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Sample records for corrosion inhibition

  1. 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.

  2. 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.

  3. INHIBITION OF CORROSION

    Science.gov (United States)

    Atherton, J.E. Jr.; Gurinsky, D.H.

    1958-06-24

    A method is described for preventing corrosion of metallic container materials by a high-temperature liquid bismuth flowing therein. The method comprises fabricating the containment means from a steel which contains between 2 and 12% chromium, between 0.5 and 1.5% of either molybdenum and silicon, and a minimum of nickel and manganese, and maintaining zirconium dissolved in the liquid bismuth at a concentration between 50 parts per million and its saturation value at the lowest temperature in the system.

  4. Graphene: corrosion-inhibiting coating.

    Science.gov (United States)

    Prasai, Dhiraj; Tuberquia, Juan Carlos; Harl, Robert R; Jennings, G Kane; Rogers, Bridget R; Bolotin, Kirill I

    2012-02-28

    We report the use of atomically thin layers of graphene as a protective coating that inhibits corrosion of underlying metals. Here, we employ electrochemical methods to study the corrosion inhibition of copper and nickel by either growing graphene on these metals, or by mechanically transferring multilayer graphene onto them. Cyclic voltammetry measurements reveal that the graphene coating effectively suppresses metal oxidation and oxygen reduction. Electrochemical impedance spectroscopy measurements suggest that while graphene itself is not damaged, the metal under it is corroded at cracks in the graphene film. Finally, we use Tafel analysis to quantify the corrosion rates of samples with and without graphene coatings. These results indicate that copper films coated with graphene grown via chemical vapor deposition are corroded 7 times slower in an aerated Na(2)SO(4) solution as compared to the corrosion rate of bare copper. Tafel analysis reveals that nickel with a multilayer graphene film grown on it corrodes 20 times slower while nickel surfaces coated with four layers of mechanically transferred graphene corrode 4 times slower than bare nickel. These findings establish graphene as the thinnest known corrosion-protecting coating.

  5. Complete corrosion inhibition through graphene defect passivation.

    Science.gov (United States)

    Hsieh, Ya-Ping; Hofmann, Mario; Chang, Kai-Wen; Jhu, Jian Gang; Li, Yuan-Yao; Chen, Kuang Yao; Yang, Chang Chung; Chang, Wen-Sheng; Chen, Li-Chyong

    2014-01-28

    Graphene is expected to enable superior corrosion protection due to its impermeability and chemical inertness. Previous reports, however, demonstrate limited corrosion inhibition and even corrosion enhancement of graphene on metal surfaces. To enable the reliable and complete passivation, the origin of the low inhibition efficiency of graphene was investigated. Combining electrochemical and morphological characterization techniques, nanometer-sized structural defects in chemical vapor deposition grown graphene were found to be the cause for the limited passivation effect. Extremely fast mass transport on the order of meters per second both across and parallel to graphene layers results in an inhibition efficiency of only ∼50% for Cu covered with up to three graphene layers. Through selective passivation of the defects by atomic layer deposition (ALD) an enhanced corrosion protection of more than 99% was achieved, which compares favorably with commercial corrosion protection methods.

  6. Inhibition of aluminum corrosion using Opuntia extract

    Energy Technology Data Exchange (ETDEWEB)

    El-Etre, A.Y

    2003-11-01

    The inhibitive action of the mucilage extracted from the modified stems of prickly pears, toward acid corrosion of aluminum, is tested using weight loss, thermometry, hydrogen evolution and polarization techniques. It was found that the extract acts as a good corrosion inhibitor for aluminum corrosion in 2.0 M HCl solution. The inhibition action of the extract was discussed in view of Langmuir adsorption isotherm. It was found that the adsorption of the extract on aluminum surface is a spontaneous process. The inhibition efficiency (IE) increases as the extract concentration is increased. The effect of temperature on the IE was studied. It was found that the presence of extract increases the activation energy of the corrosion reaction. Moreover, the thermodynamic parameters of the adsorption process were calculated. It was found also that the Opuntia extract provides a good protection to aluminum against pitting corrosion in chloride ion containing solutions.

  7. Encapsulated Multifunction Corrosion Inhibitive Primer.

    Science.gov (United States)

    1983-11-01

    Tec #19 (alkaline detergent), scrubbed vigorously with cheese cloth, then perform R.I.A. drop test for cleanliness (ASTM 7.1.6.22) (Turco Air Tec...Systems, DOE/NASA TM-78180 (1978). 39. Gouda , V.K. and Shater, M.A., Corrosion Sci. 15 199 (1975). 40. Controlled release, Pesticide Symposium 41

  8. Corrosion inhibition for distillation apparatus

    Science.gov (United States)

    Baumert, Kenneth L.; Sagues, Alberto A.; Davis, Burtron H.; Schweighardt, Frank K.

    1985-01-01

    Tower material corrosion in an atmospheric or sub-atmospheric distillation tower in a coal liquefaction process is reduced or eliminated by subjecting chloride-containing tray contents to an appropriate ion-exchange resin to remove chloride from such tray contents materials.

  9. 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.

  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. 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)

  12. Corrosion Chemistry in Inhibited HDA.

    Science.gov (United States)

    1980-11-30

    Titanium and chromium have sufficiently low Flade potentials to pass- ivate in non-oxidising acids, but Iron will only exhibit self-passivity if the...inhibition e.g. involving organic and pickling inhibitors* the rest potential can actually 4.5,4.6become more negative " This is due to cathodic rather...media. 321 stainless steel, titanium stabilised, was the particular steel studied, being very similar in composition to the 347also stainless steel

  13. Assessment of Commercial Corrosion Inhibiting Admixtures for Reinforced Concrete

    OpenAIRE

    Brown, Michael Carey

    1999-01-01

    Corrosion of reinforcing steel in concrete exposed to chloride-laden environments is a well-known and documented phenomenon. The need for cost effective systems for protection against corrosion has become increasingly clear since the first observations of severe corrosion damage to interstate bridges in the 1960's. As one potential solution to the mounting problem of corrosion deterioration of structures, corrosion-inhibiting admixtures have been researched and introduced into service. ...

  14. Biofilms: strategies for metal corrosion inhibition employing microorganisms.

    Science.gov (United States)

    Zuo, Rongjun

    2007-10-01

    Corrosion causes dramatic economic loss. Currently widely used corrosion control strategies have disadvantages of being expensive, subject to environmental restrictions, and sometimes inefficient. Studies show that microbial corrosion inhibition is actually a common phenomenon. The present review summarizes recent progress in this novel strategy: corrosion control using beneficial bacteria biofilms. The possible mechanisms may involve: (1) removal of corrosive agents (such as oxygen) by bacterial physiological activities (e.g., aerobic respiration), (2) growth inhibition of corrosion-causing bacteria by antimicrobials generated within biofilms [e.g., sulfate-reducing bacteria (SRB) corrosion inhibition by gramicidin S-producing Bacillus brevis biofilm], (3) generation of protective layer by biofilms (e.g., Bacillus licheniformis biofilm produces on aluminum surface a sticky protective layer of gamma-polyglutamate). Successful utilization of this novel strategy relies on advances in study at the interface of corrosion engineering and biofilm biology.

  15. 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.

  16. Corrosion Inhibition of High Speed Steel by Biopolymer HPMC Derivatives

    OpenAIRE

    Shih-Chen Shi; Chieh-Chang Su

    2016-01-01

    The corrosion inhibition characteristics of the derivatives of biopolymer hydroxypropyl methylcellulose (HPMC), hydroxypropyl methylcellulose phthalate (HPMCP), and hydroxypropyl methylcellulose acetate succinate (HPMCAS) film are investigated. Based on electrochemical impedance spectroscopic measurements and potentiodynamic polarization, the corrosion inhibition performance of high speed steel coated with HPMC derivatives is evaluated. The Nyquist plot and Tafel polarization demonstrate prom...

  17. Corrosion Inhibition of High Speed Steel by Biopolymer HPMC Derivatives

    Directory of Open Access Journals (Sweden)

    Shih-Chen Shi

    2016-07-01

    Full Text Available The corrosion inhibition characteristics of the derivatives of biopolymer hydroxypropyl methylcellulose (HPMC, hydroxypropyl methylcellulose phthalate (HPMCP, and hydroxypropyl methylcellulose acetate succinate (HPMCAS film are investigated. Based on electrochemical impedance spectroscopic measurements and potentiodynamic polarization, the corrosion inhibition performance of high speed steel coated with HPMC derivatives is evaluated. The Nyquist plot and Tafel polarization demonstrate promising anti-corrosion performance of HPMC and HPMCP. With increasing film thickness, both materials reveal improvement in corrosion inhibition. Moreover, because of a hydrophobic surface and lower moisture content, HPMCP shows better anti-corrosion performance than HPMCAS. The study is of certain importance for designing green corrosion inhibitors of high speed steel surfaces by the use of biopolymer derivatives.

  18. Influence of bacteria on film formation inhibiting corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Gunasekaran, G.; Chongdar, Shobhana; Gaonkar, S.N.; Kumar, Pradeep

    2004-08-01

    Mild steel coupons were incubated separately in two bacterial cultures namely Pseudomonas flava and Pseudomonas stutzeri. A significant reduction in the corrosion rate was observed in presence of P. flava. With a view to understand the mechanisms of microbially influenced corrosion/corrosion inhibition, various electrochemical and biological experiments such as weight change measurements and electrochemical impedance spectroscopy (EIS) measurements were made. The exposed surfaces were examined using scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDAX). The scraped surface film was also examined using FT-IR (Fourier transform infra red) spectroscopy. The results suggest that P. flava have enhancing effect on corrosion inhibitive properties of phosphate film.

  19. Electrochemical and Corrosion Inhibition Studies of Cucurbita Maxima

    Directory of Open Access Journals (Sweden)

    K. Anbarasi

    2016-08-01

    Full Text Available The influence of the acid extract of peel of Cucurbita maxima (PCM on the corrosion of mild steel in 1N H2SO4 was investigated by weight loss, polarization and impedance methods and SEM analysis. The inhibition efficiency increases with extract concentration and immersion period. Weight loss and corrosion rates of mild steel decreased as the concentration of inhibitor increased. The results showed that PCM was potential corrosion inhibitor and maximum inhibition efficiency (IE % obtained was 98% for 3%PCM at 1h. Impedance measurement results an increase in charge transfer resistance (Rct, which also confirms the corrosion inhibitive nature of the plant extract. Potentiodynamic study showed that PCM acts as a mixed type of inhibitor, which controls both the anodic and cathodic reactions. Scanning electron microscopic studies provided the evidence of improved surface condition for the corrosion protection, due to the adsorption.

  20. Electrochemical impedance spectroscopy study on corrosion inhibition of benzyltriethylammonium chloride

    Science.gov (United States)

    Idris, Mohd Nazri; Daud, Abdul Razak; Othman, Norinsan Kamil

    2013-11-01

    Electrochemical Impedance Spectroscopy (EIS) was employed to study the corrosion inhibition behavior of benzyltriethylammonium chloride (BTC) for carbon steel corrosion. The inhibition efficiency was investigated in 1.0 M HCl solution at room temperature (25°C) by varying the BTC concentration. EIS results indicated that the double layer capacitance of electrolyte/carbon steel interface decreases with the increasing of BTC concentration and consequently enhances the polarization resistance of equivalence Randles circuit. The results indicated that inhibition efficiency of as high as 65% could be achieved when 10mM BTC was present in 1.0 M HCl solution as compared to inhibitor-free solution. The inhibition process of BTC on the carbon steel corrosion was found to obey Langmuir adsorption isotherm. This study revealed that BTC is suitable to be used as a corrosion inhibitor in acid media.

  1. Inhibition behavior for copper corrosion by photoelectrochemical methods

    Institute of Scientific and Technical Information of China (English)

    徐群杰; 周国定

    2003-01-01

    The application of photoelectrochemical methods in the inhibition effects for copper corrosion was described. The methods include cyclic voltammetry photocurrent measurements, intensity modulated photocurrent spectrum(IMPS) and laser-scanning photoelectrochemical microscopic method(PEM) which have been applied to the evaluation of inhibitors and inhibition behavior. The inhibition effect of BTA for copper corrosion is better than that of 4CBTA, 5CBTA, CBT-1, PTD, BT-250, CBTME and CBTBE at the same concentration. The inhibition mechanism of the derivatives of BTA with-COOH group(4CBTA, 5CBTA, CBT-1) is different from those with estergroup(CBTME, CBTBE).

  2. 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.

  3. Chemical treatment of zinc surface and its corrosion inhibition studies

    Indian Academy of Sciences (India)

    S K Rajappa; T V Venkatesha; B M Praveen

    2008-02-01

    The surface treatment of zinc and its corrosion inhibition was studied using a product (BTSC) formed in the reaction between benzaldehyde and thiosemicarbozide. The corrosion behaviour of chemically treated zinc surface was investigated in aqueous chloride–sulphate medium using galvanostatic polarization technique. Zinc samples treated in BTSC solution exhibited good corrosion resistance. The measured electrochemical data indicated a basic modification of the cathode reaction during corrosion of treated zinc. The corrosion protection may be explained on the basis of adsorption and formation of BTSC film on zinc surface. The film was binding strongly to the metal surface through nitrogen and sulphur atoms of the product. The formation of film on the zinc surface was established by surface analysis techniques such as scanning electron microscopy (SEM–EDS) and Fourier transform infrared spectroscopy (FTIR).

  4. Corrosion inhibition of mild steel by aerobic biofilm

    Energy Technology Data Exchange (ETDEWEB)

    Chongdar, Shobhana [Naval Materials Research Laboratory, Addl. Ambarnath 421506 (India); Gunasekaran, G. [Naval Materials Research Laboratory, Addl. Ambarnath 421506 (India)]. E-mail: gunanmrl@rediffmail.com; Kumar, Pradeep [Naval Materials Research Laboratory, Addl. Ambarnath 421506 (India)

    2005-08-30

    Mild steel electrodes were incubated in phosphate-buffered basal salt solution (BSS) having two different aerobic bacteria, viz. Pseudomonas alcaligenes and Pseudomonas cichorii. In the medium containing P. cichorii, significant reduction in the corrosion rate was observed due to the surface reaction leading to the formation of corrosion inhibiting bacterial biofilm. With a view to understand the mechanism of microbially influenced corrosion/corrosion inhibition, electrochemical and biological experiments such as electrochemical impedance spectroscopy (EIS) measurements and biochemical analysis were made. The exposed surfaces were examined using scanning electron micrographs (SEM), energy dispersive spectroscopy (EDS) and electron spectroscopy for chemical analysis (ESCA). The scraped surface film was also examined using FT-IR spectroscopy. The results suggested that mild steel surface contained iron oxide-phosphate layer covered with bacteria and exo polymeric substance (EPS)/iron-EPS complex for P. cichorii and iron oxides and iron phosphate for P. alcaligenes.

  5. Corrosion inhibition performance of a ionic liquid surfactant Br

    Directory of Open Access Journals (Sweden)

    Jing LIU

    2016-02-01

    Full Text Available In order to study the novel green organic mercury-substituting inhibitors, the ionic liquid surfactant 1-methyl-3-dodecyl imidazole bromide ( Br is synthesized with N-methyl imidazole and 1-bromodecane as raw materials. The corrosion inhibition of Br for zinc in zinc-manganese batteries is investigated using electrochemical methods and weight loss methods. The results show that corrosion inhibition efficiency increases with the increase of the concentration of Br, and when the concentration is higher than 8×10-3 mol/L, the inhibition efficiency tends to be stable. The polarization curve shows that Br belongs to mixed-type corrosion inhibitor. The thermodynamic parameters show that Br is spontaneously adsorbed on the zinc surface, forming a monomolecular adsorption layer, which fits with Langmuir adsorption isotherm with physical and chemical adsorption mechanism.

  6. Corrosion inhibition of carbon steel by sodium metavanadate

    Directory of Open Access Journals (Sweden)

    VIJAYA GOPAL SRIBHARATHY

    2012-08-01

    Full Text Available The inhibition efficiency of sodium metavanadate (SMV-adipic acid (AA system in controlling corrosion of carbon steel in an aqueous solution containing 60 ppm of Cl- has been evaluated by weight-loss method; 250 ppm of SMV exhibits inhibition efficiency of 56 %. Addition of adipic acid to SMV improves the inhibition efficiency of the system. The formulation consisting of 250 ppm of SMV and 250 ppm of adipic acid has inhibition efficiency of 98 %. A synergistic effect exists between SMV and adipic acid with the synergism parameters greater than 1. Mecha¬nistic aspects of corrosion inhibition have been studied by electrochemical methods like potentiodynamic polarization and electrochemical impedance spectroscopy. FTIR spectra reveal that the protective film consists of Fe2+-SMV complex and Fe2+-adipic acid complex. The protective film has been analyzed by fluorescence spectra, SEM and EDAX.

  7. Fouling and the inhibition of salt corrosion. [hot corrosion of superalloys

    Science.gov (United States)

    Deadmore, D. L.; Lowell, C. E.

    1980-01-01

    In an attempt to reduce fouling while retaining the beneficial effects of alkaline earth inhibitors on the hot corrosion of superalloys, the use of both additives and the intermittent application of the inhibitors were evaluated. Additions of alkaline earth compounds to combustion gases containing sodium sulfate were shown to inhibit hot corrosion. However, sulfate deposits can lead to turbine fouling in service. For that reason, dual additives and intermittant inhibitor applications were evaluated to reduce such deposit formation. Silicon in conjunction with varium showed some promise. Total deposition was apparently reduced while the inhibition of hot corrosion by barium was unimpaired. The intermittant application of the inhibitor was found to be more effective and controllable.

  8. Corrosion inhibition property of polyester-groundnut shell biodegradable composite.

    Science.gov (United States)

    Sounthari, P; Kiruthika, A; Saranya, J; Parameswari, K; Chitra, S

    2016-12-01

    The use of natural fibers as reinforcing materials in thermoplastics and thermoset matrix composites provide optimistic environmental profits with regard to ultimate disposability and better use of raw materials. The present work is focused on the corrosion inhibition property of a polymer matrix composite produced by the use of groundnut shell (GNS) waste. Polyester (PE) was synthesized by condensation polymerization of symmetrical 1,3,4-oxadiazole and pimelic acid using sodium lauryl sulfate as surfactant. The polyester-groundnut shell composite (PEGNS) was prepared by ultrasonication method. The synthesized polyester-groundnut shell composite was characterized by FT-IR, TGA and XRD analysis. The corrosion inhibitory effect of PEGNS on mild steel in 1M H2SO4 was investigated using gravimetric method, electrochemical impedance spectroscopy, potentiodynamic polarization, atomic absorption spectroscopy and scanning electron microscopy. The results showed that PEGNS inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiency increased with increasing inhibitor concentration and decrease with increasing temperature. The composite inhibited the corrosion of mild steel through adsorption following the Langmuir adsorption isotherm. Changes in the impedance parameters Rt, Cdl, Icorr, Ecorr, ba and bc suggested the adsorption of PEGNS onto the mild steel surface, leading to the formation of protective film.

