihydrazino-6-methoxy-1,3,5-triaizine (DHMeT) gave the best corrosion protection performance among the other hydrazino derivatives even at a low concentration of 25 ppm (95%). The number of hydrazino groups play an important role in the corrosion inhibition, where the two hydrazine groups increased the electrostatic interactions between the protonated tested compounds, the negatively charged steel surface resulted from the adsorption of the chloride anions, and the presence of the methoxy group made the compound more reliable for formation of film protection on the surface of steel through the lone pair of oxygen atoms. Electrochemical Impedance Spectroscopy (EIS) measurements suggested that the corrosion process of steel in presence of the hydrazino-s-triazine derivatives (TH₃, DMeHT and DHMeT) were being controlled by the charge transfer reaction. Polarization curves indicated that the examined TH₃, DMeHT and DHMeT behaved as mixed type inhibitors.

  4. Hydrazino-methoxy-1,3,5-triazine Derivatives’ Excellent Corrosion Organic Inhibitors of Steel in Acidic Chloride Solution

    Directory of Open Access Journals (Sweden)

    Ayman El-Faham

    2016-06-01

    Full Text Available The corrosion inhibition performance of 2-hydrazino-4,6-dimethoxy-1,3,5-tirazine (DMeHT, 2,4-dihydrazino-6-methoxy-1,3,5-triaizine (DHMeT, and 2,4,6-tridydrazino-1,3,5-triaizne (TH3 on steel corrosion in acidic media was examined using electrochemical techniques. The results showed 2,4-Ddihydrazino-6-methoxy-1,3,5-triaizine (DHMeT gave the best corrosion protection performance among the other hydrazino derivatives even at a low concentration of 25 ppm (95%. The number of hydrazino groups play an important role in the corrosion inhibition, where the two hydrazine groups increased the electrostatic interactions between the protonated tested compounds, the negatively charged steel surface resulted from the adsorption of the chloride anions, and the presence of the methoxy group made the compound more reliable for formation of film protection on the surface of steel through the lone pair of oxygen atoms. Electrochemical Impedance Spectroscopy (EIS measurements suggested that the corrosion process of steel in presence of the hydrazino-s-triazine derivatives (TH3, DMeHT and DHMeT were being controlled by the charge transfer reaction. Polarization curves indicated that the examined TH3, DMeHT and DHMeT behaved as mixed type inhibitors.

  5. Evaluation of Corrosion Behavior of Galvanized Steel Treated with Conventional Conversion Coatings and a Chromate-Free Organic Inhibitor

    Directory of Open Access Journals (Sweden)

    Laura A. Hernandez-Alvarado

    2012-01-01

    Full Text Available Conventional weight loss tests and both DC and AC electrochemical techniques were used to study if an organic inhibitor containing an alkanolamine salt of a polycarboxylic acid can substitute toxic coatings as chromating and certain phosphating procedures in the protection of galvanized steel. The electrolyte used was a 0.5 M aerated NaCl solution. All tests gave concordant results, indicating that the chromate-free organic inhibitor does protect galvanized steel in this environment, even though the provided protection was less than that of the chromate conversion coating. It was observed that, after a moderate initial attack, the corrosion rate diminishes due to the appearance and growth of passivating corrosion products layers, mainly constituted by zinc hydroxychloride (Zn5(OH8CI2⋅H2O and two varieties of zinc hydroxide, among other crystalline compounds.

  6. The Corrosion and Preservation of Iron Antiques.

    Science.gov (United States)

    Walker, Robert

    1982-01-01

    Discusses general corrosion reactions (iron to rust), including corrosion of iron, sulfur dioxide, chlorides, immersed corrosion, and underground corrosion. Also discusses corrosion inhibition, including corrosion inhibitors (anodic, cathodic, mixed, organic); safe/dangerous inhibitors; and corrosion/inhibition in concrete/marble, showcases/boxes,…

  7. Erosion-corrosion in carbon dioxide saturated systems in presence of sand, inhibitor, oil, and high concentration of salt

    Science.gov (United States)

    Hassani, Shokrollah

    Oil and gas production is usually accompanied by formation water which typically contains high levels of chloride. Some effects of chloride concentration on corrosion are not widely known in the literature, and this can result in misleading conclusions. One goal of this research was to contribute to a better understanding of the effects of chloride concentration in CO2 corrosion. Experimental and theoretical studies conducted in the present work have shown that increasing the NaCl concentration in solution has three important effects on corrosion results. First, standard pH meter readings in high NaCl concentration solutions require corrections. Second, increasing the NaCl concentration decreases the CO2 concentration in solution and therefore contributes to a decrease in the corrosion rate. Third, increasing the NaCl concentration increases the solubility of FeCO3 and therefore reduces the likelihood of forming an iron carbonate scale. High NaCl concentration also decreases the sand erosion rate of the metal slightly by increasing the density and viscosity of the liquid. There are two main contributions of this research. The first contribution is the experimental characterization of inhibited erosion-corrosion behavior of mild steel under CO2-saturated conditions with a high salt concentration. Chemical inhibition is one the most important techniques for controlling erosion-corrosion in offshore mild steel pipelines, tubing and pipe fittings in oil and gas industry. The second contribution is the introduction of a new approach for predicting inhibited erosion-corrosion in mild steel pipes including the effects of flow and environmental conditions, sand production, and an oil phase. Sand erosion can decrease the efficiency of corrosion protection systems including iron-carbonate scale formation and chemical inhibition. The need to be able to predict inhibitor performance under sand production conditions is particularly acute when the wells are deep or off

  8. The New-generation of Green Surfactant(Alkylpolyglucoside)as an Inhibitor to the Corrosion of 907 Steel in Seawater

    Institute of Scientific and Technical Information of China (English)

    Min DU; Rong Jie GAO; Ping GONG; Qing Zhang WANG

    2004-01-01

    Weight-loss trials and potentiodynamic polarization curves have been used to study the inhibitive properties of alkylpolyglucoside (APG) towards the 907 steel in seawater.The inhibition was different, if the length of alkyl chain APG was different.As the result, calcium gluconate, zinc sulfate and APG can protect 907 steel from being corrupted in static seawater.The compound corrosion inhibitor was found to control both the anodic process and the cathodic process.

  9. Corrosion inhibition mechanisms of aluminum alloy 2024-T3 by selected non-chromate inhibitors

    Science.gov (United States)

    Lopez-Garrity, Omar A.

    The pursuit to find a chromate-alternative has led to the development of several chromate-free aerospace primers and coating systems that offer good protection. However, fundamental understanding of the functionality of the chromate-free pigments that are embedded within these coating systems is lacking. The objective of this study was to understand the fundamental mechanism of corrosion inhibition of aluminum alloy 2024-T3 by molybdate (MoO 42-), silicate (SiO32-), and praseodymium (Pr3+) with the goal of developing the kind of understanding that was accomplished for chromate. Furthermore, since most inhibiting conversion coatings and pigments act by releasing soluble species into the local environment, it was of interest to understand the mechanism of inhibition in aqueous 0.1 M NaCl solution. The mechanism of inhibition of AA2024-T3 by the select non-chromate inhibitors was investigated using various electrochemical, microscopic and spectroscopic techniques. Naturally aerated polarization curves showed that molybdate provided mixed inhibition in near-neutral pH and at a threshold concentration of 0.1 M. The largest effect was a 250 mV increase in the breakdown potential associated with pitting and a 350 mV decrease in the open-circuit potential (OCP). In addition, electrochemical impedance indicated that the corrosion inhibition mechanism is oxygen-dependent owing to the protection afforded by Mo(VI) species. It was proposed that the corrosion inhibition of AA2024-T3 by molybdate may occur following a two-step process whereby molybdate is rapidly reduced to MoO.(OH)2 over the intermetallic particles and is subsequently oxidized to intermediate molybdenum oxides (e.g. Mo4O11) in the presence of oxygen which is reduced. This in turn may lead to a local acidification, promoting the condensation and polymerization of molybdate species in solution to form polymolybdate species (Mo7O24 6- and Mo8O264-). Furthermore, S-phase particle dissolution is decreased

  10. Preparation and Application of Crosslinked Poly(sodium acrylate-Coated Magnetite Nanoparticles as Corrosion Inhibitors for Carbon Steel Alloy

    Directory of Open Access Journals (Sweden)

    Ayman M. Atta

    2015-01-01

    Full Text Available This work presents a new method to prepare poly(sodium acrylate magnetite composite nanoparticles. Core/shell type magnetite nanocomposites were synthesized using sodium acrylate as monomer and N,N-methylenebisacrylamide (MBA as crosslinker. Microemulsion polymerization was used for constructing core/shell structures with magnetite nanoparticles as core and poly(sodium acrylate as shell. Fourier transform infrared spectroscopy (FTIR was employed to characterize the nanocomposite chemical structure. Transmittance electron microscopy (TEM was used to examine the morphology of the modified poly(sodium acrylate magnetite composite nanoparticles. These particle will be evaluated for effective anticorrosion behavior as a hydrophobic surface on stainless steel. The composite nanoparticles has been designed by dispersing nanocomposites which act as a corrosion inhibitor. The inhibition effect of AA-Na/magnetite composites on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS. Polarization measurements indicated that the studied inhibitor acts as mixed type corrosion inhibitor. EIS spectra exhibit one capacitive loop. The different techniques confirmed that the inhibition efficiency reaches 99% at 50 ppm concentration. This study has led to a better understanding of active anticorrosive magnetite nanoparticles with embedded nanocomposites and the factors influencing their anticorrosion performance.

  11. Preparation and application of crosslinked poly(sodium acrylate)--coated magnetite nanoparticles as corrosion inhibitors for carbon steel alloy.

    Science.gov (United States)

    Atta, Ayman M; El-Mahdy, Gamal A; Al-Lohedan, Hamad A; El-Saeed, Ashraf M

    2015-01-14

    This work presents a new method to prepare poly(sodium acrylate) magnetite composite nanoparticles. Core/shell type magnetite nanocomposites were synthesized using sodium acrylate as monomer and N,N-methylenebisacrylamide (MBA) as crosslinker. Microemulsion polymerization was used for constructing core/shell structures with magnetite nanoparticles as core and poly(sodium acrylate) as shell. Fourier transform infrared spectroscopy (FTIR) was employed to characterize the nanocomposite chemical structure. Transmittance electron microscopy (TEM) was used to examine the morphology of the modified poly(sodium acrylate) magnetite composite nanoparticles. These particle will be evaluated for effective anticorrosion behavior as a hydrophobic surface on stainless steel. The composite nanoparticles has been designed by dispersing nanocomposites which act as a corrosion inhibitor. The inhibition effect of AA-Na/magnetite composites on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). Polarization measurements indicated that the studied inhibitor acts as mixed type corrosion inhibitor. EIS spectra exhibit one capacitive loop. The different techniques confirmed that the inhibition efficiency reaches 99% at 50 ppm concentration. This study has led to a better understanding of active anticorrosive magnetite nanoparticles with embedded nanocomposites and the factors influencing their anticorrosion performance.

  12. Experimental and quantum chemical studies on two triazole derivatives as corrosion inhibitors for mild steel in acid media

    Energy Technology Data Exchange (ETDEWEB)

    Li, W.; Tian, H.; Hou, B. [Key Laboratory of Corrosion Science, Shandong, Institute of Oceanology, Chinese Academy of Sciences, Qingdao (China); Hu, L.; Tao, Z. [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing (China)

    2011-11-15

    Two triazole derivatives [1-phenyl-2-(5-(1,2,4) triazol-1-ylmethyl-(1,3,4) oxadizaol-2-ylsulphanyl)-ethanone (PTOE) and 2-(4-tert-butyl-benzylsulphanyl)-5-(1,2,4) triazol-1-ylmethyl-(1,3,4) oxadiazole (TBTO)] were synthesized as new corrosion inhibitors for the corrosion of mild steel in 1 M hydrochloric acid solutions. The inhibiting efficiency of the different inhibitors was evaluated by means of weight loss and electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and polarization curves. The electrochemical investigation results indicate that these compounds act as mixed-type inhibitors retarding the anodic and cathodic corrosion reactions and do not change the mechanism of either hydrogen evolution reaction or mild steel dissolution. The studied compounds followed the Langmuir adsorption isotherm, and the thermodynamic parameters were determined and discussed. The effect of molecular structure on the inhibition efficiency has been investigated with ab initio calculations. The electronic properties such as highest occupied molecular orbital (HOMO) energy level, lowest unoccupied molecular orbital (LUMO) energy level, dipole moment ({mu}) and molecular orbital densities were calculated. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  13. Bio-testing integral toxicity of corrosion inhibitors, biocides and oil hydrocarbons in oil-and gas-processing industry

    Energy Technology Data Exchange (ETDEWEB)

    Chugunov, V.A.; Kholodenko, V.P.; Irkhina, I.A.; Fomchenkov, V.M.; Novikov, I.A. [State Research Center for Applied Microbiology, Obolensk, Moscow (Russian Federation)

    2004-07-01

    In recent years bioassays have been widely used for assessing levels of contamination of the environment. This is due to the fact that test-organisms provide a general response to toxicants present in samples. Based on microorganisms as test objects, it is possible to develop cheap, sensitive and rapid assays to identify environmental xenobiotics and toxicants. The objective of the research was to develop different microbiological assays for assessing integral toxicity of water environments polluted with corrosion inhibitors, biocides and hydrocarbons in oil- and gas-processing industry. Bio-luminescent, electro-orientational, osmo-optic and microorganism reducing activity assays were used for express evaluation of integral toxicity. They are found to determine promptly integral toxicity of water environments containing various pollutants (oil, oil products, corrosion inhibitors, biocides). Results conclude that the assays may be used for analyzing integral toxicity of water polluted with hydrocarbons, as well as for monitoring of water changes as a result of biodegradation of pollutants by microorganisms and their associations. Using a kit of different assays, it is also possible to evaluate ecological safety of biocides, corrosion inhibitors, and their compositions. Bioassays used as a kit are more effective than each assay individually, allowing one to get complete characterization of a reaction of bacterial test organisms to different environments. (authors)

  14. Study on improvement of durability for reinforced concrete by surface-painting migrating corrosion inhibitor and engineering application

    Science.gov (United States)

    Song, Ning; WANG, Zixiao; LIU, Zhiyong; Zhou, Jiyuan; Zheng, Duo

    2017-01-01

    The corrosion currents of steel bar in concrete with three W/B and four chloride contents after surface-painting two migrating corrosion inhibitors (PCI-2015 and MCI-A) 14d to 150d in atmospheric condition were measured. The results showed that the corrosion current density (I corr) of steel bar reduced to 0.1 μA.cm-2 from the initial highest 3.833 μA.cm-2 (W/B=0.65, NaCl-1%) after surface-painting PCI-2015 14 d, and the I corr was still lower than 0.1 μA.cm-2 until 150d. The compressive strength and chloride migration coefficient of concrete specimens were tested. The possible reasons of the mechanisms of durability improvement for reinforced concrete by applying PCI-2015 inhibitor were PCI-2015 may be reacted with calcium hydroxide in cement concrete and lots of inhibitor particles may be adsorbed on the active sites first and then a stable protective layer may be formed. The I corr of steel bars in a hydraulic aqueduct concrete structure after painting PCI-2015, MCI-A (the United States) and MCI-B (Europe) during 6 months was monitored by Gecor 8 tester. The results showed that the average values of I corr of steel bars after painting the PCI-2015 150d fulfilled the specification requirements in “Design code for concrete structure strengthening (E.3) ”(GB 50367-2013).

  15. Electrochemical evaluation of sodium metabisulfite as environmentally friendly inhibitor for corrosion of aluminum alloy 6061 in a chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    Zaid, B., E-mail: zaidbachir@yahoo.com [Département de métallurgie, Division de Technologie du Combustible, Centre de Recherche Nucléaire de Draria CRND, BP. 43 Draria, Alger (Algeria); Maddache, N.; Saidi, D. [Département de métallurgie, Division de Technologie du Combustible, Centre de Recherche Nucléaire de Draria CRND, BP. 43 Draria, Alger (Algeria); Souami, N. [Centre de Recherche Nucléaire d’Alger CRNA, 2 Bd. Frantz Fanon, Alger (Algeria); Bacha, N. [Département de Mécanique, Université SAAD Dahleb, Blida (Algeria); Si Ahmed, A. [Im2np, UMR 7334 CNRS, Aix-Marseille Université, 13397 Marseille Cedex 20 (France)

    2015-04-25

    Highlights: • Sodium metabisulfite acts as cathodic-type inhibitor. • The polarization resistance increases with the inhibitor concentration. • The pit nucleation rate decreases with increasing inhibitor concentration. • The current rise linked to pit propagation drops as inhibitor content increases. • The reactions involved in the inhibition actions are pointed out. - Abstract: Inhibition properties of sodium metabisulfite (Na{sub 2}S{sub 2}O{sub 5}) on pitting corrosion of 6061 aluminum alloy, in 5 × 10{sup −2} M NaCl solution of pH near 7.2 at 298 K, are characterized using open circuit potential, polarization resistance, cyclic and chrono-amperometric polarization measurements. In addition, scanning electron microscopy coupled with energy dispersive spectroscopy and X-ray photoelectrons are employed. Sodium metabisulfite, which is well compatible with environmental requirements, seems to act as a cathodic-type corrosion inhibitor. The passivation range and the polarization resistance increase with Na{sub 2}S{sub 2}O{sub 5} concentration. The inhibition effects are also reflected through the substantial reduction of both the rate of pit nucleation and the current rise characterizing the pit propagation progress. The SEM–EDS and XPS analyses reveal the formation of a passive film, which contains sulfur atoms.

  16. Corrosion mitigation of N-(2-hydroxy-3-trimethyl ammonium)propyl chitosan chloride as inhibitor on mild steel.

    Science.gov (United States)

    Sangeetha, Y; Meenakshi, S; SairamSundaram, C

    2015-01-01

    The biopolymer N-(2-hydroxy-3-trimethyl ammonium)propyl chitosan chloride (HTACC) was synthesised and its influence as a novel corrosion inhibitor on mild steel in 1M HCl was studied using gravimetric and electrochemical experiments. The compound obtained was characterised using FTIR and NMR studies. The inhibition efficiency increased with the increase in concentration and reached a maximum of 98.9% at 500 ppm concentration. Polarisation studies revealed that HTACC acts both as anodic and cathodic inhibitor. Electrochemical impedance studies confirmed that the inhibition is through adsorption on the metal surface. The extent of inhibition exhibits a negative trend with increase in temperature. Langmuir isotherm provides the best description on the adsorption nature of the inhibitor. SEM analysis indicated the presence of protective film formed by the inhibitor on the metal surface.

  17. In situ analysis of corrosion inhibitors using a portable mass spectrometer with paper spray ionization

    KAUST Repository

    Jjunju, Fred Paul Mark

    2013-01-01

    Paper spray (PS) ambient ionization is implemented using a portable mass spectrometer and applied to the detection of alkyl quaternary ammonium salts in a complex oil matrix. These salts are commonly used as active components in the formulation of corrosion inhibitors. They were identified in oil and confirmed by their fragmentation patterns recorded using tandem mass spectrometry (MS/MS). The cations of alkyl and benzyl-substituted quaternary ammonium salts showed characteristic neutral losses of CnH2n (n carbon number of the longest chain) and C7H8, respectively. Individual quaternary ammonium compounds were detected at low concentrations (<1 ng μL-1) and over a dynamic range of ∼5 pg μL-1 to 500 pg μL-1 (ppb). Direct detection of these compounds in complex oil samples without prior sample preparation or pre-concentration was also demonstrated using a home-built miniature mass spectrometer at levels below 1 ng μL-1.© 2013 The Royal Society of Chemistry.

  18. SERS and DFT study of copper surfaces coated with corrosion inhibitor

    Directory of Open Access Journals (Sweden)

    Maurizio Muniz-Miranda

    2014-12-01

    Full Text Available Azole derivatives are common inhibitors of copper corrosion due to the chemical adsorption occurring on the metal surface that gives rise to a protective film. In particular, 1,2,4-triazole performs comparable to benzotriazole, which is much more widely used, but is by no means an environmentally friendly agent. In this study, we have analyzed the adsorption of 1,2,4-triazole on copper by taking advantage of the surface-enhanced Raman scattering (SERS effect, which highlights the vibrational features of organic ligand monolayers adhering to rough surfaces of some metals such as gold, silver and copper. To ensure the necessary SERS activation, a roughening procedure was implemented on the copper substrates, resulting in nanoscale surface structures, as evidenced by microscopic investigation. To obtain sufficient information on the molecule–metal interaction and the formation of an anticorrosive thin film, the SERS spectra were interpreted with the aid of theoretical calculations based on the density functional theory (DFT approach.

  19. In situ analysis of corrosion inhibitors using a portable mass spectrometer with paper spray ionization.

    Science.gov (United States)

    Jjunju, Fred P M; Li, Anyin; Badu-Tawiah, Abraham; Wei, Pu; Li, Linfan; Ouyang, Zheng; Roqan, Iman S; Cooks, R Graham

    2013-07-01

    Paper spray (PS) ambient ionization is implemented using a portable mass spectrometer and applied to the detection of alkyl quaternary ammonium salts in a complex oil matrix. These salts are commonly used as active components in the formulation of corrosion inhibitors. They were identified in oil and confirmed by their fragmentation patterns recorded using tandem mass spectrometry (MS/MS). The cations of alkyl and benzyl-substituted quaternary ammonium salts showed characteristic neutral losses of CnH2n (n carbon number of the longest chain) and C7H8, respectively. Individual quaternary ammonium compounds were detected at low concentrations (<1 ng μL(-1)) and over a dynamic range of ∼5 pg μL(-1) to 500 pg μL(-1) (ppb). Direct detection of these compounds in complex oil samples without prior sample preparation or pre-concentration was also demonstrated using a home-built miniature mass spectrometer at levels below 1 ng μL(-1).

  20. Effect of Organic Inhibitors on Chloride Corrosion of Steel Rebars in Alkaline Pore Solution

    Directory of Open Access Journals (Sweden)

    Marina Cabrini

    2015-01-01

    Full Text Available The inhibition properties of aspartic and lactic acid salts are compared with nitrite ions with regard to their effect on critical chloride concentration. The tests were carried out on carbon steel specimens in simulated pore solutions with initial pH in the range of 12.6 to 13.8. The critical chloride concentrations were estimated through multiple specimen potentiostatic tests at potentials in the usual range for passive rebar in noncarbonated concrete structures. During tests, chloride ions were progressively added until all specimens showed localized attack, obtaining cumulative distribution curves reporting the fraction of corroded specimens as a function of chloride concentration. The presence of the organic inhibitors on the passivity film was detected by IR spectra. The results confirm that 0.1 M aspartate exhibits an inhibiting effect comparable with nitrite ions of the same concentration. Calcium lactate does not increase critical chloride concentration; however it appears to promote the formation of a massive scale, reducing the corrosion propagation.

  1. Substituted benzotriazoles as inhibitors of copper corrosion in borate buffer solutions

    Science.gov (United States)

    Agafonkina, M. O.; Andreeva, N. P.; Kuznetsov, Yu. I.; Timashev, S. F.

    2017-08-01

    The adsorption of substituted 1,2,3-benzotriazoles (R-BTAs) onto copper is measured via ellipsometry in a pure borate buffer (pH 7.4) and satisfactorily described by Temkin's isotherm. The adsorption free energy (-Δ G a 0 ) values of these azoles are determined. The (-Δ G a 0 ) values are found to rise as their hydrophobicity, characterized by the logarithm of the partition coefficient of a substituted BTA in a model octanol-water system (log P), grows. The minimum concentration sufficient for the spontaneous passivation of copper ( C min) and a shift in the potential of local copper depassivation with chlorides ( E pt) after an azole is added to the solution (i.e., Δ E = E pt in - E pt backgr characterizing the ability of its adsorption to stabilize passivation) are determined in the same solution containing a corrosion additive (0.01M NaCl) for each azole under study. Both criteria of the passivating properties of azoles (log C min and Δ E) are shown to correlate linearly with log P, testifying to the role played by surface activity of this family of organic inhibitors in protecting copper in an aqueous solution.

  2. Binary Mixtures of Nonyl Phenol with Alkyl Substituted Anilines as Corrosion Inhibitors for Mild Steel in Acidic Medium

    Directory of Open Access Journals (Sweden)

    H. S. Shukla

    2012-01-01

    Full Text Available The present study deals with the evaluation of the corrosion inhibition effectiveness of the two binary mixtures of nonyl phenol (NPH with 2, 4 dimethyl aniline (DMA and 2 ethyl aniline (EA at different concentration ratios (from 1:7 to 7:1 for mild steel in H2SO4 (pH=1 solution by weight loss and potentiodynamic polarization method. Corrosion inhibition ability of the compounds has been tested at different exposure periods (6 h to 24 h and at different temperatures (303 K to 333 K. The binary mixture of NPH and EA (at 7:1 concentration ratio has afforded maximum inhibition (IE% 93.5% at 6 h exposure period and at room temperature. The adsorption of both the inhibitors is found to accord with Temkin adsorption isotherm. Potentiodynamic polarization study reveals that the tested inhibitors are mixed type inhibitor and preferentially act on cathodic areas. Electrochemical impedance study suggests formation of an inhibition layer by the adsorption of the inhibitors on the metal surface. An adsorption model of the inhibitor molecules on the metal surface has been proposed after immersion test in the inhibited acid showed characteristic shift of N-H and O-H bond frequencies towards lower side compared to that of the respective pure samples which indicated the donation of electron pair through N and O atom of the inhibitor molecule in the surface adsorption phenomena. SEM study has revealed formation of semi globular inhibitor products on the metal surface. The comparisons of the protection efficiencies of these compounds according to their relative electron density on the adsorption centre and projected molecular area of the inhibitor molecules have been made.

  3. The mixture of dicyclohexilamine and oleylamine as corrosion inhibitor for mild steel in NaCl solution saturated with CO2 under both continual immersion and top of the line corrosion

    Directory of Open Access Journals (Sweden)

    Jevremović Ivana

    2012-01-01

    Full Text Available This paper presents a comprehensive method to evaluate the mixture of dicyclohexilamine and oleylamine (DCHA+OA as corrosion inhibitor for mild steel in CO2 environment in liquid and vapor phase. Corrosion inhibitor volatile properties were investigated in order to determine if DCHA+OA can be used to control the severity of the top of the line (TLC corrosion attack. Corrosion measurements were performed using electrochemical impedance spectroscopy, linear polarization resistance, potentiodynamic sweep measurements, as well as the electrical resistance measurements and weight loss measurements, in order to determine the inhibitive performances of dicyclohexilamine and oleylamine. In order to define surface morphological characteristics scanning electron microscopy technique was applied. The electrochemical study and weight loss measurements indicated that DCHA+OA significantly decreased the corrosion rate in liquid phase when 50 ppm of DCHA+OA was added. Scanning electron microphotographs indicated protective inhibitor film has formed on the steel surface and revealed that good protection was achieved, along with the decrease in the corrosion rate determined by weight loss and electrochemical techniques. Using electrical resistance measurements in vapor phase it was shown that concentration of 1000 ppm DCHA+OA significantly decreased the corrosion rate at the top of the line, only when it was carried there within its own foam and not due its volatility.

  4. Adsorption properties of Rosmarinus officinalis oil as green corrosion inhibitors on C38 steel in 0.5 M H_2SO_4

    Institute of Scientific and Technical Information of China (English)

    E.El; Ouariachi; J.Paolini; M.Bouklah; A.Elidrissi; A.B

    2010-01-01

    Rosmarinus officinalis essential oil obtained by hydrodistillation was tested as corrosion inhibitor of steel in 0.5 M H2SO4 using weight loss measurements,and electrochemical polarisation methods.Results obtained indicate that the corrosion rate is reduced and R.officinalis oil adsorbs on the metal surface and then inhibits corrosion process.Its inhibition effciency increases with oil increasing content to reach 61% at 1 g/L.Polarisation curves indicate that RO acts as a cathodic inhibitor.The inhibition e...

  5. Studies on the Corrosion Inhibitor of Zinc in Hydrolfuoric Acid Solution%氢氟酸介质中锌缓蚀剂的研制

    Institute of Scientific and Technical Information of China (English)

    林冬; 焦庆祝; 赵斌; 贺淼; 张涵; 赵丽; 张爽; 王佳

    2015-01-01

    本文采用正交实验方法对有机盐类、无机盐类和季铵盐类化合物进行复配得到一种氢氟酸介质中金属锌的优良缓蚀剂。利用失重法和电化学极化曲线法对该缓蚀剂进行了评价,并研究了金属腐蚀速率随缓蚀剂浓度,酸度,温度,时间等变化趋势。实验结果表明,该复合缓蚀剂用量在0.5%,温度小于50℃,酸度小于7%时具有良好的缓蚀效果,该缓蚀剂为阴极型缓蚀剂。%A composite corrosion inhibitor of zinc in hydrofluoric acid solution was developed by orthogonal test with the compound of organic salt, inorganic salt and quaternary ammonium salt. The corrosion inhibitor was evaluated by weight-loss method and electrochemical method. The change of zinc corrosion rate with concentration of corrosion inhibitor, hydrofluoric acid acidity, temperature and reaction time was investigated. It was shown by the results that the corrosion inhibitor has an excellent corrosion inhibition when the quantity of the corrosion inhibitor is more than 0.5%, the temperature is below 50℃and the concentration of hydrofluoric acid is under 7%. The composite corrosion inhibitor is a kind of electrochemical cathode type inhibitor.

  6. DEVELOPMENT OF AN ENVIRONMENTALLY BENIGN MICROBIAL INHIBITOR TO CONTROL INTERNAL PIPELINE CORROSION

    Energy Technology Data Exchange (ETDEWEB)

    Bill W. Bogan; Brigid M. Lamb; John J. Kilbane II

    2004-10-30

    The overall program objective is to develop and evaluate environmentally benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is to develop one or more environmentally benign (a.k.a. ''green'') products that can be applied to maintain the structure and dependability of the natural gas infrastructure. Previous testing indicated that the growth, and the metal corrosion caused by pure cultures of sulfate reducing bacteria were inhibited by hexane extracts of some pepper plants. This quarter tests were performed to determine if chemical compounds other than pepper extracts could inhibit the growth of corrosion-associated microbes and to determine if pepper extracts and other compounds can inhibit corrosion when mature biofilms are present. Several chemical compounds were shown to be capable of inhibiting the growth of corrosion-associated microorganisms, and all of these compounds limited the amount of corrosion caused by mature biofilms to a similar extent. It is difficult to control corrosion caused by mature biofilms, but any compound that disrupts the metabolism of any of the major microbial groups present in corrosion-associated biofilms shows promise in limiting the amount/rate of corrosion.

  7. Novel naphthenate surfactants based on petroleum acids and nitrogenous bases as corrosion inhibitors for C1018-type mild steel in CO2-saturated brine

    Directory of Open Access Journals (Sweden)

    Hany M. Abd El-Lateef

    2015-06-01

    Full Text Available The efficiency of two natural naphthenate surfactants (Naphthenic-dimethylamine and Naphthenic-diethylamine complexes, as corrosion inhibitors for mild steel in CO2-saturated 1% NaCl solution, has been determined by linear polarization resistance corrosion rate and potentiodynamic polarization measurements. These compounds inhibit corrosion even at very low concentrations (25 ppm, and Naphthenic-diethylamine complex is the best inhibitor giving maximum inhibition efficiency (99.76 at 100 ppm. Polarization curves indicate that, the two investigated compounds are mixed inhibitors, affecting both cathodic and anodic corrosion currents. Adsorption of naphthenate surfactants on the mild steel surface is in good agreement with the Langmuir adsorption isotherm model, and the calculated Gibbs free energy values confirm the chemical nature of the adsorption. Energy dispersive X-ray fluorescence microscopy (EDRF and scanning electron microscope (SEM observations confirmed the existence of such an adsorbed film on the mild steel surface.

  8. Study on the Applications of Corrosion Inhibitor in Military Aircraft Maintenance%缓蚀剂在军用飞机维护中的应用研究

    Institute of Scientific and Technical Information of China (English)

    孙祚东; 李云仲; 韦利军

    2014-01-01

    Objective To study the validity of the hard film water-displacing corrosion inhibitor which is used in the joint sections of military aircraft in marine environment. Methods The performance of corrosion inhibitor was evaluated through functional penetration test and environment spectrum accelerated corrosion contrast test, and the practical applica-tion effect was verified by the lead probation on typical structure sections of a certain aircraft. Results The penetration rate of the corrosion inhibitor was 85%. The applications of corrosion inhibitor in the military aircraft internal structures could effectively retard the development of corrosion,and postpone the occurrence time of corrosion. Conclusion The applications of corrosion inhibitor in the military aircraft maintenance as an effective means to prevent corrosion is valuable for populari-zation and application.%目的:验证海洋环境下硬膜水置换型缓蚀剂应用于军用飞机连接部位的有效性。方法采用功能渗透性试验、环境谱加速腐蚀对比试验对缓蚀剂性能进行评价,并通过在某型飞机典型结构部位的领先试用验证缓蚀剂的实际应用效果。结果缓蚀剂渗透率可达到85%。应用于军用飞机内部,对腐蚀的发展有明显的抑制作用,可显著延长腐蚀发生的时间。结论应用缓蚀剂作为腐蚀预防的有效手段,可在军用飞机维护中推广应用。

  9. Effect of Mercapto and Methyl Groups on the Efficiency of Imidazole and Benzimidazole-based Inhibitors of Iron Corrosion.

    Science.gov (United States)

    Milošev, Ingrid; Kovačević, Nataša; Kokalj, Anton

    2016-01-01

    We report on the combined experimental and computational study of imidazole- and benzimidazole-based corrosion inhibitors containing methyl and/or mercapto groups. Electrochemical measurements and long-term immersion tests were performed on iron in NaCl solution, whilst computational study explicitly addresses the molecular level details of the bonding on iron surface by means of density functional theory calculations (DFT). Experimental data were the basis for the determination of inhibition efficiency and mechanism. Methyl group combined with mercapto group has a beneficial effect on corrosion inhibition at all inhibitor concentrations. The beneficial effect of mercapto group combined with benzene group is not so pronounced as when combined with methyl group. The latter is in stark contrast with the behaviour found previously on copper, where the effect of methyl group was detrimental and that of mercapto and benzene beneficial. Explicit DFT calculations reveal that methyl-group has a small effect on the inhibitor-surface interaction. In contrast, the presence of mercapto group involves the strong S-surface bonding and consequently the adsorption of inhibitors with mercapto group is found to be more exothermic.

  10. Wet-gas transport in the Mediterranean Sea. Selection of a combined kinetic hydrate/corrosion inhibitor system

    Energy Technology Data Exchange (ETDEWEB)

    Zettlitzer, M. [RWE Dea AG, Wietze (Germany); Rozengard, N.; Koeckritz, V. [Technical Univ. Freiberg (Germany); Malt, E. [RWE Dea AG (Egypt)

    2007-09-13

    Raw gas will be collected on a platform in the centre of the field. Due to volume and weight constraints, condensing fluids will not be separated from the gas on the platform so that the raw gas will be transported in three-phase mode (gas, water, and condensate) via a 33 km long pipeline to a gas treatment plant. Under the calculated pipeline pressure of about 100 barg, hydrate formation is - according to the outcome of thermodynamic simulations - to be expected at temperatures of 19 C and below while the pipeline may cool down to about 15 C in winter conditions. Due to logistical, environmental and economic reasons, RWE Dea decided to inhibit hydrate formation with kinetic hydrate inhibitors (KHI). As the gas also contains carbon dioxide, certain corrosivity was forecasted and addition of a corrosion inhibitor turned out to be necessary. Laboratory tests were carried out to confirm the feasibility of the concept and to define the required dosage of KHI. Service companies were contacted and several kinetic hydrate and corrosion inhibitors were screened. Experiments with the different chemicals were performed at the University of Freiberg in a high-pressure cell at the pipeline pressure of 100 barg. Hydrate formation was detected by continuous pressure registration during temperature changes and by observation through a glass window. In order to preselect the chemicals, first tests were performed with pure methane. These tests also served for calibration of the equipment with literature data and especially as an indication for the minimum chemical concentration required. A second test series was performed with synthetic gas in a composition close to that of the field gas under consideration in order to verify the results obtained with methane. Finally, the optimum kinetic hydrate inhibitor was identified as well as the required dosage concentration. Compatibility of KHI and corrosion inhibitor was experimentally proven. A further set of kinetic inhibitor tests with

  11. Quinoxaline derivatives as corrosion inhibitors for mild steel in hydrochloric acid medium: Electrochemical and quantum chemical studies

    Science.gov (United States)

    Olasunkanmi, Lukman O.; Kabanda, Mwadham M.; Ebenso, Eno E.

    2016-02-01

    The corrosion inhibition potential of four quinoxaline derivatives namely, 1-[3-(4-methylphenyl)-5-(quinoxalin-6-yl)-4,5-dihydropyrazol-1-yl]butan-1-one (Me-4-PQPB), 1-(3-(4-methoxyphenyl)-5-(quinoxalin-6-yl)-4,5-dihydropyrazol-1-yl)butan-1-one (Mt-4-PQPB), 1-[3-(3-methoxyphenyl)-5-(quinoxalin-6-yl)-4,5-dihydropyrazol-1-yl]butan-1-one (Mt-3-PQPB) and 1-[3-(2H-1,3-benzodioxol-5-yl)-5-(quinoxalin-6-yl)-4,5-dihydropyrazol-1-yl]butan-1-one (Oxo-1,3-PQPB) was studied for mild steel corrosion in 1 M HCl solution using electrochemical, spectroscopic techniques and quantum chemical calculations. The results of both potentiodynamic polarization and electrochemical impedance spectroscopic studies revealed that the compounds are mixed-type inhibitors and the order of corrosion inhibition efficiency at 100 ppm is Me-4-PQPB>Mt-3-PQPB>Oxo-1,3-PQPB>Mt-4-PQPB. Fourier transform infrared (FTIR) and ultraviolet-visible (UV-vis) spectroscopic analyses confirmed the presence of chemical interactions between the inhibitors and mild steel surface. The adsorption of the inhibitor molecules on mild steel surface was found to be both physisorption and chemisorption but predominantly chemisorption. The experimental data obey Langmuir adsorption isotherm. Scanning electron microscopy studies revealed the formation of protective films of the inhibitors on mild steel surface. Quantum chemical parameters obtained from density functional theory (DFT) calculations support experimental results.

  12. The imidazoline receptors and ligands in pain modulation

    Directory of Open Access Journals (Sweden)

    Nurcan Bektas

    2015-01-01

    Full Text Available Pain is an unpleasant experience and effects daily routine negatively. Although there are various drugs, many of them are not entirely successful in relieving pain, since pain modulation is a complex process involving numerous mediators and receptors. Therefore, it is a rational approach to identify the factors involved in the complex process and develop new agents that act on these pain producing mechanisms. In this respect, the involvement of the imidazoline receptors in pain modulation has drawn attention in recent years. In this review, it is aimed to focus on the imidazoline receptors and their ligands which contribute to the pain modulation. It is demonstrated that imidazoline-2 (I2 receptors are steady new drug targets for analgesics. Even if the mechanism of I2receptor is not well known in the modulation of pain, it is known that it plays a role in tonic and chronic pain but not in acute phasic pain. Moreover, the I2receptor ligands increase the analgesic effects of opioids in both acute and chronic pain and prevent the development of opioid tolerance. So, they are valuable for the chronic pain treatment and also therapeutic coadjuvants in the management of chronic pain with opiate drugs due to the attenuation of opioid tolerance and addiction. Thus, the use of the ligands which bind to the imidazoline receptors is an effective strategy for relieving pain. This educational forum exhibits the role of imidazoline receptors and ligands in pain process by utilizing experimental studies.

  13. Evaluation of Inhibitors for Corrosion Control of Canadian Forces Ships’ Air Conditioning Hydronic Water Systems.

    Science.gov (United States)

    1986-10-01

    de fer hydrat6, ce qui causait une perte de rendement, on a d~couvert que certaines pi~ces 6taient en acier doux. La corrosion des pieces en acier ...moyens de limiter la corrosion de pieces en acier dans de l’eau soit riche, soit pauvre en oxyg~ne. ii TABLE OF CONTENTS PAGE ABSTRACT ii LIST OF TABLES

  14. Experimental and theoretical studies of xanthan gum and its graft co-polymer as corrosion inhibitor for mild steel in 15% HCl

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Amrita; Pal, Sagar; Udayabhanu, G., E-mail: g_udayabhanu@hotmail.com

    2015-10-30

    Highlights: • Xanthan gum and its graft co-polymer used as corrosion inhibitors for mild steel in 15% HCl. • Electrochemical and weight loss studies give comparable corrosion rates. • Both the inhibitors are mixed type in nature. • Modified graft co-polymer is a more effective corrosion inhibitor. • Theoretical calculations taking monomer units of the polymer support the experimental results. - Abstract: Xanthan gum (XG) and its graft co-polymer have been investigated as corrosion inhibitors for mild steel in 15% HCl. Gravimetric analysis, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods were employed for investigating the effectiveness of these inhibitors. Results indicate that both the inhibitors are of mixed type and follow Langmuir adsorption isotherm. Scanning electron microscopy (SEM) study also confirmed the protection of the metal surface by XG and xanthan gum-graft-poly(acrylamide) (XG-g-PAM). Theoretical calculations using Density Functional Theory (DFT) were used to establish the correlation between the structure and corrosion protection efficiencies.