  9. C10H18N2Na2O10 inhibition and adsorption mechanism on concrete steel-reinforcement corrosion in corrosive environments

    National Research Council Canada - National Science Library

    Okeniyi, Joshua Olusegun

    2016-01-01

    C10H18N2Na2O10 (ethylenediaminetetra-acetic acid disodium salt) inhibition and adsorption mechanism on the corrosion of steel-reinforcement corrosion in concrete immersed in corrosive environments were investigated in this paper...

  10. Inhibition of Mild Steel Corrosion in Acidic Medium by Aqueous Extract of Tridax procumbens L.

    OpenAIRE

    Ilayaraja, G.; Sasieekhumar, A. R.; Dhanakodi, P.

    2011-01-01

    The inhibition efficiency (IE) of an aqueous extract of Tridax procumbens L. in controlling corrosion of mild steel has been investigated by weight loss method in the absence and presence of corrosion inhibitor at different time interval at room temperature. The result showed that the corrosion inhibition efficiency of these compounds was found to vary with different time interval and different acid concentration. Also, it was found that the corrosion inhibition behavior of Tridax procumbens ...

  11. Corrosion inhibition of copper with benzotriazole and other organic surfactants

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Y.; Guan, Y.; Han, K.N. [South Dakota School of Mines and Technology, Rapid City, SD (United States). Dept. of Metallurgical Engineering

    1995-05-01

    The corrosion behavior of copper with various organic inhibitors in aerated solutions at pH 1 to pH 2 was studied using a potentiostat. The inhibitors studied included benzotriazole (BTAH), hydroxy benzophenoximes, L-hydroxy-5-nonylacetophenone oxime, and sodium octyl hydroxamate (SOH). BTAH was shown to be the most effective of the inhibitors tested. Morphology of the copper substrate after corrosion in the presence and absence of BTAH was examined using scanning electron microscopy (SEM). Fourier transform infrared spectroscopy (FTIR) was used to identify the spectra of the adsorbed complexes (BTA). The surface film was identified as a polymeric Cu(I)-BTA complex that totally covered the copper surface, exhibiting strong corrosion inhibition. The formation of Cu(I)-BTA was found to have been accomplished after the adsorption of BTAH on the copper surface. The effect of annealing of copper plate on the rate of corrosion also was investigated, and results indicated that the annealed copper exhibited better corrosion resistance than copper plate that had not been annealed.

  12. Corrosion Inhibition by – Phthalic Acid - Zn2+ System

    Directory of Open Access Journals (Sweden)

    R. Mohan

    2014-05-01

    Full Text Available The inhibition effect of Phthalic acid(PA – Zn2+ system controls the corrosion of carbon steel has been studied by weight – loss method. The weight – loss study reveals that the formulation consisting of 60 ppm of Zn2+, 50 ppm of phthalic acid has 82 % inhibition efficiency. Synergistic effect exists between phthalic acid- Zn2+ system. The influence of N-cetyl- N, N, N-trimethylammonium bromide(CTAB on the PA- Zn2+ system control the microbial corrosion. The value of the separation factor, RL indicated the phthalic acid- Zn2+ system was favorable adsorption. The Adsorption equilibrium exhibited better fit to Langmuir isotherm than Freundlich isotherm. The protective film consists of Fe2+ - Phthalic acid and Zn(OH2 by FTIR spectroscopy.

  13. Corrosion inhibition of powder metallurgy Mg by fluoride treatments.

    Science.gov (United States)

    Pereda, M D; Alonso, C; Burgos-Asperilla, L; del Valle, J A; Ruano, O A; Perez, P; Fernández Lorenzo de Mele, M A

    2010-05-01

    Pure Mg has been proposed as a potential degradable biomaterial to avoid both the disadvantages of non-degradable internal fixation implants and the use of alloying elements that may be toxic. However, it shows excessively high corrosion rate and insufficient yield strength. The effects of reinforcing Mg by a powder metallurgy (PM) route and the application of biocompatible corrosion inhibitors (immersion in 0.1 and 1M KF solution treatments, 0.1M FST and 1M FST, respectively) were analyzed in order to improve Mg mechanical and corrosion resistance, respectively. Open circuit potential measurements, polarization techniques (PT), scanning electrochemical microscopy (SECM) and electrochemical impedance spectroscopy (EIS) were performed to evaluate its corrosion behavior. SECM showed that the local current of attacked areas decreased during the F(-) treatments. The corrosion inhibitory action of 0.1M FST and 1M FST in phosphate buffered solution was assessed by PT and EIS. Under the experimental conditions assayed, 0.1M FST revealed better performance. X-ray photoelectron spectroscopy, energy dispersive X-ray and X-ray diffraction analyses of Mg(PM) with 0.1M FST showed the presence of KMgF(3) crystals on the surface while a MgF(2) film was detected for 1M FST. After fluoride inhibition treatments, promising results were observed for Mg(PM) as degradable metallic biomaterial due to its higher yield strength and lower initial corrosion rate than untreated Mg, as well as a progressive loss of the protective characteristics of the F(-)-containing film which ensures the gradual degradation process.

  14. A computational study on corrosion inhibition performances of novel quinoline derivatives against the corrosion of iron

    Science.gov (United States)

    Erdoğan, Şaban; Safi, Zaki S.; Kaya, Savaş; Işın, Dilara Özbakır; Guo, Lei; Kaya, Cemal

    2017-04-01

    In this computational study, the adsorption and corrosion inhibition properties of some novel quinoline derivatives namely, 2-amino-7-hydroxy-4-phenyl-1,4-dihydroquinoline-3-carbonitrile (Q1), 2-amino-7-hydroxy-4-(p-tolyl)-1,4-dihydroquinoline-3-carbonitrile (Q2), 2-amino-7-hydroxy-4-(4-methoxyphenyl)-1,4-dihydroquinoline-3-carbonitrile) (Q3) and 2-amino-4-(4-(dimethylamino)phenyl)-7-hydroxy-1,4-dihydroquinoline-3-carbonitrile (Q4) on the corrosion of iron were investigated using quantum chemical and molecular dynamics simulation approaches. Quantum chemical calculations section of the study provides enough calculation and discussion on the relationship between corrosion inhibition and global reactivity descriptors such as EHOMO, ELUMO, HOMO-LUMO energy gap (ΔE), chemical hardness (η), softness (σ), electronegativity (χ), chemical potential (μ), electrophilicity (ω), nucleophilicity (ɛ), electrons transferred from inhibitors to metal surface (ΔN), initial molecule-metal interaction energy (Δψ), total electronic energy (E), the energy change during electronic back-donation process (ΔEb-d). The adsorption behaviors of studied compounds on Fe (110) surface were investigated with the help of molecular dynamics simulation approach. The binding energies calculated on Fe (110) surface of mentioned quinoline derivatives followed the order: Q4 > Q3 > Q2 > Q1. It should be noted that the results obtained in the study are in good agreement with experimental inhibition efficiency results earlier reported.

  15. Adsorption and corrosion inhibiting effect of riboflavin on Q235 mild steel corrosion in acidic environments

    Energy Technology Data Exchange (ETDEWEB)

    Chidiebere, Maduabuchi A. [Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Rd, Shenyang 110016 (China); Electrochemistry and Materials Science Research Laboratory, Department of Chemistry, Federal University of Technology Owerri, PMB 1526 Owerri (Nigeria); Oguzie, Emeka E. [Electrochemistry and Materials Science Research Laboratory, Department of Chemistry, Federal University of Technology Owerri, PMB 1526 Owerri (Nigeria); Liu, Li [Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Rd, Shenyang 110016 (China); Li, Ying, E-mail: liying@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Rd, Shenyang 110016 (China); Wang, Fuhui [Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Rd, Shenyang 110016 (China)

    2015-04-15

    The inhibiting effect of Riboflavin (RF) on Q235 mild steel corrosion in 1 M HCl and 0.5 M H{sub 2}SO{sub 4} at 30 °C temperature was investigated using electrochemical techniques (electrochemical impedance spectroscopy and potentiodynamic polarization). The obtained results revealed that RF inhibited the corrosion reaction in both acidic solutions. Maximum inhibition efficiency values in 1 M HCl and 0.5 M H{sub 2}SO{sub 4} were 83.9% and 71.4%, respectively, obtained for 0.0012 M RF. Polarization data showed RF to be a mixed-type inhibitor, while EIS results revealed that the RF species adsorbed on the metal surface. The adsorption of RF followed Langmuir adsorption isotherm. Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) studies confirmed the formation of a protective layer adsorbed on the steel surface. Quantum chemical calculations were used to correlate the inhibition ability of RF with its electronic structural parameters. - Highlights: • The inhibitory mechanism was influenced by the nature of acid anions. • RF has reasonable inhibition effect especially in 1 M HCl solution. • Polarization studies showed that RF functioned as a mixed type inhibitor. • Improved surface morphology was observed in the presence of RF.

  16. Synergistic Effect on Corrosion Inhibition Efficiency of Ginger Affinale Extract in Controlling Corrosion of Mild Steel in Acid Medium

    Energy Technology Data Exchange (ETDEWEB)

    Subramanian, Ananth Kumar; Arumugam, Sankar [Kandaswami Kandar' s College, Namakkal (India); Mallaiya, Kumaravel; Subramaniam, Rameshkumar [PSG College of Technology Peelamedu, Coimbatore (India)

    2013-12-15

    The corrosion inhibition nature of Ginger affinale extract for the corrosion of mild steel in 0.5N H{sub 2}SO{sub 4} was investigated using weight loss, electrochemical impedance and potentiodynamic polarization methods. The results revealed that Ginger affinale extract acts as a good corrosion inhibitor in 0.5N H{sub 2}SO{sub 4} medium. The inhibition efficiency increased with an increase in inhibitor concentration. The inhibition could be attributed to the adsorption of the inhibitor on the steel surface.

  17. Adsorption and corrosion-inhibiting effect of Dacryodis edulis extract on low-carbon-steel corrosion in acidic media.

    Science.gov (United States)

    Oguzie, E E; Enenebeaku, C K; Akalezi, C O; Okoro, S C; Ayuk, A A; Ejike, E N

    2010-09-01

    The inhibition of low-carbon-steel corrosion in 1M HCl and 0.5M H(2)SO(4) by extracts of Dacryodis edulis (DE) was investigated using gravimetric and electrochemical techniques. DE extract was found to inhibit the uniform and localized corrosion of carbon steel in the acidic media, affecting both the cathodic and anodic partial reactions. The corrosion process was inhibited by adsorption of the extracted organic matter onto the steel surface in a concentration-dependent manner and involved both protonated and molecular species. Molecular dynamics simulations were performed to illustrate the process of adsorption of some specific components of the extract.

  18. Corrosion Inhibition of Mild Steel in Seawater using Jatropha Stem

    Directory of Open Access Journals (Sweden)

    Olawale Olamide

    2016-10-01

    Full Text Available The present work investigate the inhibition of Jatropha Stem Extract (JSE in sea water using mild steel coupons of dimension 5 × 5 × 0.5 cm. The cupons were immersed in test solutions of sea water and varied concentrations of extracts of 0.1g/l to 0.9g/l was used. The functional groups of the compounds was analyzed using an FTIR. The results showed that as the concentration of the extract increases, there was a reduction in the corrosion rates. Furthermore, as the extract concentrations increased from 0.1g/l to 0.4g/l at 48hrs exposure time, the weight loss decreased by 14.3% in the medium. However, the Jatropha Stem Extract was absorbed on the substrate surface to inhibit corrosion, the morphology of phases formed from the scanning Electron Microscopy examination confirmed this trend. Hence, JSE is a good and safe inhibitor in sea water solution. The FT-IR results also indicates the presence of active corrosion inhibitor present in the Jatropha Stem.

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Acid Corrosion Inhibition and Adsorption Behaviour of Ethyl Hydroxyethyl Cellulose on Mild Steel Corrosion

    Directory of Open Access Journals (Sweden)

    I. O. Arukalam

    2014-01-01

    Full Text Available The corrosion inhibition of mild steel in 1.0 M H2SO4 solution by ethyl hydroxyethyl cellulose has been studied in relation to the concentration of the additive using weight loss measurement, EIS, polarization, and quantum chemical calculation techniques. The results indicate that EHEC inhibited corrosion reaction in the acid medium and inhibition efficiency increased with EHEC concentration. Further increase in inhibition efficiency is observed in the presence of iodide ions, due to synergistic effect. Impedance results reveal that EHEC is adsorbed on the corroding metal surface. Adsorption followed a modified Langmuir isotherm, with very high negative values of the free energy of adsorption (ΔGads. The polarization data indicate that the inhibitor was of mixed type, with predominant effect on the cathodic partial reaction. The frontier molecular orbitals, HOMO (the highest occupied molecular orbital and LUMO (the lowest unoccupied molecular orbital as well as local reactivity of the EHEC molecule, were analyzed theoretically using the density functional theory to explain the adsorption characteristics at a molecular level. The theoretical predictions showed good agreement with experimental results.

  1. Quantum Chemical Study on the Corrosion Inhibition of Some Oxadiazoles

    Directory of Open Access Journals (Sweden)

    Hong Ju

    2015-01-01

    Full Text Available Quantum chemical calculations based on DFT method were performed on three nitrogen-bearing heterocyclic compounds used as corrosion inhibitors for the mild steel in acid media to determine the relationship between the molecular structure of inhibitors and inhibition efficiency. The structural parameters, such as energy and distribution of highest occupied molecular orbital (HOMO and lowest unoccupied molecular orbital (LUMO, the charge distribution of the studied inhibitors, the absolute electronegativity (χ values, and the fraction of electrons (ΔN transfer from inhibitors to mild steel were also calculated and correlated with inhibition efficiencies. The results showed that the inhibition efficiency of inhibitors increased with the increase in energy of HOMO and decrease in energy gap of frontier molecular orbital, and the areas containing N and O atoms are most possible sites for bonding the steel surface by donating electrons to the mild steel.

  2. Corrosion inhibition of aluminum 6063 using some pharmaceutical compounds

    Energy Technology Data Exchange (ETDEWEB)

    Fouda, A.S. [Department of Chemistry, Faculty of Science, El-Mansoura University, El-Mansoura 35516 (Egypt)], E-mail: asfouda@mans.edu.eg; Al-Sarawy, A.A. [Department of Chemistry, Faculty of Engineering, El-Mansoura University, El-Mansoura (Egypt); Ahmed, F.Sh. [Department of Chemistry, Faculty of Science (Demitta), El-Mansoura University, El-Mansoura (Egypt); El-Abbasy, H.M. [Department of Chemistry, Faculty of Science, El-Mansoura University, El-Mansoura 35516 (Egypt)

    2009-03-15

    The corrosion inhibition characteristics of some pharmaceutical compounds on aluminum 6063 in 0.5 mol l{sup -1} H{sub 3}PO{sub 4} has been studied using weight loss and galvanostatic polarization techniques. Results showed that the inhibition occurs through adsorption of the inhibitor molecules on the metal surface. The inhibition efficiency increased with increasing inhibitor concentration, but decreased with increasing temperature. The adsorption of first group pharmaceutical compounds on the metal surface is found to obey Frumkin's adsorption isotherm, but the adsorption of second group pharmaceutical compounds is found to obey Temkin's adsorption isotherm. Thermodynamic parameters for adsorption process were determined. Galvanostatic polarization studies showed that first and second groups' pharmaceutical compounds are mixed-type inhibitors and the results obtained from the two techniques are in good agreement.

  3. Influence of Benzotriazole on Corrosion Inhibition of Mild Steel in Citric Acid Medium

    OpenAIRE

    P. Matheswaran; A. K. Ramasamy

    2010-01-01

    Benzotriazole an organic compounds has been studied as corrosion inhibition for mild steel in 1 N citric acid by weight loss method. The result showed that the corrosion inhibition efficiency of the compound was found to be varying with the temperature and acid concentration. Also it was found that the corrosion inhibition behaviour of benzotriazole is better when the concentration of inhibitor is increased. The kinetic treatment of the results shows first order kinetics.

  4. Novel package for inhibition of aluminium corrosion in alkaline solutions

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Gaber, A.M., E-mail: ashrafmoustafa@yahoo.com [Chemistry Department, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt); Khamis, E.; Abo-Eldahab, H.; Adeel, Sh. [Chemistry Department, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt)

    2010-11-01

    Inhibition of aluminium corrosion in 2 M sodium hydroxide solution by a package composed of the cationic surfactant cetyl trimethyl ammonium bromide (CTAB) and lupine seed extract has been investigated employing different electrochemical techniques and chemical gasometry measurements. Potentiodynamic polarization curve measurements showed that lupine seed extract controls both the anodic dissolution of aluminium and the hydrogen gas evolved at the cathodic sites of aluminium surface. Nyquist plots showed two capacitive semicircles in the high and low frequency regions separated by an inductive loop at intermediate frequencies. The inductive loop may be explained by the occurrence of adsorbed intermediates on the surface. A proposed equivalent circuit was used to analyse the impedance spectra for aluminium in NaOH solutions. The corrosion inhibition data have been analysed using different isotherms. The results showed excellent agreement between the kinetic-thermodynamic model and Flory-Huggins isotherm. Gasometry measurements showed that the Inhibitive effect of the surfactant increases at a composition around its critical micelle concentration (cmc). The presence of both the surfactant and lupine seed extract did not indicate synergistic action between them. The mode of adsorption of the surfactant molecules corresponding to their structure is also discussed.

  5. Synergistic effects in the inhibition of copper corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, S.; Laz, M.M.; Souto, R.M. (Univ. de La Laguna, Tenerife, (Spain). Dept. de Quimica Fisica); Salvarezza, R.C.; Arvia, A.J. (Univ. Nacional de La Plata, (Argentina))

    1993-06-01

    Benzotriazole (BTA), thiourea (TU), and potassium ethylxanthate (KEX), behave as copper (Cu) corrosion inhibitors under certain conditions. These chemicals have been investigated to establish whether they provided synergistic effects. The Cu corrosion inhibition was followed through changes in electrochemical characteristics. Cu specimens were tested at 25 C in two aggressive media, 0.1 M NaCl and 1 M NaClO[sub 4] using the linear potential sweep technique at 0.001 V/s and by scanning electron microscopy of Cu specimens subjected to potentiodynamic and potentiostatic routines. A comparative behavior of the different substances for Cu was presented in the 6.6 [le] pH [le] 11 range. For KEX-BTA mixtures, synergistic inhibition effects were found in 0.1 M NaCl (7 [le] pH [le] 11). The apparent synergistic inhibition was explained tentatively by an increase in the compactness of the polymer-like passivating layer of KEX-Cu, which formed in the presence of BTA and Cl[minus] ions.

  6. Outstanding inhibitive effect of colchicine on aluminium alloy 6061 corrosion

    Directory of Open Access Journals (Sweden)

    Mudigere Krishnegowda Pavithra

    2015-12-01

    Full Text Available The corrosion protection ability of colchicine (CC on Aluminium alloy 6061 (AA6061 in 3.5% NaCl medium was examined by potentiodynamic polarization, electrochemical impedance, and chronoamperometric techniques. About 99 % of protection efficiency was achieved by 2 mM concentration of CC in 3.5% NaCl solution.The adsorption of CC on AA6061 surface obeys Langmuir isotherm by following both physisorption and chemisorption mechanism. Variation in the surface morphology of inhibited and uninhibited metal samples was examined by scanning electron microscopy. 

  7. Corrosion inhibition of carbon steel by extract of Buddleia perfoliata

    Directory of Open Access Journals (Sweden)

    ROY LOPES-SESENES

    2012-06-01

    Full Text Available Buddleia perfoliata leaves extract has been investigated as a carbon steel corrosion inhibitor in 0.5 M sulfuric acid by using polarization curves, electrochemical impedance spectroscopy and weight-loss tests at different concentrations (0, 100, 200, 300, 400 and 500 ppm and temperatures, namely 25, 40 and 60 °C. Results showthat inhibition efficiency increases as the inhibitor concentration increases, decreases with temperature, and reaches a maximum value after 12 h of exposure, decreasing with a further increase in the exposure time. It was found that the inhibitory effect is due to the presence of tannines on this extract.

  8. 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.

  9. Corrosion Inhibition by Sodium Gluconate-Zn2+-DTPMP System

    Directory of Open Access Journals (Sweden)

    P. Manjula

    2009-01-01

    Full Text Available The inhibition efficiency of a phosphonic acid, Diethylene Triamine Pentamethylene Phosphonic acid (DTPMP in controlling corrosion of carbon steel immersed in an aqueous solution containing 60 ppm of Cl- has been evaluated by weight loss method in the absence and presence of Zn2+. The formulation consisting of DTPMP and Zn2+ has excellent inhibition efficiency (IE. A synergistic effect is noticed between Zn2+ and DTPMP. Addition of sodium gluconate (SG enhances the IE of Zn2+ and DTPMP system. The DTPMP-Zn2+-SG system function as a mixed inhibitor as revealed by polarization study. AC impedance spectrum, optical and atomic force micrographs reveal the formation of a protective film on the metal surface. FTIR spectra reveal that the protective film consists of Fe2+-DTPMP complex, Fe2+-SG complex and Zn(OH2.

  10. Inhibition of acidic corrosion of aluminum by triazoline derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Khamis, E. (Alexandria Univ., Ibrahimia (Egypt). Dept. of Chemistry); Atea, M. (Alexandria Univ., Ibrahimia (Egypt). Dept. of Materials Science)

    1994-02-01

    Inhibition of the corrosion of aluminum (Al) in hydrochloric acid (HCl) by some triazoline derivatives was studied in relation to the concentration of the inhibitors using gasometry, the weight-loss method, and the potentiodynamic technique. All compounds investigated were found to be inhibitors of the mixed type. The inhibitory character of the additives depended upon the +R (resonance) and +I (inductive) powers of alkyl or aryl groups of the triazoline derivatives. Inhibition was ascribed to the adsorption of the inhibitor onto the metal oxide surface following the Flory-Huggins isotherm. The compounds were adsorbed on the metal surface. Each molecule of the inhibitors occupied an average of 3.8 active sites on the metal surface. The values of activation free energies varied between [minus]30 kJ/mol and [minus]45 kJ/mol.

  11. Electrochemical study of corrosion inhibition of stainless steel in phosphoric medium

    Energy Technology Data Exchange (ETDEWEB)

    Hnini, K.; Chtaini, A. [Laboratoire d' Electrochimie et de Bio Corrosion, Faculte des Sciences et Techniques, Beni-Mellal (Morocco); Khouili, M.; Elbouadili, A. [Laboratoire de Chimie Organique et Analytique, Faculte des Sciences et Techniques, Beni-Mellal (Morocco)

    2004-07-01

    The corrosion of metals represents a terrible waste of both natural resources and money, the failure of some stainless steel resulting from pitting corrosion is some times considered a technological problem, consequently, much effort has been expended in attempting to understand and overcome the corrosion therefore, many stainless steel/ environment combinations have been studied. The use of heterocyclic compounds as inhibitors is one of the most practical methods for protection against corrosion in acidic media. In continuation of our work on development of macrocyclic compounds as corrosion inhibitors we report in our study the corrosion inhibiting behaviour of organic compound Methoxy-2-Allyl-4 Phenol (MAP) containing coordinating and conjugation groups, at three forms (natural, polymerized and chemically treated) on the corrosion of stainless steel in phosphoric acid. This study focused on the comparison for corrosion inhibition proprieties of these different applications using potentiodynamic polarization, electrochemical impedance spectroscopy and SEM. The specimen was evaluated to determine change in his corrosion potential and resistance polarization; These MAP products have exhibited corrosion inhibition by maintaining a high resistance polarization (low corrosion rate) in each application. These results reveal that this compound is efficient inhibitor in all forms; the most inhibition efficiency is obtained with polymerized form. To further evaluate the test data, the steel surfaces were analyzed using scanning electron microscopy, SEM observations of surface treated concrete confirmed presence of inhibitor on the steel surfaces. (authors)

  12. Attenuated total reflectance spectroscopy of simultaneous processes: Corrosion inhibition of cuprous oxide by benzotriazole

    Science.gov (United States)

    Bratescu, Maria Antoaneta; Allred, Daniel B.; Saito, Nagahiro; Sarikaya, Mehmet; Takai, Osamu

    2008-03-01

    Attenuated total reflectance (ATR) spectroscopy was used to perform in situ studies of the corrosion inhibition of cuprous oxide (Cu 2O) by benzotriazole (BTA) in aqueous solution at concentrations from 1 to 20 μM. Because two separate processes occur simultaneously, that of Cu 2O corrosion and corrosion inhibition by BTA adsorption, the spectral information was subjected to deconvolution by a conjugate gradient minimization algorithm. Under these conditions, a solution phase concentration of 7-10 μM BTA nearly completely inhibited the corrosion of Cu 2O in deionized water. Using a Langmuir adsorption model, this represented only 25% of the maximally covered surface area.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Inhibition of Mild Steel Corrosion in Acidic Medium by Aqueous Extract of Tridax procumbens L.

    Directory of Open Access Journals (Sweden)

    G. Ilayaraja

    2011-01-01

    Full Text Available The inhibition efficiency (IE of an aqueous extract of Tridax procumbens L. in controlling corrosion of mild steel has been investigated by weight loss method in the absence and presence of corrosion inhibitor at different time interval at room temperature. The result showed that the corrosion inhibition efficiency of these compounds was found to vary with different time interval and different acid concentration. Also, it was found that the corrosion inhibition behavior of Tridax procumbens L. is greater in sulphuric acid than hydrochloric acid medium. So Tridax procumbens L. can be used as a good inhibitor for preventing mild steel material.

  15. Influence of Formazan Derivatives on Corrosion Inhibition of Mild Steel in Hydrochloric Acid Medium

    Directory of Open Access Journals (Sweden)

    P. Venkatesan

    2009-01-01

    Full Text Available Formazan of benzaldehyde (FB and formazan of p-dimethyl amino benzaldehyde (FD were synthesized. These compounds were studied as corrosion inhibitor for mild steel in 1.11 N hydrochloric acid by weight loss method. The result showed that the corrosion inhibition efficiency of these compounds was found to vary with the temperature and acid concentration. Also, it was found that the corrosion inhibition behaviour of FD is greater than that of FB. The kinetic treatment of the results gave first order kinetics. The relative corrosion inhibition efficiency of these compounds has been explained on the basis of structure dependent - electron donor properties of the inhibitors.

  16. Corrosion Inhibition and Adsorption Properties of Ethanolic Extract of Calotropis for Corrosion of Aluminium in Acidic Media

    OpenAIRE

    Sudesh Kumar; Suraj Prakash Mathur

    2013-01-01

    The corrosion inhibition of aluminium in sulfuric acid solution in the presence of different plant parts, namely, leaves, latex, and fruit was studied using weight loss method and thermometric method. The ethanolic extracts of Calotropis procera and Calotropis gigantea act as an inhibitor in the acid environment. The inhibition efficiency increases with increase in inhibitor concentration. The plant parts inhibit aluminium, and inhibition is attributed, due to the adsorption of the plant part...

  17. Corrosion Inhibition Synergism between Lanthanum(Ⅲ) Ion and 8-Hydroxyquinoline for Zinc in Hydrochloric Acid

    Institute of Scientific and Technical Information of China (English)

    木冠南; 唐丽斌; 李学铭

    2002-01-01

    The effects of La3+ ion and chelate reagent 8-hydroxyquinoline on the corrosion rate of zinc in hydrochloric acid were investigated by using weight loss method and electrochemical method. It is found that in a specific concentration range of La3+ ion and 8-hydroxyquinoline, the obvious corrosion inhibition synergism is obtained. The mechanism of corrosion inhibition synergism was discussed on basis of adsorption theory.

  18. Influence of Formazan Derivatives on Corrosion Inhibition of Mild Steel in Hydrochloric Acid Medium

    OpenAIRE

    Venkatesan, P.; Anand, B.; P. Matheswaran

    2009-01-01

    Formazan of benzaldehyde (FB) and formazan of p-dimethyl amino benzaldehyde (FD) were synthesized. These compounds were studied as corrosion inhibitor for mild steel in 1.11 N hydrochloric acid by weight loss method. The result showed that the corrosion inhibition efficiency of these compounds was found to vary with the temperature and acid concentration. Also, it was found that the corrosion inhibition behaviour of FD is greater than that of FB. The kinetic treatment of the results gave firs...

  19. Corrosion Inhibition of Carbon Steel in HCl Solution by Some Plant Extracts

    Directory of Open Access Journals (Sweden)

    Ambrish Singh

    2012-01-01

    Full Text Available The strict environmental legislations and increasing ecological awareness among scientists have led to the development of “green” alternatives to mitigate corrosion. In the present work, literature on green corrosion inhibitors has been reviewed, and the salient features of our work on green corrosion inhibitors have been highlighted. Among the studied leaves, extract Andrographis paniculata showed better inhibition performance (98% than the other leaves extract. Strychnos nuxvomica showed better inhibition (98% than the other seed extracts. Moringa oleifera is reflected as a good corrosion inhibitor of mild steel in 1 M HCl with 98% inhibition efficiency among the studied fruits extract. Bacopa monnieri showed its maximum inhibition performance to be 95% at 600 ppm among the investigated stem extracts. All the reported plant extracts were found to inhibit the corrosion of mild steel in acid media.

  20. Inhibition of carbon steel corrosion by 11-aminoundecanoic acid

    Directory of Open Access Journals (Sweden)

    Saad Ghareba

    2015-12-01

    Full Text Available The current study reports results on the investigation of the possibility of using 11-aminoundecanoic acid (AA as an inhibitor of general corrosion of carbon steel (CS in HCl under a range of experimental conditions: inhibitor concentration, exposure time, electrolyte temperature and pH and CS surface roughness. It was found that AA acts as a mixed-type inhibitor, yielding maximum inhibition efficiency of 97 %. The adsorption of AA onto the CS surface was described by the Langmuir adsorption isotherm. The corresponding apparent Gibbs free energy of AA adsorption on CS at 295 K was calculated to be −30.2 kJ mol–1. The adsorption process was found to be driven by a positive change in entropy of the system. PM-IRRAS measurements revealed that the adsorbed AA layer is amorphous, which can be attributed to the repulsion between the neighboring positively charged amine groups and a high heterogeneity of the CS surface. It was also found that the AA provides very good corrosion protection of CS of various surface roughness, and over a prolonged time.

  1. Inhibition of mild steel corrosion using Jatropha Curcas leaf extract

    Directory of Open Access Journals (Sweden)

    OLORUNFEMI MICHAEL AJAYI

    2014-05-01

    Full Text Available Jatropha Curcas leaf was investigated as a green inhibitor on the degradation of mild steel in 4 M HCl and 4 M H2SO4 aqueous solutions using gasometric technique. Mild steel coupons of dimension 2 × 1.5 cm were immersed in test solutions of uninhibited acid and also those with extract concentrations of 4 ml, 6 ml, 8 ml and 10 ml at 30 oC, for up to 30 minutes. The results showed that as the concentration of the extract increases, there was reduction in the corrosion rate. As the extract concentration increased from 4 ml to 10 ml at 30 minutes exposure, the volume of hydrogen gas evolved decreased from 19.1 cm3 to 11.2 cm3 in H2SO4 medium, while it reduced to 5 cm3 from 9 cm3 in HCl medium. Also, the metal surface-phytoconstituent interaction mechanism showed that 6 minutes is the best exposure time for the adsorption of the extract in both acidic media. The Jatropha Curcas leaf extract was adsorbed on the mild steel surface to inhibit corrosion, while the experimental data obtained at 30 minutes exposure in both acidic media were well fitted with the Langmuir adsorption isotherm. Hence, Jatropha Curcas leaf extract is a good and safe inhibitor in both acidic solutions.

  2. Effect of heat treatment on the inhibition of the acidic corrosion aluminium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Khamis, E. (Alexandria Univ. (Egypt). Dept. of Chemistry); El-Gamal, M. (Alexandria Univ. (Egypt). Dept. of Material Science); El-Toukhy, A. (Alexandria Univ. (Egypt). Dept. of Material Science); Atea, M. (Alexandria Univ. (Egypt). Dept. of Material Science)

    1994-12-01

    The effect of heat treatment on the inhibition of acid corrosion of duralumin has been studied using gasometry, mass loss measurements and potentiodynamic technique. All the data reveal that the duralumin generally developed good corrosion resistance after heat treatment and the corrosion rate ranked as follows: Non treated > Naturally aged > quenched. This improvement in the corrosion resistance was attributed to the structural homogeneity of the heat-treated alloys. The presence of some selected aryl and alkyl triazoline derivatives at the threshold concentration of 5 x 10[sup -3] M indicate that these compounds retard the corrosion rate of duralumin and the extent of inhibition depends on the molecular structure of the inhibitors. Polarization curves show that the triazoline compounds act as mixed-type inhibitors affecting both the cathodic and anodic processes. Moreover, there is no noticeable difference in the degree by which the triazoline derivatives inhibit the corrosion of pure aluminium and heat treated duralumin alloy. (orig.)

  3. A Comparative Study on Corrosion Inhibition of Mild Steel Using Piper Nigrum L. in Different Acid Medium

    OpenAIRE

    Anand, B.; Balasubramanian, V

    2010-01-01

    The inhibition of corrosion of mild steel using Piper nigrum L in different acid medium by weight loss method was investigated. The corrosion inhibition was studied in hydrochloric acid and sulphuric acid by weight loss method at different time interval at room temperature. The result showed that the corrosion inhibition efficiency of this compound was found to vary with different time interval and different acid concentration. Also, it was found that the corrosion inhibition behavior of Pipe...

  4. 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.

  5. Corrosion Inhibition of Cast Iron in Arabian Gulf Seawater by Two Different Ionic Liquids

    Directory of Open Access Journals (Sweden)

    El-Sayed M. Sherif

    2015-06-01

    Full Text Available In this paper we report on the corrosion inhibition of cast iron in Arabian Gulf seawater by two different ionic liquids namely, 1-ethyl-3-methylimidazolium chloride ([EMIm]Cl and 1-butyl-1-methylpyrrolidinium chloride ([Py1,4]Cl. The inhibiting influence of the employed ionic liquids was investigated by weight loss, open circuit potential electrochemical impedance spectroscopy, and cyclic potentiodynamic polarization. The results show the corrosion inhibition impact of the employed ionic liquids (ILs. Compared with [Py1,4]Cl, [EMIm]Cl shows a higher inhibition efficiency at a short immersion time, for the examined ILs concentrations. However, [Py1,4]Cl exhibits a higher efficiency upon increasing the immersion time indicating the persistence of the inhibiting influence. The corrosion inhibition of the employed ionic liquids is attributed to the adsorption of the cations of the ionic liquids onto the surface of cast iron forming a corrosion barrier.

  6. Inhibition of the Cu65/Zn35 brass corrosion by natural extract of Camellia sinensis

    Energy Technology Data Exchange (ETDEWEB)

    Ramde, Tambi, E-mail: t_ramde@univ-ouaga.bf [Equipe Chimie Physique et Electrochimie, Laboratoire de Chimie Moléculaire et des Matériaux, Université de Ouagadougou, 03 BP 7021 Ouagadougou 03 (Burkina Faso); Department of Industrial Engineering, University of Trento, via Sommarive 9, 38123 Trento (Italy); Rossi, Stefano; Zanella, Caterina [Department of Industrial Engineering, University of Trento, via Sommarive 9, 38123 Trento (Italy)

    2014-07-01

    In this work, the corrosion inhibition of brass was studied using natural plant extract, Camellia sinensis, in 0.1 M Na2SO4 solutions with pH 7 and pH 4. Electrochemical techniques (potentiodynamic polarization, electrochemical impedance spectroscopy) and scanning electron microscopy (SEM) were applied to study the brass corrosion behavior in presence and absence of the extract. The results indicated that the extract is a very effective corrosion inhibitor for brass corrosion process in both the acidic and neutral media by virtue of adsorption. The inhibition effect increases by time as demonstrated by the EIS monitoring for 120 h. In the blank solution the corrosion process leads to the formation of a dark oxide patina at pH 7 and induces localized corrosion morphology at pH 4. The extract presence can avoid both the dark patina and the pits formation.

  7. Effects of Solution Hydrodynamics on Corrosion Inhibition of Steel by Citric Acid in Cooling Water

    Science.gov (United States)

    Ashassi-Sorkhabi, H.; Asghari, E.; Mohammadi, M.

    2014-08-01

    Corrosion is a major problem in cooling water systems, which is often controlled using corrosion inhibitors. Solution hydrodynamics is one of the factors affecting corrosion inhibition of metals in these systems. The present work focuses on the study of the combined effects of citric acid concentration (as a green corrosion inhibitor) and fluid flow on corrosion of steel in simulated cooling water. Electrochemical techniques including Tafel polarization and electrochemical impedance spectroscopy were used for corrosion studies. Laminar flow was simulated using a rotating disk electrode. The effects of solution hydrodynamics on inhibition performance of citric acid were discussed. The citric acid showed low inhibition performance in quiescent solution; however, when the electrode rotated at 200 rpm, inhibition efficiency increased remarkably. It was attributed mainly to the acceleration of inhibitor mass transport toward metal surface. The efficiencies were then decreased at higher rotation speeds due to enhanced wall shear stresses on metal surface and separation of adsorbed inhibitor molecules. This article is first part of authors' attempts in designing green inhibitor formulations for industrial cooling water. Citric acid showed acceptable corrosion inhibition in low rotation rates; thus, it can be used as a green additive to the corrosion inhibitor formulations.