  15. A Study of N,N-Diethylammonium O,O′-Di(p-methoxyphenyldithiophosphate as New Corrosion Inhibitor for Carbon Steel in Hydrochloric Acid Solution

    Directory of Open Access Journals (Sweden)

    Chuan Lai

    2016-01-01

    Full Text Available N,N-Diethylammonium O,O′-di(p-methoxyphenyldithiophosphate (EAPP as a new corrosion inhibitor was synthesized in the present work. The corrosion inhibition of EAPP in hydrochloric acid for carbon steel was evaluated by potentiodynamic polarization measurements, electrochemical impedance spectroscopy, weight loss measurements, and scanning electron microscopy. The results indicate that the EAPP is mixed type inhibitor, and the adsorption of EAPP on carbon steel surface obeys Langmuir isotherm. In addition, the inhibition efficiency increases with increasing the concentration of inhibitor and decreases with increasing the hydrochloric acid concentration, temperature, and storage time.

  16. 气田缓蚀剂的筛选及评价%Selection and Evaluation of Corrosion Inhibitors for Gas Fields

    Institute of Scientific and Technical Information of China (English)

    司小明; 刘小丽

    2013-01-01

      针对土库曼斯坦某天然气田中酸性气体组成,以静态试验和动态试验对不同缓蚀剂进行筛选,用挂片失重法评价了缓蚀剂的缓蚀性能,并对温度及加药量进行了考察。缓蚀效果评价结果表明,新研制的缓蚀剂KO具有很好的防腐效果,可适用于酸性腐蚀介质。%Aiming at the composition of acid gas from a gas field in Turkmenistan, corrosion inhibitors were selected for the gas field by static trial and dynamic trial, and the corrosion inhibition properties were evaluated by weight loss method. Effects of corrosion inhibitor dosage and using temperature on the corrosion inhibition properties were studied. The results show that newly-developed corrosion inhibitor KO has excellent anti-corrosion property, and it can be suitable in acid corrosive environment.

  17. Galvanic secondary lithium battery with corrosion inhibitor dissolved in the electrolyte. Galvanisches Lithium-Sekundaerelement mit im Elektrolyten geloestem Korrosionsinhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Besenhard, J.; Fritz, H.P.; Guertler, J.; Komenda, P.; Paxinos, A.

    1987-08-27

    Saturated hydrocarbons with more than 5 C atoms, in particular saturated cyclic hydrocarbons with 5-20 C atoms such as the compounds decalin, perhydrofluorene and tricyclodecane, which are relatively soluble in electrolytic solvents such as propylene carbonate (PC) and which reversibly cover the electrolyte surface, are suitable corrosion inhibitors for lithium alloy electrodes and for lithium alloy electrodes in rechargeable galvanic lithium batteries. In this way, they inhibit the corrosion reactions between the electrode and the electrolyte or the electrolytic solvent. Besides, they support smooth metal deposition during the charging of Li electrodes. The sheltering effect manifests itself in a good charge conservation of the electrodes lasting over a longer storage period, e.g. in a solution of LiClO/sub 4//PC.

  18. Density functional theory study of ATA, BTAH, and BTAOH as copper corrosion inhibitors: adsorption onto Cu(111) from gas phase.

    Science.gov (United States)

    Kokalj, Anton; Peljhan, Sebastijan

    2010-09-21

    A low-coverage gas-phase adsorption of three corrosion inhibitors-3-amino-1,2,4-triazole (ATA), benzotriazole (BTAH), and 1-hydroxybenzotriazole (BTAOH)-on perfect Cu(111) surface has been studied and characterized using density functional theory calculations. We find that the molecules in neutral form chemisorb weakly to the perfect surface in an upright geometry. The strength of the chemisorption increases in the order BTAH BTA· with the adsorption energies of -1.65, -2.22, and -2.78 eV, respectively. This order is compatible with the trend of experimentally observed corrosion inhibition effectiveness on copper in near-neutral chloride solutions. Although the calculations are performed at the metal/vacuum interface, they provide enough insight to rationalize why in some experiments the BTAH was observed to be adsorbed with an upright geometry and in the others with parallel geometry.

  19. Inhibitor effects of sodium benzoate on corrosion resistance of Al6061-B4C composites in NaCl and H3BO3 solutions

    Science.gov (United States)

    Rafi-ud-din; Shafqat, Q. A.; Shahzad, M.; Ahmad, Ejaz; Asghar, Z.; Rafiq, Nouman; Qureshi, A. H.; Syed, Waqar adil; asim Pasha, Riffat

    2016-12-01

    Sodium benzoate (SB) is used for the first time to inhibit the corrosion of Al6061-B4C composites in H3BO3 and NaCl solutions. Al6061100-x -x wt% B4C (x = 0, 5, and 10) composites are manufactured by a powder metallurgy route. The corrosion inhibition efficiency of SB is investigated as a function of the volume fractions of B4C particles by using potentiodynamic polarization and electrochemical impedance techniques. Without the use of an inhibitor, an increase of the B4C particles in the composite decreases the corrosion resistance of Al6061-B4C composites. It is found that SB is an efficient corrosion inhibitor for Al6061-B4C composites in both investigated solutions. The corrosion inhibition efficiency of SB increases with an increase in B4C content. Since SB is an adsorption type inhibitor, it is envisaged that an extremely thin layer of molecules adsorbs onto the surface and suppresses the oxidation and reduction. It is found that the inhibitor effect of SB is more pronounced in a H3BO3 environment than in NaCl solution. Further, the mechanism of corrosion inhibition by SB is illustrated by using optical and scanning electron microscopy of corroded samples. It is found that the adsorption of benzoate ions on the Al surface and its bonding with Al3+ ions forms a hydrophobic layer on top of the exposed Al surface, which enhances the protection against dissolved boride ions.

  20. Effect of inorganic inhibitors on the corrosion behavior of 1018 carbon steel in the LiBr + ethylene glycol + H{sub 2}O mixture

    Energy Technology Data Exchange (ETDEWEB)

    Samiento-Bustos, E. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico); Rodriguez, J.G. Gonzalez [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico)], E-mail: ggonzalez@uaem.mx; Uruchurtu, J. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico); Dominguez-Patino, G. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico); U.A.E.M. Facultad de Ciencias Quimicas e Ingenieria, Av. Universidad 1001, 62209, Cuernavaca, Morelos (Mexico); Salinas-Bravo, V.M. [Instituto de Investigaciones Electricas, Gerencia de Materiales y Proceso Quimicos, Av. Reforma 113, Col. Palmira, CP 62490, Cuernavaca, Morelos (Mexico)

    2008-08-15

    The effect of inorganic inhibitors on the corrosion behavior of 1018 carbon steel in the mixture LiBr (55%) + ethylene glycol + H{sub 2}O at room temperature has been evaluated. Used inhibitors included LiNO{sub 3} (Lithium Nitrate), Li{sub 2}MoO{sub 4} (Lithium Molybdate) and Li{sub 2}CrO{sub 4} (Lithium Chromate) at concentrations of 5, 20 and 50 ppm. Electrochemical techniques included potentiodynamic polarization curves, electrochemical noise resistance (EN) and electrochemical impedance spectroscopy (EIS) measurements. Additionally, adsorption isotherms were calculated. The results obtained showed that both, the corrosion rate and the passive current density decreased with inhibitors, and, in general terms, inhibitors efficiency increased with inhibitor concentration, except in the case of Li{sub 2}CrO{sub 4,} where the highest efficiency was obtained with 20 ppm of inhibitor. Pitting potential with 5 ppm of inhibitor, regardless its chemical composition, was more active than in absence of inhibitor, increased at 20 ppm, especially with Li{sub 2}CrO{sub 4}, and remained unaltered with 50 ppm. EN measurements showed that at 5 ppm of inhibitor, the number of film rupture/repassivation events was higher than that obtained at 20 or 50 ppm. Adsorption isotherms suggested a different adsorption mechanism for each inhibitor, whereas EIS results suggested that the corrosion process when nitrates were added was under charge transfer control, but in the case of molybdates or chromates was under diffusion control.

  1. Sargassum Wightii Extract as a Green Inhibitor for Corrosion of Brass in 0.1 N Phosphoric Acid Solution

    Directory of Open Access Journals (Sweden)

    R. Selva Kumar

    2015-06-01

    Full Text Available The effect of marine algae Sargassum wightii extract on corrosion inhibition of brass in phosphoric acid was investigated by weight-loss method, potentiodynamic polarization and electrochemical impedance spectroscopy studies. The inhibition efficiency is found to increase with increasing concentration of extract and decreases with rise in temperature. The inhibitive effect could be attributed to the phytochemical constituents present in the inhibitor containing N, S, O atoms. The activation energy, thermodynamic parameters (free energy, enthalpy and entropy change and kinetic parameters (rate constant and half-life for inhibition process were calculated. These thermodynamic and kinetic parameters indicate a strong interaction between the inhibitor and the brass surface. The inhibition is assumed to occur via adsorption of inhibitor molecules on the brass surface, which obeys Temkin adsorption isotherm. The adsorption of inhibitor on the brass surface is exothermic, physical, and spontaneous, follows first order kinetics. The polarization measurements showed that the inhibitor behaves as a mixed type inhibitor. Inhibition efficiency values were found to show good trend with weight-loss method, potentiodynamic polarization and electrochemical impedance spectroscopy studies. Surface study techniques (FT-IR and SEM were carried out to ascertain the inhibitive nature of the algal extract on the brass surface.

  2. 苯并咪唑类缓蚀剂缓蚀机理以及研究趋势%Corrosion-inhibiting mechanism and research tendency of the benzimidazole corrosion inhibitor

    Institute of Scientific and Technical Information of China (English)

    王娴

    2012-01-01

    Benzimidazole corrosion inhibitor was a kind of hydrochloride pickling inhibitor. It was possessed various inhibition efficiency because of the distinction of substitutional group. It was occupied the characteristics of high performance,low mammalian toxicity and biodegradation. It also was a kind of adsorption corrosion inhibitor, it also was involved many aspects of resistance chemical corrosion, molecular interface adsorption, the groups covering effects as well as hydrogen-bonding association effects. It was analysised and introduced the preparation method, corrosion-inhibiting mechanism and research tendency of the benzimidazole corrosion inhibitor in this article.%苯并咪唑类缓蚀剂是一类盐酸酸洗缓蚀剂,当取代基不同,其分子呈现不同的缓蚀效率。苯并咪唑类缓蚀剂具有高效、低毒和生物易降解等特点。苯并咪唑缓蚀剂是吸附型缓蚀剂,它涉及到阻化效应、分子界面吸附、基团覆盖效应和氢键缔合效应等多方面。文中介绍了苯并咪唑类缓蚀剂的制备方式、缓释机理以及发展状况。

  3. Optimization of a Three-Component Green Corrosion Inhibitor Mixture for Using in Cooling Water by Experimental Design

    Science.gov (United States)

    Asghari, E.; Ashassi-Sorkhabi, H.; Ahangari, M.; Bagheri, R.

    2016-04-01

    Factors such as inhibitor concentration, solution hydrodynamics, and temperature influence the performance of corrosion inhibitor mixtures. The simultaneous studying of the impact of different factors is a time- and cost-consuming process. The use of experimental design methods can be useful in minimizing the number of experiments and finding local optimized conditions for factors under the investigation. In the present work, the inhibition performance of a three-component inhibitor mixture against corrosion of St37 steel rotating disk electrode, RDE, was studied. The mixture was composed of citric acid, lanthanum(III) nitrate, and tetrabutylammonium perchlorate. In order to decrease the number of experiments, the L16 Taguchi orthogonal array was used. The "control factors" were the concentration of each component and the rotation rate of RDE and the "response factor" was the inhibition efficiency. The scanning electron microscopy and energy dispersive x-ray spectroscopy techniques verified the formation of islands of adsorbed citrate complexes with lanthanum ions and insoluble lanthanum(III) hydroxide. From the Taguchi analysis results the mixture of 0.50 mM lanthanum(III) nitrate, 0.50 mM citric acid, and 2.0 mM tetrabutylammonium perchlorate under the electrode rotation rate of 1000 rpm was found as optimum conditions.

  4. Electrochemical and quantum chemical studies of some indole derivatives as corrosion inhibitors for C38 steel in molar hydrochloric acid

    Energy Technology Data Exchange (ETDEWEB)

    Lebrini, M. [Laboratoire Materiaux et Molecules en Milieu Amazonien, CNRS 8172-UMR ECOFOG, Campus Trou Biran, Cayenne 97337, French Guiana (France); Robert, F. [Laboratoire Materiaux et Molecules en Milieu Amazonien, UAG-UMR ECOFOG, Campus Trou Biran, Cayenne 97337, French Guiana (France); Vezin, H. [Laboratoire de Chimie Organique et Macromoleculaire, UMR-CNRS 8009, USTL BatC4 F-59655 Villeneuve d' Ascq Cedex (France); Roos, C., E-mail: christophe.roos@guyane.univ-ag.f [Laboratoire Materiaux et Molecules en Milieu Amazonien, UAG-UMR ECOFOG, Campus Trou Biran, Cayenne 97337, French Guiana (France)

    2010-10-15

    A comparative study of 9H-pyrido[3,4-b]indole (norharmane) and 1-methyl-9H-pyrido[3,4-b]indole (harmane) as inhibitors for C38 steel corrosion in 1 M HCl solution at 25 {sup o}C was carried out. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were applied to study the metal corrosion behavior in the absence and presence of different concentrations of these inhibitors. The OCP as a function of time were also established. Cathodic and anodic polarization curves show that norharmane and harmane are a mixed-type inhibitors. Adsorption of indole derivatives on the C38 steel surface, in 1 M HCl solution, follows the Langmuir adsorption isotherm model. The {Delta}G{sub ads}{sup o} values were calculated and discussed. The potential of zero charge (PZC) of the C38 steel in inhibited solution was studied by the EIS method, and a mechanism for the adsorption process was proposed. Raman spectroscopy confirmed that indole molecules strongly adsorbed onto the steel surface. The electronic properties of indole derivates, obtained using the AM1 semi-empirical quantum chemical approach, were correlated with their experimental efficiencies using the linear resistance model (LR).

  5. Effect of Nitrite Inhibitor on the Macrocell Corrosion Behavior of Reinforcing Steel

    Directory of Open Access Journals (Sweden)

    Zhonglu Cao

    2015-01-01

    Full Text Available The effect of nitrite ions on the macrocell corrosion behavior of reinforcing steel embedded in cement mortar was investigated by comparing and analyzing the macrocell corrosion current, macrocell polarization ratios, and slopes of anodic and cathodic steels. Based on the experimental results, the relationship between macrocell potential difference and macrocell current density was analyzed, and the mechanism of macrocell corrosion affected by nitrite ions was proposed. The results indicated that nitrite ions had significant impact on the macrocell polarization ratios of cathode and anode. The presence of nitrite could reduce the macrocell current by decreasing the macrocell potential difference and increasing the macrocell polarization resistance of the anode.

  6. Novel Schiff-base molecules as efficient corrosion inhibitors for mild steel surface in 1 M HCl medium: experimental and theoretical approach.

    Science.gov (United States)

    Saha, Sourav Kr; Dutta, Alokdut; Ghosh, Pritam; Sukul, Dipankar; Banerjee, Priyabrata

    2016-07-21

    In order to evaluate the effect of the functional group present in the ligand backbone towards corrosion inhibition performances, three Schiff-base molecules namely, (E)-4-((2-(2,4-dinitrophenyl)hydrazono)methyl)pyridine (L(1)), (E)-4-(2-(pyridin-4-ylmethylene)hydrazinyl)benzonitrile (L(2)) and (E)-4-((2-(2,4-dinitrophenyl)hydrazono)methyl)phenol (L(3)) were synthesized and used as corrosion inhibitors on mild steel in 1 M HCl medium. The corrosion inhibition effectiveness of the studied inhibitors was investigated by weight loss and several sophisticated analytical tools such as potentiodynamic polarization and electrochemical impedance spectroscopy measurements. Experimentally obtained results revealed that corrosion inhibition efficiencies followed the sequence: L(3) > L(1) > L(2). Electrochemical findings showed that inhibitors impart high resistance towards charge transfer across the metal-electrolyte interface and behaved as mixed type inhibitors. Scanning electron microscopy (SEM) was also employed to examine the protective film formed on the mild steel surface. The adsorption as well as inhibition ability of the inhibitor molecules on the mild steel surface was investigated by quantum chemical calculation and molecular dynamic (MD) simulation. In quantum chemical calculations, geometry optimized structures of the Schiff-base inhibitors, electron density distribution in HOMO and LUMO and Fukui indices of each atom were employed for their possible mode of interaction with the mild steel surfaces. MD simulations revealed that all the inhibitors molecules adsorbed in parallel orientation with respect to the Fe(110) surface.

  7. Arachidonic acid release from PC12 pheochromocytoma cells is regulated by I1-imidazoline receptors.

    Science.gov (United States)

    Ernsberger, P

    1998-10-15

    Rat PC 12 pheochromocytoma cells lack alpha2-adrenergic receptors but express plasma membrane I1-imidazoline receptors. In response to the I1-agonist moxonidine, diglycerides are generated via phosphatidylcholine-selective phospholipase C, and prostaglandin E2 is released. This report characterizes I-receptor-mediated release of arachidonic acid, the precursor to the prostaglandins. PC12 cells were incubated with [3H]arachidonic acid for 24 h and superfused with 0.01% bovine serum albumin in Krebs' physiological buffer at 1 ml/min. Calcium ionophore increased arachidonic acid release only marginally, implying that in PC12 cells arachidonic acid release is not driven by calcium. The I1-agonist moxonidine at concentrations between 10 nM and 1.0 microM rapidly elicited up to two-fold increases in [3H]arachidonic acid release. Guanabenz, a potent alpha2-agonist and I2-ligand, had no effect. The selective I1-antagonist efaroxan blocked the action of moxonidine. The phospholipase A2 inhibitor aristolochic acid had no effect, suggesting that arachidonic acid release may be through an indirect pathway, possibly involving diglycerides. Thus, I1-imidazoline receptors in PC12 cells are coupled to arachidonic acid release through an as yet unknown pathway.

  8. Efficient Complex Surfactants from the Type of Fatty Acids as Corrosion Inhibitors for Mild Steel C1018 in CO{sub 2}-Environments

    Energy Technology Data Exchange (ETDEWEB)

    Abbasov, Vagif M.; Abd Ellatee, Hany M.; Aliyeva, Leylufer I.; Ismayilov, Ismayil T.; Qasimov, Elmar E.; Narmin, Mamedova M. [National Academy of Sciences of Azerbaijan, Baku (Azerbaijan)

    2013-02-15

    The efficiency of three complex surfactants based on sunflower oil and nitrogen containing compounds as corrosion inhibitors for mild steel in CO{sub 2}-saturated 1% NaCl solution, has been determined by weight loss and LPR corrosion rate measurements. These compounds inhibit corrosion even at very low concentrations. The inhibition process was attributed to the formation of an adsorbed film on the metal surface that protects the metal against corrosive media. The inhibition efficiency increases with increasing the concentration of the studied inhibitors. Maximum inhibition efficiency of the surfactants is observed at concentrations around its critical micellar concentration (CMC). Adsorption of complex surfactants on the mild steel surface is in agreement with the Langmuir adsorption isotherm model, and the calculated Gibbs free energy values confirm the chemical nature of the adsorption. Energy dispersive X-ray fluorescence microscopy (EDRF) observations of the electrode surface confirmed the existence of such an adsorbed film.

  9. Standard practice for evaluating and qualifying oil field and refinery corrosion inhibitors using the rotating cylinder electrode

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 This practice covers a generally accepted procedure to use the rotating cylinder electrode (RCE) for evaluating corrosion inhibitors for oil field and refinery applications in defined flow conditions. 1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

  10. Application of Argan plant extract as green corrosion inhibitor for steel in 1 mol/L HCl

    Institute of Scientific and Technical Information of China (English)

    L. Afia; R. Salghi; L. Bammou; Lh. Bazzi; B. Hammouti; L. Bazzi

    2012-01-01

    The effect of Argan plant extract (APE) on the corrosion of the steel in hydrochloric acid medium was studied using gravimetric,electrochemical polarization and impedance spectroscopy (EIS) measurements. Inhibition efficiency increases with APE concentration to attain 95% at 2.5 g/L.We note good agreement between gravimetric and electrochemical methods (potentiodynamic polarization and EIS).Effect of temperature is also made in the 298-328 K range.Polarization measurements show also that APE act as a mixed inhibitor.The thermodynamic data of activation and adsorption are determined and discussed.

  11. Synthesis of imidazoline-based dissymmetric bis-quaternary ammonium gemini surfactant and its inhibition mechanism on Q235 steel in hydrochloric acid medium

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J.; Gong, X.L.; Song, W.W.; Jiang, B.; Du, M. [Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, College of Chemistry and Chemical Engineering, Ocean University of China, Qingdao, Shandong Province (China)

    2012-07-15

    An imidazoline-based dissymmetric bis-quaternary ammonium gemini surfactant has been synthesized. Its surface active properties at equilibrium in water at 25 C were determined. The inhibitive effect of the compound on Q235 steel in 1 M hydrochloric solution was investigated by the weight-loss method, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) analysis, and quantum chemical calculations. The results indicate that the compound has high surface properties and the inhibition efficiency (IE) increases with the increase in inhibitor concentration, which attain the maximum value around the CMC value. The imidazoline-based dissymmetric bis-quaternary ammonium acts as a mixed type inhibitor mainly inhibiting the cathodic processes and does not change the mechanism of either hydrogen evolution reaction or mild steel dissolution. The best IE is obtained at the immersion time of 144 h. The adsorption of the studied inhibitor on Q235 steel can be fitted to a Langmuir isotherm and the adsorption process is a spontaneous chemical adsorption. Quantum chemistry calculation results show that the imidazoline ring and heteroatoms of N, O, are the active sites of the inhibitors. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. Valoniopsis pachynema Extract as a Green Inhibitor for Corrosion of Brass in 0.1 N Phosphoric Acid Solution

    Science.gov (United States)

    Selva Kumar, R.; Chandrasekaran, V.

    2016-04-01

    The effect of marine alga Valoniopsis pachynema extract on corrosion inhibition of brass in phosphoric acid was investigated by weight-loss method, potentiodynamic polarization, and electrochemical impedance spectroscopy studies. The inhibition efficiency is found to increase with increasing concentration of extract and decreases with rise in temperature. The activation energy, thermodynamic parameters (free energy, enthalpy, and entropy change) and kinetic parameters (rate constant and half-life) for inhibition process were calculated. These thermodynamic and kinetic parameters indicate a strong interaction between the inhibitor and the brass surface. The inhibition is assumed to occur via adsorption of inhibitor molecules on brass surface, which obeys Temkin adsorption isotherm. The adsorption of inhibitor on the brass surface is exothermic, physical, and spontaneous, and follows first-order kinetics. The polarization measurements showed that the inhibitor behaves as a mixed type inhibitor and the higher inhibition surface coverage on the brass was predicted. Inhibition efficiency values were found to show good trend with weight-loss method, potentiodynamic polarization, and electrochemical impedance spectroscopy studies. Surface study techniques (FT-IR and SEM) were carried out to ascertain the inhibitive nature of the algal extract on the brass surface.

  13. Theoretical Study of Chloro-N-(4-methoxybenzylideneaniline Derivatives as Corrosion Inhibitors for Zinc in Hydrochloric Acid

    Directory of Open Access Journals (Sweden)

    S. Kumar

    2013-01-01

    Full Text Available The density functional theory (DFT was used to investigate the corrosion inhibition of three inhibitors on zinc. Quantum chemical parameters such as the energy of highest occupied molecular orbital (EHOMO, the energy of lowest unoccupied molecular orbital (ELUMO, energy gap (ΔE, hardness (η, softness (σ, electrophilicity index (ω, the fraction of electrons transferred (ΔN from inhibitor molecule to the metal surface, energy change when both processes occur, namely, charge transfer to the molecule and backdonation from the molecule (ΔEbackdonation, natural charge (qN, and Fukui functions have been calculated by using B3LYP/6-31+G(d basis set. The relation between the inhibition efficiency and quantum chemical parameters has been discussed in order to elucidate the inhibition mechanism of the chloro-N-(4-methoxybenzylideneaniline derivatives.

  14. Research on Corrosion Inhibitor of Oil and Gas Pipe%油气管道腐蚀缓蚀剂的研究

    Institute of Scientific and Technical Information of China (English)

    曹登祥; 臧子璇; 张家兰; 彭晓青; 林玉梓

    2000-01-01

    根据缓蚀剂对金属腐蚀的机理,选用不同性能的缓蚀剂和表面活性剂进行复配,对模拟的油、气管道常规输送工况进行了静、动态对比试验。通过试验数据分析,寻求了最佳的缓蚀剂与表面活性剂的配比。%According to principle of corrosion inhibitor, by means of selecting different property corrosion inhibitors and surface active material to mix, comparing static with dynamic experiment was carried out in simulating conventional transfer condition of oil and gas pipe. The experiment results show that the correct and effective corrosion control is to find out the best mixed proportion of corrosion inhibitor and surface active material which can improve the corrosion inhibitor property and decrease preventing cost from corruptness of oil and gas pipe.

  15. Alkaloids extract of Retama monosperma (L.) Boiss. seeds used as novel eco-friendly inhibitor for carbon steel corrosion in 1 M HCl solution: Electrochemical and surface studies

    Science.gov (United States)

    El Hamdani, Naoual; Fdil, Rabiaa; Tourabi, Mustapha; Jama, Charafeddine; Bentiss, Fouad

    2015-12-01

    Current research efforts now focus on the development of non-toxic, inexpensive and environmentally friendly corrosion inhibitors as alternatives to different organic and non-organic compounds. In this field, alkaloids extract of Retama monosperma (L.) Boiss. seeds (AERS) was tested for the first time as corrosion inhibitor for carbon steel in 1 M HCl medium using electrochemical and surface characterization techniques. The obtained results showed that this plant extract's acts as an efficient corrosion inhibitor for carbon steel in 1 M HCl and an inhibition efficiency of 94.4% was reached with 400 mg/L of AERS at 30 °C. Ac impedance experimental data revealed a frequency distribution of the capacitance, simulated as constant phase element. Impedance results demonstrated that the addition of the AERS in the corrosive solution decreases the charge capacitance and simultaneously increases the function of the charge/discharge of the interface, facilitating the formation of an adsorbed layer over the steel surface. Polarization curves indicated that AERS is a mixed inhibitor. Adsorption of such alkaloid extract on the steel surface obeyed to the Langmuir adsorption isotherm. X-ray photoelectron spectroscopy (XPS) showed that the inhibition of steel corrosion in normal hydrochloric solution by AERS is mainly controlled by a physisorption process and the inhibitive layer is composed of an iron oxide/hydroxide mixture where AERS molecules are incorporated.

  16. Comparative study on lithium borates as corrosion inhibitors of aluminum current collector in lithium bis(fluorosulfonyl)imide electrolytes

    Science.gov (United States)

    Park, Kisung; Yu, Sunghun; Lee, Chulhaeng; Lee, Hochun

    2015-11-01

    Lithium bis(fluorosulfonyl)imide (LiFSI) is a promising salt that can possibly overcome the limitations of lithium hexafluorophosphate (LiPF6) in current Li-ion batteries (LIBs). Aluminum (Al) corrosion issue, however, is a major bottleneck for the wide use of LiFSI. This study investigates lithium borate salts as Al corrosion inhibitors in LiFSI electrolytes. Through a systematic comparison among lithium tetrafluoroborate (LiBF4), lithium bis(oxalato)borate (LiBOB), and lithium difluoro(oxalato)borate (LiDFOB), and LiPF6, the inhibition ability of the additives is revealed to be in the following order: LiDFOB > LiBF4 ≈ LiPF6 > LiBOB. In particular, the inhibition effect of LiDFOB is outstanding; the anodic behavior of Al in 0.8 M LiFSI + 0.2 M LiDFOB ethylene carbonate (EC)-based electrolyte is comparable to that of corrosion-free 1 M LiPF6 solution. The superior inhibition ability of LiDFOB is attributed to the formation of a passive layer composed of Al-F, Al2O3, and B-O species, as evidenced by X-ray photoelectron spectroscopy (XPS) measurements. A LiCoO2/graphite cell with 0.8 M LiFSI + 0.2 M LiDFOB electrolyte exhibits a rate capability comparable to a cell with 1 M LiPF6 solution, whereas a cell with 0.8 M LiFSI solution without LiDFOB suffers from poor power performance resulting from severe Al corrosion.

  17. EVELOPMENT OF AN ENVIRONMENTALLY BENIGN MICROBIAL INHIBITOR TO CONTROL INTERNAL PIPELINE CORROSION

    Energy Technology Data Exchange (ETDEWEB)

    Bill W. Bogan; Wendy R. Sullivan; Kristine M. H. Cruz; Kristine L. Lowe; John J. Kilbane II

    2004-04-30

    The overall program objective is to develop and evaluate environmentally benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is to develop one or more environmentally benign (a.k.a. ''green'') products that can be applied to maintain the structure and dependability of the natural gas infrastructure. Previous testing of pepper extracts resulted in preliminary data indicating that some pepper extracts inhibit the growth of some corrosion-associated microorganisms. This quarter additional tests were performed to more specifically investigate the ability of three pepper extracts to inhibit the growth, and to influence the metal corrosion caused by two microbial species: Desulfovibrio vulgaris, and Comomonas denitrificans. All three pepper extracts rapidly killed Desulfovibrio vulgaris, but did not appear to inhibit Comomonas denitrificans. While corrosion rates were at control levels in experiments with Desulfovibrio vulgaris that received pepper extract, corrosion rates were increased in the presence of Comomonas denitrificans plus pepper extract. Further testing with a wider range of pure bacterial cultures, and more importantly, with mixed bacterial cultures should be performed to determine the potential effectiveness of pepper extracts to inhibit MIC.

  18. State of the Art on Cactus Additions in Alkaline Media as Corrosion Inhibitors

    Directory of Open Access Journals (Sweden)

    A. A. Torres-Acosta

    2012-01-01

    Full Text Available This research in progress includes results on the corrosion performance of reinforcing steel in alkaline media when two different dehydrated cacti (Opuntia ficus-indica—Nopal—and Aloe Vera were used as additions in pH 12.5 and 13.3 solutions and in concrete. The dehydrated cactus addition was mixed at different concentrations by either solution or cement mass (0.10%, 0.25%, 0.5%, 1.0%, and 2.0%. Half-cell potentials and LPR measurements were performed at different time periods to characterize the possible corrosion inhibiting effect of the cactus additions tested in such alkaline media. Results showed good corrosion inhibiting effect of dehydrated Nopal on reinforcing steel, in all tested solutions, when chloride ions are present. Aloe Vera did show also corrosion inhibiting improvements in some extent. The addition of such cactus led to an apparent formation of a denser and more packed oxide/hydroxide surface layer on the steel surface that decreased corrosion activity. This oxide/hydroxide layer growth was confirmed by microscopic evaluation of the metal surface layer performed at the end of the research program. The preliminary findings suggest that adding Nopal at concentrations between 1% and 2%, by mass, might be suitable for durability enhancing applications in alkaline media, especially in concrete structures.

  19. Benevolent behavior ofKleinia grandifloraleaf extract as a green corrosion inhibitor for mild steel in sulfuric acid solution

    Institute of Scientific and Technical Information of China (English)

    Muthukrishnan Pitchaipillai; Karthik Raj; Jeyaprabha Balasubramanian; Prakash Periakaruppan

    2014-01-01

    The ethanolic extract ofKleinia grandifloraleaves was characterized and tested for its potential anticorrosion properties on mild steel in 1 M H2SO4 medium using mass-loss analysis, potentiodynamic polarization measurements, electrochemical impedance spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, UV–visible spectroscopy, and X-ray diffraction analysis. The effect of temperature on the corrosion behavior of mild steel was studied in the range of 308 to 328 K. The inhibition efficiency was observed to increase with increasing concentration of the extract. Polarization curves revealed that theKleinia grandiflora leaf extract is a mixed inhibitor. Impedance diagrams revealed that an increase ofKleinia grandiflora leaf extract concentration increased the charge transfer resistance and decreased the double-layer capacitance. The adsorption process obeys Langmuir’s model, with a standard free energy of adsorption (∆Gads) of−18.62 kJ/mol. The obtained results indicate that theKleinia grandiflora leaf extract can serve as an effective inhibitor for the corrosion of mild steel in a sulfuric acid medium.

  20. Experimental and DFT Studies on the Behavior of Caffeine as Effective Corrosion Inhibitor of Copper in 1M HNO3

    Directory of Open Access Journals (Sweden)

    Victorien Kouakou

    2016-04-01

    Full Text Available Caffeine was tested as copper corrosion inhibitor in 1M HNO3 using mass loss technique at 308-328K and theoretical studies based on quantum chemistry. The inhibition efficiency is concentration and temperature dependent: Caffeine showed an inhibition efficiency of 78% at 5mM for T =328K. The thermodynamic adsorption parameters ( were determined and analyzed. They revealed a spontaneous adsorption process and a strong interaction between Caffeine and the metal surface. Adsorption isotherms including Langmuir, Temkin and El-Awady were tested. It was found that Caffeine adsorbs on copper according to the modified Langmuir adsorption isotherm. The Dubinin Raduskevitch model was used to distinguish between chemisorption and physisorption. Activation parameters ( were also determined and discussed. Furthermore, the quantum chemical properties/descriptors most relevant to the potential action of the molecule as corrosion inhibitor such as highest occupied molecular energy (EHOMO, lowest unoccupied molecular orbital energy (ELUMO, energy gap(∆E, dipole moment ( and charges on heteroatoms were calculated using DFT at B3LYP level with 6-31+G (d and LanL2DZ basis sets. Fukui indices were also determined and discussed. The theoretical results are consistent with the experimental data reported. DOI: http://dx.doi.org/10.17807/orbital.v8i2.804 

  1. pH-responsive nanovalves based on hollow mesoporous silica spheres for controlled release of corrosion inhibitor

    Science.gov (United States)

    Chen, Tao; Fu, JiaJun

    2012-06-01

    In the present study, a new encapsulation technique for corrosion inhibitor is proposed. The hollow mesoporous silica spheres (HMSs) were synthesized by the co-templates method as nanocontainers for corrosion inhibitor, benzotriazole (BTA) and the supramolecular nanovalves, consisting of cucurbit[6]uril (CB[6]) rings and the functional stalks attached to the surface of HMSs achieved on-demand release. The synthesis process of HMSs and the assembly process of the nanovalves were confirmed by SEM, TEM, N2 adsorption/desorption, FTIR, TGA and solid-state 13C CP/MAS NMR. The encapsulation capacity and release characteristics of BTA-loaded, assembled HMSs were investigated. The HMSs assembled with the nanovalves possessed a higher encapsulation capacity for BTA than MCM-41 assembled under the same procedure due to its huge hollow internal structure. The pH-controlled release properties of BTA from the assembled HMSs under different pH environments were monitored by ultraviolet absorption spectra. The release profiles showed that there was almost no leakage of BTA from the assembled HMSs in neutral solution, while in alkaline solution BTA released very quickly, and the release rate increased with increasing pH values. Such a property makes the HMSs assembled with the pH-responsive nanovalves have great potential applications in smart anticorrosion coatings.

  2. pH-responsive nanovalves based on hollow mesoporous silica spheres for controlled release of corrosion inhibitor.

    Science.gov (United States)

    Chen, Tao; Fu, JiaJun

    2012-06-15

    In the present study, a new encapsulation technique for corrosion inhibitor is proposed. The hollow mesoporous silica spheres (HMSs) were synthesized by the co-templates method as nanocontainers for corrosion inhibitor, benzotriazole (BTA) and the supramolecular nanovalves, consisting of cucurbit[6]uril (CB[6]) rings and the functional stalks attached to the surface of HMSs achieved on-demand release. The synthesis process of HMSs and the assembly process of the nanovalves were confirmed by SEM, TEM, N(2) adsorption/desorption, FTIR, TGA and solid-state (13)C CP/MAS NMR. The encapsulation capacity and release characteristics of BTA-loaded, assembled HMSs were investigated. The HMSs assembled with the nanovalves possessed a higher encapsulation capacity for BTA than MCM-41 assembled under the same procedure due to its huge hollow internal structure. The pH-controlled release properties of BTA from the assembled HMSs under different pH environments were monitored by ultraviolet absorption spectra. The release profiles showed that there was almost no leakage of BTA from the assembled HMSs in neutral solution, while in alkaline solution BTA released very quickly, and the release rate increased with increasing pH values. Such a property makes the HMSs assembled with the pH-responsive nanovalves have great potential applications in smart anticorrosion coatings.

  3. sym-Trisubstituted 1,3,5-Triazine Derivatives as Promising Organic Corrosion Inhibitors for Steel in Acidic Solution.

    Science.gov (United States)

    El-Faham, Ayman; Dahlous, Kholood A; Al Othman, Zeid A; Al-Lohedan, Hamad A; El-Mahdy, Gamal A

    2016-03-31

    Triazine derivatives, namely, 2,4,6-tris(quinolin-8-yloxy)-1,3,5-triazine (T3Q), N²,N⁴,N⁶-tris(pyridin-2-ylmethyl)-1,3,5-triazine-2,4,6-triamine (T3AMPy) and 2,2',2''-[(1,3,5-triazine-2,4,6-triyl)tris(azanediyl)] tris(ethan-1-ol) (T3EA) were synthesized and their inhibition of steel corrosion in hydrochloric acid solution was investigated using electrochemical techniques. The corrosion protection of the prepared compounds increased with increasing concentration and reached up to 98% at 250 ppm. The adsorption of T3Q, T3AMPy, and T3EA on the steel surface was in accordance with the Langmuir adsorption isotherm. The electrochemical results revealed that T3Q, T3AMPy and T3EA act as excellent organic inhibitors and can labeled as mixed type inhibitors. The efficiencies of the tested compounds were affected by the nature of the side chain present in the triazine ring, where T3EA gave the least inhibition while T3Q and T3AMPy gave higher and almost the same inhibition effects. The inhibition efficiencies obtained from the different electrochemical techniques were in good agreement.

  4. Benevolent behavior of Kleinia grandiflora leaf extract as a green corrosion inhibitor for mild steel in sulfuric acid solution

    Science.gov (United States)

    Pitchaipillai, Muthukrishnan; Raj, Karthik; Balasubramanian, Jeyaprabha; Periakaruppan, Prakash

    2014-11-01

    The ethanolic extract of Kleinia grandiflora leaves was characterized and tested for its potential anticorrosion properties on mild steel in 1 M H2SO4 medium using mass-loss analysis, potentiodynamic polarization measurements, electrochemical impedance spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, UV-visible spectroscopy, and X-ray diffraction analysis. The effect of temperature on the corrosion behavior of mild steel was studied in the range of 308 to 328 K. The inhibition efficiency was observed to increase with increasing concentration of the extract. Polarization curves revealed that the Kleinia grandiflora leaf extract is a mixed inhibitor. Impedance diagrams revealed that an increase of Kleinia grandiflora leaf extract concentration increased the charge transfer resistance and decreased the double-layer capacitance. The adsorption process obeys Langmuir's model, with a standard free energy of adsorption (Δ G ads) of -18.62 kJ/mol. The obtained results indicate that the Kleinia grandiflora leaf extract can serve as an effective inhibitor for the corrosion of mild steel in a sulfuric acid medium.

  5. Investigation of SiO{sub 2}:Na{sub 2}O ratio as a corrosion inhibitor for metal alloys

    Energy Technology Data Exchange (ETDEWEB)

    Mohamad, N.; Othman, N. K. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan (Malaysia); Jalar, A. [Institute of Micro Engineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan (Malaysia)

    2013-11-27

    The silicate is one of the potential compounds used as a corrosion inhibitor for metal alloys. The mixture between silica and sodium hydroxide (NaOH) succeeded to produce the silicate product. The formulation of a silicate product normally variable depended by the different ratio of SiO{sub 2}:Na{sub 2}O. This research utilized the agriculture waste product of paddy using its rice husk. In this study, the amorphous silica content in rice husk ash was used after rice husk burnt in a muffle furnace at a certain temperature. The X-ray diffraction (XRD) analysis was done to determine the existence of amorphous phase of silica in the rice husk ash. There are several studies that recognized rice husk as an alternative source that obtained high silica content. The X-ray fluorescence (XRF) analysis was carried out to clarify the percentage amount of Si and O elements, which referred the silica compound in rice husk ash. The preparation of sodium silicate formulation were differ based on the SiO{sub 2}:Na{sub 2}O ratio (SiO{sub 2}:Na{sub 2}O ratio = 1.00, 2.00 and 3.00). These silicate based corrosion inhibitors were tested on several testing samples, which were copper (99.9%), aluminum alloy (AA 6061) and carbon steel (SAE 1045). The purpose of this study is to determine the appropriate SiO{sub 2}:Na{sub 2}O ratio and understand how this SiO{sub 2}:Na{sub 2}O ratio can affect the corrosion rate of each metal alloys immersed in acidic medium. In order to investigate this study, weight loss test was conducted in 0.5 M hydrochloric acid (HCl) for 24 hours at room temperature.

  6. 曼尼希碱型缓蚀剂的研究现状与展望%Prospect and Progress of Resarch on New Acidizing Corrosion Inhibitor

    Institute of Scientific and Technical Information of China (English)

    周也

    2012-01-01

    结合现有的国内外对新型缓蚀剂的研究现状,阐述了曼尼希碱型缓蚀剂的合成及缓蚀机理,讨论了其应用现状和发展前景。%Combined existing domestic and foreign synthesis of Mannich base inhibitors and corrosion status and development prospects. research status of new corrosion inhibitor. inhibition mechanism. Also discussed its Explained application

  7. Green corrosion inhibitors for carbon steel by green leafy vegetables extracts in 1 M HCl

    Directory of Open Access Journals (Sweden)

    Ghadah M. Al-Senani

    2015-12-01

    Full Text Available The effect of some Green Leafy Vegetables (GLV extracts namely Lactuca sativa (Lactuca, Eruca Sativa (Arugula, Petroselinum crispum (Parsley, and Anethum Graveolens (Dill were investigated on inhibition of corrosion carbon steel in 1 M HCl solution using gravimetric (weight loss method. The inhibition efficiency has increased as concentration of the extract increased. The inhibition efficiency has decreased as the temperature increased. The results obtained showed that GLV extracts inhibited the corrosion process by a physical adsorption mechanism that followed the Langmuir, Freundlich, and Temkin adsorption isotherm models. The adsorption thermodynamic parameters that were calculated include, free energy of adsorption (∆G°ads, activation energy (Ea, enthalpy of adsorption (ΔH°ads, and entropy of adsorption (ΔS°ads are proposed for the corrosion of carbon steel in 1 M HCl in the absence and presence of GLV extract.