  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. Experimental and quantum chemical studies on corrosion inhibition performance of fluconazole in hydrochloric acid solution

    Indian Academy of Sciences (India)

    P Malekmohammadi Nouri; M M Attar

    2015-04-01

    The corrosion inhibition effect of fluconazole (FLU) was investigated on steel in 1 M hydrochloric acid solution. Weight loss measurements and atomic force microscope analysis were utilized to investigate the corrosion inhibition properties and film formation behaviour of FLU. Quantum chemical approach was also used to calculate some electronic properties of the molecule in neutral and protonated form in order to find any correlation between the inhibition effect and molecular structure of FLU molecule. The results showed that FLU can act as a good corrosion inhibitor for steel in hydrochloric acid solution at different temperatures and it can inhibit steel corrosion up to 95%. The adsorption followed the Langmuir isotherm and the thermodynamic parameters were also determined and discussed. Quantum chemical studies showed that in adsorption process of FLU molecules, nitrogen and oxygen atoms and benzene ring act as active centres.

  10. Application of transient analysis using Hilbert spectra of electrochemical noise to the identification of corrosion inhibition

    NARCIS (Netherlands)

    Homborg, A.M.; Westing, E.P.M. van; Tinga, T.; Ferrari, G.M.; Zhang, X.; Wit, J.H.W. de; Mol, J.M.C.

    2014-01-01

    This study validates the ability of Hilbert spectra to investigate transients in an electrochemical noise signal for an aqueous corrosion inhibition process. The proposed analysis procedure involves the identification and analysis of transients in the electrochemical current noise signal. Their

  11. Inhibition of Mild Steel Corrosion in Hydrochloric Acid Solution by Ciprofloxacin Drug

    OpenAIRE

    2013-01-01

    The inhibition of mild steel corrosion in hydrochloric acid solution by ciprofloxacin drug as an eco-friendly and commercially available inhibitor was studied at room temperature by weight loss technique. It was found that the test drug has a promising inhibitory action against corrosion of mild steel in the medium investigated. The inhibition efficiency was found to increase with a corresponding increase in the concentration of the inhibitor. It was also found that the adsorption as well as ...

  12. Comparison Of Metal Corrosion Inhibition By Gravimetric And Linear Polarization Resistance Methods

    OpenAIRE

    1992-01-01

    Studies were conducted to evaluate the effectiveness of various dosages of the selected silicate and phosphate compounds applied for corrosion inhibition of cast iron, copper, lead, and galvanized steel specimens. The compounds selected for study were zinc polyphosphate (Calgon C-39), zinc orthophosphate (Virchem V-931), sodium metasilicate and glassy silicate. The effectiveness of these compounds for corrosion inhibition were studied under differing water quality conditions using gravimetric...

  13. Three-Layer PE Corrosion-Inhibiting Coating for Steel Pipeline

    Institute of Scientific and Technical Information of China (English)

    Li Aiguo; Zheng Aijing

    1994-01-01

    @@ RIET (Research Institute of Engineering Technology of China National Petroleum Corporation)had got a lender contract for manufacturing corrosion-inhibiting coating for steel pipe piles through international competitive bidding in the extension section project of Dandong Port (China)in 1992. The contract had been completed by May 1993. Now, brief descriptions of the corrosion-inhibiting coating manufactured by RIETare presented as following.

  14. Method for inhibiting corrosion of nickel-containing alloys

    Science.gov (United States)

    DeVan, J.H.; Selle, J.E.

    Nickel-containing alloys are protected against corrosion by contacting the alloy with a molten alkali metal having dissolved therein aluminum, silicon or manganese to cause the formation of a corrosion-resistant intermetallic layer. Components can be protected by applying the coating after an apparatus is assembled.

  15. The Corrosion Inhibition Characteristics of Sodium Nitrite Using an On-line Corrosion Rate Measurement System

    Energy Technology Data Exchange (ETDEWEB)

    Park, Mal-Yong; Kang, Dae-Jin [Korea Polytechnic University, Shiheung (Korea, Republic of); Moon, Jeon-Soo [Future Technology Research Laboratory, KEPCO Research Institute, Daejeon (Korea, Republic of)

    2015-04-15

    An on-line corrosion rate measurement system was developed using a personal computer, a data acquisition board and program, and a 2-electrode corrosion probe. Reliability of the developed system was confirmed with through comparison test. With this system, the effect of sodium nitrite (NaNO{sub 2}) as a corrosion inhibitor were studied on iron and aluminum brass that were immersed in sodium chloride (NaCl) solution. Corrosion rate was measured based on the linear polarization resistance method. The corrosion rates of aluminum brass and iron in 1% NaCl solutions were measured to be 0.290 mm per year (mmpy) and 0.2134 mmpy, respectively. With the addition of 200 ppm of NO{sub 2}{sup -}, the corrosion rates decreased to 0.0470 mmpy and 0.0254 mmpy. The addition of NO{sub 2}{sup -} caused a decrease in corrosion rates of both aluminum brass and iron, yet the NO{sub 2}{sup -} acted as a more effective corrosion inhibitor for iron. than aluminum brass.

  16. Inhibition of the corrosion of steel in 1 M HCl by eugenol derivatives

    Science.gov (United States)

    Chaieb, E.; Bouyanzer, A.; Hammouti, B.; Benkaddour, M.

    2005-06-01

    The effect of eugenol (Eug) and its derivative acetyleugenol (AcEug) extracted from the nail of giroflier on the corrosion of steel in molar hydrochloric acid has been studied using weight loss measurements, electrochemical polarisation and EIS methods. The naturally substances reduce the corrosion rate. The inhibition efficiency was found to increase with acetyleugenol content to attain 91% at 0.1737 g/l. Eugenol compounds act as mixed type inhibitors. The effect of temperature on the corrosion behaviour of steel indicates that inhibition efficiency of the natural substance increases with the rise of temperature. The adsorption of natural product on the steel is found to follow the Langmuir adsorption isotherm.

  17. Application of electrochemical frequency modulation for monitoring corrosion and corrosion inhibition of iron by some indole derivatives in molar hydrochloric acid

    Energy Technology Data Exchange (ETDEWEB)

    Khaled, K.F. [Electrochemistry Research Laboratory, Chemistry Department, Faculty of Education, Ain Shams University, Roxy, Cairo (Egypt)], E-mail: khaled@asunet.shams.edu.eg

    2008-11-15

    The corrosion inhibition effect of four indole derivatives, namely indole (IND), benzotriazole (BTA), benzothiazole (BSA) and benzoimidazole (BIA), have been used as possible corrosion inhibitors for pure iron in 1 M HCl. In this study, electrochemical frequency modulation, EFM was used as an effective method for corrosion rate determination in corrosion inhibition studies. By using EFM measurements, corrosion current density was determined without prior knowledge of Tafel slopes. Corrosion rates obtained using EFM, were compared to that obtained from other chemical and electrochemical techniques. The results obtained from EFM, EIS, Tafel and weight loss measurements were in good agreement. Tafel polarization measurements show that indole derivatives are cathodic-type inhibitors. Molecular simulation studies were applied to optimize the adsorption structures of indole derivatives. The inhibitor/iron/solvent interfaces were simulated and the adsorption energies of these inhibitors were calculated. Quantum chemical calculations have been performed and several quantum chemical indices were calculated and correlated with the corresponding inhibition efficiencies.

  18. Corrosion Inhibition of Carbon Steel In Sulfuric Acid by Sodium Caprylate

    Directory of Open Access Journals (Sweden)

    Saad Ghareba

    2016-01-01

    Full Text Available The interaction of a sodium salt of octanoic acid, sodium caprylate (SC, with a carbon steel (CS surface was investigated, using range of experimental techniques. It was shown that SC acts as a good CS general corrosion inhibitor, yielding a maximum corrosion inhibition efficiency of 77%. This high inhibition efficiency is maintained even at higher temperatures. It was determined that SC inhibits both partial corrosion reactions, and can thus be considered to be a mixed-type inhibitor. The adsorption of SC on the CS surface was described by the Langmuir adsorption isotherm. It was found that this process is spontaneous, irreversible and driven by the entropy gain. The CS surface morphology was studied by SEM and it was demonstrated that SC is a very effective general corrosion inhibitor of CS. This also was confirmed by contact angle measurements which showed that the CS surface became more hydrophobic when the SC was added to the solution.

  19. Inhibitive Performance of Benzotriazole for Steel Corrosion Studied by Electrochemical and AFM Characterization

    Science.gov (United States)

    Feng, Yuanchao; Cheng, Y. Frank

    2015-12-01

    In this work, the inhibiting effect of benzotriazole (BTA) on corrosion of X65 pipeline steel in bicarbonate solution was investigated by electrochemical measurements, including open-circuit potential, potentiodynamic polarization curves and electrochemical impedance spectroscopy, and atomic force microscopy characterization. It is found that BTA is effective to inhibit the steel corrosion, and the inhibiting efficiency is increased by the increasing inhibitor concentration. The BTA is an anodic inhibitor, which shifts the corrosion potential of the steel less negatively and decreases the anodic current density at individual potential. A layer of inhibitor film is formed on the steel surface to reduce the corrosion rate of the steel. The formed film is quite smooth, with a roughness at the nano-meter scale.

  20. INHIBITION OF THE CORROSION OF MILD STEEL IN ...

    African Journals Online (AJOL)

    explained in terms of the difference in their molecular structures and solubility rather than .... Kinetic and thermodynamic data for the corrosion of mild steel in 0.1 M HCl solution containing ... transition state theory for ING and IN, respectively.

  1. 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.

  2. Inorganic Corrosion-Inhibitive Pigments for High-Temperature Alkali-activated Well Casing Foam Cement

    Energy Technology Data Exchange (ETDEWEB)

    Sugama, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Pyatina, T. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-11-01

    This study evaluates inorganic pigments for improving carbon steel (CS) brine-corrosion protection by the sodium metasilicate-activated calcium aluminate cement/Fly Ash blend at 300°C. Calcium borosilicate (CBS) and zinc phosphate, significantly improved CS corrosion-protection by decreasing cement’s permeability for corrosive ions and inhibiting anodic corrosion. An amorphous Na2O-Al2O3-SiO2-H2O phase tightly attached to CS surface formed at 300oC in CBS-modified cement pore solution. The corrosion rate of the CS covered with this phase was nearly 4-fold lower than in the case of nonmodified cement pore solution where the major phase formed on the surface of CS was crystalline analcime.

  3. Inorganic Corrosion-Inhibitive Pigments for High-Temperature Alkali-activated Well Casing Foam Cement

    Energy Technology Data Exchange (ETDEWEB)

    Sugama, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Pyatina, T. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-11-14

    This study evaluates inorganic pigments for improving carbon steel (CS) brine-corrosion protection by the sodium metasilicate-activated calcium aluminate cement/Fly Ash blend at 300°C. Calcium borosilicate (CBS) and zinc phosphate, significantly improved CS corrosion-protection by decreasing cement’s permeability for corrosive ions and inhibiting anodic corrosion. An amorphous Na2O-Al2O3-SiO2-H2O phase tightly attached to CS surface formed at 300oC in CBS-modified cement pore solution. The corrosion rate of the CS covered with this phase was nearly 4-fold lower than in the case of nonmodified cement pore solution where the major phase formed on the surface of CS was crystalline analcime.

  4. Inhibition effects of acetyl coumarines and thiazole derivatives on corrosion of zinc in acidic medium

    Indian Academy of Sciences (India)

    A V Shanbhag; T V Venkatesha; R A Prabhu; B M Praveen

    2011-06-01

    The corrosion inhibition characteristics of acetyl coumarine (AC), bromo acetyl coumarine (BAC) and thiazole derivatives (BTMQ and BTCQ) on the corrosion of zinc in 0.1 M HCl solution were investigated by weight loss, potentiodynamic polarization and impedance techniques. The inhibition efficiency increased with increase in inhibitor concentration upto 5 × 10-4 M, then gave almost same inhibition efficiency. The polarizationmeasurements indicated the mixed nature of inhibitors. The adsorption of compounds obeyed Langmuir’s adsorption isotherm. The thermodynamic functions for adsorption processes were evaluated.

  5. Inhibition of Aluminium Corrosion in Hydrochloric Acid Using Nizoral and the Effect of Iodide Ion Addition

    Directory of Open Access Journals (Sweden)

    I. B. Obot

    2010-01-01

    Full Text Available The effect of nizoral (NZR on the corrosion inhibition of aluminium alloy AA 1060 in 2 M HCl solution was investigated using the mylius thermometric technique. Results of the study revealed that nizoral acts as corrosion inhibitor for aluminium in the acidic medium. In general, at constant acid concentration, the inhibition efficiency increases with increase in the inhibitor concentration. The addition of KI to the inhibitor enhanced the inhibition efficiency to a considerable extent. The adsorption of nizoral onto the aluminium surface was found to obey the Fruendlich adsorption isotherm. The value of the free energy for the adsorption process shows that the process is spontaneous.

  6. Inhibition of Mild Steel Corrosion in Hydrochloric Acid Solution by Ciprofloxacin Drug

    Directory of Open Access Journals (Sweden)

    Inemesit A. Akpan

    2013-01-01

    Full Text Available The inhibition of mild steel corrosion in hydrochloric acid solution by ciprofloxacin drug as an eco-friendly and commercially available inhibitor was studied at room temperature by weight loss technique. It was found that the test drug has a promising inhibitory action against corrosion of mild steel in the medium investigated. The inhibition efficiency was found to increase with a corresponding increase in the concentration of the inhibitor. It was also found that the adsorption as well as the inhibition process followed a first-order kinetics and obeyed Langmuir’s adsorption isotherm.

  7. Corrosion inhibition of mild steel in hydrochloric acid solution by some double Schiff bases

    Energy Technology Data Exchange (ETDEWEB)

    Soltani, N. [Payame Noor University (PNU), Shahin Shahr Branch, Isfahan (Iran, Islamic Republic of)], E-mail: N.Soltani@kashanu.ac.ir; Behpour, M.; Ghoreishi, S.M.; Naeimi, H. [Department of Chemistry, Faculty of Science, University of Kashan, Kashan (Iran, Islamic Republic of)

    2010-04-15

    The inhibition effect of four double Schiff bases on the corrosion of mild steel in 2 M HCl has been studied by polarization, electrochemical impedance spectroscopy (EIS) and weight loss measurements. The inhibitors were adsorbed on the steel surface according to the Langmuir adsorption isotherm model. From the adsorption isotherm, some thermodynamic data for the adsorption process were calculated and discussed. Kinetic parameters activation such as E{sub a}, {delta}H*, {delta}S* were evaluated from the effect of temperature on corrosion and inhibition processes. Quantum chemical calculations have been performed and several quantum chemical indices were calculated and correlated with the corresponding inhibition efficiencies.

  8. Corrosion Inhibition of the Galvanic Couple Copper-Carbon Steel in Reverse Osmosis Water

    Directory of Open Access Journals (Sweden)

    Irene Carrillo

    2011-01-01

    Full Text Available The purpose of this paper is to evaluate the electrochemical behaviour of corrosion inhibition of the copper-carbon steel galvanic couple (Cu-CS, exposed to reverse osmosis water (RO used for rinsing of heat exchangers for heavy duty machinery, during manufacture. Molybdate and nitrite salts were utilized to evaluate the inhibition behaviour under galvanic couple conditions. Cu-CS couple was used as working electrodes to measure open circuit potential (OCP, potentiodynamic polarization (PP, and electrochemical impedance spectroscopy (EIS. The surface conditions were characterized by scanning electron microscopy (SEM and electron dispersive X-ray spectroscopy (EDS. The most effective concentration ratio between molybdate and nitrite corrosion inhibitors was determined. The morphological study indicated molybdate deposition on the anodic sites of the galvanic couple. The design of molybdate-based corrosion inhibitor developed in the present work should be applied to control galvanic corrosion of the Cu-CS couple during cleaning in the manufacture of heat exchangers.

  9. The corrosion inhibition of iron and aluminum by various naturally occurring biological molecules

    Energy Technology Data Exchange (ETDEWEB)

    McCafferty, E.; Hansen, D.C. [Naval Research Lab., Washington, DC (United States)

    1995-12-31

    Biological polymers that exhibit a strong affinity for metal surfaces are increasingly becoming the focus of research toward the development of environmentally friendly corrosion inhibitors. This paper deals with the use of various naturally occurring organic molecules as corrosion inhibitors for iron or aluminum. Among the organic molecules considered are catecholate and hydroxamate siderophores isolated from bacteria, the adhesive protein from the blue mussel Mytilus edulis L, and caffeic acid and chlorogenic acid. FTIR analysis, anodic polarization curves, and AC impedance measurements were used to determine the adsorption and effectiveness of the various organic molecules as corrosion inhibitors. Parabactin, a catecholate siderophore, was effective in inhibiting both the corrosion of iron in hydrochloric acid and the pitting of aluminum in 0.1 M sodium chloride. The adhesive protein from the blue mussel was also effective in inhibiting the pitting of aluminum.

  10. A Comparative Study on Corrosion Inhibition of Mild Steel Using Piper Nigrum L. in Different Acid Medium

    Directory of Open Access Journals (Sweden)

    B. Anand

    2010-01-01

    Full Text Available The inhibition of corrosion of mild steel using Piper nigrum L in different acid medium by weight loss method was investigated. The corrosion inhibition was studied in hydrochloric acid and sulphuric acid by weight loss method at different time interval at room temperature. The result showed that the corrosion inhibition efficiency of this compound was found to vary with different time interval and different acid concentration. Also, it was found that the corrosion inhibition behavior of Piper nigrum L is greater in sulphuric acid than hydrochloric acid. So, Piper nigrum L can be used as a good inhibitor for preventing mild steel material.

  11. Corrosion inhibition efficiency of water soluble ethoxylated trimethylol propane by gravimetric analysis

    Directory of Open Access Journals (Sweden)

    A.A. Abdel-Azim

    2014-03-01

    Full Text Available Polyoxyethylenated trimethylol propane monolaurate surfactants with varied ethylene oxide content were tested as corrosion inhibitors via the weight loss method. Weight loss measurements for carbon steel dissolution were performed in 1 N HCl containing different inhibitor concentrations at 30, 40 and 50 °C. These measurements were utilized for calculating corrosion rate, surface coverage area and percentage inhibition. The obtained data show that the adsorption of these inhibitors obeys Langmuir adsorption isotherm. Thermodynamic parameters (ΔG∗, ΔH∗ and ΔS∗ of the corrosion process are evaluated and correlated to inhibitors structures.

  12. An Electrochemical Study on the Corrosion Inhibition of Stainless Steel by Polyaniline Film

    Institute of Scientific and Technical Information of China (English)

    Hao WANG; Lin NIU; Qiu Hong LI; Su Xiang WU; Feng Hua WEI

    2004-01-01

    Polyaniline(PANI) film was electrosynthesized on 304 stainless steel by cyclic voltammetry using aqueous oxalic acid as supporting electrolyte. The potential sweep rates were changed to achieve the PANI film with different thickness and structures. Protective properties of the PANI film for corrosion of stainless steel in 3% NaCl aqueous solution were investigated by monitoring potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS).The results showed that the PANI film which was formed with lower sweep rate led to more positive shift of corrosion potential and greater charge transfer resistance, reflecting higher inhibition for corrosion of the stainless steel.

  13. Corrosion Inhibition Property of Some 1, 3, 4- Thiadiazolines on Mild Steel in Acidic Medium

    Directory of Open Access Journals (Sweden)

    A. Shamitha Begum

    2010-01-01

    Full Text Available The present work deals with the corrosion behavior of mild steel in acidic medium. The inhibitive effect of substituted 1, 3, 4-Thiadiazol-2-amines on the corrosion of mild steel in 1 M H2SO4 has been studied by weight loss and electrochemical methods. The electrochemical parameters for mild steel in acidic solution with and without inhibitor were calculated. The effect of temperature on the corrosion rate, activation energy and free energy of adsorption were also calculated. The synergistic effect has been studied by weight loss and electrochemical methods. The electrochemical parameters for mild steel in acidic solution were also calculated.

  14. Corrosion inhibiting repair and rehabilitation treatment process for reinforced concrete structures

    OpenAIRE

    1994-01-01

    A repair and rehabilitation treatment process for reinforced concrete structures involves the removal of concrete from above rebar or other metal reinforcement material in the concrete structure. After removal of concrete, the metal reinforcement materials are saturated with corrosion inhibiting agents. Saturation is best achieved by multiple spray applications of the corrosion inhibitor. The cavity in the concrete structure with the treated rebar or other metal reinforcement materials is the...

  15. 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.

  16. Functionalization of Titanium Alloy Surface by Graphene Nanoplatelets and Metal Oxides: Corrosion Inhibition.

    Science.gov (United States)

    Mondal, Jayanta; Aarik, Lauri; Kozlova, Jekaterina; Niilisk, Ahti; Mändar, Hugo; Mäeorg, Uno; Simões, Alda; Sammelselg, Väino

    2015-09-01

    Corrosion inhibition of metallic substrates is an important and crucial step for great economical as well as environmental savings. In this paper, we introduce an extra thin effective corrosion inhibitive material having layered structure designed for protection and functionalization of Ti Grade 5 alloy substrates. The coating consists of a first layer made of thin graphene nanoplatelets, on top of which a multilayer Al2O3 and TiO2 films is applied by low-temperature atomic layer deposition. The amorphous structure of the metal oxide films was confirmed by micro-Raman and X-ray diffraction analysis. Corrosion inhibition ability of the prepared coatings was analyzed by open circuit potential, potentiodynamic plot and by voltammetric analysis, in aqueous potassium bromide solution. The open circuit potential of the graphene-metal oxide coated substrate showed much passive nature than bare substrate or graphene coated or only metal oxide coated substrates. The localized corrosion potential of the graphene-metal oxide coated, only metal oxide coated, and bare substrates were found 5.5, 3.0, and 1.1 V, respectively. In addition, corrosion current density values of the graphene-metal oxide and only metal oxide coated substrates showed much more passive nature than the bare and graphene coated substrates. Long immersion test in the salt solution further clarified the effective corrosion inhibition of the graphene-metal oxide coated substrate. The analyzed results reflect that the graphene-metal oxide films can be used to prepare better and effective corrosion inhibition coatings for the Ti Grade 5 alloy to increase their lifetime.

  17. 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.

  18. Corrosion inhibition of α,β-unsaturated carbonyl compounds on steel in acid medium

    Institute of Scientific and Technical Information of China (English)

    Gao Jiancun; Weng Yongji; Salitanate; Feng Li; Yue Hong

    2009-01-01

    Corrosion inhibition of three α,β-unsaturated carbonyl compounds on N80 steel at high temperature and in concentrated acid medium was evaluated, and the inhibition mechanism was investigated.The results proved that both cinnamaidehyde and benzalacetone had an evident anticorrosion effect and could reduce the corrosion of steel effectively in acid medium, α,β-unsaturated carbonyl compounds with a benzene ring structure had good adsorption on steel surface.The experiments proved that polymerization of α,β-unsaturated carbonyl compounds on the steel surface at a high temperature and in concentrated acid medium resulted in a good corrosion inhibiting effect, which was attributed to the structures of α,β-unsaturated carbonyl compounds.

  19. Adsorption and corrosion inhibition of mild steel in acidic media by expired pharmaceutical drug

    Directory of Open Access Journals (Sweden)

    P. Geethamani

    2015-12-01

    Full Text Available The inhibitive action of an examined expired Ambroxol drug on the corrosion of mild steel in 1 M HCl and 1 M H2SO4 acid medium has been studied by weight loss and electrochemical techniques. The weight loss techniques result was discussed. The inhibition efficiency increases with increasing the concentration of the inhibitor. Electrochemical studies data support that examined expired drug is an efficient inhibitor for mild steel corrosion. The adsorption of the examined drug obeys Langmuir’s adsorption isotherm. Polarization studies indicate that this inhibitor acts as a mixed type inhibition. The various thermodynamic parameters were calculated and discussed. The protective film formed on the surface was confirmed by SEM. The data collected from the studied techniques are in good agreement to confirm the ability of using expired Ambroxol drug as corrosion inhibitor for mild steel in both acid media.

  20. Corrosion Inhibition of Mild Steel in Citric Acid by Aqueous Extract of Piper Nigrum L.

    Directory of Open Access Journals (Sweden)

    P. Matheswaran

    2012-01-01

    Full Text Available The inhibition efficiency (IE of an aqueous extract of Piper Nigrum L. in controlling corrosion of mild steel at pH 12 has been evaluated by weight loss method in the absence and presence of inhibitor in citric acid medium at different concentration. The result showed that the corrosion inhibition efficiency of these compounds was found to vary with the different concentration at two hour time interval at room temperature. Also, it was found that the corrosion inhibition behaviour of Piper Nigrum L. is greater in 2 N Citric acid than 1 N Citric acid medium. So Piper Nigrum L. can be used has a good inhibitor for preventing mild steel material which is used in many construction purpose.

  1. Corrosion and Inhibition Effects of Mild Steel in Hydrochloric Acid Solutions Containing Organophosphonic Acid

    Directory of Open Access Journals (Sweden)

    Manish Gupta

    2013-01-01

    Full Text Available A study has been made on the mechanism of corrosion of mild steel and the effect of nitrilo trimethylene phosphonic (NTMP acid as a corrosion inhibitor in acidic medium, that is, 10% HC1 using the weight loss method and electrochemical techniques, that is, potentiodynamic and galvanostatic polarization measurements. Although corrosion is a long-time process, but it takes place at a faster rate in the beginning which goes on decreasing with due course of time. The above-mentioned methods of corrosion rate determination furnish an average value for a long-time interval. Looking at the versatility and minimum detection limit of the voltammetric method, the authors have developed a new voltammetric method for the determination of corrosion rate at short-time intervals. The results of corrosion of mild steel in 10% HC1 solution with and without NTMP inhibitor at short-time intervals have been reported. The corrosion inhibition efficiency of NTMP is 93% after 24 h.

  2. Properties of bacterial corrosion of stainless steel and its inhibition by protamine coating.

    Science.gov (United States)

    Matsumura, Yoshinobu; Yamada, Kaoru; Takahashi, Mitsuo; Kikuchi, Yasushi; Tsuchido, Tetsuaki

    2007-03-01

    We investigated characteristics of the corrosion of stainless steel specimens by bacteria and the effects of using antimicrobial coating on the surface for inhibiting corrosion. Bacillus sp. 2-A and Staphylococcus sp. 2-1 cells adhered tightly to a stainless steel SUS304 specimen, formed a microcolony or biofilm, and had highly corrosive activities. Microbially influenced corrosion (MC) was observed under or around adhering cells. However, dead cells were markedly less active than viable cells not only in corroding the specimen but also in adhering to its surface. The culture supernatant was not able to induce the corrosion of SUS304 effectively. A protamine coating on the specimen killed bacterial cells only on its surface, interfered with cell adhesion, and inhibited MC. From these results, adhesion of viable cells to the surface of a SUS304 specimen led to the outbreak of MC. Protamine was also found to be an effective substance tested for protecting the specimen from both cell adhesion and surface MC. We suggest that a protamine coating can be applied as a convenient and inexpensive corrosion prevention method.

  3. Adsorption and Inhibitive Properties of Triazolo- pyrimidine Derivatives in Acid Corrosion of Mild Steel

    Directory of Open Access Journals (Sweden)

    K. Parameswari

    2011-01-01

    Full Text Available Inhibitive and adsorption properties of synthesized triazolo- pryimidine derivatives (P1, P2 & P3 for the corrosion of mild steel was investigated using weight loss and electrochemical methods. Inhibition efficiency increased as the concentration of the inhibitor increased but decreased with increase in temperature. The triazolopyrimidines were found to act as adsorption inhibitors for the corrosion of mild steel. The adsorption mechanism of the triazolopyrimidine was found to be physisorption, spontaneous and exothermic. Also the adsorption followed Langmuir adsorption isotherm. polarisation studies showed that the inhibitors behave as cathodic type.

  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. Inhibition of hot salt corrosion by metallic additives

    Science.gov (United States)

    Deadmore, D. L.; Lowell, C. E.

    1978-01-01

    The effectiveness of several potential fuel additives in reducing the effects of sodium sulfate-induced hot corrosion was evaluated in a cyclic Mach 0.3 burner rig. The potential inhibitors examined were salts of Al, Si, Cr, Fe, Zn, Mg, Ca, and Ba. The alloys tested were IN-100, U-700, IN-738, IN-792, Mar M-509, and 304 stainless steel. Each alloy was exposed for 100 cycles of 1 hour each at 900 C in combustion gases doped with the corrodant and inhibitor salts and the extent of attack was determined by measuring maximum metal thickness loss. The most effective and consistent inhibitor additive was Ba (NO3)2 which reduced the hot corrosion attack to nearly that of simple oxidation.

  6. Corrosion Behaviour of Nickel in Chloroacetic Acids and its Inhibition

    Institute of Scientific and Technical Information of China (English)

    S.M. Rashwan; A.Emam; S.M. Abd El-Wahab; M.M. Mohamed

    2004-01-01

    Anodic dissolution behaviour of Ni in mono-, di- and trichloroacetic acids has been investigated by measuring current densities of Ni electrode (versus SCE) at different potentials. Effects of acid concentration, pH, scan rate and additive inhibitor on the potential were studied and they revealed that there is a considerable shift of potential.Potentiodynamic polarization measurements show that the corrosion rate of Ni in chloroacetic acid solutions increases by increasing the previous factors. However, by adding inhibitor, it decreases.

  7. Corrosion inhibition of magnesium heated in wet air, by surface fluoridation; Inhibition de la corrosion du magnesium chauffe dans l'air humide, par fluoruration superficielle

    Energy Technology Data Exchange (ETDEWEB)

    Caillat, R.; Darras, R.; Leclercq, D. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The maximum temperature (350 deg. C) of magnesium corrosion resistance in wet air may be raised to 490-500 deg. C by the formation of a superficial fluoride film. This can be obtained by two different ways: either by addition of hydrofluoric acid to the corroding medium in a very small proportion such as 0,003 mg/litre; at atmospheric pressure, or by dipping the magnesium in a dilute aqueous solution of nitric and hydrofluoric acids at room temperature before exposing it to the corroding atmosphere. In both cases the corrosion inhibition is effective over a very long time, even several thousand hours. (author) [French] La temperature limite (350 deg. C) de resistance du magnesium a la corrosion par l'air humide, peut etre elevee jusque 490-500 deg. C par la formation d'une couche fluoruree superficielle. Deux procedes permettent d'obtenir ce resultat: l'atmosphere corrodante peut etre additionnee d'acide fluorhydrique a une concentration aussi faible que 0,003 mg/litre, a la pression atmospherique, ou bien le magnesium peut etre traite a froid, avant exposition a la corrosion, dans une solution aqueuse diluee d'acides nitrique et fluorhydrique. Dans les deux cas, la protection est assuree, meme pour de tres longues durees d'exposition: plusieurs milliers d'heures. (auteur)

  8. Corrosion inhibition efficiency of linear alkyl benzene derivatives for carbon steel pipelines in 1M HCl

    Directory of Open Access Journals (Sweden)

    A.M. Al-Sabagh

    2011-06-01

    Full Text Available Linear alkyl benzene sulfonic acid (L and three of its ester derivatives (L1, L2, L3 were prepared, followed by quaternization of these esters (L1Q, L2Q, L3Q. The corrosion inhibition effect on carbon steel in 1 M HCl was studied using weight loss and potentiodynamic polarization measurements. The adsorption of the inhibitors on carbon steel surface obeyed the Langmuir’s adsorption isotherm. The associated activation energy of corrosion and other thermodynamic parameters such as enthalpy (ΔH∗, entropy (ΔS∗ of activation, adsorption–desorption equilibrium constant (Kads, standard free energy of adsorption (ΔGoads, heat (ΔHoads, and entropy of adsorption (ΔSoads were calculated to elaborate the corrosion inhibition mechanism.

  9. Effect of piperidones on hydrogen permeation and corrosion inhibition of mild steel in acidic solutions

    Indian Academy of Sciences (India)

    S Muralidharan; R Chandrasekar; S V K Iyer

    2000-04-01

    The influence of 3-methyl-2,6-diphenyl piperidin-4-one (MDPO) and 2-phenyl decahydroquinoline-4-one (PDQO) synthesised in the laboratory on hydrogen permeation and corrosion inhibition of mild steel in 1N H2SO4 has been studied using weight loss and various electrochemical AC and DC corrosion-monitoring techniques. Both the compounds inhibit the corrosion of mild steel in H2SO4 Potentiodynamic polarisation studies clearly reveal that they behave predominantly as cathodic inhibitors. The extent of decrease in hydrogen permeation current through steel surfaces has been studied by the hydrogen electropermeation technique. Double layer capacitance () and charge transfer resistance () values are derived from Nyquist plots obtained from AC impedance studies. The adsorption of these compounds on mild steel surfaces from H2SO4 obeys Temkin’s adsorption isotherm.

  10. INHIBITION OF CORROSION OF ZINC IN (HNO3 + HCl ACID MIXTURE BY ANILINE

    Directory of Open Access Journals (Sweden)

    R.T. Vashi

    2015-05-01

    Full Text Available Corrosion of Zinc metal in (HNO3 + HCl binary acid mixture and inhibition efficiency of aniline has been studied by weight loss method and polarization technique. Corrosion rate increases with the concentration of acid mixture and the temperature. Inhibition efficiency (I.E. of aniline increases with the concentration of inhibitor while decreases with the increase in concentration of acid. As temperature increases corrosion rate increases while percentage of I.E. decreases. A plot of log (θ/1-θ versus log C results in a straight line suggest that the inhibitor cover both the anodic and cathodic regions through general adsorption following Longmuir isotherm. Galvenostatic polarization curves show polarization of both anodes as well as cathodes.

  11. Corrosion Inhibition of Carbon Steel in Chloride and Sulfate Solutions

    Directory of Open Access Journals (Sweden)

    Amr Ahmed Elsayed

    2016-02-01

    Full Text Available Corrosion is a major problem in industry and in infrastructure; a huge sum of expenditure every year is spent on preventing, retarding, and repairing its damages. This work studies the engineering of an inhibitor for carbon steel metal used in the cooling systems containing high concentration of chloride and sulfate ions. For this purpose, the synergy between the dichromate, molybdate and nitrite inhibitors is examined and optimized to the best results. Moreover, care was taken that the proposed inhibitor is compliant with the environmental laws and regulations.

  12. Density Functional Theory and Electrochemical Studies: Structure-Efficiency Relationship on Corrosion Inhibition.

    Science.gov (United States)

    Camacho-Mendoza, Rosa L; Gutiérrez-Moreno, Evelin; Guzmán-Percástegui, Edmundo; Aquino-Torres, Eliazar; Cruz-Borbolla, Julián; Rodríguez-Ávila, José A; Alvarado-Rodríguez, José G; Olvera-Neria, Oscar; Thangarasu, Pandiyan; Medina-Franco, José L

    2015-11-23

    The relationship between structure and corrosion inhibition of a series of 30 imidazol, benzimidazol, and pyridine derivatives has been established through the investigation of quantum descriptors calculated with PBE/6-311++G**. A quantitative structure-property relationship model was obtained by examination of these descriptors using a genetic functional approximation method based on a multiple linear regression analysis. Our results indicate that the efficiency of corrosion inhibitors is strongly associated with aromaticity, electron donor ability, and molecular volume descriptors. In order to calibrate and validate the proposed model, we performed electrochemical impedance spectroscopy (EIS) studies on imidazole, 2-methylimidazole, benzimidazole, 2-chloromethylbenzimidazole, pyridine, and 2-aminopyridine compounds. The experimental values for efficiency of corrosion inhibition are in good agreement with the estimated values obtained by our model, thus confirming that our approach represents a promising and suitable tool to predict the inhibition of corrosion attributes of nitrogen containing heterocyclic compounds. The adsorption behavior of imidazole or benzimidazole heterocyclic molecules on the Fe(110) surface was also studied to elucidate the inhibition mechanism; the aromaticity played an important role in the adsorbate-surface complex.

  13. Application of transient analysis using Hilbert spectra of electrochemical noise to the identification of corrosion inhibition

    NARCIS (Netherlands)

    Homborg, A.M.; Westing, E.P.M. van; Tinga, T.; Ferrari, G.M.; Zhang, X.; Wit, J.H.W. de; Mol, J.M.C.

    2014-01-01

    This study validates the ability of Hilbert spectra to investigate transients in an electrochemical noise signal for an aqueous corrosion inhibition process. The proposed analysis procedure involves the identification and analysis of transients in the electrochemical current noise signal. Their deco

  14. Application of transient analysis using Hilbert spectra of electrochemical noise to the identification of corrosion inhibition

    NARCIS (Netherlands)

    Homborg, A.M.; Westing, van E.P.M.; Tinga, T.; Ferrari, G.M.; Zhang, X.; Wit, de J.H.W.; Mol, J.M.C.