  8. Research on Inhibition Effect of Multi-function Pickling Corrosion Inhibitor%多功能酸洗缓蚀剂缓蚀效果的研究

    Institute of Scientific and Technical Information of China (English)

    张晓冬; 喻果; 徐飞

    2016-01-01

    Hydrochloric acid pickling, sulfuric acid pickling, nitric acid pickling corrosion experiments of multifunctional pickling corrosion inhibitor developed by our company were carried out. The experimental results show that the multifunctional pickling corrosion inhibitor in hydrochloric acid pickling, sulfuric acid, nitric acid pickling process has very good inhibition effect for carbon steel and16 mn steel; different drug concentration has different corrosion inhibition effect. Multifunctional pickling corrosion inhibitor concentration commonly is 3‰~5‰, 10% hydrochloric acid pickling corrosion inhibition rate can reach 98.8%, 10% sulfuric acid pickling corrosion inhibition rate can reach 99.8%, 10% nitric acid pickling corrosion inhibition rate can reach 77%.%对威海翔宇环保科技股份有限公司研发的多功能酸洗缓蚀剂进行了盐酸酸洗、H2SO4 酸洗、硝酸酸洗缓蚀实验,实验结果表明,多功能酸洗缓蚀剂在盐酸酸洗、H2SO4酸洗、硝酸酸洗过程中对碳钢、16mn 钢都有很好的缓蚀效果,加药浓度不同,缓蚀效果不同.多功能酸洗缓蚀剂的加药浓度一般在 3‰~5‰,10%的盐酸酸洗的缓蚀率可达到 98.8%、10%的 H2SO4酸洗的缓蚀率可达到 99.8%、10%的硝酸酸洗的缓蚀率可达到 77%以上.

  9. Volatile Corrosion Inhibitors Part III- Ammonium stearate and M-Dinitrobenezene

    Directory of Open Access Journals (Sweden)

    K. S. Rajagopalan

    1962-07-01

    Full Text Available In earlier studies while screening various chemical compound for their vapour phase inhibiting properties. Some ammonium salts and nitro-compounds had shown promising results. Of these, ammonium stearate and m-dinitrobenzene gave the best results in accelerated short term tests. In the present paper a more detailed investigation on the corrosion protection given by them has been made.Ammonium stearate and m-dinitrobenzene, both, have been found to perform satisfactorily under all test conditions except SOsub2 test where m-dinitrobenzene failed. Their indigenous availability, low cost and good corrosion inhibiting properties demands favorable consideration for their adoption as VCIs for general use.

  10. the study of henna leaves extract as green corrosion inhibitor for ...

    African Journals Online (AJOL)

    Chaudhari H.G and Vashi R.T

    2016-05-01

    May 1, 2016 ... Key words: corrosion; mild steel; acetic acid; henna leaves extract; .... The heat of adsorption ∆H°ads can be calculated from the Vant Hoff equation ..... The effect of bitter leaf on the nhibition of mild steel in HCl and H2SO4.

  11. Synergistic effect of mixed cationic and anionic surfactants on the corrosion inhibitor behavior of mild steel in 3.5% NaCl

    Energy Technology Data Exchange (ETDEWEB)

    Javadian, Soheila, E-mail: Javadian_s@modares.ac.ir [Department of Chemistry, Faculty of Science, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Yousefi, Ali [Department of Chemistry, Faculty of Science, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Neshati, Jaber [Corrosion Department, Coating Research Center, Research Institute of Petroleum Industry (RIPI), P.O. Box 18745-4163, Tehran (Iran, Islamic Republic of)

    2013-11-15

    The corrosion inhibition characteristics of cation-rich and anion-rich catanionic mixtures of cetyltrimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS), as corrosion inhibitor of mild steel (MS), in aqueous solution of 3.5% NaCl were investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and scanning electron microscopy (SEM). Solutions of CTAB/SDS mixtures showed more appropriate inhibition properties compared to the solutions of the individual surfactants, due to strong adsorption on the metal surface and formation of a protective film. Potentiodynamic polarization investigations indicated that the inhibitors studied were mixed type inhibitors. Adsorption of the inhibitors on the mild steel surface obeyed the Flory–Huggins adsorption isotherm. Furthermore, the values of the adsorption free energy (ΔG°{sub ads}) in both mixtures decreased compared with a single surfactant which is attributed to stronger interactions in mixtures.

  12. Novel triazolyl bis-amino acid derivatives readily synthesized via click chemistry as potential corrosion inhibitors for mild steel in HCl

    Energy Technology Data Exchange (ETDEWEB)

    Deng Qiong; Shi Hongwei; Ding Nana; Chen Baoqin [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237 (China); He Xiaopeng, E-mail: xphe@ecust.edu.cn [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237 (China); Liu Guixia; Tang Yun [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237 (China); Long Yitao, E-mail: ytlong@ecust.edu.cn [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237 (China); Chen Guorong, E-mail: mrs_guorongchen@ecust.edu.cn [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237 (China)

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Triazolyl bis-amino acids as new corrosion inhibitors. Black-Right-Pointing-Pointer EIS and polarization demonstrate their potency. Black-Right-Pointing-Pointer Inhibitor 4 obeys Langmuir isotherm. Black-Right-Pointing-Pointer Modeling study suggests the triazole ring essential for surface adsorption. - Abstract: Triazolyl bis-amino acid derivatives readily synthesized via click chemistry were identified as novel potent corrosion inhibitors for mild steel in HCl. The inhibitive characteristic of compound 4 was studied in detail via gravimetric measurement, electrochemical impedance spectroscopy, potentiodynamic polarization and scanning electron microscopy. In addition, a quantum chemical study suggests that the triazole ring involved in these inhibitors is structurally essential for the protection of metal surface.

  13. Effect of the Diesel, Inhibitor, and CO2 Additions on the Corrosion Performance of 1018 Carbon Steel in 3% NaCl Solution

    Directory of Open Access Journals (Sweden)

    J. Porcayo-Calderon

    2014-01-01

    Full Text Available In order to determine the diesel contribution in the coadsorption process of the oil-soluble inhibitors, electrochemical impedance spectroscopy measurements have been carried out to study the performance of oil-soluble inhibitors in both presence and absence of diesel and CO2. The results showed that the presence of the oil phase provides some protection to the steel because the water-soluble fractions are capable of being adsorbed on the steel surface thereby reducing the corrosion rate. The oily phase does not contribute to the adsorption process of the inhibitor because the inhibitor is absorbed into the water-soluble fractions. The oil-soluble inhibitors are effective only when the solution is saturated with CO2. CO2 saturation causes a decrease in the pH of the solution causing both an increase of the inhibitor solubility and a better dispersion of the inhibitor into the electrolyte.

  14. Thermodynamic properties of 2,5-bis(4-methoxyphenyl)-1,3,4-oxadiazole as a corrosion inhibitor for mild steel in normal sulfuric acid medium

    Energy Technology Data Exchange (ETDEWEB)

    Bouklah, M. [Laboratoire de Chimie des eaux et Corrosion, Faculte des Sciences, B.P. 717, Oujda (Morocco); Hammouti, B. [Laboratoire de Chimie des eaux et Corrosion, Faculte des Sciences, B.P. 717, Oujda (Morocco); Lagrenee, M. [Laboratoire de Cristallochimie et Physicochimie du Solide, UMR 8012 ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Bentiss, F. [Laboratoire de Cristallochimie et Physicochimie du Solide, UMR 8012 ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France) and Laboratoire de Chimie de Coordination et d' Analytique, Universite Chouaib Doukkali, Faculte des Sciences, B.P. 20, El Jadida (Morocco)]. E-mail: f.bentiss@pop.ensc-lille.fr

    2006-09-15

    The corrosion rates in the presence of 2,5-bis(4-methoxyphenyl)-1,3,4-oxadiazole (4-MOX) as a steel corrosion inhibitor in 0.5 M sulfuric acid, were measured by the weight loss method, in the range of temperatures from 303 to 343 K. Results obtained revealed that 4-MOX performed excellently as a corrosion inhibitor for mild steel in sulfuric acid media and its efficiency attains more than 96.19% at 8 x 10{sup -4} M at 333 K. The inhibition was assumed to occur via adsorption of the oxadiazole molecules on the metal surface. The Langmuir adsorption isotherm was tested for their fit to the experimental data. The apparent activation energies, enthalpies and entropies of the dissolution process and the free energies and enthalpies for the adsorption process were determined and discussed. The fundamental thermodynamic functions were used to glean important information about 4-MOX inhibitory behaviour.

  15. The influence of adding corrosion inhibitor and pH on the electrochemical properties of hybrid films applied to galvanised steel

    Directory of Open Access Journals (Sweden)

    Sandra Raquel Kunst

    2012-10-01

    Full Text Available This study was aimed at coating galvanised steel with a hybrid film obtained from a sol consisting of silane precursors 3 - (trimetoxisil-ilpropil methacrylate (TMSPMA and tetraethoxysilane (TEOS. The pH of the hydrolysed-silane solution was 1 and 3. The influence of adding corrosion inhibitor (i.e. 0.01M cerium nitrate was evaluated for all samples. The hybrid films were deposited by dip-coating. The film was characterised scanning electron microscopy (SEM, profilometry, contact angle measurement, potentiodynamic polarisation and electrochemical impedance spectroscopy. The results showed that solution pH influenced hybrid film formation and final surface properties. Additionally, cerium nitrate as corrosion inhibitor addition enhances corrosion resistance of the films.

  16. The microwave assisted synthesis of 1-alkyl-3-methylimidazolium bromide as potential corrosion inhibitor toward carbon steel in 1 M HCl solution saturated with carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Pasasa, Norman Vincent A., E-mail: npasasa@gmail.com; Bundjali, Bunbun; Wahyuningrum, Deana [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha No. 10 Bandung, Jawa Barat (Indonesia)

    2015-09-30

    Injection of corrosion inhibitor into the fluid current of oil and gas pipelines is an effective way to mitigate corrosion rate on the inner-surface parts of pipelines, especially carbon steel pipelines. In this research, two alkylimidazolium ionic liquids, 1-decyl-3-methylimidazolium bromide (IL1) and 1-dodecyl-3-methylimidazolium bromide (IL2) have been synthesized and studied as a potential corrosion inhibitor towards carbon steel in 1 M HCl solution saturated with carbon dioxide. IL1 and IL2 were synthesized using microwave assisted organic synthesis (MAOS) method. Mass Spectrometry analysis of IL1 and IL2 showed molecular mass [M-H+] peak at 223.2166 and 251.2484, respectively. The FTIR,{sup 1}H-NMR and {sup 13}C-NMR spectra confirmed that IL1 and IL2 were successfully synthesized. Corrosion inhibition activity of IL1 and IL2 were determined using weight loss method. The results showed that IL1 and IL2 have the potential as good corrosion inhibitors with corrosion inhibition efficiency of IL1 and IL2 are 96.00% at 100 ppm (343 K) and 95.60% at 50 ppm (343 K), respectively. The increase in the concentration of IL1 and IL2 tends to improve their corrosion inhibition activities. Analysis of the data obtained from the weight loss method shows that the adsorption of IL1 and IL2 on carbon steel is classified into chemisorption which obeys Langmuir’s adsorption isotherm.

  17. 菜籽油直接胺解法制备咪唑啉衍生物的缓蚀性能研究%Preparation of imidazoline derivatives from rapeseed oil by way of direct aminolysis and its inhibition behavior

    Institute of Scientific and Technical Information of China (English)

    樊国栋; 崔梦雅; 林振宇

    2012-01-01

    The paper intends to introduce a new method of preparing imidazoline derivatives from rapeseed oil by way of direct aminolysis and its inhibition behavior. As is known, imidazoline derivative is a kind of environment-friendly corrosion-inhibitors, widely used in rust-removing of metal pickling, descaling by acid pickling of industrial e-quipmem and technology for acidulating oil extraction. In hoping to reduce the cost of raw materials and reduce the environmental pollution , this paper would like to introduce a new approach to synthesizing imidazoline intermediate (1M-1) by solvent method with rape- seed oil and 2-(aminoethylamino) ethanol. And next, we have modified the 1M - 1 by adding benzyl chloride and sulfamic acid to obtain cationic and arnphoteric derivate IM 2 and IM - 3, respectively. When the improved products were analyzed with IR spectrum and HNMR spectrum, it would be possible to select optimal inhibitor from the two said products by way of static weight-loss measurement. And then the amphoteric derivative IM - 3 can also be selected out of the original product through the following tests. Since the addition of inorganic anions 1- can help to raise the corrosion inhibition efficiency, it would be possible to gain finally a complex system (IM - 4) through selecting from and mixing them with KI (20:1) . Its inhibition behavior can be evaluated by static weight-loss measurement and dynamic weight-loss measurement. And, now, we can explore the film-forming behavior on the surface of A3 steel in different concentrations and different times with the newly prepared inhibitor IM - 4. Afterwards, we can apply the scanning electron microscope to the investigation of the shape patterns Dn the surface of A3 steel in hydrochloric acid before and after the corrosion. Comparing IM - 4 with other common inhibitors, such as thiourea and hexam-ethylenetetramine in inhibiting behavior, we can get the results that the IM - 4 has stronger corrosion inhibiting ability

  18. Investigation on the Effect of Green Inhibitors for Corrosion Protection of Mild Steel in 1 M NaOH Solution

    Directory of Open Access Journals (Sweden)

    Premjith Jayakumar Ramakrishnan

    2014-01-01

    Full Text Available Alkaline corrosion is one of the main issues faced by the industries. The main chemicals abundantly used in industries are NaOH, H3PO4, HCl, and H2SO4. Corrosion control of metals has technical, economical, environmental, and aesthetical importance. The use of inhibitors is one of the best options to protect metals and alloys against corrosion. The corrosion protection of mild steel in 1 M NaOH solution by mix of Henna/Zeolite powder was studied at different temperatures by weight loss technique. Adsorption, activation, and statistical studies were addressed in this work. Adsorption studies showed that inhibitor adsorbed on metal surface according to Langmuir isotherm. Surface studies were performed by using UV-spectra and SEM. The adsorption of inhibitor on the steel surface was found to obey Langmuir’s adsorption isotherm. The inhibition efficiency increased with increasing concentration of the inhibitor in NaOH medium. Inhibition mechanism is deduced from the concentration and temperature dependence of the inhibition efficiency, Langmuir’s adsorption isotherm, SEM, and UV spectroscopic results.

  19. Study of New Thiazole Based Pyridine Derivatives as Potential Corrosion Inhibitors for Mild Steel: Theoretical and Experimental Approach

    Directory of Open Access Journals (Sweden)

    T. K. Chaitra

    2016-01-01

    Full Text Available Three new thiazole based pyridine derivatives 5-(4-methoxy-phenyl-thiazole-2-carboxylic acid pyridin-2-ylmethylene-hydrazide (2-MTPH, 5-(4-methoxy-phenyl-thiazole-2-carboxylic acid pyridin-3-ylmethylene-hydrazide (3-MTPH, and 5-(4-methoxy-phenyl-thiazole-2-carboxylic acid pyridin-4-ylmethylene-hydrazide (4-MTPH were synthesized and characterized. Corrosion inhibition performance of the prepared compounds on mild steel in 0.5 M HCl was studied using gravimetric, potentiodynamic polarisation, and electrochemical impedance techniques. Inhibition efficiency has direct relation with concentration and inverse relation with temperature. Thermodynamic parameters for dissolution and adsorption process were evaluated. Polarisation study reveals that compounds act as both anodic and cathodic inhibitors with emphasis on the former. Impedance study shows that decrease in charge transfer resistance is responsible for effective protection of steel surface by inhibitors. The film formed on the mild steel was investigated using FTIR, SEM, and EDX spectroscopy. Quantum chemical parameters like EHOMO, ELUMO, ΔE, hardness, softness, and ionisation potential were calculated. Higher value of EHOMO and lower value of ΔE indicate the better inhibition efficiency of the compounds. Lower ionisation potential of inhibitors indicates higher reactivity and lower chemical stability.

  20. A New Green Ionic Liquid-Based Corrosion Inhibitor for Steel in Acidic Environments

    Directory of Open Access Journals (Sweden)

    Ayman M. Atta

    2015-06-01

    Full Text Available This work examines the use of new hydrophobic ionic liquid derivatives, namely octadecylammonium tosylate (ODA-TS and oleylammonium tosylate (OA-TS for corrosion protection of steel in 1 M hydrochloric acid solution. Their chemical structures were determined from NMR analyses. The surface activity characteristics of the prepared ODA-TS and OA-TS were evaluated from conductance, surface tension and contact angle measurements. The data indicate the presence of a double bond in the chemical structure of OA-TS modified its surface activity parameters. Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS measurements, scanning electron microscope (SEM, Energy dispersive X-rays (EDX analysis and contact angle measurements were utilized to investigate the corrosion protection performance of ODA-TS and OA-TS on steel in acidic solution. The OA-TS and ODA-TS compounds showed good protection performance in acidic chloride solution due to formation of an inhibitive film on the steel surface.

  1. Decrease in cytotoxicity of copper-based intrauterine devices (IUD) pretreated with 6-mercaptopurine and pterin as biocompatible corrosion inhibitors.

    Science.gov (United States)

    Alvarez, Florencia; Grillo, Claudiaa; Schilardi, Patricial; Rubert, Aldo; Benítez, Guillermo; Lorente, Carolina; de Mele, Mónica Fernández Lorenzo

    2013-01-23

    The copper intrauterine device (IUD) based its contraceptive action on the release of cupric ions from a copper wire. Immediately after the insertion, a burst release of copper ions occurs, which may be associated to a variety of side effects. 6-Mercaptopurine (6-MP) and pterin (PT) have been proposed as corrosion inhibitors to reduce this harmful release. Pretreatments with 1 × 10(-4) M 6-MP and 1 × 10(-4) M PT solutions with 1h and 3h immersion times were tested. Conventional electrochemical techniques, EDX and XPS analysis, and cytotoxicity assays with HeLa cell line were employed to investigate the corrosion behavior and biocompatibility of copper with and without treatments. Results showed that copper samples treated with PT and 6-MP solutions for 3 and 1 h, respectively, are more biocompatible than those without treatment. Besides, the treatment reduces the burst release effect of copper in simulated uterine solutions during the first week after the insertion. It was concluded that PT and 6-MP treatments are promising strategies able to reduce the side effects related to the "burst release" of copper-based IUD without altering the contraceptive action.

  2. EDTA as a corrosion inhibitor for Al in 0.5 M HCl: adsorption, thermodynamic and theoretical study

    Directory of Open Access Journals (Sweden)

    Rehab Ebaid Azooz

    2016-09-01

    Full Text Available In this study; EDTA is used in very small amount (10-10 M as an inhibitor for the Al corrosion in 0.5 M HCl. Thermodynamic and adsorption parameters are calculated. The result shows that, in this range of concentrations, EDTA is chemisorbed at the Al surface, forming a stable complex with Al and give inhibition efficiency up to 89 %. For more con­centration, unstable complex is formed and acceleration of corrosion occurs. The adsorp­tion fit well to Langmuir, Temkin isotherms and El-awady model. Density functional theory (DFT is used to study the geometrical optimizations of EDTA. From the obtained optimized structure, The highest occupied molecular orbital (EHOMO, the lowest unoc­cupied molecular orbital (ELUMO and their energy difference (ΔE, the total energy (TE, electronegativity (χ, dipole moment (µ, global hardness (η, global softness (σ, elec­tron affinity (A, ionization potential (I, the fraction of electrons transferred (∆N and were determined using B3LYP/6-31G(d,p basis set.

  3. Investigation of Diospyros Kaki L.f husk extracts as corrosion inhibitors and bactericide in oil field.

    Science.gov (United States)

    Zhang, Jie; Song, Yingpan; Su, Huijun; Zhang, Li; Chen, Gang; Zhao, Jingrui

    2013-07-01

    Hydrochloric acid is used in oil-well acidizing commonly for improving the crude oil production of the low-permeable reservoirs, while it is a great challenge for the metal instruments involved in the acidification. Developing natural products as oilfield chemicals is a straight way to find less expensive, green and eco-friendly materials. The great plant resources in Qin-ling and Ba-shan Mountain Area of Shannxi Province enable the investigating of new green oil field chemicals. Diospyros Kaki L.f (persimmon), a famous fruit tree is widely planted in Qin-ling and Ba-shan Mountain Area of Shaanxi Province. It has been found that the crude persimmon extracts are complex mixtures containing vitamins, p-coumaric acid, gallic acid, catechin, flavonoids, carotenoids and condensed tannin and so on, which indicates the extracts of persimmon husk suitable to be used as green and eco-friendly corrosion inhibitors. Extracts of persimmon husk were investigated, by using weight loss and potentiodynamic polarisation techniques, as green and eco-friendly corrosion inhibitors of Q235A steel in 1M HCl. The inhibition efficiency of the extracts varied with extract concentration from 10 to 1,000 mg/L. There are some synergistic effects between the extracts and KI, KSCN and HMTA. Potentiodynamic polarization studies indicate that extracts are mixed-type inhibitors. Besides, the extracts were screened for antibacterial activity against oil field microorganisms, and they showed good to moderate activity against SRB, IB and TGB. The inhibition efficiency of the extracts varied with extract concentration from 10 to 1,000 mg/L, and the highest reaches to 65.1% with the con concentration of 1,000 mg/L WE. KI, KSCN and HMTA they can enhance the IE of WE effectively to 97.3% at most, but not effective for KI and KSCN to AE. Tafel polarisation measurements indicate the extracts behave as mixed type inhibitor. Investigation of the antibacterial activity against oil field microorganism showed

  4. Corrosion inhibition in 2.0 M sulfuric acid solutions of high strength maraging steel by aminophenyl tetrazole as a corrosion inhibitor

    Science.gov (United States)

    Sherif, El-Sayed M.

    2014-02-01

    The corrosion of high strength maraging steel after varied immersion times in concentrated solution, 2.0 M, of sulfuric acid has been investigated. The work was also extended to study the effect of 5-(3-aminophenyl)-tetrazole (APTA) on the inhibition of the steel corrosion. The study has been carried out using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and scanning electron microscope (SEM) along with energy dispersive X-ray analyzer (EDX) investigations. EIS spectra showed that the corrosion and polarization resistances decrease with increasing the immersion time of the steel before measurement and increase in the presence of APTA and the increase of its concentration. Polarization data agreed with the EIS measurements and indicated that the increase of immersion time increases the corrosion of steel by increasing its corrosion current and corrosion rate and lowering its polarization resistance. On the other hand, the addition of APTA and the increase of its concentration minimized the corrosion of steel through decreasing the corrosion current and corrosion rate and increasing the polarization resistance at all exposure test periods. SEM and EDX investigations confirmed that the inhibition of the maraging steel in the 2.0 M H2SO4 solutions is achieved via the adsorption of the APTA molecules onto the steel protecting its surface from being dissolved easily.

  5. 喹啉缓蚀剂对N80石油管道钢小孔腐蚀的影响%Influence of Quinoline Corrosion Inhibitor on Micropore Corrosion of N80 Petroleum Pipeline Steel

    Institute of Scientific and Technical Information of China (English)

    陈蕊; 李善建; 冯拉俊; 李向红

    2013-01-01

    模拟石油开采环境中石油管道的小孔腐蚀,通过对闭塞区内、外溶液进行腐蚀介质浓度分析、电化学分析以及对闭塞区内金属表面腐蚀形貌进行观察,研究了喹啉缓蚀剂(QA)对N80石油管道钢在0.5%CH3COOH+5%NaCl的饱和H2S溶液体系中小孔腐蚀的缓蚀性。结果表明:55℃时随着本体溶液中QA缓蚀剂浓度的增加,闭塞区Cl-和S2-浓度逐渐降低,抑制闭塞区溶液的pH值下降,对闭塞区的缓蚀效率逐渐增加。在本体溶液中添加0.6%~0.8%的QA缓蚀剂时,对小孔内材料的缓蚀率可达96.58%以上。%Simulating micropore corrosion of pipeline in petroleum exploitation environment, it studied the influence of quinoline corrosion inhibitor on micropore corrosion of N80 pipeline steel in 0.5%CH3COOH+ 5%NaCl saturated H2S solution system, through analysis on corrosion medium concentration of occlusion area inside and outside solution ,electrochemical analysis and corrosion morphology observation of metal surface. The result indicated that at 55℃with concentration of QA corrosion inhibitor increasing in solution, the concentration of Cl-and S2-gradually decrease in occlusion area, and control pH value in occlusion area solution decreasing can increase corrosion inhibition efficiency gradually. When adding 0.6%~0.8%QA corrosion inhibitor, the inhibition rate of micropore can reach more than 96.58%.

  6. A theoretical study on the inhibition efficiencies of some amino acids as corrosion inhibitors of nickel

    Energy Technology Data Exchange (ETDEWEB)

    Gece, Goekhan, E-mail: gokhangc@gmail.co [Department of Physical Chemistry, Faculty of Science, Ankara University, Besevler, 06100 Ankara (Turkey); Bilgic, Semra [Department of Physical Chemistry, Faculty of Science, Ankara University, Besevler, 06100 Ankara (Turkey)

    2010-10-15

    To clarify the inhibition efficiencies of a total of 12 amino acids for the corrosion of nickel in acidic medium, a density functional theory (DFT) study was carried out using the B3LYP/LANL2DZ method. Quantum chemical descriptors such as the energy of highest occupied molecular orbital (E{sub HOMO}), energy of lowest unoccupied molecular orbital (E{sub LUMO}), and the energy gap ({Delta}E) were calculated. Equations were proposed using linear regression analysis to determine the most effective parameter on inhibition efficiency. The theoretically obtained results were found to be consistent with the experimental data reported.

  7. The Activity of Trace Metals in Aqueous Systems and the Effect of Corrosion Control Inhibitors

    Science.gov (United States)

    1975-10-01

    corrosion product on metallic zinc 49 Uncombined slilica as quartz or cristobalite forms by the hydrothermal alteration of solid zilicates or by direct...175ml vol. pH K, umhos/cm 8. Polymer JB **Stein, Hall, and Co., 0.05 g 6.83 12.3 Inc; 3-D gel formation which plugs or diverts addati ves. 9. Polymer F...it aids in the formation of acids (Eq. 31) or it may oxidize any metallic material pre- sent in solution. 3. Water Correction. The proper method of

  8. Wettability of steel surfaces at CO{sub 2} corrosion conditions. 1: Effect of surface active compounds in aqueous and hydrocarbon media

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, G. [Iserlohn Univ. of Applied Sciences (Germany). Lab. for Corrosion Protection; Stradmann, N. [Corp. para la Investigation de la Corrosion, Bucamaranga (Colombia)

    1998-12-31

    The wettability of carbon steel surfaces with aqueous media (distilled water, brines) and hydrocarbon media (crude oils) was studied under CO{sub 2} corrosion conditions at 75 and 80 C and 5 bar CO{sub 2} with respect to the effect of surface active compounds (inhibitors, demulsifiers) by quasi-insitu and insitu contact angle measurements in a high pressure test cell. Fatty alcohol ethoxylates, quats, amines and imidazolines influence the hydro-philic/hydrophobic properties of carbonate scales on corroding carbon steel, but inhibiting mechanisms cannot be explained by hydrophobing effects alone. The method yields easy and quick information on substance effects, specifically in case of insitu measurements in oil-in-water systems.

  9. Pitting corrosion of copper in aqueous solutions containing phosphonic acid as an inhibitor. Hosuhon san wo inhibita toshite fukumu suiyoekichu ni okeru do no koshiku ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Y. (Muroran Univ., Hokkaido (Japan). Graduate School); Seri, O.; Tagashira, K. (Muroran Univ., Hokkaido (Japan)); Nagata, K. (Sumitomo Light Metal Co. Ltd., Tokyo (Japan). Technical Research Lab.)

    1993-09-15

    Phosphonic acid-based inhibitors that are poured into cooling water for copper-tube circulation systems for open heat-accumulators were studied on their influence on pitting corrosion of copper. Amino trimethylene phosphonic acid (ATMP) dissolved into distilled water to 50 ppm was used for the immersion corrosion test. The corrosion-proof effect of additives such as ZnSO4, benzotriazole (BTA) was tested too. 0.5 mm thick phosphate-treated copper plates with a hole of 5 mm in diameter were used as test specimens. Pitting corrosion on the copper plate occurred when ATMP, BTA and ZnSO4 coexisted. It was proved that SO4 [sup 2-] is essential since Na2SO4 in stead of ZnSO4 induced also corrosion. The pitting took place when 0.6 ppm or more of SO4 [sup 2-] was present in a BTA-added ATMP solution. It was observed that the pitting is prone to occur with increase of SO4 [sup 2-] and the number of pitting increases. The following relationship is established when pitting corrosion occurs; E[sub b] [le] E[sub corr], where the former is a potential value at which current density shows a steep increase and the latter is an average value of spontaneous electrode potential showing a plateau. 8 refs., 11 figs., 1 tab.

  10. DEVELOPMENT OF AN ENVIRONMENTALLY BENIGN MICROBIAL INHIBITOR TO CONTROL INTERNAL PIPELINE CORROSION

    Energy Technology Data Exchange (ETDEWEB)

    Kristine L. Lowe; Bill W. Bogan; Wendy R. Sullivan; Kristine Mila H. Cruz; Brigid M. Lamb; John J. Kilbane II

    2004-07-30

    The overall program objective is to develop and evaluate environmentally benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is to develop one or more environmentally benign (a.k.a. ''green'') products that can be applied to maintain the structure and dependability of the natural gas infrastructure. Previous testing indicated that the growth, and the metal corrosion caused by pure cultures of sulfate reducing bacteria were inhibited by hexane extracts of some pepper plants. This quarter tests were performed with mixed bacterial cultures obtained from natural gas pipelines. Treatment with the pepper extracts affected the growth and metabolic activity of the microbial consortia. Specifically, the growth and metabolism of sulfate reducing bacteria was inhibited. The demonstration that pepper extracts can inhibit the growth and metabolism of sulfate reducing bacteria in mixed cultures is a significant observation validating a key hypothesis of the project. Future tests to determine the effects of pepper extracts on mature/established biofilms will be performed next.

  11. The influence of long term use of inhibitors in hydrochloric acid pickling baths on hydrogen induced stress corrosion cracking

    Energy Technology Data Exchange (ETDEWEB)

    Feser, R.; Friedrich, A.; Scheide, F. [Fachhochschule Suedwestfalen, University of Applied Science, Frauenstuhlweg 31, D-58644 Iserlohn (Germany)

    2002-09-01

    The influence of commercially available inhibitors on the absorption of hydrogen by steel (St 52, StE 460, StE 690, 42CrMo4) in 15% hydrochloric acid was studied. The pickling bath aged continuously due to the chemical reaction with oxidized steel sheets. The H{sup +}- and inhibitor concentration decreased with time. The influence of this ageing process on hydrogen-induced stress corrosion cracking was tested by in-situ tensile tests in the bath solution. With increasing ageing of the bath, the reduction in fracture area was reduced and approached the values measured for non-inhibited acid baths. Furthermore hydrogen permeation was investigated. Permeation current densities rose with increasing ageing of the pickling solution. (Abstract Copyright[2002], Wiley Periodicals, Inc.) [German] Der Einfluss von kommerziell erhaeltlichen Inhibitoren auf die Wasserstoffabsorption von Stahl (St 52, StE 460, StE 690, 42CrMo4) wurde in Salzsaeure untersucht. Die Beizbaeder wurden kontinuierlich durch die chemische Reaktion mit oxidierten Stahlblechen gealtert. Die H{sup +}- und Inhibitorkonzentration nahm mit der Zeit ab. Der Einfluss dieses Alterungsprozesses auf die wasserstoffinduzierte Spannungsrisskorrosion wurde durch in-situ Zugversuche mit Badloesung untersucht. Mit zunehmender Alterung des Bades nahm die Brucheinschnuerung ab und erreichte Werte wie sie auch in der nicht inhibierten Saeure erreicht werden. Weiterhin wurde die Wasserstoff-Permeation untersucht. Die Permeationsstromdichte steigt mit zunehmender Alterung der Beizloesung. (Abstract Copyright[2002], Wiley Periodicals, Inc.)

  12. 缓蚀剂对LY12铝合金搭接件疲劳寿命的影响%Influence of Corrosion Inhibitors on Fatigue Life of LY12 Aluminium Alloy Lap Joints

    Institute of Scientific and Technical Information of China (English)

    张勇; 卞贵学; 陈跃良; 张泰峰

    2013-01-01

    模拟飞机服役环境,对未涂抹及涂抹缓蚀剂的航空LY12铝合金搭接试验件进行了腐蚀试验和疲劳试验.通过对试验件分解检查,分析了腐蚀环境对涂抹缓蚀剂航空LY12铝合金典型螺栓搭接件的影响.对缓蚀剂对搭接件的疲劳性能的影响进行了统计和分析.结果表明,相同腐蚀时间,未涂抹缓蚀剂试验件的螺栓孔附近和搭接面腐蚀程度较涂抹缓蚀剂试验件严重,缓蚀剂可有效减缓腐蚀,且不同的缓蚀剂类型对腐蚀的减缓程度不同.一般环境下,涂抹缓蚀剂的试验件比未涂抹缓蚀剂试验件的疲劳寿命有所减少,应力水平越小影响程度越明显;腐蚀40 d后,涂抹缓蚀剂的试验件较未涂抹缓蚀剂的试验件寿命育所增加,且不同应力水平和缓蚀剂类型对疲劳寿命的影响程度不同.%Corrosion test and fatigue test were carried out for LYl2 aluminium alloy lap joints with and without corrosion inhibitors.Influence of corrosion environment on LY12 aluminium alloy typical bolt lap joints daubed with corrosion inhibitors was analysed by overhauling specimens.Influence of corrosion inhibitors on fatigue property of lap joints was collected and analysed.The results show that faying surface of specimens without corrosion inhibitors corroded more severely during the same time,corrosion inhibitors can inhibite corrosion,and the effectiveness of various corrosion inhibitors is different In general environment,the fatigue life of specimens daubed with corrosion inhibitors reduced,influence extent is increasing obviously with the decrease of stess level.After 40 d corrosion,the fatigue life of specimens daubed with corrosion inhibitors increased,and influence extent is different with various stress level and corrosion inhibitors.

  13. Effect of superficially applied ZrO{sub 2} inhibitor on the high temperature corrosion performance of some Fe-, Co- and Ni-base superalloys

    Energy Technology Data Exchange (ETDEWEB)

    Goyal, G. [National Institute of Technology, Srinagar, Jammu and Kashmir (India)], E-mail: gitagoyal@rediffmail.com; Singh, H. [Baba Banda Singh Bahadur Engineering College, Fatehgarh Sahib, Punjab (India)], E-mail: harpreet.singh@bbsbec.ac.in; Prakash, S. [Indian Institute of Technology Roorkee, Roorkee, Uttrakhand (India)], E-mail: truthfmt@iitr.ernet.in

    2008-08-15

    High temperature corrosion is an acute form of corrosion occurring at elevated temperature in the presence of an oxidizing gas and is associated with a thin electrolytic deposit (salt or ash) on alloy. Inhibitors and fuel additives have been used with varying success to combat oil ash corrosion. In this paper, the effect of an oxide additive namely ZrO{sub 2} on the hot corrosion behaviour of some superalloys, viz. Superfer 800H (alloy A), Superco 605 (alloy B) and Superni 75 (alloy C) has been investigated in an Na{sub 2}SO{sub 4}-60%V{sub 2}O{sub 5} environment at 900 deg. C for 50 cycles. Each cycle consisted of 1 h heating in a Silicon Carbide Tube furnace followed by 20 min cooling in ambient air. Weight change measurements after each cycle were taken by an electronic balance having an accuracy of 0.01 mg. XRD, SEM and EPMA analyses of the exposed specimens were carried out to characterize the oxide scales. In the Na{sub 2}SO{sub 4}-60%V{sub 2}O{sub 5} environment, the corrosion rate for the Co-base alloy was found to be highest, whereas that for the Ni-base Superni 75 a lowest. Whereas, with ZrO{sub 2} superficial coating, the overall weight gains got reduced for the alloys B and C, however the inhibitor was marginally effective in the alloy A. A thick scale was observed in the latter case, which was rich in Cr, Ni, Fe and V. Absence of protective continuous chromia layer and presence of less protective NiO was probably the main reason for more corrosion rate in this case.

  14. Evidence for the involvement of the noradrenergic system, dopaminergic and imidazoline receptors in the antidepressant-like effect of tramadol in mice.

    Science.gov (United States)

    Jesse, Cristiano R; Wilhelm, Ethel A; Bortolatto, Cristiani F; Nogueira, Cristina W

    2010-05-01

    The involvement of the noradrenergic system, imidazoline, dopaminergic and adenosinergic receptors in the antidepressant-like action of tramadol in the mouse forced swimming test (FST) was evaluated in this study. The antidepressant-like effect of tramadol (40mg/kg, per oral, p.o.) in the FST was blocked with yohimbine (1mg/kg, i.p., an alpha(2)-adrenoceptor antagonist), alpha-methyl-para-tyrosine methyl ester (AMPT, 100mg/kg, i.p., an inhibitor of tyrosine hydroxylase), efaroxan (1mg/kg, i.p., an imidazoline I(1)/alpha(2)-adrenoceptor antagonist), idazoxan (0.06mg/kg, i.p., an imidazoline I(2)/alpha(2)-adrenoceptor antagonist), antazoline (5mg/kg, i.p., a ligand with high affinity for the I(2) receptor), haloperidol (0.2mg/kg, i.p., a non selective dopamine receptor antagonist), SCH23390 (0.05mg/kg, subcutaneously, s.c., a dopamine D(1) receptor antagonist), sulpiride (50mg/kg, i.p., a dopamine D(2) and D(3) receptor antagonist) but was not reversed by prazosin (1mg/kg, intraperitoneally, i.p., an alpha(1)-adrenoceptor antagonist) and caffeine (3mg/kg, i.p., a nonselective adenosine receptor antagonist). Monoamine oxidase-A and -B (MAO-A and MAO-B) activities were neither inhibited in the whole brain nor in specific brain regions of mice treated with tramadol. These data demonstrated that the antidepressant-like effect caused by oral administration of tramadol in the mouse FST is mediated by the noradrenergic system, dopaminergic and imidazoline receptors.

  15. Quantum chemical studies of some rhodanine azosulpha drugs as corrosion inhibitors for mild steel in acidic medium

    Science.gov (United States)

    Ebenso, Eno E.; Arslan, Taner; Kandemirli, Fatma; Caner, Necmettin; Love, Ian

    The density functional theory (DFT) at the B3LYP/6-31G (d,p) and B3LYP/6-311G(d,p) basis set levels and ab initio calculations using the HF/6-31G (d,p) and HF/6-311G(d,p) methods were performed on four rhodanine azosulpha drugs (namely 5-sulfadiazineazo-3-phenyl-2-thioxo-4-thiazolidinone, 5- sulfamethazineazo-3-phenyl-2-thioxo-4-thiazolidinone, 5-sulfadimethoxineazo-3-phenyl-2-thioxo- 4-thiazolidinone, and 5-sulfamethoxazoleazo-3-phenyl-2-thioxo-4-thiazolidinone) used as corrosion inhibitors for mild steel in acidic medium to determine the relationship between the molecular structure of the rhodanine azosulpha drugs and inhibition efficiency(%IE). The quantum chemical parameters/descriptors, namely, EHOMO (highest occupied molecular orbital energy), ELUMO (lowest unoccupied molecular orbital energy), the energy difference (ΔE) between EHOMO and ELUMO, dipole moment (μ), electron affinity (A), ionization potential (I), the absolute electronegativity (X), absolute hardness (η), softness (σ), polarizability (α), the Mulliken charges, and the fraction of electrons (ΔN) transfer from inhibitors to iron, were calculated and correlated with the experimental %IE. Quantitative structure activity relationship (QSAR) approach has been used, and a composite index of some quantum chemical parameters/descriptors was performed to characterize the inhibition performance of the studied molecules. The results showed that the inhibition efficiency (%IE) of the rhodanine azo sulfa drugs studied was closely related to some of the quantum chemical parameters/descriptors but with varying degrees of correlation coefficient (R2). The %IE also increased with the increase in EHOMO and decrease in EHOMO-ELUMO; and the areas containing N atoms are the most possible sites for bonding to the metal iron surface by donating electrons to the metal. The HOMO orbitals consist of 61.73-63.04% double bonded S atom (7(S)), and most of the rest are concentrated on the rhodanine group; so, the

  16. Alkanediyl-α, ω-bis (dimethyl cetylammonium bromide gemini surfactants as novel corrosion inhibitors for mild steel in formic acid

    Directory of Open Access Journals (Sweden)

    Mohammad Mobin

    2012-12-01

    Full Text Available Gemini surfactants, butanediyl 1,4-bis(dimethyl cetylammonium bromide, pentanediyl 1,5 - bis (dimethyl cetylammonium bromide and hexanediyl 1,6 - bis (dimethyl cetylammonium bromide from Alkanediyl-α, ω-bis (dimethyl cetylammonium bromide series were synthesized in laboratory and were characterized by using Nuclear Magnetic Resonance (NMR spectroscopy. The surfactants were tested as corrosion inhibitors for mild steel in 20% formic acid. The influence of surfactants on mild steel corrosion inhibition was investigated by measuring the corrosion rate of mild steel in their absence and presence by weight loss measurements, solvent analysis of iron ions into the test solution and potentiodynamic polarization measurements. The surface morphology of the corroded steel samples in presence and absence of surfactants was evaluated by using Scanning Electron Microscopy (SEM. The synthesized gemini surfactants performed as excellent corrosion inhibitor, the inhibition efficiency (IE being in the range of 76.66-97.41%. The IE of surfactants is slightly affected by the spacer length. The IE increased with increase in surfactant concentration and temperature. The adsorption of gemini surfactants on the steel surface was found to obey Langmuir adsorption isotherm. The results of the potentiodynamic polarization studies are consistent with the results of weight loss studies.

  17. Simple preparation of aminothiourea-modified chitosan as corrosion inhibitor and heavy metal ion adsorbent.

    Science.gov (United States)

    Li, Manlin; Xu, Juan; Li, Ronghua; Wang, Dongen; Li, Tianbao; Yuan, Maosen; Wang, Jinyi

    2014-03-01

    By a simple and convenient method of using formaldehyde as linkages, two new chitosan (CS) derivatives modified respectively with thiosemicarbazide (TSFCS) and thiocarbohydrazide (TCFCS) were synthesized. The new compounds were characterized and studied by Fourier transform infrared spectroscopy, elemental analysis, thermal gravity analysis and differential scanning calorimetry, and their surface morphologies were determined via scanning electron microscopy. These CS derivatives could form pH dependent gels. The behavior of 304 steel in 2% acetic acid containing different inhibitors or different concentrations of inhibitor had been studied by potentiodynamic polarization test. The preliminary results show that the new compound TCFCS can act as a mixed-type metal anticorrosion inhibitor in some extent; its inhibition efficiency is 92% when the concentration was 60 mg/L. The adsorption studies on a metal ion mixture aqueous solution show that two samples TSFCS and TCFCS can absorb As (V), Ni (II), Cu (II), Cd (II) and Pb (II) efficiently at pH 9 and 4.

  18. Hydroxyethyl cellulose as efficient organic inhibitor of zinc-carbon battery corrosion in ammonium chloride solution: Electrochemical and surface morphology studies

    Science.gov (United States)

    Deyab, M. A.

    2015-04-01

    Hydroxyethyl cellulose (HEC) has been investigated as corrosion inhibitor for zinc-carbon battery by polarization and electrochemical impedance spectroscopy (EIS) measurements. The obtained results show that the maximum inhibition efficiency by HEC in 26% NH4Cl solution at 300 ppm and 298 K is 92.07%. Tafel polarization studies reveal that HEC acts as an efficient mixed inhibitor. The corrosion rate is suppressed by the adsorption of HEC on the zinc surface. HEC adsorption obeys the Langmuir isotherm and the thermodynamic parameters Kads and Δ Gadso have been also calculated and discussed. Both physisorption and chemisorption may occur on the zinc surface. Surface characterization investigation using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) is used to ascertain the nature of the protective film.

  19. DEVELOPMENT OF AN ENVIRONMENTALLY BENIGN MICROBIAL INHIBITOR TO CONTROL INTERNAL PIPELINE CORROSION

    Energy Technology Data Exchange (ETDEWEB)

    J. Robert Paterek; Gemma Husmillo

    2002-07-01

    The overall program objective is to develop and evaluate environmental benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is one or more environmental benign, a.k.a. ''green'' products that can be applied to maintain the structure and dependability of the natural gas infrastructure. Capsicum sp. extracts and pure compounds were screened for their antimicrobial activity against MIC causing bacteria. Studies on the ability of these compounds to dissociate biofilm from the substratum were conducted using microtiter plate assays. Tests using laboratory scale pipeline simulators continued. Preliminary results showed that the natural extracts possess strong antimicrobial activity being comparable to or even better than the pure compounds tested against strains of sulfate reducers. Their minimum inhibitory concentrations had been determined. It was also found that they possess bactericidal properties at minimal concentrations. Biofilm dissociation activity as assessed by microtiter plate assays demonstrated varying degrees of differences between the treated and untreated group with the superior performance of the extracts over pure compounds. Such is an indication of the possible benefits that could be obtained from these natural products. Confirmatory experiments are underway.

  20. A comparative electrochemical and quantum chemical calculation study of BTAH and BTAOH as copper corrosion inhibitors in near neutral chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    Finsgar, Matjaz; Lesar, Antonija; Kokalj, Anton [Jozef Stefan Institute, Department of Physical and Organic Chemistry, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Milosev, Ingrid [Jozef Stefan Institute, Department of Physical and Organic Chemistry, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Valdoltra Orthopaedic Hospital, Jadranska c. 31, SI-6280 Ankaran (Slovenia)], E-mail: ingrid.milosev@ijs.si

    2008-11-30

    The inhibition of copper corrosion in 3% NaCl solution was studied by using a well-known inhibitor, benzotriazole (BTAH), and its not so extensively explored derivative, 1-hydroxybenzotriazole (BTAOH). Electrochemical methods, i.e., linear polarization, Tafel and potentiodynamic curve measurements and electrochemical quartz crystal microbalance (EQCM) measurements were used. Corrosion parameters and inhibition effectiveness were determined. Experimental results showed that benzotriazole is a more effective inhibitor of the corrosion of copper in chloride media than 1-hydroxybenzotriazole. Whereas in the presence of BTAH a protective Cu-BTA layer is formed on the Cu surface, in the presence of BTAOH a thick, poorly protective layer is formed, which readily dissolves in chloride solution. Kinetic parameters were calculated based on EQCM results. Adsorption of BTAOH follows a linear growth law, in contrast to BTAH, whose film growth can be best represented at first by a parabolic, and later by logarithmic, growth law. Different mechanisms of growth imply different mechanisms of inhibition and account for the different inhibition effectiveness. Density functional theory calculations were performed to characterize certain features of the molecular structures, including the electronic parameters related to the inhibition effectiveness of these inhibitors. Introduction of the -OH group into the benzotriazole molecules does not change their electronic parameters significantly neither in gas phase nor in the presence of water solvent. Other parameters, therefore, affect the inhibition effectiveness of these corrosion inhibitors. In particular, superior inhibition effectiveness of BTAH is attributed to interplay of planar molecular structure, physisorption and intermolecular H-bonding, which cooperatively may result in formation of thin and protective film on the surface.

  1. Adsorption and Corrosion Inhibition Studies of Some Selected Dyes as Corrosion Inhibitors for Mild Steel in Acidic Medium: Gravimetric, Electrochemical, Quantum Chemical Studies and Synergistic Effect with Iodide Ions

    Directory of Open Access Journals (Sweden)

    Thabo Peme

    2015-09-01

    Full Text Available The corrosion inhibition properties of some organic dyes, namely Sunset Yellow (SS, Amaranth (AM, Allura Red (AR, Tartrazine (TZ and Fast Green (FG, for mild steel corrosion in 0.5 M HCl solution, were investigated using gravimetric, potentiodynamic polarization techniques and quantum chemical calculations. The results showed that the studied dyes are good corrosion inhibitors with enhanced inhibition efficiencies. The inhibition efficiency of all the studied dyes increases with increase in concentration, and decreases with increase in temperature. The results showed that the inhibition efficiency of the dyes increases in the presence of KI due to synergistic interactions of the dye molecules with iodide (I− ions. Potentiodynamic polarization results revealed that the studied dyes are mixed-type inhibitors both in the absence and presence of KI. The adsorption of the studied dyes on mild steel surface, with and without KI, obeys the Langmuir adsorption isotherm and involves physical adsorption mechanism. Quantum chemical calculations revealed that the most likely sites in the dye molecules for interactions with mild steel are the S, O, and N heteroatoms.

  2. Adsorption and Corrosion Inhibition Studies of Some Selected Dyes as Corrosion Inhibitors for Mild Steel in Acidic Medium: Gravimetric, Electrochemical, Quantum Chemical Studies and Synergistic Effect with Iodide Ions.

    Science.gov (United States)

    Peme, Thabo; Olasunkanmi, Lukman O; Bahadur, Indra; Adekunle, Abolanle S; Kabanda, Mwadham M; Ebenso, Eno E

    2015-09-02

    The corrosion inhibition properties of some organic dyes, namely Sunset Yellow (SS), Amaranth (AM), Allura Red (AR), Tartrazine (TZ) and Fast Green (FG), for mild steel corrosion in 0.5 M HCl solution, were investigated using gravimetric, potentiodynamic polarization techniques and quantum chemical calculations. The results showed that the studied dyes are good corrosion inhibitors with enhanced inhibition efficiencies. The inhibition efficiency of all the studied dyes increases with increase in concentration, and decreases with increase in temperature. The results showed that the inhibition efficiency of the dyes increases in the presence of KI due to synergistic interactions of the dye molecules with iodide (I(-)) ions. Potentiodynamic polarization results revealed that the studied dyes are mixed-type inhibitors both in the absence and presence of KI. The adsorption of the studied dyes on mild steel surface, with and without KI, obeys the Langmuir adsorption isotherm and involves physical adsorption mechanism. Quantum chemical calculations revealed that the most likely sites in the dye molecules for interactions with mild steel are the S, O, and N heteroatoms.

  3. N-methyl-2-(2-nitrobenzylidene) hydrazine carbothioamide-A new corrosion inhibitor for mild steel in 1 mol·L-1 hydrochloric acid

    Institute of Scientific and Technical Information of China (English)

    K Krishnaveni; K Sampath; J Ravichandran; C Jayabalakrishnan

    2015-01-01

    The corrosion inhibition of mild steel in 1 mol·L−1 hydrochloric acid by N-methyl-2-(2-nitrobenzylidene) hydrazine carbothioamide (MNBHC) was studied using weight loss and electrochemical studies. Results obtained indicate that the inhibitor is effective in hydrochloric acid medium and the efficiency decreases with increase in temperature. Added halide additives improve the efficiency of the inhibitor. The AC impedance studies reveal that the process of inhibition is through charge transfer. Polarization studies indicate the mixed nature of the in-hibitor. From the thermodynamic, spectral and surface analyses the nature of adsorption has been found out. The adsorption of the inhibitor on mild steel follows the Langmuir isotherm.

  4. Experimental and theoretical studies on some amino acids and their potential activity as inhibitors for the corrosion of mild steel, part 2

    Directory of Open Access Journals (Sweden)

    Nnabuk O. Eddy

    2011-01-01

    Full Text Available Substituent constants and quantum chemical parameters were calculated from PM6, PM3, AM1, RM1 and MNDO. Hamiltonians were used to predict the corrosion inhibition potential of nine amino acids grouped under three skeletons. Skeleton I consisted of cysteine (CYS, serine (SER and amino butyric acid (ABU. Those in skeleton II included threonine (THR, alanine (ALA and valine (VAL while those in skeleton III are aromatic amino acids, which included phenylalanine (PHE, tryptophan (TRP and tyrosine (TYR. Trends obtained from substituent constants were not entirely useful in predicting the corrosion inhibition potentials of the studied amino acids. However, the results obtained from quantum chemical parameters indicated that the trends for the variation of corrosion inhibition potentials of the studied amino acids in skeletons I, II and III are CYS > SER > ABU, THR > ALA > VAL and TRP > TYR > PHE, respectively. Highest values of inhibition efficiency were obtained for inhibitors in skeleton III and are attributed to the presence of aromatic ring in the molecule while the corrosion inhibition potential of inhibitors in skeletons I and II are attributed to the presence of –SH and –OH functional groups, respectively. Analysis of data obtained from relative nucleophilicity/electrophilicity, condensed Fukui and softness functions indicated that the sites for electrophilic attacks for the amino acids in skeletons I and II are in the amine bonds but for those in skeleton III the sites were in their respective phenyl ring. The author proposed that quantum chemical parameters may be used to predict the corrosion inhibition potentials of amino acids.

  5. Electrochemical and quantum chemical studies of N,N'-bis(4-hydroxybenzaldehyde)-2,2-dimethylpropandiimine Schiff base as corrosion inhibitor for low carbon steel in HCl solution.

    Science.gov (United States)

    Jafari, Hojat; Danaee, Iman; Eskandari, Hadi; Rashvandavei, Mehdi

    2013-01-01

    A synthesized Schiff base N,N'-bis(4-hydroxybenzaldehyde)-2,2-dimethylpropandiimine (p-HBDP) was studied as green inhibitor for the corrosion of low carbon steel in 1 M HCl solution using electrochemical, surface and quantum chemical methods. Results showed that the inhibition occurs through the adsorption of the inhibitor molecules on the metal surface. The inhibition efficiency was found to increase with increasing inhibitor concentration and de-creased with increasing temper-ature, which is due to the fact that the rate of corrosion of steel is higher than the rate of adsorption. Thermodynamic parameters for adsorp-tion and activation processes were determined. Polarization data indicated that this compound act as mixed-type inhibitors and the adsorption isotherm basically obeys the Langmuir adsorption isotherm. The calculations of reactivity indices of p-HBDP such as softness and natural charge distributions together with local reactivity by means of Fukui indices were used to explain the electron transfer mechanism between the p-HBDP molecules and the steel surface.

  6. TiO{sub 2} coated multi-wall carbon nanotube as a corrosion inhibitor for improving the corrosion resistance of BTESPT coatings

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuping; Zhu, Hongzheng; Zhuang, Chen [Institute of Materials Science and Engineering, Ocean University of China, Songling Road 238, Qingdao, 266100 (China); Chen, Shougang, E-mail: sgchen@ouc.edu.cn [Institute of Materials Science and Engineering, Ocean University of China, Songling Road 238, Qingdao, 266100 (China); Wang, Longqiang [Institute of Materials Science and Engineering, Ocean University of China, Songling Road 238, Qingdao, 266100 (China); Dong, Lihua [Institute of Ocean Materials and Engineering, Shanghai Maritime University, Shanghai, 200135 (China); Yin, Yansheng, E-mail: ysyin@shmtu.edu.cn [Institute of Ocean Materials and Engineering, Shanghai Maritime University, Shanghai, 200135 (China)

    2016-08-15

    The composite coatings of TiO{sub 2} coated multi-wall carbon nanotube (MWCNTs)/bis-[triethoxysilylpropyl]tetrasulfide (BTESPT) with different components were prepared on AA 2024 by the cathodic electrophoretic deposition technique and the experimental conditions were optimized to attain the appropriate volume ratio. The modified MWCNTs obviously improved the corrosion resistance of BTESPT and BTESPT/TiO{sub 2} coatings, especially for the long-term corrosion resistance ability because of the good dispersion of MWCNTs. The geometry of composite coatings were explored by scanning electron microscopy, fourier transform infrared spectra and the surface coverage rate (θ), the results indicate that the composite coatings produce good cross-linked structure at the interfacial layer, the coating compactness increases gradually with the addition of TiO{sub 2} and/or MWCNTs, and the composite coating effectively postpones the production of cracks with the addition of MWCNTs. - Highlights: • The composite coatings with different components were prepared on AA 2024 by the cathodic electrophoretic deposition technology. • The formation of composite coating on AA 2024 surface considerably improved the corrosion resistance ability. • The composite coating with a TiO{sub 2} to MWCNTs volume ratio of 4/1 shows the best corrosion resistance. • The kinetic evaluation of inhibitive behavior for different coatings against immersion time was explored.

  7. 一种环保型阻垢缓蚀剂的性能%Performance of an environmentally friendly scale and corrosion inhibitor

    Institute of Scientific and Technical Information of China (English)

    陈燕敏; 孙彩霞; 吴晋英; 黄长山

    2014-01-01

    A new kind of efficient environmentally-friendly composite scale and corrosion inhibitor consisting of polyepoxysuccinic acid (PESA) , polyacrylic acid (PAA) , hydrolyzed polymaleic anhydride (HPMA) , benzotriazole (BTA) was developed. The optimal concentrations of such components obtained from orthogonal experiments were PESA(1.0 mg/L)/PAA(1.0 mg/L)/HPMA (0.6 mg/L)/BTA(0.5 mg/L). Its scale inhibition and corrosion inhibition performance was studied with bubble method,electrochemical experiment and rotary weight loss/hanging-piece corrosion experiment. The scale inhibiting rate and corrosion inhibiting rates for A3 carbon steel,copper,stainless steel of the scale and corrosion inhibitor were 92%and 83%,97%,99%,respectively. Further dynamic simulated test also indicated that the scale and corrosion inhibitor meet the demand of circulating cooling water.%以聚环氧琥珀酸(PESA)、聚丙烯酸(PAA)、水解聚马来酸酐(HPMA)、苯并三氮唑(BTA)为原料,研制出一种新型具有环保功能的复合型高效阻垢缓蚀剂。通过正交试验确定该阻垢缓蚀剂中各组分的最佳浓度为:PESA(1.0 mg/L)/PAA(1.0 mg/L)/HPMA (0.6 mg/L)/BTA(0.5 mg/L)。分别采用鼓泡法、电化学试验和旋转挂片腐蚀试验研究了其阻垢缓蚀性能。试验结果表明,该阻垢缓蚀剂的阻垢率为92%,对A3碳钢、铜、不锈钢的缓蚀率分别达到了83%、97%、99%,动态模拟试验结果也显示该阻垢缓蚀剂满足循环冷却水运行要求。

  8. Cassava starch graft copolymers an eco-friendly corrosion inhibitor for steel in H{sub 2}SO{sub 4} solution

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xianghong; Deng, Shuduan [Southwest Forestry University, Kunming (China)

    2015-11-15

    Cassava starch graft copolymer (CSGC) was prepared by grafting acryl amide (AA) onto cassava starch (CS). The inhibition effect of CSGC on the corrosion of cold rolled steel (CRS) in 1.0M H{sub 2}SO{sub 4} solution was first studied by weight loss, potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM) methods. The results show that CSGC is a good inhibitor, and inhibition efficiency of CSGC is higher than that of CS or AA. The adsorption of CSGC on steel surface obeys Langmuir adsorption isotherm. CSGC is a mixed-type inhibitor at 20 .deg. C, while mainly a cathodic inhibitor at 50 .deg. C.

  9. Studies of Self-assembled Monolayers Formed by Imidazoline on Iron Surface by SEM and SECM

    Institute of Scientific and Technical Information of China (English)

    Xiu Yu LIU; Shen Hao CHEN; Shuai MIAO; Su Xiang WU; Li Xia SHEN; Yuan Xing CAI; Hong Yan ZHAI

    2006-01-01

    The self-assembled monolayers (SAMs) of imidazoline (IM) on the iron surface were characterized by scanning electron microscope (SEM) and scanning electrochemical microscopy(SECM). The results showed that SAMs were an effective inhibition film for iron.

  10. Inhibition mechanism analysis & research of the poly aspartic acid corrosion inhibitor%聚天冬氨酸缓蚀剂缓蚀机理分析研究

    Institute of Scientific and Technical Information of China (English)

    王娴

    2012-01-01

    文中介绍了聚天冬氨酸缓蚀剂缓蚀机理,并对聚天冬氨酸缓蚀剂机理的研究现状以及发展趋势进行了综述。%It was introduced inhibition mechanism of the poly aspartic acid corrosion inhibitor. Mean- while, it was summarizeed the research progress of the inhibition meehanismf the poly aspartic acid cor- rosion inhibitor and the development trend of the poly aspartic acid corrosion inhibitor in this article.

  11. The inhibitors of corrosion and hydrogen entry into carbon steel in the H{sub 2}S and CO{sub 2} media

    Energy Technology Data Exchange (ETDEWEB)

    Tsygankova, L. E.; Vigdorovich, V. I.; Mozharov, A.V. [Derzhavin State University 33, Internatsionalnaya St., Tambov, 392622 (Russian Federation)

    2004-07-01

    The efficiency of Mannich's Phenol Bases (MPB) as the universal inhibitors of carbonic-acid and hydrogen-sulphide corrosion and hydrogen entry into carbon steel (St3) has been studied. Two Mannich's Phenol Bases were used: MPB 9 and MPB 9-20. Second of them has 20 ethoxy groups in the molecule. The HCl solutions (0.005 - 0.1 mole/l) saturated with CO{sub 2} (1-2 atm) and H{sub 2}S (50 - 400 mg/l) separately and together have been used. Protective efficiency of the inhibitors increases with increasing inhibitor concentration (10-200 mg/l), medium acidity and in the presence of CO{sub 2} and H{sub 2}S. The effect of the inhibitors is high enough in the presence of the liquid hydrocarbon (decane) in the used HCl solutions (1:10) too. Depending on the conditions the inhibitors slow down the anodic process (0.005 - 0.01 M HCl) or both partial electrode reactions (0.1 M HCl). In the presence of H{sub 2}S and CO{sub 2} separately and together Mannich's Phenol Bases decrease hydrogen entry into the steel membrane both at the corrosion potential and in the conditions of the anodic and cathodic polarization. An analysis of the mechanism of the hydrogen entry retardation in the presence of the inhibitors has been made taking into account a rate determining stage of the hydrogen evolution reaction and the existence of two forms of the adsorbed hydrogen atoms: subsurface and raised above surface. (authors)

  12. The water soluble composite poly(vinylpyrrolidone–methylaniline: A new class of corrosion inhibitors of mild steel in hydrochloric acid media

    Directory of Open Access Journals (Sweden)

    R. Karthikaiselvi

    2017-02-01

    Full Text Available In recent years poly methyl aniline has been reported as one of the efficient corrosion inhibitors of mild steel in acidic media. In view of the major limitation of the insolubility of polymethyl aniline PMA, we propose to convert PMA into a water soluble composite using supporting polymer polyvinylpyrrolidone to get higher solubility and corrosion inhibition efficiency. The water soluble composite poly(vinylpyrrolidone-methyl aniline was synthesized by chemical oxidative polymerization and its inhibitive effect on mild steel in 1 M HCl has been investigated using weight loss and electrochemical techniques (potentiodynamic polarization studies and impedance spectroscopy. SEM and EDX analyses are carried out to establish a protective film formation on the metal surface.

  13. Characterization of Imidazoline Receptors in Blood Vessels for the Development of Antihypertensive Agents

    OpenAIRE

    Mei-Fen Chen; Jo-Ting Tsai; Li-Jen Chen; Tung-Pi Wu; Jia-Jang Yang; Li-Te Yin; Yu-lin Yang; Tai-An Chiang; Han-Lin Lu; Ming-Chang Wu

    2014-01-01

    It has been indicated that activation of peripheral imidazoline I2-receptor (I-2R) may reduce the blood pressure in spontaneously hypertensive rats (SHRs). Also, guanidinium derivatives show the ability to activate imidazoline receptors. Thus, it is of special interest to characterize the I-2R using guanidinium derivatives in blood vessels for development of antihypertensive agent(s). Six guanidinium derivatives including agmatine, amiloride, aminoguanidine, allantoin, canavanine, and metform...

  14. Evaluation of the potential of additives as corrosion inhibitors of CA-50 carbon steel used as reinforcement in concretes; Avaliacao da potencialidade de aditivos como inibidores de corrosao do aco carbono CA-50 usado como armadura de estruturas de concreto

    Energy Technology Data Exchange (ETDEWEB)

    Mennucci, Marina Martins

    2006-07-01

    In this work, various compounds were tested to evaluate their potential capability for their use as corrosion inhibitors of carbon steel reinforcement in concretes. The additives tested were sodium benzoate, polyethylene glycol, hexamethylenetetramine, benzotriazole and yttrium carbonate. Initially, exploratory tests were carried out to select the ones to be used as corrosion inhibitors, based on the inhibit ion efficiency determined from electrochemical tests, specifically polarization tests and electrochemical impedance spectroscopy. These tests were carried out in a solution composed of 0.01 N sodium hydroxide (NaOH) and 0.05 N potassium hydroxide (KOH) to simulate the composition of the solution inside the pores in concretes. The additive that presented the most promising potential to be used as corrosion inhibitor was benzotriazole (BTA). After the elimination of some compounds and selection of the additive with higher corrosion inhibit ion efficiency in the test medium, the effect of its concentration on the corrosion inhibition efficiency was evaluated. Sodium nitrite solutions with the same concentrations as those solutions with BTA were tested for comparison reasons. Sodium nitrite is a well established corrosion inhibitor for carbon steel reinforcement in concretes but it has been related to toxic effects. The BTA was associated to higher corrosion inhibition efficiencies than that of sodium nitrite in similar concentrations. A blackish adherent film was formed on the steel surface exposed to BTA solutions during long periods of immersion in the alkaline medium. The results suggest that BTA is a potential candidate for substitution of nitrites as corrosion inhibitor of reinforcements in concrete. (author)

  15. Corrosion Behavior of Environmental Friendly Inhibitor of Theobroma cacao Peels Extract for Mild Steel in NaCl 1.5 M

    Directory of Open Access Journals (Sweden)

    Yuli Yetri

    2016-01-01

    Full Text Available In this investigation, the inhibition effect of TCPE (Theobroma cacao peels extract on mild steel in NaCl 1.5 M solution has been studied by using weight loss, potentiodynamic polarization (Tafel and electrochemical impedance spectroscopy (EIS methods. Infrared spectra and GC-MS performed to determine the extract compounds that played a role in the inhibition process. Sample surface morphology was observed by using a scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX. The obtained changes in polarization and impedance parameters values (Icorr, Rct and Cdl that has been obtained indicate that the adsorbed protective film grew with the sign of increasing concentration of inhibitor. The adsorption of used compound on mild steel found to obey Langmuir isotherm. Some thermodynamic parameters such as Gibs energy (ΔG, enthalpy (ΔH, entropy (ΔS and activation energy (Ea were calculated to elaborate the mechanism of corrosion inhibition. Based on the results of surveying activity, it revealed that the corrosion rate decreased with the increase of the extract concentration and increased with increasing temperature. Corrosion inhibition efficiency of 91.93 (weight loss and 85.90% (Tafel, 90.19% (Rp and 75.23% (EIS were at a concentration of 2.5% extract. The Schiff base used for investigation was considered an effective inhibitor in reducing the attack surface corrosion on mild steel. in NaCl 1.5 M solution. The obtained results from various techniques were in good agreement.

  16. Comparative study of N-[(4-methoxyphenyl (morpholin-4-ylmethyl]acetamide (MMPA and N-[morpholin-4-yl(phenylmethyl]acetamide (MPA as corrosion inhibitors for mild steel in sulfuric acid solution

    Directory of Open Access Journals (Sweden)

    A. Jamal Abdul Nasser

    2017-02-01

    Full Text Available Two Mannich bases namely, N-[(4-methoxyphenyl(morpholin-4-ylmethyl]acetamide (MMPA and N-[morpholin-4-yl(phenylmethyl]acetamide (MPA were synthesized and their influence on the inhibition of corrosion of mild steel in 1.0 M H2SO4 was investigated by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS, scanning electron microscopy (SEM and FT-IR spectroscopy. The weight loss measurements showed that these inhibitors have excellent inhibiting effect at a concentration of 0.01 M. The inhibitor efficiency was found to depend on both concentration and molecular structure of the inhibitor. Both the compounds have been found to be relatively good inhibitors. Potentiodynamic polarization curves revealed that the studied inhibitors represent a mixed-type, predominantly cathodic control. An equivalent circuit is suggested based on an analysis of EIS data. The negative value of standard free energy of adsorption in the presence of inhibitor suggests spontaneous adsorption of inhibitors on the mild steel surface. The activation energy of corrosion and other thermodynamic parameters were calculated to elaborate the mechanism of corrosion inhibition. The Temkin isotherm was found to provide an accurate description of the adsorption behavior of the inhibitors. Surface analysis using scanning electron microscope (SEM shows a significant morphological improvement on the mild steel surface with the addition of inhibitors. FT-IR spectra revealed the interaction between inhibitor molecules and mild steel surface.

  17. High temperature corrosion behaviour of some Fe-, Co- and Ni-base superalloys in the presence of Y{sub 2}O{sub 3} as inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Harpreet, E-mail: harpreet.singh@bbsbec.ac.in [Mechanical Engineering, Baba Banda Singh Bahadur Engineering College, Fatehgarh Sahib, Punjab 140407 (India); Gitanjaly, [National Institute of Technology, Srinagar, Jammu and Kashmir (India); Singh, Surendra; Prakash, S. [Indian Institute of Technology Roorkee, Roorkee, Uttrakhand (India)

    2009-05-15

    High temperature corrosion is accelerated degradation of materials at higher temperatures of operation caused by the presence of a deposit of salt or ash. Inhibitors and fuel additives have been investigated with varying success to control this type of corrosion. In this work, effect of an oxide additive namely Y{sub 2}O{sub 3} on the hot corrosion behaviour of some superalloys viz Superfer 800H (alloy A), Superco 605 (alloy B) and Superni 75 (alloy C) has been investigated in an Na{sub 2}SO{sub 4}-60%V{sub 2}O{sub 5} environment at 900 deg. C for 50 cycles. Each cycle consisted of 1 h heating in a Silicon Carbide Tube Furnace followed by 20 min cooling in ambient air. Weight data were taken by an electronic balance having an accuracy of 0.01 mg after each cycle. Subsequently, the exposed alloys were characterized by XRD, SEM and EPMA analyses to evaluate the role of the oxide additive. In the Na{sub 2}SO{sub 4}-60%V{sub 2}O{sub 5} environment, the corrosion rate for the Co-base alloy was found to be highest, whereas that for the Ni-base Superni 75 the lowest. Superficially applied Y{sub 2}O{sub 3} was observed to be useful in reducing the high temperature corrosion of the alloys. It was found to be most effective for the alloy A for which the oxide scale was continuous and rich in protective Cr. Alloy B showed the formation of medium size scale rich in Cr and Co. The oxide scale for the alloy C contained mainly Cr and Ni.

  18. Characterization of Imidazoline Receptors in Blood Vessels for the Development of Antihypertensive Agents

    Directory of Open Access Journals (Sweden)

    Mei-Fen Chen

    2014-01-01

    Full Text Available It has been indicated that activation of peripheral imidazoline I2-receptor (I-2R may reduce the blood pressure in spontaneously hypertensive rats (SHRs. Also, guanidinium derivatives show the ability to activate imidazoline receptors. Thus, it is of special interest to characterize the I-2R using guanidinium derivatives in blood vessels for development of antihypertensive agent(s. Six guanidinium derivatives including agmatine, amiloride, aminoguanidine, allantoin, canavanine, and metformin were applied in this study. Western blot analysis was used for detecting the expression of imidazoline receptor in tissues of Wistar rats. The isometric tension of aortic rings isolated from male rats was also estimated. The expression of imidazoline receptor on rat aorta was identified. However, guanidinium derivatives for detection of aortic relaxation were not observed except agmatine and amiloride which induced a marked relaxation in isolated aortic rings precontracted with phenylephrine or KCl. Both relaxations induced by agmatine and amiloride were attenuated by glibenclamide at concentration enough to block ATP-sensitive potassium (KATP channels. Meanwhile, only agmatine-induced relaxation was abolished by BU224, a selective antagonist of imidazoline I2-receptors. Taken together, we suggest that agmatine can induce vascular relaxation through activation of peripheral imidazoline I2-receptor to open KATP channels. Thus, agmatine-like compound has the potential to develop as a new therapeutic agent for hypertension in the future.

  19. Characterization of imidazoline receptors in blood vessels for the development of antihypertensive agents.

    Science.gov (United States)

    Chen, Mei-Fen; Tsai, Jo-Ting; Chen, Li-Jen; Wu, Tung-Pi; Yang, Jia-Jang; Yin, Li-Te; Yang, Yu-Lin; Chiang, Tai-An; Lu, Han-Lin; Wu, Ming-Chang

    2014-01-01

    It has been indicated that activation of peripheral imidazoline I2-receptor (I-2R) may reduce the blood pressure in spontaneously hypertensive rats (SHRs). Also, guanidinium derivatives show the ability to activate imidazoline receptors. Thus, it is of special interest to characterize the I-2R using guanidinium derivatives in blood vessels for development of antihypertensive agent(s). Six guanidinium derivatives including agmatine, amiloride, aminoguanidine, allantoin, canavanine, and metformin were applied in this study. Western blot analysis was used for detecting the expression of imidazoline receptor in tissues of Wistar rats. The isometric tension of aortic rings isolated from male rats was also estimated. The expression of imidazoline receptor on rat aorta was identified. However, guanidinium derivatives for detection of aortic relaxation were not observed except agmatine and amiloride which induced a marked relaxation in isolated aortic rings precontracted with phenylephrine or KCl. Both relaxations induced by agmatine and amiloride were attenuated by glibenclamide at concentration enough to block ATP-sensitive potassium (KATP) channels. Meanwhile, only agmatine-induced relaxation was abolished by BU224, a selective antagonist of imidazoline I2-receptors. Taken together, we suggest that agmatine can induce vascular relaxation through activation of peripheral imidazoline I2-receptor to open KATP channels. Thus, agmatine-like compound has the potential to develop as a new therapeutic agent for hypertension in the future.

  20. Corrosion inhibition capacity of non-phosphorus corrosion inhibitor in water with moderate alkalinity and moderate hardness for A3 carbon steel%无磷缓蚀剂在中碱中硬水质中对A3碳钢的缓蚀性能

    Institute of Scientific and Technical Information of China (English)

    王超; 李颜云; 陶蕾; 秦立娟; 王昊

    2015-01-01

    开发了一种酰胺类无磷缓蚀剂,在中碱度中硬度水质中进行了缓蚀应用研究。选用A3碳钢作为测试对象,采用旋转挂片失重法和电化学阻抗法对酰胺类无磷缓蚀剂的缓蚀性能进行研究。测试结果表明,该酰胺类无磷缓蚀剂在中碱度中硬度的循环水水质下具有良好的缓蚀性能,能够有效地满足循环水系统的金属缓蚀需求。%A kind of amide derivative non-phosphorus corrosion inhibitor has been synthesized. Its application to corrosion inhibition in water with moderate alkalinity and moderate hardness is studied. Using carbon steel A3 as de-tection target,the corrosion inhibiting capacity of amide derivative non-phosphorus corrosion inhibitor by rotary coupon weight-loss method and electrochemical impedance method is studied. The results indicate that the amide derivative non-phosphorus corrosion inhibitor has good corrosion inhibiting capacity in circulating water with moder-ate alkalinity and moderately hardness ,being able to effectively meet the metal corrosion inhibition requirements for circulating water systems.

  1. 一种复合型无磷缓蚀阻垢剂的研制%Research on a complex phosphate-free corrosion and scale inhibitor

    Institute of Scientific and Technical Information of China (English)

    曾德芳; 严欢

    2012-01-01

    A complex phosphate-free corrosion and scale inhibitors is made from 2 - acrylamido - 2 - methylpropane sulfonic acid (AMPS), inhibitor A, zinc salt , ascorbic acid. The formulations is se- lected from the static scale inhibition experiments and rotation coupon corrosion test. The results show when the quality of each component: 2 -acrylamido -2 -methylpropane sulfonic acid (AMPS) : BTA: zinc salts: inhibitor A = 5: 0. 3: 1.2:4 and when the dosage of the phosphate-free corrosion and scale inhibitor was 40 mg/L, the maximum inhibition and scale inhibition exceeded 92. 89% and 95.12% , respectively . Compared with the traditional corrosion and scale inhibitors , the corrosion inhibition ef- ficiency of this complex phosphate-free corrosion and scale inhibitors is almost the same, the inhibi- tion rate increased by 1.91%, and cost reduced by 16.67%. Since the recipe is Phosphate-free, it does not cause environmental eutrophication, so it has obvious environmental and economic benefits.%以2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、缓蚀剂A、锌盐、抗坏血酸为原料进行复配,开发出一种复合型无磷缓蚀阻垢剂。通过静态阻垢实验、旋转挂片腐蚀实验、动电位电化学测试实验对配方进行筛选和测定。结果表明在各组分质量比为:2-丙烯酰胺基-2-甲基丙磺酸(AMPS):苯并三氮唑:锌盐:缓蚀剂A=5:0.3:1.2:4,复合型无磷缓蚀阻垢剂质量浓度为40mg/L时,缓蚀率达到92.89%,阻垢率达到95.12%。通过与传统含磷配方对比,该复合型无磷缓蚀阻垢剂与传统含磷配方缓蚀率相当,阻垢率提高1.91%,成本降低16.67%。由于该配方无磷,不会造成环境富营养化,具有明显环境与经济效益。

  2. The Effect of Inhibitors on the Susceptibility of Al 6013/SiC Interface to Localized Corrosion

    Science.gov (United States)

    Ahmad, Zaki; Aleem, B. J. Abdul

    2009-03-01

    Al 6013-20 SiC (p) in tempers T4, O, and F is sensitive to localized corrosion in 3.5 wt.% NaCl because of the preponderance of the secondary phase particles of Cu, Fe, and Cr at the Al/SiC interface. Treatment with cerium chloride effectively inhibited the localized corrosion of the alloy by suppressing the cathodic reactions at Al 6013/SiC interface as shown by electrochemical investigations. Morphological studies showed the formation of a protective cerium oxide/hydroxide films, which suppresses the corrosion of the alloy.

  3. An Investigation of a Combined Thiourea and Hexamethylenetetramine as Inhibitors for Corrosion of N80 in 15% HCl Solution: Electrochemical Experiments and Quantum Chemical Calculation

    Directory of Open Access Journals (Sweden)

    Jun Hu

    2015-01-01

    Full Text Available The inhibition mechanism of thiourea (TU and hexamethylenetetramine (HMTA mixed in 15% HCl solution on N80 surface was investigated by potentiodynamic polarization, electrochemical impedance spectroscopy measurements, and surface morphology analysis. Quantum chemical calculations and molecular dynamics simulations were performed to study the properties of TU and HMTA. The results showed that the inhibitors can form strong bonds and stable films on the surface, which inhibits the cathodic and anodic reactions in HCl solution and reduces the diffusion coefficients of corrosive particles.

  4. Microencapsulation Technology for Corrosion Mitigation by Smart Coatings

    Science.gov (United States)

    Buhrow, Jerry; Li, Wenyan; Jolley, Scott; Calle, Luz M.

    2011-01-01

    A multifunctional, smart coating for the autonomous control of corrosion is being developed based on micro-encapsulation technology. Corrosion indicators as well as corrosion inhibitors have been incorporated into microcapsules, blended into several paint systems, and tested for corrosion detection and protection effectiveness. This paper summarizes the development, optimization, and testing of microcapsules specifically designed to be incorporated into a smart coating that will deliver corrosion inhibitors to mitigate corrosion autonomously. Key words: smart coating, corrosion inhibition, microencapsulation, microcapsule, pH sensitive microcapsule, corrosion inhibitor, corrosion protection pain

  5. Electrochemical corrosion studies

    Science.gov (United States)

    Knockemus, W. W.

    1986-01-01

    The objective was to gain familiarity with the Model 350 Corrosion Measurement Console, to determine if metal protection by grease coatings can be measured by the polarization-resistance method, and to compare corrosion rates of 4130 steel coated with various greases. Results show that grease protection of steel may be determined electrochemically. Studies were also conducted to determine the effectiveness of certain corrosion inhibitors on aluminum and steel.

  6. 水泥基迁移型钢筋阻锈涂料性能研究%Performance of Cement-based Migrating Corrosion Inhibitor Coating

    Institute of Scientific and Technical Information of China (English)

    雷霜如; 唐军务

    2011-01-01

    The performance of cernent-hased migrating corrosion inhibitors was studied through various tests, such as strength tests, grip between concrete and steel, dry-wet cycle test, chlorine ion resistant test and anode polarization tests. The results show that the corrosion inhabitation coating, when applied to the surface of reinforcement, can resist the corrosion of the steel bars and the bonding between concrete and steel without any adverse influence on the performance of reinforced concrete.%通过强度、握裹力、干湿冷热循环、抗氯离子渗透、阳极极化试验等方法,研究了水泥基迁移型钢筋阻锈涂料各种性能.结果表明该涂料涂刷于钢筋表面可有效抑制钢筋腐蚀,并能提高握裹力,对混凝土性能无不利影响.

  7. Assessment of cytotoxic and cytogenetic effects of a 1,2,5-thiadiazole derivative on CHO-K1 cells. Its application as corrosion inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Grillo, C.A. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA, CCT La Plata-CONICET), Facultad de Ciencias Exactas, Departamento de Quimica, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata (Argentina); Mirifico, M.V. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA, CCT La Plata-CONICET), Facultad de Ciencias Exactas, Departamento de Quimica, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata (Argentina); Facultad de Ingenieria, Areas Departamentales Ingenieria Quimica and Mecanica, Universidad Nacional de La Plata, Calle 47 y 1, 1900 La Plata (Argentina); Morales, M.L. [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA, CCT La Plata-CONICET), Facultad de Ciencias Exactas, Departamento de Quimica, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata (Argentina); Reigosa, M.A. [IMBICE (Instituto Multidisciplinario de Biologia Celular), CICPBA, CONICET, Calle 526 entre 10 y 11, 1900 La Plata (Argentina); Mele, M. Fernandez Lorenzo de, E-mail: mmele@inifta.unlp.edu.ar [Instituto de Investigaciones Fisicoquimicas Teoricas y Aplicadas (INIFTA, CCT La Plata-CONICET), Facultad de Ciencias Exactas, Departamento de Quimica, Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4, 1900 La Plata (Argentina); Facultad de Ingenieria, Areas Departamentales Ingenieria Quimica and Mecanica, Universidad Nacional de La Plata, Calle 47 y 1, 1900 La Plata (Argentina)

    2009-10-30

    This work focuses on the possible use of phenanthro[9,10-c]-1,2,5-thiadiazole 1,1-dioxide (TDZ) as a harmless corrosion inhibitor. TDZ range-dose providing minimum adverse effects to the environment and human health, with satisfactory corrosion-inhibiting properties was evaluated. Cytotoxicity and genotoxicity of TDZ at 0.57-12.50 {mu}M concentration range were tested by neutral red, chromosomal aberrations, mitotic index, and colony formation assays. Results showed a significant increase of chromatid-type aberrations for the highest concentration of TDZ assayed (12.50 {mu}M). Additionally, a reduction in the proliferative rate for lower concentrations was detected by the MI assay. We concluded that TDZ should be used at concentrations lower than 1.16 {mu}M. Corrosion assays performed showed good inhibition effect (ca. 50%) at low (0.65 {mu}M) TDZ concentration. Consequently, our results indicated that TDZ induced a time- and dose-dependent genotoxic and cytotoxic response on CHO-K1 cells. Short assays should be complemented with long exposure tests to simulate chronic contact with TDZ since lower threshold levels may be found for shorter exposures and a wrong safety range could be determined.