    2013-01-01

    This study validates the ability of Hilbert spectra to investigate transients in an electrochemical noise signal for an aqueous corrosion inhibition process. The proposed analysis procedure involves the identification and analysis of transients in the electrochemical current noise signal. Their deco

  15. Corrosion inhibition properties of pyrazolylindolenine compounds on copper surface in acidic media

    Directory of Open Access Journals (Sweden)

    Ebadi Mehdi

    2012-12-01

    Full Text Available Abstract Background The corrosion inhibition performance of pyrazolylindolenine compounds, namely 4-(3,3-dimethyl-3H-indol-2-yl-pyrazole-1-carbothioamide (InPzTAm, 4-(3,3-dimethyl-3H-indol-2-yl-1H-pyrazole-1-carbothiohydrazide (InPzTH and 3,3-dimethyl-2-(1-phenyl-1H-pyrazol-4-yl-3H-indole (InPzPh, on copper in 1M HCl solution is investigated by electrochemical impedance spectroscopy (EIS, open circuit potential (OCP and linear scan voltammetry (LSV techniques. Results The results show that the corrosion rate of copper is diminished by the compounds with the inhibition strength in the order of: InPzTAm> InPzTH > InPzPh. The corrosion inhibition efficiencies for the three inhibitors are 94.0, 91.4 and 79.3, for InPzTAm, InPzTH and InPzPh respectively with the same inhibitor concentration (2 mM. Conclusion From the EIS, OCP and LSV results it was concluded that pyrazolylindolenine compounds with S-atom (with an amine group have illustrated better corrosion inhibition performance compared to hydrazine and phenyl group.

  16. Corrosion Inhibition Studies of Mild Steel in Acid Medium Using Musa Acuminata Fruit Peel Extract

    Directory of Open Access Journals (Sweden)

    N. Gunavathy

    2012-01-01

    Full Text Available The inhibition effect of unripe fruit peel extract of Musa acuminata (Cultivar variety – Nendran (MNP on corrosion of mild steel in 1 N HCl has been investigated by weight loss and electrochemical impedance spectroscopy (EIS with various concentrations of the extract. The effect of temperature on the corrosion inhibition of mild steel in the temperature range of 30°C – 80°C was carried out. The results indicate that MNP extract act as an effective inhibitor in the acid environment and is of mixed type inhibitor having efficiency as high as 96% at 2% inhibitor concentration. The inhibition efficiency of MNP extract increases with the increase of concentration but decreases with the increase in temperature. The inhibitor achieves its inhibition by physical adsorption of nutrients of the peel extract on the surface of the mild steel. The experimental data revealed that the adsorption occurred according to the Langmuir and Temkin adsorption isotherm.

  17. Physicochemical studies of glucose, gellan gum, and hydroxypropyl cellulose--inhibition of cast iron corrosion.

    Science.gov (United States)

    Rajeswari, Velayutham; Kesavan, Devarayan; Gopiraman, Mayakrishnan; Viswanathamurthi, Periasamy

    2013-06-05

    Glucose, gellan gum, and hydroxypropyl cellulose were studied against the acid corrosion of cast iron by means of weight loss, potentiodynamic polarization, and AC impedance spectroscopy techniques. The inhibition efficiency was found to increase with increasing concentration of the inhibitors. The effect of immersion time and temperature were also studied. The addition of potassium iodide to the corrosion-inhibition system showed both antagonism and synergism toward inhibition efficiency. Polarization studies revealed the mixed-type inhibiting nature of the carbohydrates. The adsorption of inhibitors on the cast iron surface obeys Langmuir adsorption isotherm model, both in presence and absence of KI. Physical interaction between the inhibitor molecules and the iron surface was suggested by the thermochemical parameters, rather than chemical interaction.

  18. Inhibition of 304 stainless steel corrosion in acidic solution by Ferula gumosa (galbanum) extract

    Energy Technology Data Exchange (ETDEWEB)

    Behpour, M.; Ghoreishi, S.M.; Soltani, N. [Department of Chemistry, Faculty of Science, University of Kashan (Iran); Kashani, M.K. [Department of Chemistry, Faculty of Science, University of Kashan (Iran); Barij Essence pharmaceutical, Kashan (Iran)

    2009-11-15

    The inhibition effect of the extract of galbanum (Ferula gummosa Boiss.) on the corrosion of 304 stainless steel in 2 M HCl solution was studied by weight loss measurements, Tafel polarization, and electrochemical impedance spectroscopy (EIS) methods. It was found that the inhibition efficiency (IE) increases as the extract concentration is increased. Tafel polarization method revealed the mixed mode inhibition of galbanum extract (GE) with predominant control of anodic reaction. The effect of temperature on the corrosion behavior of steel indicates that inhibition efficiency of the natural substance increases with the rise in temperature. At all temperatures, the adsorption of the extract components onto the steel surface was found to follow the Temkin adsorption isotherm. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  19. Inhibition of Chloride Induced Crevice Corrosion in Alloy 22 by Fluoride Ions

    Energy Technology Data Exchange (ETDEWEB)

    Carranza, R M; Rodr?guez, M A; Rebak, R B

    2005-10-09

    Alloy 22 (N06022) is highly resistant to localized corrosion. Alloy 22 may be susceptible to crevice corrosion in pure chloride (Cl{sup -}) solutions under aggressive environmental conditions. The effect of the fluoride (F{sup -}) over the crevice corrosion induced by chloride ions is still not well established. The objective of the present work was to explore the crevice corrosion resistance of this alloy to different mixtures of fluorides and chlorides. Cyclic potentiodynamic polarization (CPP) tests were conducted in deaerated aqueous solutions of pure halide ions and also in different mixtures of chloride and fluoride at 90 C and pH 6. The range of chloride concentration [Cl{sup -}] was 0.001 M {le} [Cl{sup -}] {le} 1 M and the range of molar fluoride to chloride ratio [F{sup -}]/[Cl{sup -}] was 0.1 {le} [F{sup -}]/[Cl{sup -}] {le} 10. Results showed that Alloy 22 was susceptible to crevice corrosion in all the pure chloride solutions but not in the pure fluoride solutions. Fluoride ions showed an inhibitor behavior only in mixtures with a molar ratio [F{sup -}]/[Cl{sup -}] > 2. For mixtures with a molar ratio [F{sup -}]/[Cl{sup -}] of 7 and 10 the inhibition of crevice corrosion was complete.

  20. EIS study on corrosion and scale processes and their inhibition in cooling system media

    Energy Technology Data Exchange (ETDEWEB)

    Marin-Cruz, J. [Universidad Autonoma Metropolitana, Departamento de Quimica, Apdo. Postal 55-534, 09340 Mexico, DF (Mexico) and Instituto Mexicano del Petroleo, Coordinacion de Ingenieria Molecular, Competencia de Quimica Aplicada, Eje Central Lazaro Cardenas No. 152, CP 07730, DF (Mexico)]. E-mail: jmarin@imp.mx; Cabrera-Sierra, R. [Universidad Autonoma Metropolitana, Departamento de Quimica, Apdo. Postal 55-534, 09340 Mexico, DF (Mexico); Escuela Superior de Ingenieria Quimica e Industrias Extractivas (ESIQIE-IPN), Departamento de Metalurgia, UPALM Zacatenco AP 75-874, CP 07338, DF (Mexico); Pech-Canul, M.A. [Departamento de Fisica Aplicada, Centro de Investigacion y de Estudios, Avanzados del IPN, AP 73 Cordemex, CP 97310, Merida, Yucatan (Mexico); Gonzalez, I. [Universidad Autonoma Metropolitana, Departamento de Quimica, Apdo. Postal 55-534, 09340 Mexico, DF (Mexico)]. E-mail: igm@xanum.uam.mx

    2006-01-20

    A study of the carbon steel/cooling water interface was carried out using electrochemical impedance spectroscopy (EIS). EIS spectra reveal that a layer of corrosion and scale products forms naturally and evolves with the immersion time modifying the carbon steel/cooling water interface and giving rise to corrosion and scale processes. In addition, the nature of the layer formed on the metal was found to depend on the inhibitor used. It was established that the corrosion inhibitor (hydroxyphosphonoacetic acid (HPA)) chelates with Ca(II) ion generating a layer with resistive properties that provides good protection against corrosion. In contrast, the scale inhibitor (1-hydroxy-ethane-1,1-diphosphonic acid (HEDP)) is incorporated into the calcium carbonate crystals at the surface, modifying the structure and diminishing scale formation in the surface; this additive additionally inhibited corrosion. These observations were supported by scanning electronic microscopy (SEM) and corroborate previous studies performed by other techniques on HPA and HEDP. Finally, a synergistic effect was observed between these inhibitors that provides good protection to steel against corrosion and scaling in cooling media.

  1. Environmentally safe corrosion inhibition of Mg-Al-Zn alloy in chloride free neutral solutions by amino acids

    Energy Technology Data Exchange (ETDEWEB)

    Helal, N.H. [Chemistry Department, Faculty of Science, Fayoum University, Fayoum (Egypt); Badawy, W.A., E-mail: wbadawy@cu.edu.eg [Chemistry Department, Faculty of Science, Cairo University, 12 613 Giza (Egypt)

    2011-07-30

    Highlights: > Phenyl alanine at a concentration of 2 x 10{sup -3} mol dm{sup -3} gives 93% corrosion inhibition efficiency for the corrosion of the Mg-Al-Zn alloy. > The corrosion inhibition process is based on the adsorption of the amino acid molecules on the active sites of the alloy surface by physical adsorption mechanism. > The adsorption free energy was 15.72 kJ mol{sup -1}. - Abstract: The corrosion inhibition of Mg-Al-Zn alloy was investigated in stagnant naturally aerated chloride free neutral solutions using amino acids as environmentally safe corrosion inhibitors. The corrosion rate was calculated in the absence and presence of the corrosion inhibitor using the polarization technique and electrochemical impedance spectroscopy. The experimental impedance data were fitted to theoretical data according to a proposed electronic circuit model to explain the behavior of the alloy/electrolyte interface under different conditions. The corrosion inhibition process was found to depend on the adsorption of the amino acid molecules on the metal surface. Phenyl alanine has shown remarkably high corrosion inhibition efficiency up to 93% at a concentration of 2 x 10{sup -3} mol dm{sup -3}. The corrosion inhibition efficiency was found to depend on the concentration of the amino acid and its structure. The mechanism of the corrosion inhibition process was discussed and different adsorption isotherms were investigated. The free energy of the adsorption process was calculated for the adsorption of different amino acids on the Mg-Al-Zn alloy and the obtained values reveal a physical adsorption of the inhibitor molecules on the alloy surface.

  2. Inhibition of localized corrosion of Ni–Ti superelastic alloy in NaCl solution by hydrogen charging

    Energy Technology Data Exchange (ETDEWEB)

    Yokoyama, Ken’ichi, E-mail: yokken@post.matsc.kyutech.ac.jp [Department of Materials Science and Engineering, Kyushu Institute of Technology, 1-1, Sensui-cho, Tobata-ku, Kitakyushu 804-8550 (Japan); Hirata, Yuki [Department of Materials Science and Engineering, Kyushu Institute of Technology, 1-1, Sensui-cho, Tobata-ku, Kitakyushu 804-8550 (Japan); Inaba, Toshiaki; Mutoh, Kenichiro [Furukawa Techno Material Co., Ltd., 5-1-8, Higashi-yawata, Hiratsuka 254-0016 (Japan); Sakai, Jun’ichi [Faculty of Science and Engineering, Waseda University, 3-4-1, Okubo, Shinjuku-ku, Tokyo 169-8555 (Japan); Kagami Memorial Laboratory for Materials Science and Technology, Waseda University, 2-8-26, Nishiwaseda, Shinjuku-ku, Tokyo 169-0051 (Japan)

    2015-08-05

    Highlights: • Hydrogen charging inhibits localized corrosion of Ni–Ti superelastic alloy. • Increasing hydrogen content increases anodic current density. • Inhibition of localized corrosion remains after polishing or superelastic deformation. • Small amount of hydrogen charging may become new surface modification. - Abstract: Inhibition of the localized corrosion of Ni–Ti superelastic alloy in 0.9% NaCl solution has been attempted by charging with a small amount of hydrogen, which causes negligible hydrogen embrittlement. Upon a small amount of hydrogen charging, no pitting potential is observed in anodic polarization curves. From scanning electron microscope observations, localized corrosion is inhibited on the entire side surface of charged specimens. With increasing amount of charged hydrogen, the corrosion potential shifts in the less noble direction and the current density increases under anodic applied potential. When the hydrogen charged specimens are aged in the atmosphere at room temperature, the corrosion potential becomes almost the same as that of the non-charged specimen, but the inhibition of localized corrosion remains. The present study indicates that a small amount of hydrogen charging is effective for inhibiting the localized corrosion of the alloy in NaCl solution.

  3. Corrosion Inhibition of Aluminium by Capparis deciduas in Acidic Media

    Directory of Open Access Journals (Sweden)

    P. Arora

    2007-01-01

    Full Text Available The inhibition efficiency of ethanolic extract of different parts of Capparis deciduas (Ker in acidic medium has been evaluated by mass loss and thermometric methods. Values of inhibition efficiency obtained from the two methods are in good agreement and are dependent upon the concentration of inhibitor and acid.

  4. Corrosion Inhibition and Adsorption Behavior of Clove Oil on Iron in Acidic Medium

    Directory of Open Access Journals (Sweden)

    Archana Saxena

    2012-01-01

    Full Text Available Corrosion behavior of iron in hydrochloric acid solution was studied using weight loss as well Scanning electron microscopy study without and with clove oil. The percentage inhibition efficiency increases with increasing clove oil concentration. All the data revel that the oil acts as an excellent inhibitor for the corrosion of iron in HCl solution. Thermodynamic, kinetic parameters and equilibrium constant for adsorption process were calculated from the experimental data. The adsorption of clove oil on experimental metals was found to follow the Langmuir adsorption isotherm at all the concentration studies. Scanning electron microscope (SEM, investigations also indicate that clove oil greatly lowers the dissolution currents.

  5. Quantum chemical study on the corrosion inhibition property of some heterocyclic azole derivatives

    Directory of Open Access Journals (Sweden)

    N. Anusuya

    2015-09-01

    Full Text Available Quantum chemical calculations based on density functional theory (DFT method were performed on heterocyclic azole derivatives as corrosion inhibitors for mild steel in acid media to investigate the relationship between molecular structure of the inhibitors and the corresponding inhibition efficiencies (%. Quantum chemical parameters most relevant to their potential action as corrosion inhibitors have been calculated in the non-protonated and protonated forms in aqueous phase for comparison. Results obtained in this study indicate thatin acidic media, both the protonated and non-protonated forms of the azoles represent the better actual experimental situation.

  6. Corrosion Inhibition Effect of Dicycloimine Hydrochloride (DCI on Mild Steel in 1M HCl

    Directory of Open Access Journals (Sweden)

    R. Rajalakshmi

    2010-01-01

    Full Text Available Addition of corrosion inhibitors is one of the widely used methods to control corrosion. In this work, an attempt has been made to explore the possibility of using dicycloimine hydrochloride (DCI as an inhibitor on mild steel in 1 M HCl. The inhibition efficiency of DCI has been evaluated by conventional weight loss method and electrochemical polarization studies. Experimental results are fitted to various adsorption isotherms. Thermodynamic parameters have also been studied from temperature studies. The results reveal that DCI acts as an effective inhibitor (around 90% of IE in HCl media.

  7. Inhibiting Effects of Rabeprazole Sulfide on the Corrosion of Mild Steel in Acidic Chloride Solution

    Directory of Open Access Journals (Sweden)

    M. K. Pavithra

    2013-01-01

    Full Text Available The corrosion inhibition effect of Rabeprazole sulfide (RS on mild steel in 1 M hydrochloric acid (HCl was investigated using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS, and chronoamperometric measurements. Protection efficiency of RS increases with the concentration and decreases with the rise in temperature. Adsorption of RS on mild steel surface in 1 M HCl follows Langmuir adsorption isotherm. The kinetic and thermodynamic parameters governing the adsorption process were calculated and discussed. The polarization results suggest that RS performed as an excellent mixed-type inhibitor for mild steel corrosion in 1 M HCl.

  8. Corrosion Inhibition of Leucaena Leucocephala Pod on Mild Steel in Sulphuric Acid Solution

    Institute of Scientific and Technical Information of China (English)

    P.Muthukrishnan; B.Jeyaprabha; P.Prakash

    2013-01-01

    The corrosion of the mild steel in 1 mol/L H2SO4 was investigated using Leucaena leucocephala pod extract (LLPE) as corrosion inhibitor by weight loss and electrochemical techniques.Inhibition efficiency of 95% was achieved with 500×10-6 of LLPE at 308 K.The polarization studies showed that LLPE acted as mixed type inhibitor.The adsorption of the studied inhibitor on mild steel obeyed Langmuir adsorption isotherm.Protective film formation against acid attack was confirmed by FT-IR,XRD and SEM techniques.

  9. Corrosion inhibition of iron in hydrochloric acid by polyacrylamide

    Directory of Open Access Journals (Sweden)

    DRAGICA CHAMOVSKA

    2007-07-01

    Full Text Available The corrosion protection and/or adsorption of polyacrylamide (PAA of number average molecular weight, , between 15,000 – 1,350,000 g mol-1 on mild steel and iron (99.99 % Fe in 3 M HCl at room temperature was studied using spectrophotometry (the phenanthroline method, the weight loss method and EIS (Electrochemical Impedance Spectroscopy. It was found that the corrosion protect­tion efficiency of the PAA – adsorbed layers strongly depends on both the molar concentration of PAA in the solution and its molecular weight, reaching limiting values between 85 and 96 %. Simultaneously, it was also concluded that a relatively high surface coverage could be obtained with very low PAA concentrations (0.5 – 2 ppm, indicating the good adsorption characteristics of PAA on mild steel and iron in hydrochloride acid. The experimentally obtained results follow a Lan­gmuir adsorption isotherm. According to the best fitting parameters, the adsorption coef­f­i­cient B ranged between 2×107 and 4×108 mol-1 and depended strongly on the mole­cular weight of the PAA: B = k (for a ≈ 0.67 and k = 2.95×104 or the size of the polymer coil. As was found by EIS, the thickness of the adsorbed PAA layer was approx. 1.1 nm (for er = 15 and corresponded only to the polymer segments attached to the metal surface. On the other hand, as was found by ellipsometry, the limiting layer of the adsorbed PAA molecules was highly voluminous and relatively thick (100 – 200 nm, containing entangled polymer coils.