  8. Application of Stabilized Silver Nanoparticles as Thin Films as Corrosion Inhibitors for Carbon Steel Alloy in 1 M Hydrochloric Acid

    Directory of Open Access Journals (Sweden)

    Ayman M. Atta

    2013-01-01

    Full Text Available Nanometer scaled materials have attracted tremendous interest as corrosion protective films due to their high ability to form self-assembled films on the metal surfaces. It is well known that the silver nanoparticles have higher reactivity towards aqueous acidic solution. The present work aims to prepare coated silver nanoparticles to protect carbon steel alloys from aqueous acidic corrosive media. In this respect, Ag nanoparticles colloid solutions were produced through reducing AgNO3 separately with trisodium citrate in an aqueous solution or in the presence of stabilizer such as poly(ethylene glycol thiol and poly(vinyl pyrrolidone. The morphology of the modified silver nanoparticles was investigated by TEM and DLS. UV-Vis absorption spectrum was used to study the effect of HCl on the stability of the dispersed silver nanoparticles. The corrosion inhibition efficiency of the poly (ethylene glycolthiol, the self-assembled monolayers of Ag nanoparticles, was determined by polarization method and electrochemical impedance spectroscopy (EIS. Polarization curves indicated that the coated silver poly (ethylene glycolthiol acted as a mixed type inhibitor. The data of inhibition efficiencies obtained measured by polarization measurements are in good agreement with those obtained with electrochemical impedance.

  9. BENZOTRIAZOLE AS CORROSION INHIBITOR

    OpenAIRE

    DİNÇER, Selman; ASAN, Abdurrahman; KIYAK, Tülin; KABASAKALOĞLU, Melike

    2010-01-01

    ABSTRACTCorrosion inhibition of benzotriazole (BTA) for 70/30 brass in 0.1 M NaCl has been evaluated by means of electrochemical polarization and solution analysis.For comparision electrochemical polarization curves were also obtained with zinc and copper electrode. Brass and copper have the same electrochemical properties in BTA containing 0,1M NaCl solution. The anodic responses of the brass in 0.1 M. NaCl containing benzotriazole displays two potential regions. At the first anodic region b...

  10. Discussion on Evaluation Methods for Corrosion Inhibitors Used in Delayed Coking Unit%延迟焦化装置缓蚀剂评价方法探讨

    Institute of Scientific and Technical Information of China (English)

    张贵英; 宫红; 姜恒

    2014-01-01

    Delayed coking process is the primary means for deep processing of residue. However, large amounts of hydrogen sulfide gas produced in this process will dissolved in coking wastewater. H2S ionizes in a humid environment to form a galvanic cell with elemental iron, which can cause serious corrosion of equipments. Corrosion inhibitor is often used to slow down the corrosion of the unit. Currently, the content of Fe2+ in coking wastewater is the major evaluation index of inhibitor. Usually, the content of Fe2+ should be less than 3.0 mg/L. In this paper, content of Fe2+ dissolved in wastewater under different conditions was calculated by the solubility product of FeS. The results show that the content of Fe2+in wastewater even without inhibitor is less than 3.0 mg/L which was provided in existing regulations. More reliable methods to evaluate the corrosion are the corrosion coupon or corrosion probe suspended in the pipeline or equipment and its monitoring data can embody the real corrosion condition.%延迟焦化工艺是目前渣油深度加工的主要手段,但在加工过程中会产生大量硫化氢气体并溶解于焦化酸性水中。在湿硫化氢环境中,硫化氢会电离,并与单质铁发生原电池反应,从而对设备造成严重腐蚀,常采用添加缓蚀剂的方法来减缓其对装置的腐蚀。目前评价缓蚀剂性能的指标是检测焦化酸性水中的铁离子含量,通常规定焦化酸性水中铁含量应小于3.0 mg/L。通过FeS的溶度积,计算了不同pH值、不同H2S含量的水溶液中 Fe2+的含量。结果显示:即使不添加缓蚀剂,焦化酸性水中 Fe2+的理论最大浓度也不会高于现行标准中所规定的3.0 mg/L。比较可靠的缓蚀评价方法是将腐蚀挂片或腐蚀探针悬挂于管道设备内部,其监测数据能够比较真实体现腐蚀状况。

  11. Electrochemical and quantum chemical calculations on 4,4-dimethyloxazolidine-2-thione as inhibitor for mild steel corrosion in hydrochloric acid

    Science.gov (United States)

    Musa, Ahmed Y.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Rahoma, Abdalhamid Ahmad B.; Mesmari, Hussein

    2010-04-01

    The inhibition ability of 4,4-dimethyloxazolidine-2-thione (DMT) for mild steel corrosion in a 1 M HCl solution at 30 °C was studied by means of potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) technique, and scanning electron microscopy (SEM). Quantum chemical calculation based on PM3 method was performed on DMT. The molecule structural parameters, such as the frontier molecular orbital energy HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital), the charge distribution and the fraction of electrons (Δ N) transfer from inhibitor to mild steel were calculated and discussed. Results showed that DMT performed as good inhibiting effect for the corrosion of mild steel in a 1 M HCl solution and inhibition efficiency is higher than 82% at 4 × 10 -3 M DMT. Results indicate that the inhibition efficiencies increased with the concentration of DMT and the area containing S atom is most possible site for bonding the mild steel surface by donating electrons to the metal. Adsorption of the inhibitor on the mild steel surface followed Langmuir adsorption isotherm and the value of the free energy of adsorption Δ G○ads indicated that the adsorption of DMT molecule was a spontaneous process and was typical of chemisorptions.

  12. Palladium(II) and zinc(II) complexes of neutral [N2O2] donor Schiff bases derived from furfuraldehyde: Synthesis, characterization, fluorescence and corrosion inhibitors of ligands

    Science.gov (United States)

    Ali, Omyma A. M.

    2014-11-01

    Metal complexes of Schiff bases derived from furfuraldehyde and 4,5-dimethyl-1,2-phenylendiamine (L1) or 4,5-dichloro-1,2-phenylendiamine (L2) have been reported and characterized based on elemental analyses, IR, 1H NMR, UV-Vis, magnetic moment, molar conductance and thermal analysis. The complexes are found to have the formulae [PdL1-2]Cl2 and [ZnL1-2](AcO)2·H2O. The molar conductance data reveal that Pd(II) and Zn(II) chelates are ionic in nature and are of the type 2:1 electrolytes. The spectral data are consistent with a square planar and tetrahedral geometry around Pd(II) and Zn(II), respectively, in which the ligands act as tetradentate ligands. The thermal behavior of some chelates is studied and the activation thermodynamic parameters are calculated using Coats-Redfern method. The corrosion inhibition of stainless steel types 410 and 304 in 1 M HCl using the synthesized Schiff bases as inhibitors have been studied by weight loss method. The obtained data considered these ligands as efficient corrosion inhibitors. The ligands and their metal complexes exhibited considerable antibacterial activity against Staphylococcusaureus, and Escherichiacoli and antifungal activity against Candida albicans.

  13. Palladium(II) and zinc(II) complexes of neutral [N2O2] donor Schiff bases derived from furfuraldehyde: synthesis, characterization, fluorescence and corrosion inhibitors of ligands.

    Science.gov (United States)

    Ali, Omyma A M

    2014-11-11

    Metal complexes of Schiff bases derived from furfuraldehyde and 4,5-dimethyl-1,2-phenylendiamine (L1) or 4,5-dichloro-1,2-phenylendiamine (L2) have been reported and characterized based on elemental analyses, IR, 1H NMR, UV-Vis, magnetic moment, molar conductance and thermal analysis. The complexes are found to have the formulae [PdL1-2]Cl2 and [ZnL1-2](AcO)2·H2O. The molar conductance data reveal that Pd(II) and Zn(II) chelates are ionic in nature and are of the type 2:1 electrolytes. The spectral data are consistent with a square planar and tetrahedral geometry around Pd(II) and Zn(II), respectively, in which the ligands act as tetradentate ligands. The thermal behavior of some chelates is studied and the activation thermodynamic parameters are calculated using Coats-Redfern method. The corrosion inhibition of stainless steel types 410 and 304 in 1 M HCl using the synthesized Schiff bases as inhibitors have been studied by weight loss method. The obtained data considered these ligands as efficient corrosion inhibitors. The ligands and their metal complexes exhibited considerable antibacterial activity against Staphylococcusaureus, and Escherichiacoli and antifungal activity against Candida albicans.

  14. Corrosion and Corrosion Inhibition of High Strength Low Alloy Steel in 2.0 M Sulfuric Acid Solutions by 3-Amino-1,2,3-triazole as a Corrosion Inhibitor

    Directory of Open Access Journals (Sweden)

    El-Sayed M. Sherif

    2014-01-01

    Full Text Available The corrosion and corrosion inhibition of high strength low alloy (HSLA steel after 10 min and 60 min immersion in 2.0 M H2SO4 solution by 3-amino-1,2,4-triazole (ATA were reported. Several electrochemical techniques along with scanning electron microscopy (SEM and energy dispersive X-ray (EDS were employed. Electrochemical impedance spectroscopy indicated that the increase of immersion time from 10 min to 60 min significantly decreased both the solution and polarization resistance for the steel in the sulfuric acid solution. The increase of immersion time increased the anodic, cathodic, and corrosion currents, while it decreased the polarization resistance as indicated by the potentiodynamic polarization measurements. The addition of 1.0 mM ATA remarkably decreased the corrosion of the steel and this effect was found to increase with increasing its concentration to 5.0 mM. SEM and EDS investigations confirmed that the inhibition of the HSLA steel in the 2.0 M H2SO4 solutions is achieved via the adsorption of the ATA molecules onto the steel protecting its surface from being dissolved easily.

  15. Preparation of the multifunctional & environment-friendly corrosion inhibitor in seawater and its capability%环境友好型多功能海水缓蚀剂的研制及性能研究

    Institute of Scientific and Technical Information of China (English)

    王昕; 刘振法; 高玉华; 刘展

    2013-01-01

    为同时解决碳钢与铜材在海水中的腐蚀问题,将聚天冬氨酸、苯并三唑等5种原料按一定的质量比复配成多功能海水缓蚀剂.利用失重法和电化学法研究了海水缓蚀剂在海水中对A3碳钢及H62黄铜的缓蚀性能.结果表明,当海水缓蚀剂用量为150 mg/L时,对碳钢与黄铜在海水中的腐蚀均有良好的抑制作用,碳钢缓蚀率达到95.17%,黄铜缓蚀率达到93.67%.该海水缓蚀剂具有优良的生物降解性能,28 d后生物降解率达到82.6%.%A kind of multifunctional and environment-friendly corrosion inhibitor has been made from polyaspartic acid (PASP),sodium gluconate,zinc sulfate,hydroxyphosphonoacetic acid (HPAA) and benzotriazole (BTA).The corrosion capability of the corrosion inhibitor in seawater for Carbon Steel A3 and Copper H62 is evaluated by weight-loss method and electrochemical method.The results show that when the dosage of this inhibitor is 150 mg/L,the corrosion inhibition effects on carbon steel and copper are pretty good.Carbon steel corrosion inhibiting rate reaches 95.17% and copper corrosion inhibiting rate 93.67%.The corrosion inhibitor has excellent biodegradability.The biodegradation rate after 28 days reaches 82.6%.

  16. Some Phthalocyanine and Naphthalocyanine Derivatives as Corrosion Inhibitors for Aluminium in Acidic Medium: Experimental, Quantum Chemical Calculations, QSAR Studies and Synergistic Effect of Iodide Ions

    Directory of Open Access Journals (Sweden)

    Masego Dibetsoe

    2015-08-01

    Full Text Available The effects of seven macrocyclic compounds comprising four phthalocyanines (Pcs namely 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine (Pc1, 2,3,9,10,16,17,23,24-octakis(octyloxy-29H,31H-phthalocyanine (Pc2, 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine (Pc3 and 29H,31H-phthalocyanine (Pc4, and three naphthalocyanines namely 5,9,14,18,23,27,32,36-octabutoxy-2,3-naphthalocyanine (nPc1, 2,11,20,29-tetra-tert-butyl-2,3-naphthalocyanine (nPc2 and 2,3-naphthalocyanine (nP3 were investigated on the corrosion of aluminium (Al in 1 M HCl using a gravimetric method, potentiodynamic polarization technique, quantum chemical calculations and quantitative structure activity relationship (QSAR. Synergistic effects of KI on the corrosion inhibition properties of the compounds were also investigated. All the studied compounds showed appreciable inhibition efficiencies, which decrease with increasing temperature from 30 °C to 70 °C. At each concentration of the inhibitor, addition of 0.1% KI increased the inhibition efficiency compared to the absence of KI indicating the occurrence of synergistic interactions between the studied molecules and I− ions. From the potentiodynamic polarization studies, the studied Pcs and nPcs are mixed type corrosion inhibitors both without and with addition of KI. The adsorption of the studied molecules on Al surface obeys the Langmuir adsorption isotherm, while the thermodynamic and kinetic parameters revealed that the adsorption of the studied compounds on Al surface is spontaneous and involves competitive physisorption and chemisorption mechanisms. The experimental results revealed the aggregated interactions between the inhibitor molecules and the results further indicated that the peripheral groups on the compounds affect these interactions. The calculated quantum chemical parameters and the QSAR results revealed the possibility of strong interactions between the studied inhibitors and metal surface. QSAR

  17. Some Phthalocyanine and Naphthalocyanine Derivatives as Corrosion Inhibitors for Aluminium in Acidic Medium: Experimental, Quantum Chemical Calculations, QSAR Studies and Synergistic Effect of Iodide Ions.

    Science.gov (United States)

    Dibetsoe, Masego; Olasunkanmi, Lukman O; Fayemi, Omolola E; Yesudass, Sasikumar; Ramaganthan, Baskar; Bahadur, Indra; Adekunle, Abolanle S; Kabanda, Mwadham M; Ebenso, Eno E

    2015-08-28

    The effects of seven macrocyclic compounds comprising four phthalocyanines (Pcs) namely 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine (Pc1), 2,3,9,10,16,17,23,24-octakis(octyloxy)-29H,31H-phthalocyanine (Pc2), 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine (Pc3) and 29H,31H-phthalocyanine (Pc4), and three naphthalocyanines namely 5,9,14,18,23,27,32,36-octabutoxy-2,3-naphthalocyanine (nPc1), 2,11,20,29-tetra-tert-butyl-2,3-naphthalocyanine (nPc2) and 2,3-naphthalocyanine (nP3) were investigated on the corrosion of aluminium (Al) in 1 M HCl using a gravimetric method, potentiodynamic polarization technique, quantum chemical calculations and quantitative structure activity relationship (QSAR). Synergistic effects of KI on the corrosion inhibition properties of the compounds were also investigated. All the studied compounds showed appreciable inhibition efficiencies, which decrease with increasing temperature from 30 °C to 70 °C. At each concentration of the inhibitor, addition of 0.1% KI increased the inhibition efficiency compared to the absence of KI indicating the occurrence of synergistic interactions between the studied molecules and I(-) ions. From the potentiodynamic polarization studies, the studied Pcs and nPcs are mixed type corrosion inhibitors both without and with addition of KI. The adsorption of the studied molecules on Al surface obeys the Langmuir adsorption isotherm, while the thermodynamic and kinetic parameters revealed that the adsorption of the studied compounds on Al surface is spontaneous and involves competitive physisorption and chemisorption mechanisms. The experimental results revealed the aggregated interactions between the inhibitor molecules and the results further indicated that the peripheral groups on the compounds affect these interactions. The calculated quantum chemical parameters and the QSAR results revealed the possibility of strong interactions between the studied inhibitors and metal surface. QSAR analysis on the

  18. Synthesis and Performance of Mannich Base Quaternary Ammonium Salt Acidizing Corrosion Inhibitor%曼尼希碱季铵盐酸化缓蚀剂的合成及性能

    Institute of Scientific and Technical Information of China (English)

    赵顺强; 孙永涛; 马增华; 付朝阳

    2014-01-01

    合成了一种新型的曼尼希碱季铵盐(BMQA)酸化缓蚀剂,通过静态失重法测试了缓蚀剂在不同浓度盐酸中的缓蚀性能。结果表明,90℃下,缓蚀剂 BMQA 在15%盐酸中加入0.1%,18%盐酸中加入0.2%,28%盐酸中加入0.5%,N80钢的腐蚀速率都能小于4 g·m-2·h-1。极化曲线测试表明该缓蚀剂是抑制阳极为主的混合型缓蚀剂,遵循 Langmuir 吸附等温式,能自发在金属表面进行化学吸附。%A new type of Mannich base quaternary ammonium salt was synthesized as an acidification corrosion inhibitor.The inhibition performance of this corrosion inhibitor was evaluated in hydrochloric acid with different concentrations by static weight loss method.The results showed that with 0.1% inhibitor in 15% hydrochloric acid, 0.2% inhibitor in 18% hydrochloric acid and 0.5% inhibitor in 28% hydrochloric acid,the corrosion rates of steel N80 were all lower than 4 g·m-2 ·h-1 at 90℃.Polarization curves indicate that the corrosion inhibitor is a mixed inhibitor but mainly prohibits the anodic corrosion process,obeys the Langmuir adsorption isothermal equation and can spontaneously absorb on the steel surface by chemisorption.

  19. The imidazoline receptors and the central regulation of the arterial blood pressure: a minireview

    Directory of Open Access Journals (Sweden)

    Eduardo Tibiriça

    1993-06-01

    Full Text Available Recently, we proposed the hypothesis according to wich the central hypotensive effect of clonidine and related substances could be related to an action upon specific receptors, requiring the imidazoline or imidazoline-like structures, rather than alpha2-adrenoceptors. Since then, direct evidences have been accumulated to confirm the existence of a population of imidazoline specific binding sites in the brainstem of animals and man, more precisely in the Nucleus Reticularis Lateralis (NRL region of the ventrolateral medulla (VLM, site of the antihypertensive action of clonidine. The purification of the putative endogenous ligand of the imidazoline receptors - named endazoline - is currently being attempted from human brain extracts. This new concept might at last lead to the expected dissociation of the pharmacological mechanisms involved, on the one hand, in the therapeutic antihypertensive effect, and on the other, in their major side-effect, which is sedation. In fact, it has been recently confirmed that hypotension is mediated by the activation of imidazoline preferring receptors (IPR within the NRL region, while sedation is attributed to the inhibition of alpha2-adrenergic mechanisms in the locus coeruleus, which is involved in the control of the sleep-waking cycle. The IPRmay constitute on interesting target for new drugs in the treatment of arterial hypertension. Finally, dysfunctions of this modulatory system which could be involved in the pathophysiologyof some forms of the hypertensive disease are under investigation.

  20. Corrosion inhibition of a hygroscopic inorganic dust-depressor

    Institute of Scientific and Technical Information of China (English)

    Longzhe Jin; Lu Wang; Dongke Chen

    2006-01-01

    Metallic corrosion is a serious problem in the application of a hygroscopic inorganic dust-depressor. The basic characteristics of a hygroscopic inorganic dust-depressor and its corrosivity, corrosion mechanism, as well as the principle of corrosion inhibition were analyzed. The static mass-loss test was carried out to investigate the corrosion behavior and the effect of the dustdepressor. The static corrosion rates of steel specimens were measured in six different corrosion inhibitor solutions of the dustdepressor, and the suitable corrosion inhibitors for the dust-depressor to reduce the corrosivity were found out.

  1. Tuning of intermolecular interactions results in packing diversity in imidazolin-5-ones

    Indian Academy of Sciences (India)

    Ashish Singh; Basanta Kumar Rajbongshi; Gurunath Ramanathan

    2014-09-01

    Crystal structures of four green fluorescent protein (GFP) chromophore analogues with different packing interactions could be tuned by appropriate substitutions around the imidazolin-5-one ring are reported here. Compound 1 was crystallized from tetrahydrofuran at room temperature while compounds 2-4 have been crystallized from a mixture of methanol and dichloromethane in 3:1 ratio. Molecule 1, 2 and 3 crystallized in monoclinic lattice while molecule 4 preferred to crystallize in a triclinic crystal system. The crystal packing of these molecules was stabilized by C-H$\\ldots$ stacking and C-H $\\ldots$ O type of supramolecular interactions. The results reveal that packing diversity can be easily accomplished in these molecules by tuning the substituents around the imidazolin-5-one ring. Photophysical studies also reveal that all have good quantum yield and fluoresce typically in red region due to presence of electron donating groups around the imidazolin-5-one ring.

  2. Synthesis of N - Alkyl Benzimidazoles as Corrosion Inhibitors for Acidification in Hydrochloric Acid and Evaluation of Their Inhibition Performance%N-烷基苯并咪唑酸化缓蚀剂的合成及性能

    Institute of Scientific and Technical Information of China (English)

    杨鹏辉; 冀生辉

    2013-01-01

    Four kinds of N - alkyl benzimidazole corrosion inhibitors were synthesized by alkylation of 2 - methyl benzimidazole or 2 - ethyl benzimidazole. The corrosion inhibition performance of as - synthesized inhibitors was evaluated by static state weight loss test and dynamic potential scanning polarization curve measurement. It was found that properly extending carbon chain of benzimidazole helped to improve the anticorrosion ability of benzimidazoles, and corrosion inhibitor N - hexadecyl - 2 - ethyl benzimidazole showed the best corrosion inhibition performance. Besides, at 60 ℃ in 15% hydrochloric acid, the corrosion rate of N80 steel decreased with increasing concentration of the corrosion inhibitor; and the corrosion rate of the steel at a corrosion inhibitor concentration of 1.0% was 1.73g/(m2 · h) , which indicated that corrosion inhibitor N-hexadecyl-2-ethyl benzimidazole was advantageous over the first-class corrosion inhibitor for acidification. Moreover, as-synthesized corrosion inhibitors were a class of mixed-type inhibitors dominated by cathode inhibition, but their inhibition performance in HCl with a concentration of above 20 % or at a temperature of above 70 ℃ was undesirable.%苯并咪唑是一类环境友好的缓蚀剂,将其衍生物用作油气田酸化缓蚀剂的报道较少.通过烷基化反应在2-甲基苯并咪唑和2-乙基苯并咪唑的1-氮原子上分别引入十二烷基和十六烷基,合成了4种N-烷基苯并咪唑,并以其为主剂制成缓蚀剂,用静态失重法和动电位扫描极化曲线对4种复配缓蚀剂在盐酸溶液中的缓蚀性能进行了评价.结果表明:适当延长1位烷基碳链,有助于提高苯并咪唑衍生物的缓蚀能力;合成的4种N-烷基苯并咪唑中,以N-十六烷基-2-乙基苯并咪唑为主剂制成缓蚀剂d的缓蚀性能最好;在60℃,15%HCl中,N80钢的腐蚀速率随缓蚀剂d用量的增大而减小,其用量为1.0%时,N80钢腐蚀速率为1.73 g/(m2·h),优于

  3. Multicomponent Synthesis and Evaluation of New 1,2,3-Triazole Derivatives of Dihydropyrimidinones as Acidic Corrosion Inhibitors for Steel

    Directory of Open Access Journals (Sweden)

    Rodrigo González-Olvera

    2016-02-01

    Full Text Available An efficient one-pot synthesis of 1,2,3-triazole derivatives of dihydropyrimidinones has been developed using two multicomponent reactions. The aldehyde-1,2,3-triazoles were obtained in good yields from in situ-generated organic azides and O-propargylbenzaldehyde. The target heterocycles were synthesized through the Biginelli reaction in which the aldehyde-1,2,3-triazoles reacted with ethyl acetoacetate and urea in the presence of Ce(OTf3 as the catalyst. The corrosion inhibition of steel grade API 5 L X52 in 1 M HCl by the synthesized compounds was investigated using the electrochemical impedance spectroscopy technique. The measurements revealed that these heterocycles are promising candidates to inhibit acidic corrosion of steel.

  4. Multicomponent Synthesis and Evaluation of New 1,2,3-Triazole Derivatives of Dihydropyrimidinones as Acidic Corrosion Inhibitors for Steel.

    Science.gov (United States)

    González-Olvera, Rodrigo; Román-Rodríguez, Viridiana; Negrón-Silva, Guillermo E; Espinoza-Vázquez, Araceli; Rodríguez-Gómez, Francisco Javier; Santillan, Rosa

    2016-02-22

    An efficient one-pot synthesis of 1,2,3-triazole derivatives of dihydropyrimidinones has been developed using two multicomponent reactions. The aldehyde-1,2,3-triazoles were obtained in good yields from in situ-generated organic azides and O-propargylbenzaldehyde. The target heterocycles were synthesized through the Biginelli reaction in which the aldehyde-1,2,3-triazoles reacted with ethyl acetoacetate and urea in the presence of Ce(OTf)₃ as the catalyst. The corrosion inhibition of steel grade API 5 L X52 in 1 M HCl by the synthesized compounds was investigated using the electrochemical impedance spectroscopy technique. The measurements revealed that these heterocycles are promising candidates to inhibit acidic corrosion of steel.

  5. Allosteric modulation of semicarbazide-sensitive amine oxidase activities in vitro by imidazoline receptor ligands

    OpenAIRE

    2004-01-01

    Evidence indicates that imidazoline I2 binding sites (I2BSs) are present on monoamine oxidase (MAO) and on soluble (plasma) semicarbazide-sensitive amine oxidase enzymes. The binding site on MAO has been described as a modulatory site, although no effects on activity are thought to have been observed as a result of ligands binding to these sites.We examined the effects in vitro of several imidazoline binding site ligands on activities of bovine plasma amine oxidase (BPAO) and porcine kidney d...

  6. Dominant $\\cdots$ interaction in the self assemblies of 4-benzylidene imidazolin-5-one analogues

    Indian Academy of Sciences (India)

    Basanta K Rajbongshi; Gurunath Ramanathan

    2009-11-01

    Crystal structures of five imidazolin-5-ones are discussed. While molecules 1-3 show a donor-acceptor type of $\\cdots$ lateral offset stacking, C-H$\\cdots$ interactions are found to play dominant roles in molecules 2 and 4. In molecule 2, C-H$\\cdots$ interactions further form lateral offset stack to form extended C-H$\\cdots$ $\\cdots$ $\\cdots$H-C hydrogen bonds. Molecule 4, however shows a layer structure with interlayer C-H$\\cdots$ $\\cdots$ H-C hydrogen bonds and interlayer stacking of imidazolin-5-one heterocycles. These structures show how weak $\\cdots$ interactions can be exploited for tailoring supramolecular assemblies.

  7. A Multifunctional Coating for Autonomous Corrosion Control

    Science.gov (United States)

    Calle, Luz M.; Li, Wenyan; Buhrow, Jerry W.; Jolley, Scott t.

    2011-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it. The multi-functionality of the coating is based on microencapsulation technology specifically designed for corrosion control applications. This design has, in addition to all the advantages of existing microcapsulation designs, the corrosion controlled release function that triggers the delivery of corrosion indicators and inhibitors on demand, only when and where needed. Microencapsulation of self-healing agents for autonomous repair of mechanical damage to the coating is also being pursued. Corrosion indicators, corrosion inhibitors, as well as self-healing agents, have been encapsulated and dispersed into several paint systems to test the corrosion detection, inhibition, and self-healing properties of the coating. Key words: Corrosion, coating, autonomous corrosion control, corrosion indication, corrosion inhibition, self-healing coating, smart coating, multifunctional coating, microencapsulation.

  8. Natural Polymer of Iraqi Apricot Tree Gum as a Novel Corrosion Inhibitor for Mild Steel in 1 M HCl Solution

    Directory of Open Access Journals (Sweden)

    I. M. Alwaan

    2016-01-01

    Full Text Available Corrosion inhibition of mild steel in 1 M hydrochloric acid using Iraqi apricot tree gum Arabic as natural polymer was studied. The weight loss method was used to predict the efficiency of the inhibitor on corrosion of mild steel in a temperature range of 17–40°C. The FTIR result of natural polymer revealed that the C=O and O-H groups were found in the structure of the natural polymer. The results of weight loss method showed that the inhibition efficiency (I% increased with the increase in both the natural polymer concentration and the temperature; therefore, chemical adsorption mechanism was suggested in this system. The different mathematical models of the adsorption isotherms were studied and the results revealed that natural polymer was found to obey Temkin, Langmuir, and Freundlich adsorption isotherm. The activation energy of adsorption, enthalpy of adsorption, and entropy of adsorption were obtained for different concentrations of natural polymer (0, 0.1, 0.2, and 0.3 g/L and the results showed that the thermodynamic properties decreased with the loading of a natural polymer. Gibbs free energy of adsorption results was a minus value that led to the conclusion of the spontaneous adsorption of the natural polymer in this system.

  9. Capsella bursa-pastoris extract as an eco-friendly inhibitor on the corrosion of Q235 carbon steels in 1 mol·L-1 hydrochloric acid☆

    Institute of Scientific and Technical Information of China (English)

    Qin Hu; Yubing Qiu; Guoan Zhang; Xingpeng Guo

    2015-01-01

    The corrosion inhibition effect of Capsel a bursa-pastoris extracts (CBE) for Q235 carbon steels in 1 mol·L−1 hy-drochloric acid solution was studied using electrochemical methods, environmental scanning electron microsco-py (SEM) and Raman microscopy analysis. The polarization plots indicate that CBE serves as an effective, mixed-type inhibitor. Linear polarization resistance shows that increasing CBE concentration and temperature results in increased inhibition efficiency. The highest inhibition efficiency can reach 97%when adding 60 mg·L−1 CBE, which is better than some reported plant extracts under the similar environment. The adsorption of CBE molecules is found to obey the Langmuir adsorption isotherm. Some thermodynamic and kinetic parameters for the adsorption process, such as the adsorption equilibrium constant (K), free energy of adsorption (ΔGads), ac-tivation energy of corrosion reaction (Ea) and the heat of adsorption (Q ads), are calculated and discussed. SEM and Raman microscopy analysis also demonstrate the formation of a CBE inhibition film on the metal surface.

  10. A new insight into resource recovery of excess sewage sludge: Feasibility of extracting mixed amino acids as an environment-friendly corrosion inhibitor for industrial pickling

    Energy Technology Data Exchange (ETDEWEB)

    Su, Wen; Tang, Bing, E-mail: renytang@163.com; Fu, Fenglian; Huang, Shaosong; Zhao, Shiyuan; Bin, Liying; Ding, Jiewei; Chen, Cuiqun

    2014-08-30

    Graphical abstract: - Highlights: • A value-added product was extracted from the municipal excess sludge. • The effective components contained in the product were mixed amino acids. • The product could provide a reliable protection to the steel from the acid medium. • A new insight into the resource recovery of excess sewage sludge was provided. - Abstract: The work mainly presented a laboratory-scale investigation on an effective process to extract a value-added product from municipal excess sludge. The functional groups in the hydrolysate were characterized with Fourier transform infrared spectrum, and the contained amino acids were measured by means of an automatic amino acid analyzer. The corrosion-inhibition characteristics of the hydrolysate were determined with weight-loss measurement, electrochemical polarization and scanning electron microscopy. Results indicated that the hydrolysate contained 15 kinds of amino acid, and their adsorption on the surface could effectively inhibit the corrosion reaction of the steel from the acid medium. Polarization curves indicated that the obtained hydrolysate was a mixed-type inhibitor, but mainly restricted metal dissolution on the anode. The adsorption accorded well with the Langmuir adsorption isotherm, involved an increase in entropy, and was a spontaneous, exothermic process.

  11. A thermodynamical, electrochemical and surface investigation of Bis (indolyl methanes as Green corrosion inhibitors for mild steel in 1 M hydrochloric acid solution

    Directory of Open Access Journals (Sweden)

    Chandrabhan Verma

    2016-10-01

    Full Text Available The influence of three Bis (indolyl methanes (BIMs namely, 3,3′-((4-nitrophenyl methylene bis (1H-indole (BIM-1, 3,3′-(phenyl methylene bis (1H-indole (BIM-2 and 4-((1H-indol-2-yl(1H-indol-3-yl methyl phenol (BIM-3 on the mild steel corrosion in 1 M HCl was studied by weight loss, electrochemical, scanning electron microscopy (SEM, and dispersive X-ray spectroscopy (EDX methods. Results showed that BIM-3 shows maximum inhibition efficiency of 98.06% at 200 mg L−1 concentration. Polarization study revealed that the BIMs act as mixed type inhibitors. Adsorption of BIMs on the mild steel surface obeyed the Langmuir adsorption isotherm. The weight loss and electrochemical results were well supported by SEM and EDX studies.

  12. Porphyrins as Corrosion Inhibitors for N80 Steel in 3.5% NaCl Solution: Electrochemical, Quantum Chemical, QSAR and Monte Carlo Simulations Studies

    Directory of Open Access Journals (Sweden)

    Ambrish Singh

    2015-08-01

    Full Text Available The inhibition of the corrosion of N80 steel in 3.5 wt. % NaCl solution saturated with CO2 by four porphyrins, namely 5,10,15,20-tetrakis(4-hydroxyphenyl-21H,23H-porphyrin (HPTB, 5,10,15,20-tetra(4-pyridyl-21H,23H-porphyrin (T4PP, 4,4′,4″,4‴-(porphyrin-5,10,15,20-tetrayltetrakis(benzoic acid (THP and 5,10,15,20-tetraphenyl-21H,23H-porphyrin (TPP was studied using electrochemical impedance spectroscopy (EIS, potentiodynamic polarization, scanning electrochemical microscopy (SECM and scanning electron microscopy (SEM techniques. The results showed that the inhibition efficiency, η% increases with increasing concentration of the inhibitors. The EIS results revealed that the N80 steel surface with adsorbed porphyrins exhibited non-ideal capacitive behaviour with reduced charge transfer activity. Potentiodynamic polarization measurements indicated that the studied porphyrins acted as mixed type inhibitors. The SECM results confirmed the adsorption of the porphyrins on N80 steel thereby forming a relatively insulated surface. The SEM also confirmed the formation of protective films of the porphyrins on N80 steel surface thereby protecting the surface from direct acid attack. Quantum chemical calculations, quantitative structure activity relationship (QSAR were also carried out on the studied porphyrins and the results showed that the corrosion inhibition performances of the porphyrins could be related to their EHOMO, ELUMO, ω, and μ values. Monte Carlo simulation studies showed that THP has the highest adsorption energy, while T4PP has the least adsorption energy in agreement with the values of σ from quantum chemical calculations.

  13. Porphyrins as Corrosion Inhibitors for N80 Steel in 3.5% NaCl Solution: Electrochemical, Quantum Chemical, QSAR and Monte Carlo Simulations Studies.

    Science.gov (United States)

    Singh, Ambrish; Lin, Yuanhua; Quraishi, Mumtaz A; Olasunkanmi, Lukman O; Fayemi, Omolola E; Sasikumar, Yesudass; Ramaganthan, Baskar; Bahadur, Indra; Obot, Ime B; Adekunle, Abolanle S; Kabanda, Mwadham M; Ebenso, Eno E

    2015-08-18

    The inhibition of the corrosion of N80 steel in 3.5 wt. % NaCl solution saturated with CO2 by four porphyrins, namely 5,10,15,20-tetrakis(4-hydroxyphenyl)-21H,23H-porphyrin (HPTB), 5,10,15,20-tetra(4-pyridyl)-21H,23H-porphyrin (T4PP), 4,4',4″,4‴-(porphyrin-5,10,15,20-tetrayl)tetrakis(benzoic acid) (THP) and 5,10,15,20-tetraphenyl-21H,23H-porphyrin (TPP) was studied using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, scanning electrochemical microscopy (SECM) and scanning electron microscopy (SEM) techniques. The results showed that the inhibition efficiency, η% increases with increasing concentration of the inhibitors. The EIS results revealed that the N80 steel surface with adsorbed porphyrins exhibited non-ideal capacitive behaviour with reduced charge transfer activity. Potentiodynamic polarization measurements indicated that the studied porphyrins acted as mixed type inhibitors. The SECM results confirmed the adsorption of the porphyrins on N80 steel thereby forming a relatively insulated surface. The SEM also confirmed the formation of protective films of the porphyrins on N80 steel surface thereby protecting the surface from direct acid attack. Quantum chemical calculations, quantitative structure activity relationship (QSAR) were also carried out on the studied porphyrins and the results showed that the corrosion inhibition performances of the porphyrins could be related to their EHOMO, ELUMO, ω, and μ values. Monte Carlo simulation studies showed that THP has the highest adsorption energy, while T4PP has the least adsorption energy in agreement with the values of σ from quantum chemical calculations.

  14. Mechanism of (NH{sub 4})S{sub 2}O{sub 8} to enhance the anti-corrosion performance of Mo-Ce inhibitor on X80 steel in acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yanhua [School of Materials Science and Engineering, Southwest Petroleum University, Chengdu 610500 (China); Zhuang, Jia, E-mail: zj-656@163.com [School of Materials Science and Engineering, Southwest Petroleum University, Chengdu 610500 (China); Zeng, Xianguang [Material Corrosion and Protection Key Laboratory of Sichuan Province, Zigong 643000 (China); Institute of Materials and Chemical Engineering, Sichuan University of Science and Engineering, Zigong 643000 (China)

    2014-09-15

    Highlights: • The 1000 mg/L Na{sub 2}MoO{sub 4} and 500 mg/L Ce(NO{sub 3}){sub 3} has best synergistic effect. • The (NH{sub 4}){sub 2}S{sub 2}O{sub 8} made the valence transformation of cerium (Ce{sup 3+} → Ce{sup 4+}) come true. • The anti-corrosion performance of Mo-Ce inhibitor was improved by (NH{sub 4}){sub 2}S{sub 2}O{sub 8}. • The coordination ability of inhibitor complexes was improved by (NH{sub 4}){sub 2}S{sub 2}O{sub 8}. • The bonding force and adsorption between inhibitor and steel surface was enhanced. - Abstract: Ce(NO{sub 3}){sub 3} and Na{sub 2}MoO{sub 4} are adopted to form (Mo-Ce) composite corrosion inhibitor in allusion to the corrosion problem of steel in acidic conditions. The experimental results showed that the anticorrosion effects were enhanced and the inhibition efficiencies were increased by (NH{sub 4}){sub 2}S{sub 2}O{sub 8}. The reason of enhancement is the increase of coordination bonds amount between Ce{sup 4+} and MoO{sub 4}{sup 2−}, the augment of combining sites of interface between anti-corrosion film and steel, and the reinforce of adsorption caused by the transformation of Ce{sup 3+} to Ce{sup 4+} by oxidants. The process and conditions for transformation of Ce{sup 3+} to Ce{sup 4+} and formation of complexes are discussed. The related thermodynamic and kinetic parameters are calculated and the possibility for (NH{sub 4}){sub 2}S{sub 2}O{sub 8} to improve the performance of Mo-Ce corrosion inhibitor is proved.

  15. Corrosion and protection of heterogeneous cast Al-Si (356) and Al-Si-Cu-Fe (380) alloys by chromate adn cerium inhibitors

    Science.gov (United States)

    Jain, Syadwad

    In this study, the localized corrosion and conversion coating on cast alloys 356 (Al-7.0Si-0.3Mg) and 380 (Al-8.5Si-3.5Cu-1.6Fe) were characterized. The intermetallic phases presence in the permanent mold cast alloy 356 are primary-Si, Al5FeSi, Al8Si6Mg3Fe and Mg2Si. The die cast alloy 380 is rich in Cu and Fe elements. These alloying elements result in formation of the intermetallic phases Al 5FeSi, Al2Cu and Al(FeCuCr) along with primary-Si. The Cu- and Fe-rich IMPS are cathodic with respect to the matrix phase and strongly govern the corrosion behavior of the two cast alloys in an aggressive environment due to formation of local electrochemical cell in their vicinity. Results have shown that corrosion behavior of permanent mould cast alloy 356 is significantly better than the die cast aluminum alloy 380, primarily due to high content of Cu- and Fe-rich phases such as Al2Cu and Al 5FeSi in the latter. The IMPS also alter the protection mechanism of the cast alloys in the presence of inhibitors in an environment. The presence of chromate in the solution results in reduced cathodic activity on all the phases. Chromate provides some anodic inhibition by increasing pitting potentials and altering corrosion potentials for the phases. Results have shown that performance of CCC was much better on 356 than on 380, primarily due to inhomogeneous and incomplete coating deposition on Cu- and Fe- phases present in alloy 380. XPS and Raman were used to characterize coating deposition on intermetallics. Results show evidence of cyanide complex formation on the intermetallic phases. The presence of this complex is speculated to locally suppress CCC formation. Formation and breakdown of cerium conversion coatings on 356 and 380 was also analyzed. Results showed that deposition of cerium hydroxide started with heavy precipitation on intermetallic particles with the coatings growing outwards onto the matrix. Electrochemical analysis of synthesized intermetallics compounds in the

  16. Preparation of Environmentally Friendly Non-phosphorus Corrosion and Scale Inhibitor%环保型无磷缓蚀阻垢剂的制备

    Institute of Scientific and Technical Information of China (English)

    郑兴文; 曾宪光; 龚敏; 金永中

    2012-01-01

    Based on the low molecular weight sodium polyacrylate(PAAS),the corrosion and scale inhibitor with non-phosphorus formula was prepareded by PAAS,sodium molybdate,D-glucose acid sodium,1,2,3-benzotriazole and hexamethylenetetramine in definite proportion.Its anti-scaling performance was evaluated by calcium carbonate deposition method,its corrosion inhibition was evaluated by rotation specimen method and electro chemical method.The best formula is sodium polyacrylate 15 mg/L,D-glucose acid sodium 14 mg/L,1,2,3-benzotriazole 13 mg/L,sodium molybdate 18 mg/L,hexamethylenetetramine 14 mg/L.The scale inhibition efficiency and corrosion inhibition efficiency of the inhibitor were 92.63% and 92.78% respectively.This formula ethibits the characteristics of no phosphorus,non-toxicity,high efficiency and being environmental friendly.There are important economic and use values.%以低分子量聚丙烯酸钠(PAAS)为基础,将聚丙烯酸钠、钼酸钠、D-葡萄糖酸钠、苯并三氮唑、六次甲基四胺等物质按一定比例复配成无磷缓蚀阻垢剂配方,采用碳酸钙沉积法评价其阻垢性能,用旋转挂片法和电化学法评价其缓蚀性能。优选出的最佳缓蚀剂配方为:聚丙烯酸钠15mg/L、D-葡萄糖酸钠14mg/L、苯并三氮唑13mg/L、钼酸钠18mg/L、六次甲基四胺14mg/L,其阻垢率为92.63%,缓蚀率为92.78%。该配方具有无磷、无毒、高效、环保等特点,具有重要的经济和利用价值。

  17. Inorganic inhibitor study in the steel corrosion in the mixture of LiBr+Etilenglicol+H{sub 2}O; Estudio de inhibidores inorganicos en la corrosion de aceros en la mezcla de LiBr+Etilenglicol+H{sub 2}O

    Energy Technology Data Exchange (ETDEWEB)

    Sarmiento Bustos, Estela

    2008-07-15

    This doctoral thesis presents the results obtained for the electrochemical kinetics of four different steels namely: carbon steel, 304, 316 and 316L in a LiBr+etilene glycol+ H{sub 2}O solution. These systems are used in heat pump absorption systems, used to recover waste heat from industrial processes output. Nevertheless, the absorbent solution is highly corrosive; therefore, materials used suffer this corrosion problem. For the latter, under different temperature conditions, three different inorganic inhibitors were evaluated: lithium nitrate, lithium molybdate and lithium chromate which are strong oxidants promoting the formation of passive layer over steels. Through electrochemical methods the best inhibitor compound was determined in terms of behavior and efficiency; for carbon steel 50 ppm lithium nitrate, for 304 5ppm lithium chromate, for 316 5ppm lithium molybdate and for 316L 5ppm lithium chromate were the best. Since carbon steel is the most economical and lithium nitrate inhibitor presented the best response and in the least harmful to the environment over lithium chromate, the study was widened to cover all heat pump operational temperature conditions. For this material study all electrochemical technique were used and electrochemical equivalent circuits simulations were performed for EIS experimental data. For electrochemical noise experimental data an alternative analysis namely, rescaled range or Hurst analysis were performed, relating the EIS depression angle with the Hurst exponent and the rugosity of the metal surface. The optimal concentration and type of inhibitor was determined for these operational conditions. The first chapter presents an introduction to the problem of corrosion of absorption heat pumps setting up the hypothesis and objective of this work. The next chapter presents the estate of the art of heat pumps as well as the electrochemical methods and its fundamental aspects. The third chapter includes the experimental procedure to

  18. Efficient Synthesis of 2-(8-Quinolinoxy)-4H-imidazolin-4-ones

    Institute of Scientific and Technical Information of China (English)

    DING Ming-wu; SHU Ya-li; LIU Zhao-jie

    2003-01-01

    The title compounds 2-(8-quinolinoxy)-4H-imidazolin-4-ones(4) were synthesized by means of base catalytic reactions of 8-hydroxyquinoline with each of carbodiimides 2, which were obtained via aza-Wittig reactions of iminophosphoranes 1 with the corresponding aromatic isocyanates.

  19. 77 FR 3646 - Products Containing Imidazolines Equivalent to 0.08 Milligrams or More

    Science.gov (United States)

    2012-01-25

    .... As nasal decongestants, imidazolines temporarily relieve nasal congestion or stuffy nose due to the... in a lung), subarachnoid hemorrhage (bleeding between brain and surrounding tissues), myocardial...,311 Nose Sprays \\2\\ 1,104 0.31 34 426-1,782 Total 5,675 0.18 172 3,666-7,684 Source: U.S....

  20. Neuroprotective effects of receptor imidazoline 2 and its endogenous ligand agmatine

    Institute of Scientific and Technical Information of China (English)

    Wei-Wen QIU; Rong-Yuan ZHENG

    2006-01-01

    Receptor imidazoline 2 (I2) is one of the imidazoline receptors with high affinity for [3H]-idazoxan. Receptor I2,being classified into I2A and I2B subtypes, is mainly localized to the outer membrane of mitochondria in liver, kidney and brain. Receptor I2, displaying high similarity of sequence with monoamine oxidase-B (MAO-B), is structurally related to MAO-B, but the I2 imidazoline binding site (I2BS) with ligand is distinct from the catalytic site of MAO-B. Agmatine is the endogenous ligand of receptor I2. Accumulating evidence have revealed that the activation of receptors I2 may produce neuroprotective effects by increasing expression of glial fibrillary acidic protein (GFAP) in astrocytes, inhibiting activity of MAO, reducing calcium overload in cells. Agmatine exerts neuroprotection against ischemia-hypoxia, injury, glutamateinduced neurotoxicity by activating imidazoline receptors, blocking N-methyl-D-aspartate (NMDA) receptor, inhibiting all isoforms of nitric oxide synthase (NOS), and selectively blocking the voltage-gated calcium channels (VGCC). It would be expected that agmatine is one of the potential neuroprotective agents.

  1. Effects of imidazolines on neurogenic contraction in isolated urinary bladder detrusor strips from rabbit.

    Science.gov (United States)

    He, Hong-Mei; Ren, Lei-Ming; Tian, He-Lin; Lu, Hai-Gang; Zhao, Ding

    2012-02-01

    Moxonidine and clonidine, which are imidazoline compounds, are sympathetic modulators used as centrally acting antihypertensive drugs. Moxonidine, clonidine, and agmatine produce extensive effects in mammalian tissues via imidazoline recognition sites (or receptors) or α(2)-adrenoceptors. To investigate the effects of imidazolines on the function of the urinary bladder, we tested the effects of moxonidine, clonidine, and agmatine on the neurogenic contraction induced by electric field stimulation, and on the post-synaptic receptors in isolated urinary bladder detrusor strips from rabbit. Both moxonidine at 1.0-10.0 µmol/L and clonidine at 0.1-10.0 µmol/L inhibited electric-field-stimulation-induced contraction in a concentration-dependent manner, but not agmatine (10.0-1000.0 µmol/L). Both moxonidine and clonidine failed to affect carbachol or adenosine-triphosphate-induced contractions; however, 1000.0 µmol/L agmatine significantly increased these contractions. Our study indicates that (i) moxonidine and clonidine produce a concentration-dependent inhibition of the neurogenic contractile responses to electric field stimulation in isolated detrusor strips from male New Zealand rabbits; (ii) post-synaptic muscarinic receptor and purinergic receptor stimulation are not involved in the responses of moxinidine and clonidine in this study; (iii) the inhibitory effects of these agents are probably not mediated by presynaptic imidazoline receptors.

  2. Corrosion Inhibition of AISI 316L and Modified-AISI 630 Stainless Steel by the New Organic Inhibitor [(CH32N]3PSe in Chloride Media:Electrochemical and Physical Study

    Directory of Open Access Journals (Sweden)

    Yafa ZARGOUNI

    2015-04-01

    Full Text Available We evaluate the effect of the Tris-dimethylaminoselenophosphoramide (SeAPon the corrosion inhibition of modified-AISI 630 and AISI 316L stainless steel (SS in 3 wt. % NaCl. The electrochemical behaviors of tested SS samples are investigated before and after adding the Seep into the chloride media by potentiodynamic polarization technique. The adsorption of SeAP onto both SS surfaces is verified by global discharge optical emission spectroscopy (GDOES.  SeAP is found to be a good inhibitor for SS corrosion, especially when added at a concentration of 0.5 wt. %.

  3. CORROSION INHIBITION AND SYNERGISTIC EFFECT OF GREEN SCALE INHIBITOR POLYEPOXYSUCCINIC ACID%绿色阻垢剂聚环氧琥珀酸的缓蚀协同效应

    Institute of Scientific and Technical Information of China (English)

    熊蓉春; 周庆; 魏刚

    2003-01-01

    The corrosion inhibition of a kind of green scale inhibitor, polyepoxysuccinic acid (PESA) was studied based on dynamic experiments. In addition, the synergistic effect among PESA, Zn2+ and sodium gluconate was also investigated. According to the experimental data, when only PESA is used, it had fairly good effect on steel. The synergy between PESA and Zn2+ or sodium gluconate was poor. However, the synergistic effect of PESA, Zn2+ and sodium gluconate is very good. Further experiments show that the corrosion inhibition of PESA is mainly affected by oxygen atom inserted.

  4. Effect of inhibitors on corrosion behavior of copper-nickel in concentrated lithium bromide solution at high temperature

    Institute of Scientific and Technical Information of China (English)

    黄乃宝; 梁成浩; 佟大维

    2002-01-01

    The conventional mass-loss tests and the electrochemical techniques were used to study the inhibition action of LiOH and Na2MoO4 either individually or in different combination for copper-nickel alloy in boiling 65%LiBr solution. It indicates that the corrosion rate of copper-nickel is decreased when LiOH or Na2MoO4 is added to the solution individually. LiOH concentration has a double-effect on the corrosion behavior of copper-nickel. Low concentration is benefit to forming oxide film. High concentration results in dissolution of oxide film. The optimal concentration of LiOH is 0.15mol/L. The dissolution of copper-nickel is effectively prevented when adding 200mg/L Na2MoO4 to boiling 65%LiBr solution with 0.15mol/L LiOH. The inhibition mechanism is considered that the films of Cu, Ni, Mo oxides and deposited nonprotective in soluble CuBr on the surface of metal could prevent Br- ion from absorption, which prevent alloy dissolving.

  5. Molecular modeling of organic corrosion inhibitors: why bare metal cations are not appropriate models of oxidized metal surfaces and solvated metal cations.

    Science.gov (United States)

    Kokalj, Anton

    2014-01-01

    The applicability of various models of oxidized metal surfaces - bare metal cations, clusters of various size, and extended (periodic) slabs - that are used in the field of quantum-chemical modeling of corrosion inhibitors is examined and discussed. As representative model systems imidazole inhibitor, MgO surface, and solvated Mg(2+) ion are considered by means of density-functional-theory calculations. Although the results of cluster models are prone to cluster size and shape effects, the clusters of moderate size seem useful at least for qualitative purposes. In contrast, the bare metal cations are useless not only as models of oxidized surfaces but also as models of solvated cations, because they bind molecules several times stronger than the more appropriate models. In particular, bare Mg(2+) binds imidazole by 5.9 eV, while the slab model of MgO(001) by only 0.35 eV. Such binding is even stronger for 3+ cations, e.g., bare Al(3+) binds imidazole by 17.9 eV. The reasons for these fantastically strong binding energies are discussed and it is shown that the strong bonding is predominantly due to electron charge transfer from molecule to metal cation, which stems from differences between molecular and metal ionization potentials.

  6. Role(s) of pretreatment, inhibitors, and other process steps that effect surface composition on the under-paint corrosion of an aluminum-copper-magnesium alloy 2024-T3

    Science.gov (United States)

    Little, Daryl A.

    2006-12-01

    Under-paint corrosion is a surface corrosion that grows under a coating. The composition of an aluminum alloy, particularly Cu and Fe content, has a direct and dominant effect on the growth rate of filiform corrosion (FFC) and scribe-creep. The Cu and Fe content leads to formation of galvanic cells between intermetallic compounds (IMCs) or replated Cu and the aluminum-rich matrix. However, there is no model which describes scribe-creep behavior and can be used to predict the effect of material and surface pretreatment parameters such as inhibitors, chemical surface pretreatment, and alloy microstructure. Surface pretreatments and aging which control the amount of surface copper and alter IMC distributions decrease the growth rate of scribe-creep. Scribe-creep was observed to be enhanced by temperature, regardless of surface pretreatment, as well as by artificial aging and surface pretreatments. Scribe-creep was accelerated by pretreatments that increased surface copper or left a high capacity for Cu-replating such as Cu-containing IMCs. Pretreatment was rationalized to decrease the cathodic oxygen reduction reaction (ORR) rate, which supports anodic undercutting at the head of the corrosion front. In this galvanic corrosion mechanism, the scribe-creep rate will be proportional to the rate of the anodic dissolution at the head. This, in turn, is proportional to the galvanic corrosion rate. Both charge transfer controlled and mass transport controlled cathodic reaction rates occurred at the fastest rates at the scratch and tail. The charge transfer controlled cathodic reaction rate was directly proportional to the surface coverage of Cu (thetaCu) while the mass transport limited rate was a complex nonlinear function of thetaCu . Based on enhanced understanding a galvanic couple model that describes scribe-creep rates in terms of the relevant processes at the tail and head as well as ohmic voltage between the head and tail was developed in order to explain scribe

  7. Study on the Synthesis and Performance of a Mannich Based Acidification Corrosion Inhibitor%曼尼希酸化缓蚀剂H-402的合成及其缓蚀性能研究

    Institute of Scientific and Technical Information of China (English)

    张勇; 陆原; 张颖; 胡廷; 赵璐

    2013-01-01

    A oilfield acidification corrosion inhibitor was synthesized by Mannich reaction of secondary amine, acetophenone and formaldehyde. The effect of the synthetic technology, including molar ratio of reactant, reaction temperature and reaction time, on the inhibition performance of the inhibitor was evaluated by coupon corrosion tests. In addition, the inhibition mechanism of the inhibitor was investigated by electrochemical test and scanning electronic microscope observation. The results showed that the inhibitor exhibited the best inhibition efficiency when the molar ratio of primary amine, acetophenone and formaldehyde was 1:2:5 and the reaction were maintained at 80℃ for 10 h. After compounded with polyether and propargyl alcohol, the inhibitor could reach the first-class level at the dosage of 0.5%. The corrosion inhibitor was assigned as a mixed inhibitor mainly which inhibited the anode process through electrochemistry method. The scanning electronic microscope observation indicated that the corrosion forms of steels were improved significantly after adding 0.5% corrosion inhibitor.%本文采用仲胺、苯乙酮、甲醛为原料,通过曼尼希缩合反应,合成了一种油田酸化缓蚀剂H-402,研究了合成工艺对产物性能的影响及缓蚀机理.结果表明:在仲胺/苯乙酮/甲醛摩尔比1∶2∶5、反应温度80℃、反应时间10h条件下,所合成的H-402的缓蚀效果最佳.该缓蚀剂与聚醚、丙炔醇等具有增效作用,加剂量为0.5%时达到缓蚀剂一级水平.该缓蚀剂为抑制阳极过程为主的混合型缓蚀剂.扫描电镜显示,加入0.5%H-402后,Q235挂片表面的腐蚀形态得到极大的改善.

  8. Synthesis and Evaluation of Poly(Sodium 2-Acrylamido-2-Methylpropane Sulfonate-co-Styrene/Magnetite Nanoparticle Composites as Corrosion Inhibitors for Steel

    Directory of Open Access Journals (Sweden)

    Gamal A. El-Mahdy

    2014-01-01

    Full Text Available Self-stabilized magnetic polymeric composite nanoparticles of coated poly-(sodium 2-acrylamido-2-methylpropane sulfonate-co-styrene/magnetite (PAMPS-Na-co-St/Fe3O4 were prepared by emulsifier-free miniemulsion polymerization using styrene (St as a monomer, 2-acrylamido-2-methylpropane sulfonic acid sodium salt (AMPS-Na as an ionic comonomer, N,N-methylenebisacrylamide (MBA as crosslinker, hexadecane (HD as a hydrophobic solvent, and 2,2-azodiisobutyronitrile (AIBN as an initiator in the presence of hydrophobic oleic acid coated magnetite particles. Hydrophobic oleic acid coated magnetite particles with an average size of about 7-10 nm were prepared with the new modified water-based magnetite ferrofluid, synthesized by a chemical modified coprecipitation method. The morphology and the particle size distributions of the crosslinked PAMPS-Na-co-St/Fe3O4 composite were observed and analyzed by transmission electron microscopy (TEM. The average Fe3O4 content of PAMPS-Na-co-St/Fe3O4 was determined by thermogravimetric analysis (TGA. The inhibitory action of PAMPS-Na-co-St/Fe3O4 towards steel corrosion in 1 M HCl solutions has been investigated by polarization and electrochemical impedance spectroscopy (EIS methods. Polarization measurements indicate that PAMPS-Na-co-St/Fe3O4 acts as a mixed type-inhibitor and the inhibition efficiency increases with inhibitor concentration. The results of potentiodynamic polarization and EIS measurements clearly showed that the inhibition mechanism involves blocking of the steel surface by inhibitor molecules via adsorption.

  9. Synthesis and evaluation of poly(Sodium 2-Acrylamido-2-Methylpropane Sulfonate-co-Styrene)/magnetite nanoparticle composites as corrosion inhibitors for steel.

    Science.gov (United States)

    El-Mahdy, Gamal A; Atta, Ayman M; Al-Lohedan, Hamad A

    2014-01-30

    Self-stabilized magnetic polymeric composite nanoparticles of coated poly-(sodium 2-acrylamido-2-methylpropane sulfonate-co-styrene)/magnetite (PAMPS-Na-co-St/Fe3O4) were prepared by emulsifier-free miniemulsion polymerization using styrene (St) as a monomer, 2-acrylamido-2-methylpropane sulfonic acid sodium salt (AMPS-Na) as an ionic comonomer, N,N-methylenebisacrylamide (MBA) as crosslinker, hexadecane (HD) as a hydrophobic solvent, and 2,2-azodiisobutyronitrile (AIBN) as an initiator in the presence of hydrophobic oleic acid coated magnetite particles. Hydrophobic oleic acid coated magnetite particles with an average size of about 7-10 nm were prepared with the new modified water-based magnetite ferrofluid, synthesized by a chemical modified coprecipitation method. The morphology and the particle size distributions of the crosslinked PAMPS-Na-co-St/Fe3O4 composite were observed and analyzed by transmission electron microscopy (TEM). The average Fe3O4 content of PAMPS-Na-co-St/Fe3O4 was determined by thermogravimetric analysis (TGA). The inhibitory action of PAMPS-Na-co-St/Fe3O4 towards steel corrosion in 1 M HCl solutions has been investigated by polarization and electrochemical impedance spectroscopy (EIS) methods. Polarization measurements indicate that PAMPS-Na-co-St/Fe3O4 acts as a mixed type-inhibitor and the inhibition efficiency increases with inhibitor concentration. The results of potentiodynamic polarization and EIS measurements clearly showed that the inhibition mechanism involves blocking of the steel surface by inhibitor molecules via adsorption.

  10. A Novel Schiff Base of 3-acetyl-4-hydroxy-6-methyl-(2Hpyran-2-one and 2,2'-(ethylenedioxydiethylamine as Potential Corrosion Inhibitor for Mild Steel in Acidic Medium

    Directory of Open Access Journals (Sweden)

    Jonnie N. Asegbeloyin

    2015-05-01

    Full Text Available The corrosion inhibition activity of a newly synthesized Schiff base (SB from 3-acetyl-4-hydroxy-6-methyl-(2H-pyran-2-one and 2,2'-(ethylenedioxydiethylamine was investigated on the corrosion of mild steel in 1 M HCl solution using potentiodynamic polarization and electrochemical impedance spectroscopic techniques. Ultraviolet-visible (UV-vis and Raman spectroscopic techniques were used to study the chemical interactions between SB and mild steel surface. SB was found to be a relatively good inhibitor of mild steel corrosion in 1 M HCl. The inhibition efficiency increases with increase in concentration of SB. The inhibition activity of SB was ascribed to its adsorption onto mild steel surface, through physisorption and chemisorption, and described by the Langmuir adsorption model. Quantum chemical calculations indicated the presence of atomic sites with potential nucleophilic and electrophilic characteristics with which SB can establish electronic interactions with the charged mild steel surface.

  11. 2,5-Bis(4-dimethylaminophenyl)-1,3,4-oxadiazole and 2,5-bis(4-dimethylaminophenyl)-1,3,4-thiadiazole as corrosion inhibitors for mild steel in acidic media

    Energy Technology Data Exchange (ETDEWEB)

    Bentiss, F.; Traisnel, M.; Vezin, H.; Hildebrand, H.F.; Lagrenee, M

    2004-11-01

    2,5-Bis(4-dimethylaminophenyl)-1,3,4-oxadiazole (DAPO) and 2,5-bis(4-dimethylaminophenyl)-1,3,4-thiadiazole (DAPT) have been synthesised and their inhibiting action on the corrosion of mild steel in 1 M HCl and 0.5 M H{sub 2}SO{sub 4} at 30 deg. C has been investigated by various corrosion monitoring techniques. At constant acid concentration, the inhibitor efficiency of both the compounds is found to increase with inhibitor concentration. DAPT is slightly more efficient in 0.5 M H{sub 2}SO{sub 4} than in 1 M HCl whereas DAPO is more efficient in 1 M HCl. Of the two, DAPT appears to be a better inhibitor. Potentiostatic polarisation studies show that both are mixed-type inhibitors in 1 M HCl but cathodic-type in 0.5 M H{sub 2}SO{sub 4}. The inhibitors function through adsorption following Langmuir isotherm in both the acids. The electronic properties of DAPO and DAPT, obtained using the AM1 semi-empirical quantum chemical approach, have been correlated with their experimental inhibition efficiencies using the linear resistance model (LR). These inhibitors are considered as a non-cytotoxic substances.

  12. Selective imidazoline agonist moxonidine in obese hypertensive patients.

    Science.gov (United States)

    Sanjuliani, A F; de Abreu, V G; Francischetti, E A

    2006-05-01

    Obesity is the major risk factor for the development of hypertension. This association accentuates the risk of cardiovascular disease, as it is frequently accompanied by the components of the metabolic syndrome. This randomised open parallel study evaluated the chronic effects of moxonidine--a selective imidazoline receptor agonist--on blood pressure, plasma catecholamines, leptin, insulin and components of the metabolic syndrome in obese hypertensives. Amlodipine was used as the control drug. Our results showed that moxonidine and amlodipine significantly reduced blood pressure when measured using the oscillometric method and 24-hour blood pressure monitoring. Moxonidine therapy decreased systolic blood pressure from 160.4 +/- 2.4 to 142.1 +/- 3.3 mmHg (p < 0.005) and diastolic blood pressure from 102.4 +/- 1.3 to 89.7 +/- 1.6 mmHg (p < 0.005) after 24 weeks of treatment. Moxonidine administration reduced the supine arterial plasma levels of adrenaline from 63.2 +/- 6.6 to 49.0 +/- 6.7 pg/ml (p < 0.005), the supine arterial plasma levels of noradrenaline from 187.9 +/- 10.7 to 149.7 +/- 13.2 pg/ml (p < 0.01) and the orthostatic venous plasma levels of noradrenaline from 258.6 +/- 25.0 to 190.3 +/- 16.4 pg/ml (p = 0.03). Those variables were not changed by amlodipine. The plasma levels of leptin and insulin 120 min after a glucose load decreased after moxonidine administration from 27.2 +/- 3.5 to 22.6 +/- 2.9 pg/ml (p < 0.05) and from 139.7 +/- 31.2 to 76.0 +/- 15.2 U/ml (p < 0.05), respectively. Amlodipine, however, did not modify those variables. This study showed a comparable reduction in blood pressure with both antihypertensive drugs. Moxonidine decreased sympathetic nervous activity, improved insulin resistance and reduced the plasma levels of leptin.

  13. ac impedance, X-ray photoelectron spectroscopy and density functional theory studies of 3,5-bis(n-pyridyl)-1,2,4-oxadiazoles as efficient corrosion inhibitors for carbon steel surface in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Outirite, Moha; Lagrenee, Michel; Lebrini, Mounim [Unite de Catalyse et de Chimie du Solide, UMR-CNRS 8181, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Traisnel, Michel; Jama, Charafeddine [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, PERF UMR-CNRS 8008, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Vezin, Herve [Laboratoire de Chimie Organique et Macromoleculaire, UMR-CNRS 8009, USTL Bat C4, F-59655 Villeneuve d' Ascq Cedex (France); Bentiss, Fouad, E-mail: fbentiss@enscl.f [Laboratoire de Chimie de Coordination et d' Analytique, Faculte des Sciences, Universite Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco)

    2010-02-01

    The corrosion inhibition properties of a new class of oxadiazole derivatives, namely 3,5-bis(n-pyridyl)-1,2,4-oxadiazoles (n-DPOX) for C38 carbon steel corrosion in 1 M HCl medium were analysed by electrochemical impedance spectroscopy (EIS). An adequate structural model of the interface was used and the values of the corresponding parameters were calculated and discussed. The experimental results showed that these compounds are excellent inhibitors for the C38 steel corrosion in acid solution and that the protection efficiency increased with increasing the inhibitors concentration. Electrochemical impedance data demonstrate that the addition of the n-DPOX derivatives in the corrosive solution decreases the charge capacitance and simultaneously increases the function of the charge/discharge of the interface, facilitating the formation of an adsorbed layer over the steel surface. Adsorption of these inhibitors on the steel surface obeys to the Langmuir adsorption isotherm. X-ray photoelectron spectroscopy (XPS) and the thermodynamic data of adsorption showed that inhibition of steel corrosion in normal hydrochloric solution by n-DPOX is due to the formation of a chemisorbed film on the steel surface. Quantum chemical calculations using the Density Functional Theory (DFT) and the Quantitative Structure Activity Relationship (QSAR) approach were performed on n-DPOX derivatives to determine the relationship between molecular structure and their inhibition efficiencies. The results of the quantum chemical calculations and experimental inhibition efficiency were subjected to correlation analysis and indicate that their inhibition effect is closely related to E{sub HOMO}, E{sub LUMO}, and dipole moment (mu).

  14. 常减压蒸馏装置缓蚀剂的合成与复配研究%The synthesis and compound of corrosion inhibitors for atmospheric and vacuum distillation unit

    Institute of Scientific and Technical Information of China (English)

    潘奇; 程丽华; 赵德智

    2013-01-01

    根据常减压蒸馏装置腐蚀环境的体系特点,合成了一种耐酸性强的高效缓蚀剂HS-1,并与目前炼厂使用的2种缓蚀剂HS-2和HS-3进行了对比.通过静态和动态挂片失重实验,对3种缓蚀剂进行了配伍性的研究.结果表明,综合评价缓蚀剂的效率HS-1> HS-3> HS-2,单独使用HS-1,用量在10~ 30 mg/L,平均缓蚀率达87.6%;静态挂片实验中,最优复配方案为HS-1∶ HS-2=1∶1(体积比),平均缓蚀效率为94.9%;动态挂片实验中最优复配方案为HS-1∶HS-3=1∶2(体积比),平均缓蚀效率为87.3%.%On the basis of corrosive environment of atmospheric and vacuum distillation unit,a kind of efficient corrosion inhibitor HS-1 with high acidresistivity is synthesised and compared with corrosion inhibitor HS-2 and corrosion inhibitor HS-3 which are used currently in oil refinery.Through the static and dynamic coupon experiments in erosive electrochemistry,compatibility research is done by three kinds of corrosion inhibitors.The results show that the efficiency is HS-1 > HS-3 > HS-2 by comprehensive evaluation.With the single usage of corrosion inhibitor HS-1,the average inhibition efficiency is 87.6% in range from 10 mg/L to 30 mg/L;in the static coupon test of weight loss,the optimum mixing proportion is HS1∶HS-2 =1∶1 (volume ratio),and the average inhibition efficiency is 94.9%,while in the dynamic coupon test,the optimum mixing proportion is HS-1 ∶ HS-3 =1 ∶ 2 (volume ratio),and the average inhibition efficiency is 87.3%.

  15. Smart Coatings for Corrosion Protection

    Science.gov (United States)

    Calle, Luz Marina; Li, Wendy; Buhrow, Jerry W.; Johnsey, Marissa N.

    2016-01-01

    Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. It is essential to detect corrosion when it occurs, and preferably at its early stage, so that action can be taken to avoid structural damage or loss of function. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional, smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it.

  16. Corrosion inhibition of steel in concrete by carboxylic acids

    Energy Technology Data Exchange (ETDEWEB)

    Sagoe-Crentsil, K.K.; Glasser, F.P. (Univ. of Aberdeen, Old Aberdeen (United Kingdom). Dept. of Chemistry); Yilmaz, V.T. (Ondokuz Mayis Univ., Samsun (Turkey))

    1993-11-01

    Water soluble carboxylic acids have been used as corrosion inhibitors. They remain largely soluble after curing in cement for up to 90d. Corrosion current measurements are presented showing malonic acid, a dicarboxylic acid, to be a very effective corrosion inhibitor even in the presence of 2.5 wt % chloride. Unfortunately, it has an initial retarding effect on the set of Portland cement. The investigation suggests that corrosion inhibitors based on carboxylic acids remain a fruitful field of investigation.

  17. A comparative electrochemical study of electrosorbed 2- and 4-mercaptopyridines and their application as corrosion inhibitors at C60 steel

    Indian Academy of Sciences (India)

    Nazly Hassan; Rudolf Holze

    2009-09-01

    The electrochemistry of self-assembled monolayers (SAMs) prepared from 2-mercaptopyridine (2 Mpy) and 4-mercaptopyridine (4 Mpy) dissolved in either water or an aqueous solution of 0.1 M H2SO4 on a polycrystalline gold electrode has been investigated in an aqueous electrolyte solution (0.5 M H2SO4) using cyclic voltammetry. Results suggest that 2 Mpy is adsorbed more strongly than 4 Mpy due to the formation of a S-Au-N chelate. The under- and over-potential deposition of copper from an aqueous solution of 0.1 M sulphuric acid is inhibited in the presence of these SAMs suggesting strong interactions between these adsorbates and the gold surface. A copper adlayer was partially displaced by adsorbing 2 Mpy and 4 Mpy. The inhibition effect of these SAMs on the corrosion of C60 steel has been investigated using electrochemical impedance measurements (EIM) in an aqueous 3.5 wt% NaCl solution. The polarization resistance and the inhibition efficiency were calculated. 2 Mpy has higher inhibition efficiency than 4 Mpy.

  18. Greener Approach towards Corrosion Inhibition

    Directory of Open Access Journals (Sweden)

    Neha Patni

    2013-01-01

    Full Text Available Corrosion control of metals is technically, economically, environmentally, and aesthetically important. The best option is to use inhibitors for protecting metals and alloys against corrosion. As organic corrosion inhibitors are toxic in nature, so green inhibitors which are biodegradable, without any heavy metals and other toxic compounds, are promoted. Also plant products are inexpensive, renewable, and readily available. Tannins, organic amino acids, alkaloids, and organic dyes of plant origin have good corrosion-inhibiting abilities. Plant extracts contain many organic compounds, having polar atoms such as O, P, S, and N. These are adsorbed on the metal surface by these polar atoms, and protective films are formed, and various adsorption isotherms are obeyed. Various types of green inhibitors and their effect on different metals are mentioned in the paper.

  19. Adsorção competitiva de inibidor de corrosão usado em poços de perfuração de petróleo sobre aço, esmectita e arenito Competitive adsorption of wellbores corrosion inhibitor onto steel, esmectite and sandstone

    Directory of Open Access Journals (Sweden)

    Ingrid A. G. A. Souza

    2009-01-01

    Full Text Available A commercial corrosion inhibitor used in petroleum production was characterized by means of infrared spectroscopy and energy dispersive spectroscopy (EDS. Predicting the adsorption behavior of corrosion inhibitor onto steel, sandstone and esmectite is the key to improve working conditions. In this study, the adsorption kinetics of inhibitor formulations in HCl 15% or in Mud Acid (HCl 13,5% and ammonium bifluoride onto steel, sandstone and esmectite was determined by means of spectrophotometry. Kinetic parameters indicated that adsorption of inhibitor in the presence of bifluoride was favored. Moreover, the adsorption constant rate was the largest when the substrate was esmectite.

  20. CORROSION INHIBITION BY CASHEW NUT SHELL

    African Journals Online (AJOL)

    is the primary step in the action of organic corrosion inhibitors (Trabanelli. 1989). ... polarized. Electrochemical Impedance Spectroscopy (EIS) measurements .... solutions and UV/VIS to determine the adsorption of the CNSL inhibitor on.

  1. Evaluation of Thymus vulgaris plant extract as an eco-friendly corrosion inhibitor for stainless steel 304 in acidic solution by means of electrochemical impedance spectroscopy, electrochemical noise analysis and density functional theory.

    Science.gov (United States)

    Ehsani, A; Mahjani, M G; Hosseini, M; Safari, R; Moshrefi, R; Mohammad Shiri, H

    2017-03-15

    Inhibition performance of Thymus vulgaris plant leaves extract (thyme) as environmentally friendly (green) inhibitor for the corrosion protection of stainless steel (SS) type 304 in 1.0molL(-1) HCl solution was studied by potentiodynamic polarization, electrochemical impedance (EIS) and electrochemical noise measurements (EN) techniques. The EN data were analyzed with FFT technique to make the spectral power density plots. The calculations were performed by MATLAB 2014a software. Geometry optimization and calculation of the structural and electronic properties of the molecular system of inhibitor have been carried out using UB3LYP/6-311++G(∗∗) level. Moreover, the results obtained from electrochemical noise analysis were compared with potentiodynamic polarization and electrochemical impedance spectroscopy. All of the used techniques showed positive effect of green inhibitor with increasing inhibitor concentration.

  2. Corrosion-Activated Micro-Containers for Environmentally Friendly Corrosion Protective Coatings

    Science.gov (United States)

    Li, Wenyan; Buhrow, J. W.; Zhang, X.; Johnsey, M. N.; Pearman, B. P.; Jolley, S. T.; Calle, L. M.

    2016-01-01

    This work concerns the development of environmentally friendly encapsulation technology, specifically designed to incorporate corrosion indicators, inhibitors, and self-healing agents into a coating, in such a way that the delivery of the indicators and inhibitors is triggered by the corrosion process, and the delivery of self-healing agents is triggered by mechanical damage to the coating. Encapsulation of the active corrosion control ingredients allows the incorporation of desired autonomous corrosion control functions such as: early corrosion detection, hidden corrosion detection, corrosion inhibition, and self-healing of mechanical damage into a coating. The technology offers the versatility needed to include one or several corrosion control functions into the same coating.The development of the encapsulation technology has progressed from the initial proof-of-concept work, in which a corrosion indicator was encapsulated into an oil-core (hydrophobic) microcapsule and shown to be delivered autonomously, under simulated corrosion conditions, to a sophisticated portfolio of micro carriers (organic, inorganic, and hybrid) that can be used to deliver a wide range of active corrosion ingredients at a rate that can be adjusted to offer immediate as well as long-term corrosion control. The micro carriers have been incorporated into different coating formulas to test and optimize the autonomous corrosion detection, inhibition, and self-healing functions of the coatings. This paper provides an overview of progress made to date and highlights recent technical developments, such as improved corrosion detection sensitivity, inhibitor test results in various types of coatings, and highly effective self-healing coatings based on green chemistry. The NASA Kennedy Space Centers Corrosion Technology Lab at the Kennedy Space Center in Florida, U.S.A. has been developing multifunctional smart coatings based on the microencapsulation of environmentally friendly corrosion

  3. Cytobiological mechanism of agmatine inhibitory effect on morphine dependence: role of I1-imidazoline receptor

    Institute of Scientific and Technical Information of China (English)

    SuRui-bin; WuNing; LiJin

    2004-01-01

    In our previous studies, agmatine was found to prevent substance dependence of morphine in mice, rats and monkeys,but the exact mechanism was not clear yet. In this study, for the first time rat μ opioid receptor (rMOR) and human I1-imidazoline receptor (hI1 R) were co-expressed stably in CHO cells (CHO-μ/I1) by means of lipofectamine transfection

  4. Mono(imidazolin-2-iminato) actinide complexes: synthesis and application in the catalytic dimerization of aldehydes.

    Science.gov (United States)

    Karmel, Isabell S R; Fridman, Natalia; Tamm, Matthias; Eisen, Moris S

    2014-12-10

    The synthesis of the mono(imidazolin-2-iminato) actinide(IV) complexes [(Im(R)N)An(N{SiMe3)2}3] (3-8) was accomplished by the protonolysis reaction between the respective imidazolin-2-imine (Im(R)NH, R = tBu, Mes, Dipp) and the actinide metallacycles [{(Me3Si)N}2An{κ(2)C,N-CH2SiMe2N(SiMe3)}] (1, An = U; 2, M = Th). The thorium and uranium complexes were obtained in high yields, and their structures were established by single-crystal X-ray diffraction analysis. The mono(imidazolin-2-iminato) actinide complexes 3-8 display short An-N bonds together with large An-N-C angles, indicating strong electron donation from the imidazolin-2-iminato moiety to the metal, corroborating a substantial π-character to the An-N bond. The reactivity of complexes 3-8 toward benzaldehyde was studied in the catalytic dimerization of aldehydes (Tishchenko reaction), displaying low to moderate catalytic activities for the uranium complexes 3-5 and moderate to high catalytic activities for the thorium analogues 6-8, among which 8 exhibited the highest catalytic activity. In addition, actinide coordination compounds showed unprecedented reactivity toward cyclic and branched aliphatic aldehydes in the catalytic Tishchenko reaction mediated by the thorium complex [(Im(Dipp)N)Th{N(SiMe3)2}3] (8), exhibiting high activity even at room temperature. Moreover, complex 8 was successfully applied in the crossed Tishchenko reaction between an aromatic or polyaromatic and an aliphatic cyclic and branched aldehyde, yielding selectively the asymmetrically substituted ester in high yields (80-100%).

  5. Comparison of agmatine with moxonidine and rilmenidine in morphine dependence in vitro: role of imidazoline I(1) receptors.

    Science.gov (United States)

    Li, Fei; Wu, Ning; Su, Rui-Bin; Liu, Yin; Lu, Xin-Qiang; Li, Jin

    2009-06-10

    Moxonidine and rilmenidine are classical imidazoline I(1) receptor agonists, and used as anti-hypertension drugs in clinical practice. Agmatine is an imidazoline I(1) receptor endogenous ligand as well as its agonist, but more and more evidences suggest it has no influence on blood pressure. In the present study we compared the effects of moxonidine, rilmenidine and agmatine in the development of morphine dependence, and investigated the role of imidazoline I(1) receptor in the effects of these agents. Chinese hamster ovary cells co-expressing mu opioid receptor and imidazoline receptor antisera-selected protein (IRAS), the strong candidate for imidazoline I(1) receptor, were used as the cell line. cAMP overshoot, which represents an opioid dependent state in vitro, was measured to study the effects on morphine dependence. siRNA against IRAS was carried out to investigate the role of imidazoline I(1) receptor. Moxonidine and rilmenidine (0.01-10 microM) were ineffective on cAMP level in the cells when given alone, and failed to inhibit chronic morphine exposure, naloxone-precipitated cAMP overshoot when co-pretreated with morphine. Agmatine (0.01-10 microM) by itself was ineffective but co-pretreated with morphine concentration-dependently inhibited chronic morphine exposure, naloxone-precipitated cAMP overshoot in the cells. Furthermore, we found that the inhibitory effect of agmatine (100 nM and 1 microM) on cAMP overshoot was significantly reduced by siRNA against IRAS. This study indicates that agmatine can inhibit the development of morphine dependence in vitro, whereas moxonidine and rilmenidine have no the effect. Imidazoline I(1) receptor plays an important role in agmatine inhibiting morphine dependence.

  6. Atmospheric Corrosivity at Australian and Overseas Airbases and Airports

    Science.gov (United States)

    2014-07-01

    protective coating systems and corrosion inhibitor treatments deteriorate and become less effective. The CLIMAT environmental corrosion test has...UNCLASSIFIED UNCLASSIFIED Atmospheric Corrosivity at Australian and Overseas Airbases and Airports J C Bitcon Maritime...Division Defence Science and Technology Organisation DSTO-TN-1320 ABSTRACT Atmospheric corrosivity at 25 airbases and airports in Australia

  7. Allantoin ameliorates chemically-induced pancreatic β-cell damage through activation of the imidazoline I3 receptors

    Directory of Open Access Journals (Sweden)

    Marie Amitani

    2015-08-01

    Full Text Available Objective. Allantoin is the primary active compound in yams (Dioscorea spp.. Recently, allantoin has been demonstrated to activate imidazoline 3 (I3 receptors located in pancreatic tissues. Thus, the present study aimed to investigate the role of allantoin in the effect to improve damage induced in pancreatic β-cells by streptozotocin (STZ via the I3 receptors.Research Design and Methods. The effect of allantoin on STZ-induced apoptosis in pancreatic β-cells was examined using the ApoTox-Glo triplex assay, live/dead cell double staining assay, flow cytometric analysis, and Western blottings. The potential mechanism was investigated using KU14R: an I3 receptor antagonist, and U73122: a phospholipase C (PLC inhibitor. The effects of allantoin on serum glucose and insulin secretion were measured in STZ-treated rats.Results. Allantoin attenuated apoptosis and cytotoxicity and increased the viability of STZ-induced β-cells in a dose-dependent manner; this effect was suppressed by KU14R and U73112. Allantoin decreased the level of caspase-3 and increased the level of phosphorylated B-cell lymphoma 2 (Bcl-2 expression detected by Western blotting. The improvement in β-cells viability was confirmed using flow cytometry analysis. Daily injection of allantoin for 8 days in STZ-treated rats significantly lowered plasma glucose and increased plasma insulin levels. This action was inhibited by treatment with KU14R.Conclusion. Allantoin ameliorates the damage of β-cells induced by STZ. The blockade by pharmacological inhibitors indicated that allantoin can activate the I3 receptors through a PLC-related pathway to decrease this damage. Therefore, allantoin and related analogs may be effective in the therapy for β-cell damage.