  10. Mechanism of acid corrosion inhibition using magnetic nanofluid

    Science.gov (United States)

    Parekh, Kinnari; Jauhari, Smita; Upadhyay, R. V.

    2016-12-01

    The inhibition effect of magnetic nanofluid on carbon steel in acid solutions was investigated using gravimetric, potentiodynamic and SEM measurement. The inhibition efficiency increases up to 95% and 75% for 51.7 mM concentration, respectively, in 1 M HCl and 1 M H2SO4 medium. The adsorption of nanoparticles to the steel surface forms a barrier between the metal and the aggressive environment, which is responsible for observed inhibition action. The adsorption of nanoparticles on steel surface is supported by the Langmuir and Freundlich adsorption isotherm and surface morphology scanned through SEM.

  11. Inhibition and promotion of copper corrosion by CTAB in a microreactor system.

    Science.gov (United States)

    Murira, Caroline M; Punckt, Christian; Schniepp, Hannes C; Khusid, Boris; Aksay, Ilhan A

    2008-12-16

    We report on an optical microscopy technique for the analysis of corrosion kinetics of metal thin films in microreactor systems and use it to study the role of cetyltrimethylammonium bromide surfactant as a corrosion inhibitor in a copper-gold galvanic coplanar microsystem. A minimum in the dissolution rate of copper is observed when the surfactant concentration is approximately 0.8 mM. To explain why the inhibitory role of the surfactant does not extend to higher concentrations, we use zero resistance ammetry with separated half cells and show that while the surfactant inhibits cathodic reactions on gold, it also promotes the corrosion of copper because of the catalytic action of bromide counterions. These two competing processes lead to the observed minimum in the dissolution rate.

  12. Standard test method for initial screening of corrosion inhibiting admixtures for steel in concrete

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This test method covers a procedure for determining the effects of chemical admixtures on the corrosion of metals in concrete. This test method can be used to evaluate materials intended to inhibit chloride-induced corrosion of steel in concrete. It can also be used to evaluate the corrosivity of admixtures by themselves or in a chloride environment. This test is not applicable for emulsions. 1.2 &solely-SI-units; 1.3 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.

  13. Inhibition Effect of 1-Butyl-4-Methylpyridinium Tetrafluoroborate on the Corrosion of Copper in Phosphate Solutions

    Directory of Open Access Journals (Sweden)

    M. Scendo

    2011-01-01

    Full Text Available The influence of the concentration of 1-Butyl-4-methylpyridinium tetrafluoroborate (4MBPBF4 as ionic liquid (IL on the corrosion of copper in 0.5 M PO43− solutions of pH 2 and 4 was studied. The research involved electrochemical polarization method, and scanning electron microscopy (SEM technique. The results obtained showed that the inhibition efficiency of corrosion of copper increases with an increase in the concentration of 4MBPBF4 but decreases with increasing temperature. The thermodynamic functions of corrosion analysis and adsorptive behavior of 4MBPBF4 were carried out. During the test, the adsorption of the inhibitor on the copper surface in the phosphate solutions was found to obey the Langmuir adsorption isotherm and had a physical mechanism.

  14. Corrosion of copper in aerated synthetic sea water solutions and its inhibition by 3-amino-1,2,4-triazole.

    Science.gov (United States)

    Sherif, El-Sayed M; Erasmus, R M; Comins, J D

    2007-05-15

    Corrosion of copper in aerated synthetic sea water (3.5% NaCl) solutions and its inhibition by 3-amino-1,2,4-triazole (ATA) have been studied using electrochemical, gravimetric, and pH measurements, along with Raman spectroscopy. Electrochemical measurements indicated that the presence of ATA and the increase of its concentration suppress the corrosion process on the copper surface. This effect decreases cathodic, anodic, and corrosion (jcorr) currents and corrosion rates (Kcorr), while increasing polarization resistance (Rp), surface coverage (theta), and inhibition efficiency (IE%). Weight loss measurements indicated that the dissolution of copper and the accompanying change of pH decreased to a minimum even after 24 days immersion due to the presence of ATA and the increase of its concentration. Raman investigations revealed that the inhibition of copper corrosion is achieved by strong adsorption of ATA molecules onto the copper surface, preventing it from being corroded easily.

  15. Corrosion inhibition of aminated hydroxyl ethyl cellulose on mild steel in acidic condition.

    Science.gov (United States)

    Sangeetha, Y; Meenakshi, S; Sairam Sundaram, C

    2016-10-05

    Aminated hydroxyethyl cellulose (AHEC) was synthesized, characterized using Fourier Transform Infrared spectroscopy (FTIR) and the corrosion inhibition of AHEC on mild steel in 1M HCl was studied using chemical and electrochemical studies. Results obtained in weight loss method showed that inhibition efficiency increased with increase in concentration of AHEC. The adsorption of the inhibitor on metal surface followed Frumkin isotherm. Polarization studies revealed that the AHEC inhibits through mixed mode. Thermodynamic parameters and activation energy were calculated and discussed. FTIR and X-ray diffraction studies (XRD) confirmed the adsorption of the inhibitor. The surface morphology was studied using Scanning Electron Microscope (SEM) and Atomic Force Microscopy (AFM).

  16. Inhibition of Copper Pitting Corrosion in Aggressive Potable Waters

    Directory of Open Access Journals (Sweden)

    Emily Sarver

    2012-01-01

    Full Text Available Copper pitting corrosion can lead to premature plumbing failures, and can be caused by aggressive potable waters characterized by high pH, free chlorine residual and low alkalinity. In such waters and under continuous flow, certain inhibitors including phosphate, silica or natural organic matter may greatly reduce pitting occurrence. In the current work, 1 mg/L phosphate (as P completely prevented initiation of pits, and 5 mg/L silica (as Si significantly decelerated pitting. However, much lower doses of these inhibitors had little benefit and actually accelerated the rate of attack in some cases. Effects of organic matter were dependent on both the type (e.g., natural versus ozonated humic substances and dosage. Dose-response effects of free chlorine and alkalinity were also investigated. Based on electrochemical data, pits initiated more rapidly with increased free chlorine, but even moderate levels of chlorine (~0.4 mg/L eventually caused severe pitting. High alkalinity decreased pit propagation rates but did not prevent pit formation.

  17. Hydroxyl carboxylate based non-phosphorus corrosion inhibition process for reclaimed water pipeline and downstream recirculating cooling water system.

    Science.gov (United States)

    Wang, Jun; Wang, Dong; Hou, Deyin

    2016-01-01

    A combined process was developed to inhibit the corrosion both in the pipeline of reclaimed water supplies (PRWS) and in downstream recirculating cooling water systems (RCWS) using the reclaimed water as makeup. Hydroxyl carboxylate-based corrosion inhibitors (e.g., gluconate, citrate, tartrate) and zinc sulfate heptahydrate, which provided Zn(2+) as a synergistic corrosion inhibition additive, were added prior to the PRWS when the phosphate (which could be utilized as a corrosion inhibitor) content in the reclaimed water was below 1.7 mg/L, and no additional corrosion inhibitors were required for the downstream RCWS. Satisfactory corrosion inhibition was achieved even if the RCWS was operated under the condition of high numbers of concentration cycles. The corrosion inhibition requirement was also met by the appropriate combination of PO4(3-) and Zn(2+) when the phosphate content in the reclaimed water was more than 1.7 mg/L. The process integrated not only water reclamation and reuse, and the operation of a highly concentrated RCWS, but also the comprehensive utilization of phosphate in reclaimed water and the application of non-phosphorus corrosion inhibitors. The proposed process reduced the operating cost of the PRWS and the RCWS, and lowered the environmental hazard caused by the excessive discharge of phosphate. Furthermore, larger amounts of water resources could be conserved as a result.

  18. Two new supramolecular metal diphosphonates: Synthesis, characterization, crystal structure and inhibiting effects on metallic corrosion

    Science.gov (United States)

    Gholivand, Khodayar; Yaghoubi, Rouhollah; Farrokhi, Alireza; Khoddami, Shahram

    2016-11-01

    Two new divalent metal(II) aminodiphosphonates with layered structure, namely, Cu(H3L1)2·2H2O (1), [H4L1=methyl-N(CH2PO3H2)2] and Cd2(H2L2)4(2), [H4L2=n-propyl-N(CH2PO3H2)2] were synthesized and characterized. The Cu(II) ions in complex 1 are octahedrally coordinated by four oxygen atoms from two chelating ligands and two phosphonate oxygen atoms from two neighboring Cu(H3L1)2 units. The Cu(H3L1)2 units are interconnected by bridging phosphonate groups, forming a 2-D metal phosphonate layer. The structure of complex 2 contains two unique Cd(II) ions octahedrally-coordinated by six phosphonate oxygen atoms from four H2L2 diphosphonate anions. Corrosion inhibition performances of 1 and 2 were also compared with each other in order to study the effect of combinations of externally added Cd/H4L2 and Cu/H4L1 (1:1 ratio) on corrosion rates of carbon steel. It was found that at pH 3.0, Cd/H4L2 or Cu/H4L1 combinations do not have noticeable corrosion inhibition efficiency for carbon steel. In contrast, at pH 7.0, higher corrosion inhibition efficiency was achieved for Cd/H4L2. Physical characterizations such as scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR) were applied to study the corrosion specimens and film material.

  19. Inhibition Effect of Substituted Thiadiazoles on Corrosion Activity of N80 Steel in HCl Solution

    Directory of Open Access Journals (Sweden)

    M. Yadav

    2013-01-01

    Full Text Available The inhibition effect of some prepared compounds, namely, thiadiazole derivatives, on N80 steel corrosion in 15% HCl solutions has been studied by using the weight loss, electrochemical polarization, and electrochemical impedance spectroscopy techniques. It was found that the inhibition efficiency of the thiadiazole derivatives, namely, 2-amino-5-(4-methoxyphenyl-1,3,4-thiazole (AMPT, 2-amino-5-phenyl-1,3,4-thiazole (APT, and 2-amino-5-(4-chlorophenyl-1,3,4-thiazole (ACPT, increases with the increase in concentration. Inhibition efficiency follows the order AMPT > APT > ACPT. The effect of temperature on the corrosion was investigated by the weight loss method, and some thermodynamic parameters were calculated. The inhibitive action may be attributed to the adsorption of inhibitor molecules on the active sites of the metal surface following Langmuir adsorption isotherm. Polarization measurements indicated that thiadiazole derivatives act as mixed-type corrosion inhibitor. The adsorption of thiadiazole derivatives on N80 surface exposed to inhibitor-containing solutions was confirmed using SEM and FT-IR spectra.

  20. Inhibition of Mild Steel Corrosion in Hydrochloric Acid Solution by New Coumarin

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    Abdul Amir H. Kadhum

    2014-06-01

    Full Text Available A new coumarin derivative, N,N′-((2E,2′E-2,2′-(1,4-phenylenebis (methanylylidenebis(hydrazinecarbonothioylbis(2-oxo-2H-chromene-3-carboxamide PMBH, was synthesized and its chemical structure was elucidated and confirmed using spectroscopic techniques (Infrared spectroscopy IR, Proton nuclear  magnetic resonance, 1H-NMR and carbon-13 nuclear magnetic resonance 13C-NMR. The corrosion inhibition effect of PMBH on mild steel in 1.0 M HCl was investigated using corrosion potential (ECORR, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS, and electrochemical frequency modulation (EFM measurements. The obtained results indicated that PMBH has promising inhibitive effects on the corrosion of mild steel in 1.0 M HCl across all of the conditions examined. Scanning electron microscopy (SEM was used to investigate the morphology of the mild steel before and after immersion in 1.0 M HCl solution containing 0.5 mM of PMBH. Surface analysis revealed improvement of corrosion resistance in presence of PMBH.

  1. Investigations of the inhibition of copper corrosion in nitric acid solutions by ketene dithioacetal derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Fiala, A. [Laboratoire de chimie moleculaire du controle de l' environnement et des mesures physico-chimiques, faculte des sciences exactes, universite Mentouri-Constantine, route de Ain-El-Bey, Constantine (Algeria)], E-mail: abdelfiala@yahoo.fr; Chibani, A. [Laboratoire de chimie moleculaire du controle de l' environnement et des mesures physico-chimiques, faculte des sciences exactes, universite Mentouri-Constantine, route de Ain-El-Bey, Constantine (Algeria); Darchen, A. [Laboratoire d' electrochimie, ecole nationale superieure de chimie de Rennes, avenue du general-Leclerc, 35700 Rennes (France); Boulkamh, A.; Djebbar, K. [Laboratoire de chimie moleculaire du controle de l' environnement et des mesures physico-chimiques, faculte des sciences exactes, universite Mentouri-Constantine, route de Ain-El-Bey, Constantine (Algeria)

    2007-10-15

    Ketene dithioacetal derivatives, namely 3-[bis(methylthio)methylene] pentane-2,4-dione (1), 3-(1,3-dithian-2-ylidene) pentane-2,4-dione (2) and 3-(1,3-dithiolan-2-ylidene) pentane-2,4-dione (3) were synthesized and their respective capacity to inhibit copper corrosion in 3 M HNO{sub 3} was investigated by means of weight loss, potentiodynamic polarization, scanning electron microscopy (SEM) and energy dispersive X-ray fluorescence (XRF). The obtained results indicate that the addition of these compounds significantly decreases the corrosion rate. Potentiodynamic polarization studies clearly showed that the inhibition efficiency increases with increasing concentration of the investigated compounds at a fixed temperature, but decreases with increasing temperature. These results on the whole showed that the studied substances are good cathodic inhibitors for copper corrosion in nitric acid medium. SEM and energy dispersive X-ray (EDAX) examination of the copper surface revealed that these compounds prevented copper from corrosion by adsorption on its surface to form a protective film, which acts as a barrier to aggressive agents. The presence of these organic compounds adsorbed on the electrode surface was confirmed by XRF investigations.

  2. Synthesis and characterization of novel coatings for corrosion protection and hydrogen embrittlement inhibition

    Science.gov (United States)

    Durairajan, Anand

    The degradation of metallic materials under the effect of corrosion is a costly problem, which nearly every industry is confronted with. By using electrochemical plating, one can alter the characteristics of a surface so as to provide improved appearance, ability to withstand corrosive agents, resistance to abrasion, improved electrocatalytic properties or other desired properties or a combination of them. The primary goal of this dissertation is to use electrochemical deposition (electrolytic and electroless) as a surface modification technique to obtain corrosion resistant high performance electrode materials for different electrochemical applications. Metal hydride alloys, which reversibly absorb/desorb hydrogen, have been used in battery applications. The continuous decrease in the absorb/desorbing capacity of these alloys has been attributed to the corrosion of the alloy. Cobalt encapsulation (electroless) has been used as a surface modification method to obtain high performance AB5 type metal hydride alloy. The coated material has a higher capacity and longer cycle life compared to the bare alloy. Pulverization and alloy oxidation---two prime reasons for capacity fading of MH alloys have been studied in greater detail using unique electrochemical and physical characterization methods. The harmful effects of hydrogen permeation (ingress) and related stress corrosion cracking (SCC) can limit the use of metals and alloys in aqueous environments. In the present work, a new Zn-Ni-Cd plating process which offers a unique way of controlling and optimizing the Zn and Cd contents in the final deposit, has been developed. The Zn Ni-Cd alloy coatings has a more anodic corrosion potential than that of Cd but higher than the corrosion potential of iron. The coatings have superior corrosion resistance (10 times higher) and barrier properties than the conventional Cd coatings. Zn-Ni-Cd coatings also inhibit the hydrogen entry into the underlying steel. The kinetic

  3. Green Approach to Corrosion Inhibition of Mild Steel by Lignin Sulfonate in Acidic Media

    Institute of Scientific and Technical Information of China (English)

    Muna A.ABU-DALO; Nathir A.F.AL-RAWASHDEH; Ahmed A.MUTLAQ

    2016-01-01

    The inhibition effect of lignin sulfonate against corrosion for mild steel in acidic solution has been examined by means of FTIR (fourier transform infrared spectroscopy),FAA (flame atomic absorption)spectroscopy,SEM (scanning electron microscope),EDS (energy dispersive X-ray spectroscopy),and mass loss techniques.The results revealed that lignin is a beneficial inhibitor for mild steel corrosion in acidic medium.It has been further found that Langmuir adsorption isotherm is obeyed by the tested lignin′s adsorption over the surface of mild steel.The range of inhibition efficiency (IE)in 2 mol·L-1 HCl was found to be 75·88%-87·88% for Reax 88A,40·72%-60·32%for Reax 88B,and 54·32%-63·03% for Reax 100M,after immersed at 298 K for 24 h time.

  4. Effect of Ammonium Molybdate Inhibition on Corrosion Behaviour of Mild Steel in Chloride and Sulphide Media

    Directory of Open Access Journals (Sweden)

    Ayo S. Afolabi

    2010-10-01

    Full Text Available The corrosion inhibition of mild steel in 3.0 M sodium chloride and 0.5 M sodium sulphide using various concentrations of ammonium molybdate was investigated in this work. The inhibition effect of this reagent in these media was monitored by weight loss and pH measurements. The analyses of the weight loss results showed that the corrosion susceptibility of mild steel in 3.0 M sodium chloride was more pronounced than in 0.5 M of sodium sulphide due to the aggressive chloride ions in the former and the weak nature of the latter. Ammonium molybdate produced a better inhibition performance of mild steel in 0.5 M sodium suphide than in 3.0 M sodium chloride medium and the higher the concentration of ammonium molybdate the more the inhibition performance on mild steel in the media studied. Optimum inhibition was obtained at 2.5 M ammonium molybdate in both media. The pH values in chloride medium remained acidic throughout the exposure period while those of sulphide medium shifted to alkaline region with exposure time; an effect that was traceable to higher inhibition obtained in the latter medium.

  5. Inhibition of Corrosion of Carbon Steel in 3.5% NaCl Solution by Myrmecodia Pendans Extract

    Directory of Open Access Journals (Sweden)

    Atria Pradityana

    2016-01-01

    Full Text Available Inhibitor is a substance that is added to the corrosive media to inhibit corrosion rate. Organic inhibitors are preferred to inorganic ones since they are environmentally friendly. One of the organic compounds which is rarely reported as a corrosion inhibitor is Myrmecodia Pendans. The organic compounds can be adsorbed on the metal surface and block the active surface to reduce the rate of corrosion. In this study, the used pipe was carbon steel API 5L Grade B with 3.5% NaCl solution as the corrosion medium. The objective of this research was to analyze the inhibition mechanism Myrmecodia Pendans towards carbon steel in a corrosion medium. Concentration variations of extract Myrmecodia Pendans were 0–500 ppm. Fourier Transform Infrared (FTIR was used for chemical characterization of Myrmecodia Pendans. Polarization and Electrochemical Impedance Spectroscopy (EIS were used to measure the corrosion rate and behaviour. From the electrochemical measurements, it was found that the addition of 400 mg/L inhibitor gave the highest inhibition efficiency. Myrmecodia Pendans acted as a corrosion inhibitor by forming a thin layer on the metal surface.