  8. Plastics for corrosion inhibition

    CERN Document Server

    Goldade, Victor A; Makarevich, Anna V; Kestelman, Vladimir N

    2005-01-01

    The development of polymer composites containing inhibitors of metal corrosion is an important endeavour in modern materials science and technology. Corrosion inhibitors can be located in a polymer matrix in the solid, liquid or gaseous phase. This book details the thermodynamic principles for selecting these components, their compatibility and their effectiveness. The various mechanisms of metal protection – barrier, inhibiting and electromechanical – are considered, as are the conflicting requirements placed on the structure of the combined material. Two main classes of inhibited materials (structural and films/coatings) are described in detail. Examples are given of structural plastics used in friction units subjected to mechano-chemical wear and of polymer films/coatings for protecting metal objects against corrosion.

  9. 唑类缓蚀剂在铜表面的吸附机理%Adsorption Mechanism of Azole Corrosion Inhibitors on Cu Surface

    Institute of Scientific and Technical Information of China (English)

    廉兵杰; 石泽民; 徐慧; 赵起锋; 王木立; 姜云瑛; 胡松青

    2015-01-01

    Objective To compare the inhibition performance of two corrosion inhibitors:1, 2, 4-triazole and benzotriazole, in order to explore their adsorption types on Cu surface and explain the inhibition mechanism from experiment and molecular simula-tion point of view. Methods Potentiodynamic polarization measurement was used to test the corrosion inhibitive efficiency of the two inhibitors. The adsorption isothermal fitting method was used to explore their adsorption types on Cu surface. Adsorption energy, deformation charge density and partial density of states were calculated using quantum chemistry calculation method to explain their inhibition mechanism. Results The results of polarization measurement showed that the inhibition efficiency of benzotriazole was higher than that of triazole at all concentrations. The relationship of concentration and coverage of the two inhibitors accorded with the Langmuir adsorption isotherm, and their adsorption free energy was in range of -35~-37 kJ/mol. The absolute value of ad-sorption energy of benzotriazole (top -4. 41eV, bridge -4. 36 eV) was larger than that of triazole (3. 28 eV). Obvious charge transfer occurred in the adsorption process, and the electron atmosphere distributed between the two bonding atoms. In addition, the s,p orbits of N atoms and the d orbit of Cu atoms overlapped during the adsorption process. Both of the neutral and protonated forms of the two inhibitors could parallelly adsorb onto Cu surface. Conclusion The inhibition performance of benzotriazole was bet-ter than that of triazole, which was due to the higher adsorptivity of benzotriazole compared to that of triazole. Both chemical ad-sorption and physical adsorption existed in the interaction of the inhibitors and the Cu surface, and the chemical adsorption of in-hibitors on Cu surface was attributed to the covalent bond between N and Cu atoms, and the bonding interaction was due to atomic orbits hybridization, while the physical adsorption between

  10. Photodegradation of 2-mercaptobenzothiazole and 1,2,3-benzotriazole corrosion inhibitors in aqueous solutions and organic solvents.

    Science.gov (United States)

    Serdechnova, Maria; Ivanov, Vladimir L; Domingues, M Rosario M; Evtuguin, Dmitry V; Ferreira, Mario G S; Zheludkevich, Mikhail L

    2014-12-07

    The photochemical degradation of 2-mercaptobenzothiazole (MBT) and 1,2,3-benzotriazole (BTA) inhibitors was studied in the present work in aqueous and in organic solutions. The extent of photodegradation was assessed by UV-Vis spectroscopy and the main reaction products were identified by tandem electrospray ionization mass spectrometry (ESI-MS/MS). The analysis of degradation products upon UV irradiation revealed the predominant formation of dimeric compounds from MBT and oligomeric structures from BTA, which were further converted into aniline. The increase of the quantum yield of MBT and BTA photodegradation reactions under aerobic conditions both in aqueous and organic solvents was explained by an increase of the spin-orbit conversion of the singlet radical pairs into the triplet radical pairs in the presence of oxygen. These triplet pairs further dissociate into free radicals, or convert to the parent compounds. At the early stage of UV irradiation, free radical coupling leads essentially to dimer formation in the case of MBT and to the formation of oligomers in the case of BTA irradiation.

  11. Corrosion protection of hydrotalcite nanocontainer loaded with zinc/molybdate corrosion inhibitor%装载锌/钼酸盐缓蚀剂的水滑石纳米容器的防腐性能

    Institute of Scientific and Technical Information of China (English)

    于湘; 俞志东; 程丽华; 潘奇

    2013-01-01

    A MoO2-4 pillared Zn/A1 nano-hydrotalcite (Zn/A1-MoO2-4) was prepared with hydrotalcite as a nano-container to load Zn2+ and MoO2-4 corrosion inhibitors, and then characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), inductively coupled plasma (ICP), and N2 adsorption-desorption isotherm, respectively. The anticorrosion effect of the nano-container on AZ31 magnesium alloy was studied by potentiodynamic polarization curve (LP) and electrochemical impedance spectroscopy (EIS). The results showed that the synthesized Zn/A1-MoO2-4 hydrotalcite nano-container has good lamellar structure and is well-crystallized with a particle size of 80 nm, 0.762 nm interlayer spacing, and a most probable pore diameter of 38 nm, implying a mesoporous material. It has good ion-exchange performance as shown by different degrees of ion-exchange based on concentration difference of C1-. The epoxy coating on AZ31 magnesium alloy which contains the Zn/A1- MoO2-4 hydrotalcite nano-container as pigment maintains good corrosion resistance after immersion in 3.5wt% NaC1 solution for 70 d.%以水滑石作为储存缓蚀剂Zn2+、MoO2-的纳米容器,制备了MoO42-柱撑Zr/A1纳米水滑石(Zn/A1-MoO42-).利用X射线衍射仪(XRD)、透射电子显微镜(TEM)、等离子体电感耦合光谱仪(ICP)和N2吸附脱附等温线对样品进行表征,采用动电位极化曲线(LP)和电化学阻抗谱(EIS)测试该纳米容器对AZ31镁合金的腐蚀防护效果.结果表明,所合成的Zn/Al-MoO42-水滑石纳米容器具有完整的层状结构,结晶良好,粒径尺寸在80 nm左右,层板间距0.762 nm,最可几孔径为38 nm,为介孔材料,而且它可根据Cl-的浓度差异发生不同程度的离子交换,具有良好的离子交换性能.将其作为颜料添加到环氧树脂中,并于镁合金表面固化成膜,所得的环氧涂层体系在质量分数为3.5%的NaCl溶液中浸泡70 d后,仍具有较好的耐腐蚀性能.

  12. Corrosion-resistant metallic coatings

    Directory of Open Access Journals (Sweden)

    F. Presuel-Moreno

    2008-10-01

    Full Text Available We describe recent computational and experimental studies on the corrosion properties of metallic coatings that can be tailored (tuned to deliver up to three corrosion-inhibiting functions to an underlying substrate. Attributes are tuned by a selection of alloy compositions and nanostructures, ideally in alloy systems that offer flexibility of choice to optimize the corrosion-resisting properties. An amorphous Al-based coating is tuned for corrosion protection by on-demand release of ionic inhibitors to protect defects in the coating, by formation of an optimized barrier to local corrosion in Cl− containing environments, as well as by sacrificial cathodic prevention. Further progress in this field could lead to the design of the next generation of adaptive or tunable coatings that inhibit corrosion of underlying substrates.

  13. Molecular dynamics and quantum chemical calculation studies on 4,4-dimethyl-3-thiosemicarbazide as corrosion inhibitor in 2.5 M H{sub 2}SO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Musa, Ahmed Y., E-mail: ahmed.musa@ymail.com [Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor (Malaysia); Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Takriff, Mohd Sobri [Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor (Malaysia)

    2011-09-15

    Highlights: {yields} This work deals with a study of chemical additives for corrosion inhibition of mild steel in acidic conditions. {yields} The effects of the additive 4,4-dimethyl-3-thiosemicarbazide (DTS) on mild steel were studied by means of electrochemical techniques. {yields} Quantum chemical calculations and molecular dynamic model were performed to characterize the inhibition mechanism. {yields} The calculations provided information that helps in the analysis/interpretation of the experimental work. - Abstract: The inhibition of mild steel corrosion in a 2.5 M H{sub 2}SO{sub 4} solution by 4,4-dimethyl-3-thiosemicarbazide (DTS) was studied at 30 deg. C using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Quantum chemical parameters were calculated for DTS using PM3-SCF method. The molecular dynamic method was performed to simulate the adsorption of the DTS molecules on Fe surface. Results showed that DTS performed excellent as inhibitor for mild steel corrosion in a 2.5 M H{sub 2}SO{sub 4} solution and indicated that the inhibition efficiencies increase with the concentration of inhibitor. Theoretical results indicated that DTS could adsorb on the mild steel surface firmly through heteroatoms.

  14. Propanoyl(1Z-N-(2,6-dimethylphenyl-2-oxopropanehydrazonoate as inhibitor for corrosion of 6061 Al alloy15 % (v SiC(p composite in hydrochloric acid media

    Directory of Open Access Journals (Sweden)

    Achutha Kini U

    2012-10-01

    Full Text Available ABSTRACT: The corrosion inhibition effect of Propanoyl(1Z-N-(2,6-dimethylphenyl-2-oxopropanehydrazonoate (PDOH in the corrosion of 6061 Aluminium alloy-15%(v SiC(p composite in 0.5 and 1M hydrochloric acid medium at four different temperatures (30, 40, 50 and 60 ⁰C was investigated using potentio-static polarization (Tafel extrapolation and Linear polarization and weight loss methods. The results obtained reveal that PDOH is an efficient corrosion inhibitor with around 96% inhibition efficiency within the range of temperature studied. Leftward and downward shifts in Tafel plots were observed with the addition of the inhibitor, indicating that PDOH inhibits the corrosion process effectively, and that it is a cathodic inhibitor. Corrosion rate increases and inhibition efficiency decreases with increase in temperature. Results obtained by Tafel extrapolation, linear polarization, and weight loss methods are in agreement. The adsorption of the inhibitor onto the surface of the 6061 Al alloy 15 % (v SiC(p composite is found to obey Temkins' adsorption isotherm that verifies the assumption of mono-layer adsorption on a uniform homogeneous composite surface with an interaction in the adsorption layer. The inhibition is therefore governed by the physisorption mechanism.ABSTRAK: Kesan perencatan kakisan Propanoyl(1Z-N-(2,6-dimethylphenyl-2-oxopropanehydrazonoate (PDOH ke atas kakisan komposit aloi Al 6061-15%(v SiC(p dalam media asid hidroklorik 0.5 dan 1M pada suhu-suhu yang berbeza (30, 40, 50 dan 60⁰C telah dikaji menggunakan polarisasi statik-upaya (extrapolarisasi Tafel dan polarisasi Linear dan kaedah kehilangan berat. Keputusan diperolehi menunjukkan PDOH adalah perencat yang efisien dengan 96 % keupayaan perencatan bagi julat suhu yag dikaji. Anjakan ke kiri dan ke bawah plot Tafel dapat dilihat dengan penambahan perencat, menunjukkan PDOH merencatkan proses kakisan dengan berkesan, dan ia adalah perencat katodik. Dengan peningkatan suhu

  15. Research Progress on Natural Products as Corrosion Inhibitor in Acid, Neutral and Alkaline Mediums%酸性、中性、碱性介质中植物型缓蚀剂的研究进展

    Institute of Scientific and Technical Information of China (English)

    郑杰; 王亚娜; 章柏林; 杨婷; 焦学敏; 何勇

    2011-01-01

    Plant extracts have become important as an environmentally acceptable, readily available and renewable source for wide range of inhibitors. In general, the plant extracts are of inhibitors with high inhibition efficiency and of non toxicant. This article summarizes the reaction mechanism and gives a vivid account of natural products which are used as corrosion inhibitors in acid, neutral and alkaline mediums. The prospects of the development trend are also discussed.%植物型缓蚀剂具有成本低,来源广,无毒,高效等特点,是未来缓蚀剂的发展方向.本文概括介绍了植物型缓蚀剂的作用机理,总结了植物型缓蚀剂在酸性、中性和碱性介质中的研究进展,并对今后的研究提出了展望.

  16. Evaluation of Iron Nickel Oxide Nanopowder as Corrosion Inhibitor: Effect of Metallic Cations on Carbon Steel in Aqueous NaCl

    Energy Technology Data Exchange (ETDEWEB)

    Chaudhry, A. U.; Mishra, Brajendra [Colorado School of Mines, Denver (United States); Mittal, Vikas [The Petroleum Institute, Abu Dhabi (United Arab Emirates)

    2016-01-15

    The aim of this study was to evaluate the use of iron-nickel oxide (Fe{sub 2}O{sub 3}.NiO) nanopowder (FeNi) as an anti-corrosion pigment for a different application. The corrosion protection ability and the mechanism involved was determined using aqueous solution of FeNi prepared in a corrosive solution containing 3.5 wt.% NaCl. Anti-corrosion abilities of aqueous solution were determined using electrochemical impedance spectroscopy (EIS) on line pipe steel (API 5L X-80). The protection mechanism involved the adsorption of metallic cations on the steel surface forming a protective film. Analysis of EIS spectra revealed that corrosion inhibition occurred at low concentration, whereas higher concentration of aqueous solution produced induction behavior.

  17. pH Responsive Microcapsules for Corrosion Control

    Science.gov (United States)

    Calle, Luz Marina; Li, Wenyan; Muehlberg, Aaron; Boraas, Samuel; Webster, Dean; JohnstonGelling, Victoria; Croll, Stuart; Taylor, S Ray; Contu, Francesco

    2008-01-01

    The best coatings for corrosion protection provide not only barriers to the environment, but also a controlled release of a corrosion inhibitor, as demanded by the presence of corrosion or mechanical damage. NASA has developed pH sensitive microcapsules (patent pending) that can release their core contents when corrosion starts. The objectives of the research presented here were to encapsulate non-toxic corrosion inhibitors, to incorporate the encapsulated inhibitors into paint formulations, and to test the ability of the paints to control corrosion. Results showed that the encapsulated corrosion inhibitors, specifically Ce(NO3)3 , are effective to control corrosion over long periods of time when incorporated at relatively high pigment volume concentrations into a paint formulation.

  18. The effects of addition of poly(vinyl) alcohol (PVA) as a green corrosion inhibitor to the phosphate conversion coating on the anticorrosion and adhesion properties of the epoxy coating on the steel substrate

    Energy Technology Data Exchange (ETDEWEB)

    Ramezanzadeh, B., E-mail: ramezanzadeh-bh@icrc.ac.ir; Vakili, H.; Amini, R.

    2015-02-01

    Highlights: • Room temperature zinc phosphate coating was applied on the surface of steel sample. • Poly(vinyl) alcohol was added to the phosphating bath as a green corrosion inhibitor. • The adhesion and anticorrosion properties of the epoxy coating were investigated. • PVA decreased the phosphate crystal size and porosity. • PVA enhanced the corrosion protection and adhesion properties of the epoxy coating. - Abstract: Steel substrates were chemically treated by room temperature zinc phosphate conversion coating. Poly(vinyl) alcohol (PVA) was added to the phosphate solution as a green corrosion inhibitor. Finally, the epoxy/polyamide coating was applied on the untreated and surface treated steel samples. The effects of PVA on the morphological properties of the phosphate coating were studied by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and contact angle measuring device. The adhesion properties of the epoxy coatings applied on the surface treated samples were investigated by pull-off and cathodic delamination tests. Also, the anticorrosion properties of the epoxy coatings were studied by electrochemical impedance spectroscopy (EIS). Results showed that addition of PVA to the phosphate coating increased the population density of the phosphate crystals and decreased the phosphate grain size. The contact angle of the steel surface treated by Zn-PVA was lower than Zn treated one. The corrosion resistance of the epoxy coating was considerably increased on the steel substrate treated by zinc phosphate conversion coating containing PVA. PVA also enhanced the adhesion properties of the epoxy coating to the steel surface and decreased the cathodic delamination significantly.

  19. Performance research of TH-607 Ⅱ corrosion and scale inhibitor used in oilfield produced water treatment%TH-607 Ⅱ油田水处理用缓蚀阻垢剂的性能研究

    Institute of Scientific and Technical Information of China (English)

    贺茂才; 孙群峰; 齐晓婧; 刘强

    2012-01-01

    考察了TH-607Ⅱ油田水处理用缓蚀阻垢剂的阻垢缓蚀性能.结果表明,TH-607Ⅱ对CaCO3、CaSO4、BaSO4垢的阻垢率分别为95.65%,97.87%,92.99%,腐蚀速率为0.0551 mm/a,符合Q/SY 126-2007标准要求,特别是对BaSO4垢的阻垢效果极佳,可用作油田注水系统、工业循环冷却水系统的阻垢分散剂,尤其适用作Ba2+、Sr2+离子稳定剂.%Study on the scale and corrosion inhibition performance of TH-607 II oifield water treatment corrosion and scale inhibitors. The results showed that the scale inhibition rate of TH-607 II for CaCO3, CaSO4 ,BaS04 is 95. 65% ,97. 87% ,92. 99% . The corrosion rate is 0.055 1 mm/a. It meets Q/SY 126-2007 corrosion and scale inhibitor for oilfield produced water treatment standard. Especially for barium sulfate, it has good scale inhibition effect. TH-607 II can be used in oilfield water injection system and industrial circulating cool system. TH-607 II can effectively stabilize Ba2 + and Sr2 + in water system.

  20. 缓蚀剂铜膜对13Cr不锈钢在残酸试验中腐蚀程度的影响%Effect of Corrosion Inhibitor Copper Film on the Corrosion Degree of13Cr Stainless Steel in Residual Acid Experiment

    Institute of Scientific and Technical Information of China (English)

    耿海龙; 杜金楠; 王茜; 杨春玉; 杨双宝

    2016-01-01

    In this paper, the effect of the corrosion inhibitor film on the corrosion degree of the surface of the 13Cr specimen in the residual acid test was studied. SEM and EDS analysis results showed that the corrosion resistance of the surface of the samples after fresh acid test was made of copper iflm; The results of corrosion evaluation tests showed that: the corrosion rate of samples with copper iflm was 200 times that of no copper iflms, the corrosion rate was decreased a third when the copper iflms were removed by ultrasonic cleaning; The electric potential of copper iflm and 13Cr under different pH values showed that the corrosion resistance of the copper film was the main reason for accelerating corrosion of 13Cr samples in the residual acid test.%本文主要研究了13Cr试样在鲜酸腐蚀过程中表面形成的缓蚀剂保护膜对该试样在后期残酸试验中腐蚀程度的影响。SEM、EDS分析结果表明:鲜酸试验后试样表面覆盖的缓蚀剂保护膜为铜膜;腐蚀评价试验结果表明:在残酸试验中,表面有铜膜附着的试样,其腐蚀速率是无铜膜试样的200倍,残酸试验前将试样表面的铜膜经超声清洗去除后,其腐蚀速率下降了1/3;不同pH值条件下铜膜与13Cr的电位测量结果表明:缓蚀剂铜膜的存在是13Cr试样在残酸试验中腐蚀加速的主要原因。

  1. Indeno-1-one [2,3-b]quinoxaline as an effective inhibitor for the corrosion of mild steel in 0.5 M H{sub 2}SO{sub 4} solution

    Energy Technology Data Exchange (ETDEWEB)

    Obot, I.B., E-mail: proffoime@yahoo.com [Department of Chemistry, Faculty of Science, University of Uyo, P.M.B. 1017, Uyo, Akwa Ibom State (Nigeria); Obi-Egbedi, N.O. [Department of Chemistry, University of Ibadan, Ibadan (Nigeria)

    2010-08-01

    Indeno-1-one [2,3-b] quinoxaline (INQUI), synthesized in our laboratory, was tested as inhibitor for the corrosion of mild steel in 0.5 M H{sub 2}SO{sub 4} using gravimetric method at 30 {sup o}C. The inhibitor (INQUI) showed about 81% inhibition efficiency (E (%)) at an optimum concentration of 10 x 10{sup -6} M. The inhibition efficiency increases with increase in inhibitor concentration but decreases with increase in immersion time. The adsorption of the inhibitor on the mild steel in the acid solution was found to accord with Temkin's adsorption isotherm. The calculated value of the free energy for the adsorption process, {Delta}G{sub ads}, reveals a strong chemisorbed bond between the inhibitor and mild steel surface and a spontaneous adsorption of the inhibitor on the mild steel surface. Density functional theory (DFT) proves that INQUI molecule is adsorbed on the mild steel surface by the most negatively charged nitrogen and oxygen atoms.

  2. Review Applications to Prevent Corrosion Reducing Gas Pipe Line

    Directory of Open Access Journals (Sweden)

    Mehrdad Setoudeh

    2012-10-01

    Full Text Available Corrosion is one of the major problems in the oil and gas industry is one that automatically allocates huge sums annually. Including ways to reduce corrosion of corrosion inhibitors is. Inhibiting substance that low amount is added to the system to slow or stop the chemical reaction does. When inhibitors of corrosion medium are added, the speed of corrosion decreases to zero takes. For the first time a deterrent mineral called arsenate sodium for inhibition steels carbon in oil wells was used to corrosion of CO2 prevented, but due to low yield was not satisfactory and therefore the other inhibitors were used. In the years 1945 to 1950 properties, excellent composition polar chain long was discovered. The discovery process of experiments related to organic inhibitors used in wells and pipes and oil Garza changed. This article examines the use of inhibitors to reduce corrosion in gas wells deals.

  3. 一种油田注水缓蚀剂的合成与性能评价%Synthesis of a New Water Injection Corrosion Inhibitor for Oilfield and Its Performance Evaluation

    Institute of Scientific and Technical Information of China (English)

    麻路; 陈维; 廖军帅; 徐波

    2012-01-01

    The oilfield water injection corrosion inhibitor was synthesized by reacting different long-chain fatty acids with tetraethylenepentamine, and the optimal synthetic conditions were obtained using orthogonal experiment method. Static coupon weight loss method was adopted to evaluate the inhibitor performance and the effects of the temperature and concentration on the performance were studied. The results showed that the corrosion inhibitor had good performance at the conditions of concentration as 800 mg/L and relatively low temperature.%以不同长链脂肪酸、四乙烯五胺为原料合成油田注水缓蚀荆,通过正交试验筛选了最优合成条件。采用静态挂片法评价了产品的缓蚀性能,并考察了用量、温度对其缓蚀性能的影响。结果表明,试验条件下此类缓释剂在用量800mg/L、相对低温的条件下缓蚀效果较好。

  4. 铜抛光液中缓蚀剂5-氨基四唑(ATA)的作用机制研究%Investigation on the Mechanisms of Corrosion Inhibitor 5-aminotetrazole Used in the Copper Chemical Mechanical Polishing

    Institute of Scientific and Technical Information of China (English)

    刘宇宏; 董莹; 戴媛静; 雒建斌

    2012-01-01

    The influences of inhibitors ( benzotriazole( BTA)and 5-aminotetrazole( ATA) )in slurry with varying pH values on the chemical mechanical polishing( CMP) of copper were studied by the methods of the static corrosion, contact angle and X-ray photoelectron spectroscopy(XPS) ,and the effective mechanisms of ATA on copper surface were discussed. The results show that BTA and ATA are excellent copper corrosion inhibitors. In the range of pH values 3 - 10, the inhibitors form the passivity films and protect the copper surface from chemical attack, resulting in the decrease of the removal rates of copper and static corrosion rates,especially in the optimum condition of pH =4. ATA has better inhibition effect for copper corrosion than BTA in the range of pH =3 ~5, because ATA molecule can be preferentially adsorbed on copper surface by nitrogen atoms of amidogen and azole to form the protect films, resulting in the inhibition of the oxide formation from hydrogen peroxide and the improvement of the surface quality. In conclusion, ATA is one of the best inhibitors suitable for acid slurry of copper CMP.%采用静态腐蚀实验、接触角测试、XPS等手段,比较在不同pH值下抛光液中缓蚀剂(5-氨基四唑(ATA),苯并三唑(BTA))对铜表面化学机械抛光(CMP)的影响,并探讨ATA在铜表面的作用机制.结果表明,BTA和ATA是优良的铜缓蚀剂,当pH值为3~10时,两者可在铜表面成膜,保护铜表面不受腐蚀,从而降低铜片的静态腐蚀速率和去除率,其中当pH =4时,2种缓蚀剂表现出最佳的缓蚀性能.当pH值为3~5时,ATA的缓蚀性能优于BTA.ATA通过四唑环上的N原子和氨基上的N原子吸附在铜表面,形成保护膜,从而抑制了H2O2对铜表面的腐蚀,改善了表面质量,是一种优良的适用于酸性铜抛光液的缓蚀剂.

  5. Sodium excretion following central administration of an I1 imidazoline receptor agonist, moxonidine.

    Science.gov (United States)

    Penner, S. B.; Smyth, D. D.

    1994-01-01

    1. Previously we have shown that an intrarenal infusion of moxonidine, an I1-imidazoline receptor agonist, resulted in a natriuresis which was inhibited by intravenous idazoxan, a selective imidazoline receptor antagonist. Therefore we examined the effects of renal function of intracerebroventricular (i.c.v.) administration of moxonidine with or without i.c.v. idazoxan. 2. Seven days after unilateral nephrectomy, Sprague-Dawley rats had i.c.v. cannulae implanted. Three days later the rats were anaesthetized (pentobarbitone), followed by cannulation of the jugular vein (fluid and drug administration), carotid artery (blood pressure) and the ureter (urine collection). 3. After a 45 min stabilization period, the effect of moxonidine was investigated by the i.c.v. administration of either isotonic saline or moxonidine (0.1, 0.3 or 1 nmol in isotonic saline) administered in 5 microliters over 1 min. All doses of moxonidine resulted in an increase in urine flow with a concomitant increase in sodium excretion without affecting blood pressure. The highest dose of moxonidine (1 nmol) also increased free water clearance. 4. In a second series of experiments, the effects of idazoxan on the natriuretic response to i.c.v. moxonidine were determined. Moxonidine (0.3 nmol) again increased sodium and water excretion as compared to the i.c.v. saline control animals. Pretreatment with i.c.v. idazoxan (0.3 nmol), at a dose which alone failed to alter sodium and water excretion, completely attenuated the renal response to moxonidine. These results are consistent with central I1-imidazoline receptors mediating a moxonidine-induced increase in sodium and water excretion at doses that do not alter blood pressure. PMID:7952868

  6. Assembly of PRR-containing receptors on scaffolds: a model for imidazoline I(1)-receptor action.

    Science.gov (United States)

    Musgrave, I F; Dehle, F C; Piletz, J

    2003-12-01

    IRAS, a putative clone of the I(1)-imidazoline receptor, possesses a proline-rich region (PRR) motif, which might interact with SH3 regions on tyrosine kinases, and an integrin-binding motif. Receptors with a PRR motif can generally assemble onto multi-element signaling complexes (eg., the beta(3)-receptor on the EGF receptor) and thereby modulate signal transduction. Integrins serve as scaffolds for multi-element signaling complexes, similar to that assembled with the EGF receptor. It is therefore possible that IRAS signals through a complex with other receptors.

  7. Influence of alkyl group of imidazolinyl-quaternary-ammonium-salt on corrosion inhibition efficiency

    Institute of Scientific and Technical Information of China (English)

    SHI Shun-cun; WANG Xue-ye; YI Ping-gui; CAO Chen-zhong; DENG Tong-tong; SU Jie-shu

    2006-01-01

    The action between imidazolinyl-quaternary-ammonium-salt(IQAS) molecule and Fe atom was studied,and the influence of the alkyl group connected with N atom of imidazoline ring on corrosion inhibition efficiency was explored. Quantum chemical methods, HF/6- 31 G and HF/Lan L2 dz, were applied successively to calculate the parameters such as front molecular orbit energy of IQAS Ⅰ-Ⅳ and chemical adsorption for IQAS Ⅰ-Ⅳ and Fe atom.The corrosion inhibition efficiency was measured with the weight loss method of carbon steel samples in acidic solution and oil field sewage. Based on the theoretical analyses and experimental results, it is concluded that N-Fe coordination bond is formed between IQAS molecule and Fe atom, corrosion inhibition efficiency is decreased in the following order(from large to small): IQAS Ⅳ, IQAS Ⅲ, IQAS Ⅱ , IQAS Ⅰ.

  8. Research Progress of Inhibition Mechanism of Benzotriazole as Corrosion Inhibitor of Copper%铜缓蚀剂苯并三氮唑缓蚀机理的研究进展

    Institute of Scientific and Technical Information of China (English)

    谢文州; 郦和生; 李志林; 杨玉

    2013-01-01

    A review was provided of the research progress of the inhibition mechanism of benzotriazole (BTA) as corrosion inhibitor for copper. The surface structure and composition as well as the corrosion inhibition type of protective films of BTA formed in acidic medium, nearly neutral medium and alkaline medium were highlighted. It was pointed out that BTA functioned to prevent Cu from corrosion by forming protective films on Cu surface. The formation of BTA protective films was affected by oxygen, anodic polarization, BTA concentration and pH value, while elevating BTA concentration and pH value favored the formation of the BTA protective films.%综述了数十年来苯并三氮唑(BTA)对铜缓蚀机理的研究成果,重点介绍了酸性、近中性、碱性及含氯介质中BTA所形成缓蚀膜的结构与组成、缓蚀作用类型:BTA通过在铜表面形成一层保护膜而抑制铜腐蚀,缓蚀膜的形成受到氧气、阳极极化、BTA浓度和pH值的影响,高BTA浓度及高pH值均有利于缓蚀膜的形成.

  9. Titanium corrosion in alkaline hydrogen peroxide environments

    Science.gov (United States)

    Been, Jantje

    1998-12-01

    The corrosion of Grade 2 titanium in alkaline hydrogen peroxide environments has been studied by weight loss corrosion tests, electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR) measurements and potentiodynamic polarography. Calcium ions and wood pulp were investigated as corrosion inhibitors. In alkaline peroxide, the titanium corrosion rate increased with increasing pH, temperature, and hydrogen peroxide concentration. The corrosion controlling mechanism is thought to be the reaction of the oxide with the perhydroxyl ion. No evidence of thermodynamically stable calcium titanate was found in the surface film of test coupons exposed to calcium-inhibited alkaline peroxide solutions. Calcium inhibition is probably the result of low local alkali and peroxide concentrations at the metal surface produced by reaction of adsorbed calcium with hydrogen peroxide. It has been shown that the inhibiting effect of calcium is temporary, possibly through an effect of calcium on the chemical and/or physical stability of the surface oxide. Pulp is an effective and stable corrosion inhibitor. Raising the pulp concentration decreased the corrosion rate. The inhibiting effect of pulp may be related to the adsorption and interaction of the pulp fibers with H 2O2, thereby decreasing the peroxide concentration and rendering the solution less corrosive. The presence of both pulp and calcium led to higher corrosion rates than obtained by either one inhibitor alone. Replacement of hydrofluoric acid with alkaline peroxide for pickling of titanium was investigated. Titanium corrosion rates in alkaline peroxide exceeded those obtained in the conventional hydrofluoric acid bath. General corrosion was observed with extensive roughening of the surface giving a dull gray appearance. Preferred dissolution of certain crystallographic planes was investigated through the corrosion of a titanium single crystal. Whereas the overall effect on the corrosion rate was small

  10. Effect of moxonidine on contractile activity of isolated large intestine in mice: role of alpha2-adrenoceptors and Ii-imidazoline receptors.

    Science.gov (United States)

    Kozaeva, L P; Korobov, N V; Medvedev, O S

    2004-03-01

    We studied the ability of moxonidine to interact with alpha2-adrenoceptors and Ii-imidazoline receptors in isolated mouse large intestine. Moxonidine caused contractions of longitudinal muscles in the large intestine, which depended on the dose of this preparation. Pretreatment with yohimbine (alpha2-adrenoceptor antagonist with low affinity for Ii-imidazoline receptors) and efaroxan (Ii-imidazoline receptor antagonist with low affinity for alpha2-adrenoceptors) abolished the effect of moxonidine. Antagonistic activity and relative selectivity of yohimbine and efaroxan suggest that the effects of moxonidine on mouse large intestine are realized via alpha2-adrenoceptors.

  11. Recent Developments on Autonomous Corrosion Protection Through Encapsulation

    Science.gov (United States)

    Li, W.; Buhrow, J. W.; Calle, L. M.; Gillis, M.; Blanton, M.; Hanna, J.; Rawlins, J.

    2015-01-01

    This paper concerns recent progress in the development of a multifunctional smart coating, based on microencapsulation, for the autonomous detection and control of corrosion. Microencapsulation has been validated and optimized to incorporate desired corrosion control functionalities, such as early corrosion detection and inhibition, through corrosion-initiated release of corrosion indicators and inhibitors, as well as self-healing agent release triggered by mechanical damage. While proof-of-concept results have been previously reported, more recent research and development efforts have concentrated on improving coating compatibility and synthesis procedure scalability, with a targeted goal of obtaining easily dispersible pigment-grade type microencapsulated materials. The recent progress has resulted in the development of pH-sensitive microparticles as a corrosion-triggered delivery system for corrosion indicators and inhibitors. The synthesis and early corrosion indication results obtained with coating formulations that incorporate these microparticles are reported. The early corrosion indicating results were obtained with color changing and with fluorescent indicators.

  12. Controlled-Release Microcapsules for Smart Coatings for Corrosion Applications

    Science.gov (United States)

    2008-01-01

    Corrosion is a serious problem that has enormous costs and serious safety implications. Localized corrosion, such as pitting, is very dangerous and can cause catastrophic failures. The NASA Corrosion Technology Laboratory at Kennedy Space Center is developing a smart coating based on pH-sensitive microcapsules for corrosion applications. These versatile microcapsules are designed to be incorporated into a smart coating and deliver their core content when corrosion starts. Corrosion indication was the first function incorporated into the microcapsules. Current efforts are focused on incorporating the corrosion inhibition function through the encapsulation of corrosion inhibitors into water core and oil core microcapsules. Scanning electron microscopy (SEM) images of encapsulated corrosion inhibitors are shown.

  13. Effect of Sodium Molybdate Inhibitor on Corrosion Resistance of 5083 Aluminum Alloy Used for Drone%钼酸钠对靶用5083铝合金耐蚀性能影响的研究

    Institute of Scientific and Technical Information of China (English)

    杨志成; 周宽; 田志强

    2016-01-01

    目的:提高靶用5083铝合金材料的耐蚀性。方法分别运用阳极极化、交流阻抗及EDS等试验技术研究钼酸钠对5083铝合金在3%氯化钠溶液中的耐蚀性能影响。结果钼酸钠加入3%氯化钠溶液以后,该铝合金的腐蚀电位下降,点蚀电位与腐蚀电位分离,维钝电流减小,阻抗值增大,抗点蚀能力提高。结论钼酸钠对5083铝合金产生缓蚀作用。%Objective To improve the corrosion resistance of 5083 aluminum alloy used for drone.Methods The polariza-tion, electrochemical impedance spectrum and energy dispersive spectrometer were employed to study the effect of sodium mo-lybdate inhibitor on the corrosion resistance of 5083 aluminum alloy in 3% NaCl solution.Results After addition of sodium molybdate in the 3% NaCl solution, the corrosion potential was decreased and separated from the pitting potential, the passi-vated current was reduced, the impedance was increased, and the capability of inhibiting pitting was promoted.Conclusion So-dium molybdate had corrosion inhibition effect on 5083 aluminum alloy.

  14. 77 FR 73294 - Requirements for Child-Resistant Packaging: Products Containing Imidazolines Equivalent to 0.08...

    Science.gov (United States)

    2012-12-10

    ... these products. This issue is discussed further in Section VI of the preamble. Packaging Issues Comment... COMMISSION 16 CFR Part 1700 Requirements for Child-Resistant Packaging: Products Containing Imidazolines...-resistant (CR) packaging for any over-the-counter or prescription product containing the equivalent of...

  15. An efficient solvent-free synthesis of imidazolines and benzimidazoles using K 4[Fe(CN 6] catalysis

    Directory of Open Access Journals (Sweden)

    Kabeer A. Shaikh

    2012-01-01

    Full Text Available Imidazolines and Benzimidazoles have been efficiently synthesized in high yields by treatment of 1,2-diamine with aldehydes using the metal co-ordinate complex K 4[Fe(CN 6] as a catalysis. The method was carried out under solvent free condition via oxidation of carbon-nitrogen bond. The process is green, mild and inexpensive.

  16. Corrosion protection

    Science.gov (United States)

    Brown, Donald W.; Wagh, Arun S.

    2003-05-27

    There has been invented a chemically bonded phosphate corrosion protection material and process for application of the corrosion protection material for corrosion prevention. A slurry of iron oxide and phosphoric acid is used to contact a warm surface of iron, steel or other metal to be treated. In the presence of ferrous ions from the iron, steel or other metal, the slurry reacts to form iron phosphates which form grains chemically bonded onto the surface of the steel.

  17. SOMC-Designed Silica Supported Tungsten Oxo Imidazolin-2-iminato Methyl Precatalyst for Olefin Metathesis Reactions

    KAUST Repository

    Qureshi, Ziyauddin S.

    2017-01-05

    Synthesis, structure, and olefin metathesis activity of a surface complex [(≡Si-O-)W(═O)(CH3)2-ImDippN] (4) (ImDipp = 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-iminato) supported on silica by a surface organometallic chemistry (SOMC) approach are reported. The reaction of N-silylated 2-iminoimidazoline with tungsten(VI) oxytetrachloride generated the tungsten oxo imidazolin-2-iminato chloride complex [ImDippNW(═O)Cl3] (2). This was grafted on partially dehydroxylated silica pretreated at 700 °C (SiO2-700) to afford a well-defined monopodal surface complex [(≡Si-O-)W(═O)Cl2-ImDippN] (3). 3 underwent alkylation by ZnMe2 to produce [(≡Si-O-)W(═O)(CH3)2-ImDippN] (4). The alkylated surface complex was thoroughly characterized by solid-state NMR, elemental microanalysis, Raman, FT-IR spectroscopies, and XAS analysis. 4 proved to be an active precatalyst for self-metathesis of terminal olefins such as propylene and 1-hexene.

  18. Predictive Models for the Determination of Pitting Corrosion Versus Inhibitor Concentrations and Temperature for Radioactive Sludge in Carbon Steel Waste Tanks

    Energy Technology Data Exchange (ETDEWEB)

    Mickalonis, J.I.

    1998-10-06

    Statistical models have been developed to predict the occurrence of pitting corrosion in carbon steel waste storage tanks exposed to radioactive nuclear waste. The levels of nitrite concentrations necessary to inhibit pitting at various temperatures and nitrate concentrations were experimentally determined via electrochemical polarization and coupon immersion corrosion tests. Models for the pitting behavior were developed based on various statistical analyses of the experimental data. Feed-forward Artificial Neural Network (ANN) models, trained using the Back-Propagation of Error Algorithm, more accurately predicted conditions at which pitting occurred than the logistic regression models developed using the same data.

  19. Synthesis and solid state structures of Chalcogenide compounds of Imidazolin-2-ylidene-1,1-Diphenyl-phosphinamine

    Indian Academy of Sciences (India)

    Naktode Kishor; Suman Das; Abhinanda Kundu; Hari Pada Nayek; Tarun K Panda

    2016-03-01

    We report the synthesis and solid state structures of 1,3-di-aryl-imidazolin-2-ylidine-1,1-diphenylphosphinamine [(aryl=mesityl (1a) and aryl=2,6-diisopripyl (1b)] and their chalcogenide compounds 3-di-aryl-imidazolin-2-ylidine-P, P-diphenylphosphinicamide (2a,b), 1,3-di-aryl-imidazolin-2-ylidine-P,P diphenyl-phosphinothioicamide (3a,b) and 1,3-diaryl-imidazolin-2-ylidine-P,P -diphenyl-phosphinoselenoicamide (4a,b).The compounds 1a,b were prepared in good yield by the reaction of 1,3-di-aryl-imidazolin-2-imine and chlorodiphenylphosphine in the presence of triethylamine in toluene. The reactions of 1a,b with elemental sulphur and selenium afforded the corresponding chalcogenide compounds 3a,b and 4a,b respectively.The corresponding oxo- derivative (2a,b) was obtained by reacting compound 1a,b with 30% aqueous hydrogen peroxide in THF. The molecular structures of 1a, 2a, 3a and 4a,b have been established by single crystal X-ray diffraction analyses. The molecular structures reveal that even C1–N1–P1 angle (124.62o) in compound 1a is less obtuse compared to the corresponding C1–N1–Si1 angles (157.8o) observed in related N-silylated 2-iminoimidazolines and trimethylsilyl iminophosphoranes. C1–N1–P1 angles are further widened in compounds 2a, 3a, and 4a,b due to the attachment of chalcogen atoms onto phosphorus atom.

  20. Are Alpha-2D Adrenoceptor Subtypes Involved in Rat Mydriasis Evoked by New Imidazoline Derivatives: Marsanidine and 7-Methylmarsanidine?

    Directory of Open Access Journals (Sweden)

    Joanna Raczak-Gutknecht

    2017-04-01

    Full Text Available The imidazoline compounds may produce mydriasis after systemic administration to some species (rats, cats, and mice. In mydriatic activity of imidazolines, α2D-adrenoceptors subtype(s seems to be involved. In this study, the pupil dilatory effect evoked by 2 newly synthesized imidazoline derivatives—α2-adrenoceptor agonists: marsanidine and 7-methylmarsanidine—was compared. The compounds were tested alone as well as in the presence of α2-adrenoceptor antagonists (nonselective, yohimbine, and selective toward the following α2-adrenoceptor subtypes—α2A-2-[(4,5-dihydro-1H-imidazol-2-ylmethyl]-2,3-dihydro-1-methyl-1H-isoindole maleate (BRL44408, α2B-2-[2-(4-(2-methoxyphenylpiperazin-1-ylethyl]-4,4-dimethyl-1,3-(2H,4H-isoquinolindione dihydrochloride (ARC239, α2C-JP1302, α2D-2-(2,3-dihydro-2-methoxy-1,4-benzodioxin-2-yl-4,5-dihydro-1H-imidazole hydrochloride [RX821002]. The agonists were studied in male Wistar rats and were administered intravenously in cumulative doses. The antagonistic compounds were given in a single dose before the experiment with marsanidine or 7-methylmarsanidine. Pupil diameter was measured with stereoscopic microscope equipped in green light filter. Marsanidine and 7-methylmarsanidine exerted marked mydriatic effects. BRL44408, JP1302, and ARC239 did not cause significant parallel shift to the right of the dose–effect curves obtained for both imidazolines. In case of yohimbine and RX821002, the marked parallel shifts of dose–response curves were observed, with the antagonistic effects of RX821002 more pronounced. In vivo pharmacodynamics experiment suggests that α2D-adrenoceptor subtype is mainly engaged in mydriatic effects evoked in rats by imidazoline derivatives, in particular by clonidine.

  1. EXTRACT OF COMBRETUM MICRANTHUM AS CORROSION ...

    African Journals Online (AJOL)

    user

    2016-10-04

    Oct 4, 2016 ... Aluminum and aluminum alloys lend themselves to many engineering ... Table 1: Elemental composition of the alloy Al-Si-Mg. Element. Si. Mg. Cu. Zn. Al. Composition (wt. ..... microstructure of the control Al- Si- Mg alloy with the lowest C.R in the ... silicate as a corrosion inhibitor for iron and zinc,. Corrosion ...

  2. Mydriasis model in rats as a simple system to evaluate α2-adrenergic activity of the imidazol(in)e compounds.

    Science.gov (United States)

    Raczak-Gutknecht, Joanna; Frąckowiak, Teresa; Nasal, Antoni; Kaliszan, Roman

    2013-01-01

    Imidazol(in)e compounds show the diversity of pharmacological effects including mydriasis, hypotension, sedation, bradycardia and hypothermia. At first it was postulated that these effects are mediated via α2-adrenoceptors exclusively. Clonidine is well known as a model agent to produce pupillary dilation in rats. However, it became obvious later that clonidine-like imidazol(in)e adrenoceptor agonists which produced mydriasis in rats, exhibit also a high affinity for imidazoline I1-receptors. That short report attempts to review the present status of studies to confirm that the mydriasis model in rats can be a selective system to evaluate the α2-adrenergic activity of potential pharmacologically active compounds of imidazol(in)e structure.

  3. Implication of Atmospheric Wetness Levels on Corrosion at a Coating Defect during Accelerated Testing

    Science.gov (United States)

    2012-08-28

    Outline • Objectives • Atmospheric corrosion • Testing Approach • Effect of RH on corrosion of steel • Effect of inhibitor addition on coated steel... inhibitor migration in the coating . For a given test method, wet and dry times will influence inhibitor mobility, and thus corrosion rate Continuous...Implication of Atmospheric Wetness Levels on Corrosion at a Coating Defect during Accelerated Testing James F. Dante Southwest Research Institute

  4. Corrosion Engineering.

    Science.gov (United States)

    White, Charles V.

    A description is provided for a Corrosion and Corrosion Control course offered in the Continuing Engineering Education Program at the General Motors Institute (GMI). GMI is a small cooperative engineering school of approximately 2,000 students who alternate between six-week periods of academic study and six weeks of related work experience in…

  5. Internal corrosion of carbon steel piping in hot aquifers service

    Directory of Open Access Journals (Sweden)

    Simičić Miloš V.

    2011-01-01

    Full Text Available Internal corrosion of carbon steel pipelines is a major problem encountered in water service. In terms of prediction of the remaining lifetime for water pipelines based on the corrosion allowance, the three main approaches are corrosion modelling, corrosion inhibitor availability, and corrosion monitoring. In this study we used two theoretical corrosion models, CASSANDRA and NORSOK M-506 of quite different origin in order to predict uniform corrosivity of hot aquifers in eight different pipelines. Because of the varying calculation criteria for the different models, these can give very different corrosion rate predictions for the same data input. This is especially true under conditions where the formation of protective films may occur, such as at elevated temperatures. The evaluation of models was conducted by comparison using weight-loss coupons and three corrosion inhibitors were obtained from commercial suppliers. The tests were performed during the 60-day period. Even though inhibitors’ efficiencies of 98% had been achieved in laboratory testing, inhibitors’ availabilities of 85% have been used due to logistics problems and other issues. The results, given in mmpy, i.e. millimeter per year, are very consistent with NORSOK M-506 prediction. This is presumably because the model considers the effect of the formation of a passive iron carbonate film at temperatures above 80 °C and significant reduction in corrosion rate. Corrosion inhibitor A showed a better performance than inhibitors B and C in all cases but the target corrosion rates of less than 0.1 mmpy were achieved for all inhibitors. The chemical type of corrosion inhibitor A is based on quaternary amines mixed with methanol, isopropyl alcohol, xylene and ethylbenzene. Based on the obtained results the carbon steel lifetime of 30 years, provided proper inhibitors are present and 3mm corrosion allowance, can be achieved for hot aquifers service with presented water compositions.

  6. Corrosion sensor

    Science.gov (United States)

    Glass, Robert S.; Clarke, Jr., Willis L.; Ciarlo, Dino R.

    1994-01-01

    A corrosion sensor array incorporating individual elements for measuring various elements and ions, such as chloride, sulfide, copper, hydrogen (pH), etc. and elements for evaluating the instantaneous corrosion properties of structural materials. The exact combination and number of elements measured or monitored would depend upon the environmental conditions and materials used which are subject to corrosive effects. Such a corrosion monitoring system embedded in or mounted on a structure exposed to the environment would serve as an early warning system for the onset of severe corrosion problems for the structure, thus providing a safety factor as well as economic factors. The sensor array is accessed to an electronics/computational system, which provides a means for data collection and analysis.

  7. 铜化学机械抛光中复合缓蚀剂的作用机制%Mechanisms of Mixed Corrosion Inhibitors in Copper Chemical Mechanical Polishing

    Institute of Scientific and Technical Information of China (English)

    龚桦; 王宁; 顾忠华; 潘国顺

    2013-01-01

    将复合缓蚀剂(苯并三氮唑(BTAH)和十二烷基磺酸钠(SDS))应用到铜的化学机械抛光液中,考察BTAH和SDS对铜表面化学机械抛光的影响,并探讨BTAH和SDS在铜表面的作用机制;分析BTAH和SDS抛光液中络合剂和表面活性剂对铜化学机械抛光性能的影响。结果表明:BTAH和SDS在铜表面形成了致密的Cu-BTAH和Cu-SDS保护膜,是优良的铜缓蚀剂。当以磷酸氢二胺(AHP)为络合剂,羟乙基纤维素(HEC)为表面活性剂时,优化后的BTAH和SDS抛光液取得了低至Ra0.2 nm的表面粗糙度,同时发现HEC有降低纳米颗粒残留的作用。%Mixed corrosion inhibitors(benzotriazole(BTAH)and sodium dodecyl sulfate(SDS))were utilized in copper chemical mechanical polishing(CMP)slurry.The influences of BTAH and SDS,complexing agent,and surfactant on the CMP of copper were studied,and the mechanisms of BTAH and SDS on copper surface were discussed.The results show that compact Cu-BTAH and Cu-SDS protective films are formed on the copper surface,and thus,which are excellent copper corrosion inhibitors.When using BTAH and SDS as mixed corrosion inhibitors,ammonium phosphate(AHP)as complexing agent,and hydroxy ethyl cellulose(HEC)as surfactant,a low surface roughness of 0.2 nm is got by this CMP slurry.The appearance of HEC in the slurry is found to be very effective in reducing the nano-sized particle deposition on copper surface.

  8. Compatibility of repair mortar with migrating corrosion inhibiting admixtures

    Energy Technology Data Exchange (ETDEWEB)

    Bjegovic, D.; Ukrainczyk, V. [Univ. of Zagreb (Croatia). Faculty of Civil Engineering; Ukrainczyk, B. [LGM, Zagreb (Croatia); Miksic, B. [CORTEC Corp., St. Paul, MN (United States)

    1997-08-01

    One of the methods for corrosion protection of reinforced concrete is the use of migrating corrosion inhibitor as an admixture in repair mortars. The admixture must be effective for corrosion protection and compatible with polymers added to repair mortar to improve properties of fresh and hardened mortar. This paper presents experimental results on compatibility of a migrating corrosion inhibitor added to two repair mortars based on an inorganic binder modified with polymers. The influence of a migrating inhibitor on the properties of fresh and hardened mortars was tested. The effectiveness on reinforcement corrosion protection has been tested according to ASTM G 109. Test results prove that the investigated migrating inhibitor is compatible with repair mortars and that it delays corrosion of the reinforcement.

  9. A Multifunctional Coating for Autonomous Corrosion Control

    Science.gov (United States)

    Calle, L. M.; Hintze, P. E.; Li, W.; Buhrow, J. W.; Jolley, S. T.

    2011-01-01

    This slide presentation reviews the effects of corrosion on various structures at the Kennedy Space Center, and the work to discover a corrosion control coating that will be autonomous and will indicate corrosion at an early point in the process. Kennedy Space Center has many environmental conditions that are corrosive: ocean salt spray, heat, humidity, sunlight and acidic exhaust from the Solid Rocket Boosters (SRBs). Presented is a chart which shows the corrosion rates of carbon steel at various locations. KSC has the highest corrosion rates with 42.0 mils/yr, leading the next highest Galeta Point Beach, in the Panama Canal Zone with 27 mils/yr corrosion. A chart shows the changes in corrosion rate with the distance from the ocean. The three types of corrosion protective coatings are described: barrier (passive), Barrier plus active corrosion inhibiting components, and smart. A smart coating will detect and respond actively to changes in its environment in a functional and predictable manner and is capable of adapting its properties dynamically. The smart coating uses microcapsules, particles or liquid drops coated in polymers, that can detect and control the corrosion caused by the environment. The mechanism for a pH sensitive microcapsule and the hydrophobic core microcapsule are demonstrated and the chemistry is reviewed. When corrosion begins, the microcapsule will release the contents of the core (indicator, inhibitor, and self healing agent) in close proximity to the corrosion. The response to a pH increase is demonstrated by a series of pictures that show the breakdown of the microcapsule and the contents release. An example of bolt corrosion is used, as an example of corrosion in places that are difficult to ascertain. A comparison of various coating systems is shown.

  10. Imidazoline receptors associated with noradrenergic terminals in the rostral ventrolateral medulla mediate the hypotensive responses of moxonidine but not clonidine.

    Science.gov (United States)

    Chan, C K S; Burke, S L; Zhu, H; Piletz, J E; Head, G A

    2005-01-01

    We determined whether the cardiovascular actions of central anti-hypertensive agents clonidine and moxonidine are dependent on noradrenergic or serotonergic innervation of the rostral ventrolateral medulla (RVLM) in conscious rabbits. 6-Hydroxydopamine (6-OHDA) or 5,6-dihydroxytriptamine (5,6-DHT) was injected into the RVLM to deplete noradrenergic and serotonergic terminals respectively. One, 2 and 4 weeks later, responses to fourth ventricular (4V) clonidine (0.65 microg/kg) and moxonidine (0.44 microg/kg) were examined. Destruction of noradrenergic pathways in the RVLM by 6-OHDA reduced the hypotensive response to 4V moxonidine to 62%, 47% and 60% of that observed in vehicle treated rabbits at weeks 1, 2 and 4 respectively. The moxonidine induced bradycardia was similarly attenuated (to 46% of vehicle). Conversely, 6-OHDA had no effect on the hypotensive or bradycardic effects of 4V clonidine. Efaroxan (I(1)-imidazoline receptor/alpha(2)-adrenoceptor antagonist; 3.5, 11, 35 microg/kg) and 2-methoxyidazoxan (alpha(2)-adrenoceptor antagonist; 0.3, 0.9, 3 microg/kg) equally reversed the hypotension to 4V clonidine, suggesting a mainly alpha(2)-adrenoceptor mechanism. Efaroxan preferentially reversed responses to moxonidine in both vehicle and 5,6-DHT groups and in the 1st week after 6-OHDA, suggesting a mechanism involving mainly I(1)-imidazoline receptors. This selectivity was subsequently lost in the 2nd and 4th weeks when the remaining hypotension was mainly mediated by alpha(2)-adrenoceptors. Depletion of serotonergic terminals did not alter the responses to either agonist nor did it change the relative effectiveness of the antagonists. Western blots of RVLM tissues probed with imidazoline and alpha(2)-adrenoceptor antisera showed a pattern of bands close to that reported in other species. The main effect of 6-OHDA was an 18% lower level of the 42 kDa imidazoline protein (P<0.05). We conclude that the hypotensive and bradycardic actions of moxonidine but not

  11. DFT and electrochemical studies of tris(benzimidazole-2-ylmethyl)amine as an efficient corrosion inhibitor for carbon steel surface

    Energy Technology Data Exchange (ETDEWEB)

    Roque, Jacinto Morales [Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Mexico D.F. 04510 (Mexico); Pandiyan, T. [Facultad de Quimica, Universidad Nacional Autonoma de Mexico, Mexico D.F. 04510 (Mexico)], E-mail: pandiyan@servidor.unam.mx; Cruz, J. [Centro de Investigaciones Quimicas, Universidad Autonoma del Estado de Hidalgo, Unidad Universitaria, Km 4.5 Carretera Pachuca-Tulancingo, C.P. 42184 Pachuca-Hidalgo (Mexico); Garcia-Ochoa, E. [Centro de Investigacion en Corrosion, Universidad Autonoma de Campeche, Mexico, Av. Agustin Melgar s/n, Colonia Buenavista, San Francisco de Campeche, Cam. C.P. 24030 (Mexico)

    2008-03-15

    The corrosion inhibition properties of tris(benzimidazole-2-ylmethyl)amine (TBMA) were analyzed by DFT and electrochemical techniques such as polarization curves and electrochemical impedance spectroscopy (EIS). DFT results clearly show that TBMA posses corrosion inhibition properties by having a delocalization region (N{sub 1}=C{sub 2}=N{sub 3}) in the benzimidazole ring that gives up their {pi} electron density through its HOMO orbital to the metal LUMO to form a adsorption layer over the metallic surface; this has been proved by interacting the TBMA and its protonated structures with the surface of Fe{sub 13} cluster, showing that the protonated moiety adsorbs strongly on the iron surface than that of the neutral structure. Electrochemical impedance data demonstrate that the interface between the electrode and the TBMA solution decreases the charge capacitance and simultaneously increases the function of the charge/discharge of the interface, facilitating the formation of adsorption layer over the iron surface.

  12. Quantum chemical modeling of adsorption of ureides, that used as inhibitor of microbiological corrosion, on the iron of st3s grade of steel

    Directory of Open Access Journals (Sweden)

    Andrei Sikachina

    2016-07-01

    Full Text Available In published work presents modeled using quantum chemical package HyperChem version 8.0.7 using the semiempirical method ZINDO/1, the process of adsorption of organic compounds of ureidе ranging from simple to more complex, a cluster of iron (present in the steel in amounts of 97%. This approach, as will be shown, with high accuracy reflects the process of corrosion protection with bacterial content by chemisorption of organic compounds on the metal surface with the formation of complex compounds. In the research process were obtained and analyzed global and local electrophilicity heteroatoms, reflects the composition of the complexes, lit a graph showing the dependence of the local electrophilicity from protective anti-corrosion effect.

  13. Corrosion Finishing/Coating Systems for DoD Metallic Substrates Based on Non-Chromate Inhibitors and UV Curable, Zero VOC Materials

    Science.gov (United States)

    2010-08-01

    After the 3000-hour exposure period get photographs taken of the test panels. Strip one of the test panels with Turco 5469 or equivalent paint stripper...test panels. Strip one of the test panels with Turco 5469 or equivalent paint stripper and photograph the stripped panels. Xenon Arc Weather...alkaline cleaning temperature on coating deposition and corrosion performance. The alkaline cleaner used, Turco 4215-NLCT from Henkel Corp., has a

  14. The effects of addition of poly(vinyl) alcohol (PVA) as a green corrosion inhibitor to the phosphate conversion coating on the anticorrosion and adhesion properties of the epoxy coating on the steel substrate

    Science.gov (United States)

    Ramezanzadeh, B.; Vakili, H.; Amini, R.

    2015-02-01

    Steel substrates were chemically treated by room temperature zinc phosphate conversion coating. Poly(vinyl) alcohol (PVA) was added to the phosphate solution as a green corrosion inhibitor. Finally, the epoxy/polyamide coating was applied on the untreated and surface treated steel samples. The effects of PVA on the morphological properties of the phosphate coating were studied by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and contact angle measuring device. The adhesion properties of the epoxy coatings applied on the surface treated samples were investigated by pull-off and cathodic delamination tests. Also, the anticorrosion properties of the epoxy coatings were studied by electrochemical impedance spectroscopy (EIS). Results showed that addition of PVA to the phosphate coating increased the population density of the phosphate crystals and decreased the phosphate grain size. The contact angle of the steel surface treated by Zn-PVA was lower than Zn treated one. The corrosion resistance of the epoxy coating was considerably increased on the steel substrate treated by zinc phosphate conversion coating containing PVA. PVA also enhanced the adhesion properties of the epoxy coating to the steel surface and decreased the cathodic delamination significantly.

  15. Laser-controllable coatings for corrosion protection.

    Science.gov (United States)

    Skorb, Ekaterina V; Skirtach, Andre G; Sviridov, Dmitry V; Shchukin, Dmitry G; Möhwald, Helmuth

    2009-07-28

    We introduce a novel and versatile approach to the corrosion protection by use of "smart" laser-controllable coating. The main advantage of the proposed technique is that one could terminate the corrosion process by very intensive healing after an appearance of corrosion centers using local laser irradiation. It is also shown that by applying a polyelectrolyte shell with noble metal particles over the mesoporous titania and silica via layer-by-layer assembly it is possible to fabricate micro- and nanoscaled reservoirs, which, being incorporated into the zirconia-organosilica matrix, are responsible for the ability of laser-driven release of the loaded materials (e.g., corrosion inhibitor). Furthermore, the resultant films are highly adhesive and could be easily deposited onto different metallic substrates. Laser-mediated remote release of incorporated corrosion inhibitor (benzotriazole) from engineered mesoporous containers with silver nanoparticles in the container shell is observed in real time on single and multicontainer levels.

  16. A Multifunctional Smart Coating for Autonomous Corrosion Control

    Science.gov (United States)

    Calle, Luz Marina; Buhrow, Jerry W.; Jolley, Scott T.

    2012-01-01

    Corrosion is a destructive process that often causes failure in metallic components and structures. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional, smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to control it. The multi-functionality of the coating is based on micro-encapsulation technology specifically designed for corrosion control applications. This design has, in addition to all the advantages of other existing microcapsules designs, the corrosion controlled release function that allows the delivery of corrosion indicators and inhibitors on demand only when and where needed. Corrosion indicators as well as corrosion inhibitors have been incorporated into microcapsules, blended into several paint systems, and tested for corrosion detection and protection efficacy. This

  17. 自组装制备铁质文物保护用纳米缓蚀颗粒%Corrosion inhibitor nano-particles for iron relics protection prepared by self-assembling

    Institute of Scientific and Technical Information of China (English)

    何本桥; 李亭亭; 张桐阳; 沈大娲

    2012-01-01

    The corrosion protection plays a very important role in the protection of iron relics. A novel corrosion inhibitor nano-particle for iron relics was fabricated by consecutively layer-by-layer self-assembling of positive polyethylene imide (PEI), negative poly(sulfonated styrene) (PSS) and positive benzotriazole (BTA) on the surface of negatively charged SiO2 nanoparticles. Transmission electron microscopy, zetasizer and X-ray photoe-lectron spectroscopy (XPS) were employed to characterize the inhibitor nano-particles. Results reveal that the size of particles increases with the increase in the number of coating layers. The surface charge appears corresponding changes. The XPS result shows that the chemical surrounding of nitrogen atoms in the inhibitor nano-particles is changed with the assembly process due to the electrostatic effect between layers. The content of BTA in the inhibitor nano-particle with mono-layer of BTA reached 35. 4mg/g SiO2, which can be readily controlled by improving the number of the PSS and BTA layers.%长效缓蚀材料对于铁质文物的长期保护有着至关重要的作用.通过层层自组装的方法,在带负电荷的SiO2胶粒表面交替组装上了带正电荷的聚乙烯亚胺(PEI)层,带负电荷的聚苯乙烯磺酸钠(PSS)层,以及带正电荷的缓蚀活性成分苯并三氮唑(BTA)层.利用透射电子显微镜、zeta电位仪、X射线光电子能谱仪(XPS)等对纳米缓蚀颗粒进行了表征.结果表明,随着组装过程的进行,胶体粒子尺寸依次增大,颗粒表面zeta电位出现负正交替变化,表面元素化学环境也随之改变,氮原子的结合能随静电作用的增强向高位移动.缓蚀剂的负载量可通过多层组装方式提高,BTA单层负载量可达到35.4mg/g SiO2.

  18. IAA as Corrosion Inhibitor for Mild Steel in H2 SO4 Solution%IAA在硫酸溶液中对碳钢的缓蚀性能研究

    Institute of Scientific and Technical Information of China (English)

    刘启承; 吕堂满; 冯利军

    2015-01-01

    effect on anodic and cathodic reactions. And there was a competitive adsorption emerged between the adsorbed water molecules and the inhibitor molecules in the process of adsorption effect, which effectively prevented the H+ from crossing, thereby inhibiting the discharge process of the corrosion H+. The adsorp-tion of IAA on carbon steel surface followed the Langmuir adsorption isotherm model, which was spontaneous and was a combination of physical and chemical adsorption. Inhibition of corrosion by inhibiting the active point of the corrosion reaction can improve the activation energy barrier and prevent corrosion of carbon steel. The inhibitor molecules reduced the metal corrosion significantly. Conclusion IAA is a mixed-type corrosion inhibitor, which can inhibit the anodic reaction. It can protect the Q235 carbon steel in 0. 1 mol/L H2 SO4 solution.

  19. A Selective Imidazoline-2-thione-Bearing Two-Photon Fluorescent Probe for Hypochlorous Acid in Mitochondria.

    Science.gov (United States)

    Xu, Qingling; Heo, Cheol Ho; Kim, Jin A; Lee, Hye Sue; Hu, Ying; Kim, Dayoung; Swamy, Kunemadihalli Mathada Kotraiah; Kim, Gyoungmi; Nam, Sang-Jip; Kim, Hwan Myung; Yoon, Juyoung

    2016-06-21

    Hypochlorite (OCl(-)) plays a key role in the immune system and is involved in various diseases. Accordingly, direct detection of endogenous OCl(-) at the subcellular level is important for understanding inflammation and cellular apoptosis. In the current study, a two-photon fluorescent off/on probe (PNIS) bearing imidazoline-2-thione as an OCl(-) recognition unit and triphenylphosphine (TPP) as a mitochondrial-targeting group was synthesized and examined for its ability to image mitochondrial OCl(-) in situ. This probe, based on the specific reaction between imidazoline-2-thione and OCl(-), displayed a selective fluorescent off/on response to OCl(-) with the various reactive oxygen species in a physiological medium. PNIS was successfully applied to image of endogenously produced mitochondrial OCl(-) in live RAW 264.7 cells via two-photon microscopy.

  20. Biphasic dose-dependent modulation of cardiac parasympathetic activity by moxonidine, an imidazoline I1-receptor agonist.

    Science.gov (United States)

    Turcani, Marian

    2008-12-01

    Peripheral beta-adrenergic blockade and activation of central alpha2-adrenergic receptors have parasympathomimetic effects. The impact of activation of central imidazoline I1-receptors on vagal activity is not yet clear, but there is some evidence that imidazoline I1-receptors agonists may inhibit the parasympathetic system. Parasympatholytic effects may represent a risk for patient with reduced parasympathetic activity. To clarify the effect of imidazoline I1-receptors stimulation on vagal activity, increasing doses of moxonidine were applied subcutaneously to rats with implanted telemetric transmitters. Heart rate and blood pressure variability and baroreflex sensitivity were analyzed. Both, low (0.04, 0.12, and 0.36 mg/kg) and high (1.08 and 3.24 mg/kg), doses of moxonidine reduced the low-frequency power of systolic pressure variability, an index of sympathetic vascular modulation. Despite this reduction, low moxonidine doses neither reduced heart rate nor increased baroreflex gain. A decline of very low frequency power of heart rate variability, a sign of parasympatholysis, was observed with low doses of moxonidine, which can explain the absence of change in heart rate. High doses of moxonidine profoundly augmented very low and high-frequency power of heart rate variability and baroreflex sensitivity. These data suggest that the stimulation of imidazoline I1-receptors is not only sympatholytic but also seems to have as well a weak parasympatholytic effect. However, high doses of moxonidine are strongly parasympathomimetic through the activation of central alpha2-adrenoceptors. Recruitment of alpha2-adrenoceptors also results in manifestation of several side effects.

  1. Imidazoline receptors in the heart: a novel target and a novel mechanism of action that involves atrial natriuretic peptides

    Directory of Open Access Journals (Sweden)

    S. Mukaddam-Daher

    2004-08-01

    Full Text Available Chronic stimulation of sympathetic nervous activity contributes to the development and maintenance of hypertension, leading to left ventricular hypertrophy (LVH, arrhythmias and cardiac death. Moxonidine, an imidazoline antihypertensive compound that preferentially activates imidazoline receptors in brainstem rostroventrolateral medulla, suppresses sympathetic activation and reverses LVH. We have identified imidazoline receptors in the heart atria and ventricles, and shown that atrial I1-receptors are up-regulated in spontaneously hypertensive rats (SHR, and ventricular I1-receptors are up-regulated in hamster and human heart failure. Furthermore, cardiac I1-receptor binding decreased after chronic in vivo exposure to moxonidine. These studies implied that cardiac I1-receptors are involved in cardiovascular regulation. The presence of I1-receptors in the heart, the primary site of production of natriuretic peptides, atrial natriuretic peptide (ANP and brain natriuretic peptide (BNP, cardiac hormones implicated in blood pressure control and cardioprotection, led us to propose that ANP may be involved in the actions of moxonidine. In fact, acute iv administration of moxonidine (50 to 150 µg/rat dose-dependently decreased blood pressure, stimulated diuresis and natriuresis and increased plasma ANP and its second messenger, cGMP. Chronic SHR treatment with moxonidine (0, 60 and 120 µg kg-1 h-1, sc for 4 weeks dose-dependently decreased blood pressure, resulted in reversal of LVH and decreased ventricular interleukin 1ß concentration after 4 weeks of treatment. These effects were associated with a further increase in already elevated ANP and BNP synthesis and release (after 1 week, and normalization by 4 weeks. In conclusion, cardiac imidazoline receptors and natriuretic peptides may be involved in the acute and chronic effects of moxonidine.

  2. Imidazoline binding sites in the endocrine pancreas: can they fulfil their potential as targets for the development of new insulin secretagogues?

    Science.gov (United States)

    Morgan, N G; Chan, S L

    2001-09-01

    A variety of compounds containing an imidazoline ring have the ability to stimulate insulin secretion. Many of these also improve glycaemia in experimental models of type 2 diabetes and in man, suggesting that this class may be useful in the development of new orally active anti-diabetic drugs. However, the mechanisms by which imidazolines promote insulin secretion have not been clarified. The response does not appear to be due to the binding of ligands to either of the two major types of "imidazoline receptor" defined by pharmacological criteria (I1 and I2 sites) but may result from interaction with a novel imidazoline binding site. One such site has been identified in association with the ATP-sensitive potassium (K(ATP)) channel in the beta-cell and has been designated "I3". Electrophysiological and biochemical evidence suggest that the I3 site may be intrinsic to the ion-conducting pore component, Kir6.2, of the K(ATP) channel, but the effects of imidazoline ligands on insulin secretion can be dissociated from the regulation of Kir6.2. Indeed, there is increasing evidence that some imidazolines can control exocytosis directly, both in beta-cells and in pancreatic alpha-cells. Thus, it is proposed that a further imidazoline binding site is primarily responsible for control of hormone secretion. Evidence is reviewed which suggests that this site occupies a central position within an amplification pathway that also mediates the effects of cAMP in the beta-cell. Characterisation of this site should provide the stimulus for the design of new insulin secretagogues that are devoid of K(ATP) channel-blocking properties.

  3. Corrosion in airframes

    OpenAIRE

    PETROVIC ZORAN C.

    2016-01-01

    The introductory chapter provides a brief reference to the issue of corrosion and corrosion damage to aircraft structures. Depending on the nature and dimensions of this non uniformity, three different categories of corrosion are defined: uniform, selective and localized corrosion. The following chapters present the forms of corrosion that can occur in three defined categories of corrosion. Conditions that cause certain types of corrosion in various corrosive environments are discussed. Examp...

  4. CORROSION IN AIRFRAMES

    OpenAIRE

    PETROVIC ZORAN C.

    2016-01-01

    The introductory chapter provides a brief reference to the issue of corrosion and corrosion damage to aircraft structures. Depending on the nature and dimensions of this non uniformity, three different categories of corrosion are defined: uniform, selective and localized corrosion. The following chapters present the forms of corrosion that can occur in three defined categories of corrosion. Conditions that cause certain types of corrosion in various corrosive environments are discussed. Examp...

  5. Performance and Application of Corrosion Inhibitor TH-658B in High Hardness and High Alkalinity Water%新型高硬高碱水缓蚀阻垢剂TH-658B的应用性能

    Institute of Scientific and Technical Information of China (English)

    贺茂才; 齐晓婧; 高灿柱

    2012-01-01

    针对华北、西北等地补充水硬度、碱度高,浓缩后极易引起结垢和腐蚀的难题,开发了高硬、高碱水缓蚀阻垢剂TH-658B。采用静态阻碳酸钙垢试验、阻硫酸钙垢试验、梯度浓缩试验等研究了TH658B的性能。结果表明,相同的药剂浓度,TH-658B的碳酸钙阻垢率均高于ATMP和HEDP且TH-658B的碳酸钙和硫酸钙阻垢率均符合Q/SY126—2007要求;TH-658B可以使高硬、高碱水浓缩至钙硬总碱之和大于1500mg/L而不会导致系统结垢。此外,参照GB/T18175-2000,在TH-658B的存在下,高硬、高碱配水(〉1500mg/L)中的碳钢、不锈钢和铜的腐蚀速率分别为0.036、0.0018、0.0012mm/a,均符合GB50050—2007的要求。通过华北一电厂的现场应用,证明了TH-658B对高硬、高碱,特别是钙硬总碱之和达到1500mg/L以上的高浓缩倍率循环水系统具有良好的缓蚀和阻垢效果。%Aiming at the scaling and corrosion problem of high hardness and alkalinity water in north and northwest of China, a new type of scale and corrosion inhibitor TH-658B was developed. The performance of TH-658B was evaluated by means of scale inhibition test, gradient concentration test and rotary coupon corrosion test. The results show that the calcium carbonate scale inhibition rate of TH-658B was higher than ATMP and HEDP under the same concentration condition. The calcium carbonate and calcium sulfate scale inhibition rate of TH-658B can meet the standard requirements of Q/SY 126--2007. Gradient enrichment test results indicate that the summation of calcium hardness and total alkalinity could reach more than 1500 mg/L as TH-658B existed in water, which is much higher than the standard requirements of GBS0050- 2007. Furthermore, TH-658B has good inhibition corrosion performance for carbon steel, stainless steel and copper in high hardness and alkalinity water. The corrosion rates for carbon steel, stainless steel and

  6. Agmatine suppresses peripheral sympathetic tone by inhibiting N-type Ca(2+) channel activity via imidazoline I2 receptor activation.

    Science.gov (United States)

    Kim, Young-Hwan; Jeong, Ji-Hyun; Ahn, Duck-Sun; Chung, Seungsoo

    2016-08-26

    Agmatine, a putative endogenous ligand of imidazoline receptors, suppresses cardiovascular function by inhibiting peripheral sympathetic tone. However, the molecular identity of imidazoline receptor subtypes and its cellular mechanism underlying the agmatine-induced sympathetic suppression remains unknown. Meanwhile, N-type Ca(2+) channels are important for the regulation of NA release in the peripheral sympathetic nervous system. Therefore, it is possible that agmatine suppresses NA release in peripheral sympathetic nerve terminals by inhibiting Ca(2+) influx through N-type Ca(2+) channels. We tested this hypothesis by investigating agmatine effect on electrical field stimulation (EFS)-evoked contraction and NA release in endothelium-denuded rat superior mesenteric arterial strips. We also investigated the effect of agmatine on the N-type Ca(2+) current in superior cervical ganglion (SCG) neurons in rats. Our study demonstrates that agmatine suppresses peripheral sympathetic outflow via the imidazoline I2 receptor in rat mesenteric arteries. In addition, the agmatine-induced suppression of peripheral vascular sympathetic tone is mediated by modulating voltage-dependent N-type Ca(2+) channels in sympathetic nerve terminals. These results suggest a potential cellular mechanism for the agmatine-induced suppression of peripheral sympathetic tone. Furthermore, they provide basic and theoretical information regarding the development of new agents to treat hypertension.

  7. INTERNAL CORROSION MONITORING IN OFFSHORE PLATFORMS

    Directory of Open Access Journals (Sweden)

    Fernando Benedicto Mainier

    2008-08-01

    Full Text Available Corrosion is one of the main causes of failures in equipment and pipes in off-shore oil production. These failures harm the process, slow the production operational chronogram, and generate high costs of maintenance, beyond generation risks to health and environment. Due to the fact that most of the equipment, tubing and pipes of production platforms are made of steel, in general, carbon steel, the industry of petroleum exploration will always coexist with the corrosive process. The use of a Corrosion Monitoring Plan to diagnostic, to control and to manage the evolution of corrosives process in off-shore oil platforms is the strategy proposed in this work to prevent problems as described above. The Internal Corrosion Monitoring Plan (ICMP, is based on lab analysis of the corrosively of fluids and residues showed periodically in off-shore operational platform; in the corrosion rate determined by the periodic use of test bodies installed inside off-shore oil platforms tubing systems, as mass loss coupons and electric resistance probes; and finally, in periodic operational data collect obtained during the off-shore oil platform systems operation. The ICMP will direct and manage the actions to be taken in case of aggravation of a corrosive process, quickly identifying to the corrosive mechanisms and its localization in the various systems of the platforms. The optimized use of the corrosion inhibitor and other chemical products are one of the main advantages of the ICMP.

  8. Effect of microcontainer loading with corrosion inhibitor on corrosion protection of coating%负载缓蚀剂的微米容器对涂层防腐性能的影响

    Institute of Scientific and Technical Information of China (English)

    武婷婷; 王立达; 孙文; 刘洋; 刘贵昌

    2013-01-01

    ZnO hollow microspheres (ZHM) were synthesized by hydrothermal method.The morphology and crystal structure of ZHM were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD).The ZHM containing benzotriazole (ZHM-BTA) was obtained by loading BTA to ZHM using impregnation method,and then characterized by Fourier transform infrared spectroscopy (FT-IR).A functional coating was prepared on the surface of copper substrate by adding the ZHM-BTA to epoxy resin.The effect of ZHM-BTA on metal corrosion caused by coating defect was studied by potentiodynamic polarization curve measurement and electrochemical impedance spectroscopy (EIS).It was found that the corrosion caused by coating defect is inhibited by doping ZHM-BTA into epoxy coating,and the ZHM-BTA has certain healing effect for coating defect.%采用水热法合成了氧化锌中空微米球(ZHM),通过扫描电子显微镜(SEM)、X射线衍射(XRD)对其进行形貌及晶体结构的表征,以浸渍法将苯并三氮唑负载到ZHM中,得到负载了苯并三氮唑的氧化锌中空微米球(ZHM-BTA),并通过红外光谱(FT-IR)对其进行了表征.将ZHM-BTA加入到环氧树脂中,在铜基体上制备了功能涂层,利用动电位极化曲线和交流阻抗谱考察了ZHM-BTA对涂层缺陷处金属腐蚀的作用.结果表明,向涂层中掺杂ZHM-BTA可以阻止涂层缺陷引起的腐蚀,ZHM-BTA对涂层缺陷具有一定的愈合作用.

  9. Mesoporous silica nanoparticles for active corrosion protection.

    Science.gov (United States)

    Borisova, Dimitriya; Möhwald, Helmuth; Shchukin, Dmitry G

    2011-03-22

    This work presents the synthesis of monodisperse, mesoporous silica nanoparticles and their application as nanocontainers loaded with corrosion inhibitor (1H-benzotriazole (BTA)) and embedded in hybrid SiOx/ZrOx sol-gel coating for the corrosion protection of aluminum alloy. The developed porous system of mechanically stable silica nanoparticles exhibits high surface area (∼1000 m2·g(-1)), narrow pore size distribution (d∼3 nm), and large pore volume (∼1 mL·g(-1)). As a result, a sufficiently high uptake and storage of the corrosion inhibitor in the mesoporous nanocontainers was achieved. The successful embedding and homogeneous distribution of the BTA-loaded monodisperse silica nanocontainers in the passive anticorrosive SiOx/ZrOx film improve the wet corrosion resistance of the aluminum alloy AA2024 in 0.1 M sodium chloride solution. The enhanced corrosion protection of this newly developed active system in comparison to the passive sol-gel coating was observed during a simulated corrosion process by the scanning vibrating electrode technique (SVET). These results, as well as the controlled pH-dependent release of BTA from the mesoporous silica nanocontainers without additional polyelectrolyte shell, suggest an inhibitor release triggered by the corrosion process leading to a self-healing effect.

  10. Inhibition of the Corrosion of Mild Steel in Acid Media by Naturally Occurring Acacia Senegal

    Directory of Open Access Journals (Sweden)

    Urvija Garg

    2010-01-01

    Full Text Available The inhibition of corrosion of mild steel in HCl solution by naturally occurring Acacia Senegal has been studied in relation to the concentration of inhibitor and concentration of corrosive medium. It has been observed that the Acacia Senegal alcoholic extract acts as a good corrosion inhibitor in hydrochloric acid solution and the adsorption of the extract provides a good protection against mild steel corrosion.

  11. Microbial Influenced Corrosion (MIC) Study

    Science.gov (United States)

    2012-05-23

    low lying areas breaks down protective coating system and causes structural corrosion , • Water and organic/inorganic nutrients BUSINESS SENSITIVE...Chemical disinfection (T.O 1-1-8 and T.O 1-1-691) • Biocidal rinses and coatings • Biocidal Corrosion Preventative Compounds or CPCs BUSINESS...Type: H    Proprietary  Coating  w/ Silver  Inhibitor   Non‐Chrome Treatment + Mg‐Rich  Primer  Coupon Type: I    Prekote® (Pantheon Chemical) N/A

  12. Silica nanocontainers for active corrosion protection

    Science.gov (United States)

    Maia, Frederico; Tedim, João; Lisenkov, Aleksey D.; Salak, Andrei N.; Zheludkevich, Mikhail L.; Ferreira, Mário G. S.

    2012-02-01

    Novel self-healing protective coatings with nanocontainers of corrosion inhibitors open new opportunities for long-term anticorrosion protection of different metallic materials. In this paper a new type of functional nanoreservoir based on silica nanocapsules (SiNC) synthesized and loaded with corrosion inhibitor 2-mercaptobenzothiazole (MBT) in a one-stage process is reported for the first time. Unlike conventional mesoporous silica nanoparticles, SiNC possess an empty core and shell with gradual mesoporosity, arising from the particular conditions of the synthetic route adopted, which confers significant loading capacity and allows prolonged and stimuli-triggered release of the inhibiting species. The kinetics of inhibitor release was studied at different pH values and concentrations of NaCl. The results show a clear dependence of the release profiles on corrosion relevant triggers such as pH and Cl- concentration. When SiNC loaded with MBT are dispersed in NaCl solution, there is a significant decrease of the corrosion activity on aluminium alloy 2024. More importantly, when SiNC-MBT is added to a conventional water-based coating formulation, the modified coating hampers corrosion activity at the metal interface, better than in the case of direct addition of corrosion inhibitor. Furthermore, self-healing is observed before and after artificially inflicting defects in the modified coatings. As a result, the developed nanocontainers show high potential to be used in new generation of active protective coatings.

  13. 1, 5-BIS [(4-DITHIOCARBOXYLATE-1-DODECYL-5-HYDROXY-3-METHYLPYRAZOLYL] PENTANE AS COPPER CORROSION INHIBITOR IN 0.1 M SULPHURIC ACID 1, 5-Bis [(4-Dithiocarboxylat-1-dodecyl-5-Hydroxy-3-METHYL PYRAZOLYL] Pentan als Kupferkorrosionsinhibitor in 0,1 M SCHWEFELSÄURE

    Directory of Open Access Journals (Sweden)

    Rosa Vera, Alfonso Oliva and Aurora Molinari

    2011-08-01

    Full Text Available The ability of tetradentate ligand 1,5-bis[(4-dithiocarboxylate-1-dodecyl-5-hydroxy-3- methylpyrazolyl]pentane (H2BDTCPP as organic surface coating to inhibit the copper corrosion in 0.1 M H2SO4 have been studied. The inhibitory properties were studied by immersion assays and the results show that H2BDTCPP behaves as a mixed inhibitor in 0.1 M H2SO4 aqueous solution, with an inhibition efficiency of 62.1 %, increasing the corrosion potential and decreasing the corrosion current of copper when it is coated over the metal surface. These properties can be attributed to the planar aromatic structure of the pyrazolyldithiocarboxylate group and to the high π/lone-pair electron density due to nitrogen, oxygen and sulphur which favour its physical and chemical adsorption.

  14. A Kinetic Study on the Anodic Desorption of Interface Corrosion Inhibitor%缓蚀剂阳极脱附的动力学