  6. Inhibitive action of some plant extracts on the corrosion of steel in acidic media

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Gaber, A.M. [Department of Chemistry, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt)]. E-mail: ashrafmoustafa@yahoo.com; Abd-El-Nabey, B.A. [Department of Chemistry, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt); Sidahmed, I.M. [Department of Chemistry, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt); El-Zayady, A.M. [Department of Chemistry, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt); Saadawy, M. [Department of Chemistry, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt)

    2006-09-15

    The effect of extracts of Chamomile (Chamaemelum mixtum L.), Halfabar (Cymbopogon proximus), Black cumin (Nigella sativa L.), and Kidney bean (Phaseolus vulgaris L.) plants on the corrosion of steel in aqueous 1 M sulphuric acid were investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. EIS measurements showed that the dissolution process of steel occurs under activation control. Potentiodynamic polarization curves indicated that the plant extracts behave as mixed-type inhibitors. The corrosion rates of steel and the inhibition efficiencies of the extracts were calculated. The results obtained show that the extract solution of the plant could serve as an effective inhibitor for the corrosion of steel in sulphuric acid media. Inhibition was found to increase with increasing concentration of the plant extract up to a critical concentration. The inhibitive actions of plant extracts are discussed on the basis of adsorption of stable complex at the steel surface. Theoretical fitting of different isotherms, Langmuir, Flory-Huggins, and the kinetic-thermodynamic model, were tested to clarify the nature of adsorption.

  7. Laccase Immobilized on Mesoporous Silica Materials and Its Corrosion Inhibition Performance in Circulating Cooling Water System

    Institute of Scientific and Technical Information of China (English)

    Liu Fang; Lü Yucui; Zhong Huiyun; Zhang Shuang; Fan Fengtao; Zhao Chaocheng

    2015-01-01

    Mesoporous SiO2 microspheres were synthesized using the sol-gel method and were characterized byTEM, FT-IR and BET techniques. The diameter of the microspheres is about 100—150 nm, and the average mesopore di-ameter is 2.55 nm, while the speciifc surface area is 1 088.9 m2/g. Mesoporous SiO2 microspheres adsorb glutaraldehyde and immobilize laccase by means of the aldehyde group in glutaral which can react with the amidogen of laccase. The im-mobilization conditions were optimized at a glutaraldehyde concentration of 0.75%, a crosslinking time of 8 h, a laccase concentration of 0.04 L/L and an immobilization time of 10 h. When diesel leakage concentration was 80 mg/L, the highest corrosion inhibition efifciency of immobilized laccase reached 49.23%, which was slightly lower than the corrosion inhibi-tion efifciency of free laccase (59%). The diesel degradation ratio could reach up to 45%. It has been proved that the immo-bilized laccase could degrade diesel to inhibit corrosion.

  8. Corrosion Inhibition Study of Mild Steel in Acidic Medium by Antibiotic Drugs: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Md. A. Aziz

    2014-04-01

    Full Text Available A comparison of the inhibiting efficiency of antibiotic drugs (ciprofloxacin, cloxacillin, and amoxicillin on the corrosion of mild steel in 1 mol·L−1 HCl were studied at room temperature using mass loss measurement. The main reason is probably be due to the formation of protective coverage by the inhibitor as other authors reported previously. Adsorption characteristics of the inhibitor has also been studied using simple equation and it was found that drugs inhibits the corrosion of mild steel by being adsorbed on the surface of mild steel by a physical adsorption mechanism. The adsorption of drugs on the mild steel surface was found to be spontaneous and obey the Langmuir adsorption isotherm model. It was observed that the test drug has a promising inhibitory action in acid medium against corrosion of mild steel. Moreover it was revealed that an inhibition efficiency of 80.1 % can be achieved with 3×10-3M ciprofloxacin drug treatment on mild steel.

  9. Corrosion inhibition and adsorption behavior of methionine on mild steel in sulfuric acid and synergistic effect of iodide ion.

    Science.gov (United States)

    Oguzie, E E; Li, Y; Wang, F H

    2007-06-01

    The corrosion inhibition of mild steel in sulfuric acid by methionine (MTI) was investigated using electrochemical techniques. The effect of KI additives on corrosion inhibition efficiency was also studied. The results reveal that MTI inhibited the corrosion reaction by adsorption onto the metal/solution interface. Inhibition efficiency increased with MTI concentration and synergistically increased in the presence of KI, with an optimum [KI]/[MTI] ratio of 5/5, due to stabilization of adsorbed MTI cations as revealed by AFM surface morphological images. Potentiodynamic polarization data suggest that the compound functioned via a mixed-inhibition mechanism. This observation was further corroborated by the fit of the experimental adsorption data to the Temkin and Langmuir isotherms. The inhibition mechanism has been discussed vis-à-vis the presence of both nitrogen and sulfur atoms in the MTI molecule.

  10. Synergistic Inhibition Effect of Zinc Acetylacetonate and Benzothiazole in Epoxy Coating on the Corrosion of Mild Steel

    Science.gov (United States)

    Amoozadeh, S. M.; Mahdavian, M.

    2015-06-01

    The corrosion inhibition effect of zinc acetylacetonate (ZAA) and benzothiazole (BTH) mixture was evaluated for mild steel in 3.5% NaCl solution. To this end, ZAA:BTH mixtures ranged from 6:1 to 1:6 mol ratios were examined by weight loss and open circuit potential to obtain optimal mole ratio. The optimal mixture of ZAA:BTH at 1:5 mol ratio showed a significant corrosion inhibition efficiency proved by electrochemical impedance spectroscopy and polarization studies. The addition of the optimal mixture of ZAA:BTH to epoxy coating showed a considerable increase of corrosion protection evaluated by salt spray exposure.

  11. Mentha pulegium extract as a natural product for the inhibition of corrosion. Part I: electrochemical studies.

    Science.gov (United States)

    Khadraoui, Abdelkader; Khelifa, Abdellah; Boutoumi, Hocine; Hammouti, Belkheir

    2014-01-01

    The inhibitory effect of Mentha pulegium extract (MPE) on steel corrosion in 1 M HCl solution was investigated using potentiodynamic polarisation and electrochemical impedance spectroscopy. The inhibition efficiency of MPE was found to increase with the concentration and reached 88% at 33% (v/v). Polarisation measurements show that the natural extract acted as a mixed inhibitor. The remarkable inhibition efficiency of MPE was discussed in terms of blocking of electrode surface by adsorption of inhibitor molecules through active centres. The adsorption of MPE was found to accord with the Temkin isotherm.

  12. Inhibition of Corrosion of Carbon Steel in Well Water by DL-Phenylalanine-Zn2+ System

    Directory of Open Access Journals (Sweden)

    A. Sahaya Raja

    2013-01-01

    Full Text Available The environmental friendly inhibitor system DL-phenylalanine-Zn2+ has been investigated by weight loss method. A synergistic effect exists between DL-phenylalanine and Zn2+ system. The formulation consisting of 150 ppm of DL-phenylalanine and 5 ppm of Zn2+ offers good inhibition efficiency of 90%. Polarization study reveals that this formulation functions as a anodic inhibitor. AC impedance spectra reveal that a protective film is formed on the metal surface. The surface morphology has been analysed by SEM and EDAX. A suitable mechanism of corrosion inhibition is proposed based on the results obtained from weight loss study and electrochemical studies.

  13. 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.

  14. Note: Inhibiting bottleneck corrosion in electrical calcium tests for ultra-barrier measurements

    Energy Technology Data Exchange (ETDEWEB)

    Nehm, F., E-mail: frederik.nehm@iapp.de; Müller-Meskamp, L.; Klumbies, H.; Leo, K. [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01069 Dresden (Germany)

    2015-12-15

    A major failure mechanism is identified in electrical calcium corrosion tests for quality assessment of high-end application moisture barriers. Accelerated calcium corrosion is found at the calcium/electrode junction, leading to an electrical bottleneck. This causes test failure not related to overall calcium loss. The likely cause is a difference in electrochemical potential between the aluminum electrodes and the calcium sensor, resulting in a corrosion element. As a solution, a thin, full-area copper layer is introduced below the calcium, shifting the corrosion element to the calcium/copper junction and inhibiting bottleneck degradation. Using the copper layer improves the level of sensitivity for the water vapor transmission rate (WVTR) by over one order of magnitude. Thin-film encapsulated samples with 20 nm of atomic layer deposited alumina barriers this way exhibit WVTRs of 6 × 10{sup −5} g(H{sub 2}O)/m{sup 2}/d at 38 °C, 90% relative humidity.

  15. Understanding corrosion inhibition with van der Waals DFT methods: the case of benzotriazole.

    Science.gov (United States)

    Gattinoni, Chiara; Michaelides, Angelos

    2015-01-01

    The corrosion of materials is an undesirable and costly process affecting many areas of technology and everyday life. As such, considerable effort has gone into understanding and preventing it. Organic molecule based coatings can in certain circumstances act as effective corrosion inhibitors. Although they have been used to great effect for more than sixty years, how they function at the atomic-level is still a matter of debate. In this work, computer simulation approaches based on density functional theory are used to investigate benzotriazole (BTAH), one of the most widely used and studied corrosion inhibitors for copper. In particular, the structures formed by protonated and deprotonated BTAH molecules on Cu(111) have been determined and linked to their inhibiting properties. It is found that hydrogen bonding, van der Waals interactions and steric repulsions all contribute in shaping how BTAH molecules adsorb, with flat-lying structures preferred at low coverage and upright configurations preferred at high coverage. The interaction of the dehydrogenated benzotriazole molecule (BTA) with the copper surface is instead dominated by strong chemisorption via the azole moiety with the aid of copper adatoms. Structures of dimers or chains are found to be the most stable structures at all coverages, in good agreement with scanning tunnelling microscopy results. Benzotriazole thus shows a complex phase behaviour in which van der Waals forces play an important role and which depends on coverage and on its protonation state and all of these factors feasibly contribute to its effectiveness as a corrosion inhibitor.

  16. THEORETICAL STUDY ON CORROSION INHIBITION PROPERTIES OF 2-ISOPROPYL-5-METHYLPHENOL

    Directory of Open Access Journals (Sweden)

    Saprizal Hadisaputra

    2016-08-01

    Full Text Available Corrosion inhibitors of 2-isopropyl-5-methylphenol and its derivatives has been elucidated by means of density functional theory at B3LYP/6-31G(d level of theory. Effect of electron donating and withdrawing groups such as NH2, SH, CHCH2, CH3, OH, CHO, COOH, F and NO2 on the corrosion inhibitor of 2-isopropyl-5-methylphenol derivatives also have been studied. The quantum chemical parameters such as the frontier orbital energies (EHOMO, ionization potential (I, electron affinity (A and electronegativity (χ are closely related to the corrosion inhibition efficiency (IE % of 2-isopropyl-5-methylphenol derivatives. The presence of electron donating groups increase IE % values meanwhile electron with drawing groups reduce IE % values. The enhancement of IE % follows NO2 < CHO < COOH < SH < F < CH3 < CHCH2 < OH < NH2. Electron donating NH2 group gives 96.38 % of IE %, pure 2-isopropyl-5-methylphenol IE % = 82.70 %. In contrast, electron withdrawing NO2 group gives IE % only 68.66 %. This theoretical study would have a significantly contribution for accelerating corrosion inhibitor experimental to gain optimum results.

  17. 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.

  18. Corrosion inhibition of C38 steel in 1 M hydrochloric acid medium by alkaloids extract from Oxandra asbeckii plant

    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.; Lecante, A. [Laboratoire Materiaux et Molecules en Milieu Amazonien, UAG-UMR ECOFOG, Campus Trou Biran, Cayenne 97337, French Guiana (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)

    2011-02-15

    Research highlights: The inhibition effect of alkaloid extract of Oxandra asbeckii plant on the corrosion of C38 steel in 1 M hydrochloric acid solution has been investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Oxandra asbeckii extract examined acted as an efficient corrosion inhibitor in 1 M HCl. Polarization studies showed that Oxandra asbeckii extract was a mixed-type inhibitor and its inhibition efficiency increased with the inhibitor concentration. - Abstract: The inhibition effect of alkaloids extract from Oxandra asbeckii plant (OAPE) on the corrosion of C38 steel in 1 M hydrochloric acid solution has been investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The corrosion inhibition efficiency increases on increasing plant extracts concentration. Cathodic and anodic polarization curves show that OAPE is a mixed-type inhibitor. The effect of temperature on the corrosion behavior of C38 steel in 1 M HCl with and without addition of plant extract was studied in the temperature range 25-55 {sup o}C. The thermodynamic functions of dissolution and adsorption processes were calculated from experimental polarization data and the interpretation of the results are given. The adsorption of this plant extract on the C38 steel surface obeys the Langmuir adsorption isotherm. Surface analysis (Raman) was also carried out to establish the corrosion inhibitive property of this plant extract in HCl solution.

  19. 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.

  20. Inhibitive effect of some thiadiazole derivatives on C-steel corrosion in neutral sodium chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    El-Taib Heakal, F., E-mail: fakihaheakal@yahoo.com [Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt); Fouda, A.S. [Chemistry Department, Faculty of Science, El-Mansoura University, El-Mansoura (Egypt); Radwan, M.S. [Petrogulf Misr Company, Maadi, Cairo (Egypt)

    2011-01-01

    Electrochemical techniques were used to investigate the effect of concentration of three new thiadiazole derivatives (I-III) on the corrosion behavior of C-steel in 0.5 M NaCl solution through the analysis of electrochemical measurements including open circuit potential (OCP), Tafel polarization and electrochemical impedance spectroscopy (EIS). Polarization curves showed that the compounds studied act as anodic type inhibitors, where the inhibition efficiency increases with increase in inhibitor concentration and decreases with rise in temperature. An adherent layer of inhibitor molecules on the surface is proposed to account for their inhibitive action in which the organic molecules adsorb on the active anodic sites following Langmuir isotherm. The thermodynamic parameters of adsorption and corrosion processes were determined and discussed. The results also indicated that pitting potential at higher anodic polarization of C-steel in 0.5 M NaCl solution becomes more positive the higher the concentration of the additive, suggesting that these inhibitors acts as retarding catalyst for pitting corrosion. EIS data confirm well the electrochemical dc results and the results are all in good agreement with the calculated quantum chemical HOMO and LUMO energies of the tested molecules, as well as with surface examination via scanning electron microscope.

  1. Inhibition of Mild Steel Corrosion in Sulfuric Acid Solution by New Schiff Base

    Directory of Open Access Journals (Sweden)

    Ahmed A. Al-Amiery

    2014-01-01

    Full Text Available The efficiency of Schiff base derived from 4-aminoantipyrine, namely 2-(1,5-dimethyl-4-(2-methylbenzylideneamino-2-phenyl-1H-pyrazol-3(2H-ylidene hydrazinecarbothioamide as a corrosion inhibitor on mild steel in 1.0 M H2SO4 was investigated using electrochemical impedance spectroscopy (EIS, potentiodynamic polarization (PD and electrochemical frequently modulation (EFM in addition to the adsorption isotherm, corrosion kinetic parameters and scanning electron microscopy (SEM. The results showed that this inhibitor behaved as a good corrosion inhibitor, even at low concentration, with a mean efficiency of 93% and, also, a reduction of the inhibition efficiency as the solution temperature increases. A polarization technique and EIS were tested for different concentrations and different temperatures to reveal that this compound is adsorbed on the mild steel, therefore blocking the active sites, and the adsorption follows the Langmuir adsorption isotherm model. The excellent inhibition effectiveness of 2-(1,5-dimethyl-4-(2-methylbenzylideneamino-2-phenyl-1H-pyrazol-3(2H-ylidenehydrazinecarbothioamide was also verified by scanning electron microscope (SEM.

  2. 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.

  3. Towards lightweight nanocomposite coatings for corrosion inhibition: Graphene, carbon nanotubes, and nanostructured magnesium as case studies

    Science.gov (United States)

    Dennis, Robert Vincent, III

    The field of nanocomposites is a burgeoning area of research due to the interest in the remarkable properties which can be achieved through their use in a variety of applications, including corrosion resistant coatings. Lightweighting is of increasing importance in the world today due to the ever growing push towards energy efficiency and the green movement and in recent years there has been a vast amount of research performed in the area of developing lightweight nanocomposites for corrosion inhibition. Many new composite materials have been developed through the use of newly developed nanomaterials (including carbonaceous and metallic constituents) and their specialized incorporation in the coating matrix materials. We start with a general review on the development of hybrid nanostructured composites for corrosion protection of base metals from a sustainability perspective in Chapter 1. This review demonstrates the ever swelling requirements for a paradigm shift in the way that we protect metals against corrosion due to the costs and environmental concerns that exist with currently used technology. In Chapter 2, we delve into the much required understanding of graphene oxide and reduced graphene oxide through near-edge X-ray absorption fine structure (NEXAFS) spectroscopy measurements to elucidate information about the electronic structure upon incorporation of nitrogen within the structure. For successful integration of the carbonaceous nanomaterials into a composite coating, a full swath of knowledge is necessary. Within this work we have shown that upon chemical defunctionalization of graphene oxide to reduced graphene oxide by means of hydrazine treatment, nitrogen is incorporated into the structure in the form of a pyrazole ring. In Chapter 3, we demonstrate that by way of in situ polymerization, graphene and multiwalled carbon nanotubes can be incorporated within a polymer (polyetherimide, PEI) matrix. Two systems have been developed including graphene and

  4. Lipopolysaccharide inhibits or accelerates biomedical titanium corrosion depending on environmental acidity.

    Science.gov (United States)

    Yu, Fei; Addison, Owen; Baker, Stephen J; Davenport, Alison J

    2015-09-14

    Titanium and its alloys are routinely used as biomedical implants and are usually considered to be corrosion resistant under physiological conditions. However, during inflammation, chemical modifications of the peri-implant environment including acidification occur. In addition certain biomolecules including lipopolysaccharide (LPS), a component of Gram-negative bacterial cell walls and driver of inflammation have been shown to interact strongly with Ti and modify its corrosion resistance. Gram-negative microbes are abundant in biofilms which form on dental implants. The objective was to investigate the influence of LPS on the corrosion properties of relevant biomedical Ti substrates as a function of environmental acidity. Inductively coupled plasma mass spectrometry was used to quantify Ti dissolution following immersion testing in physiological saline for three common biomedical grades of Ti (ASTM Grade 2, Grade 4 and Grade 5). Complementary electrochemical tests including anodic and cathodic polarisation experiments and potentiostatic measurements were also conducted. All three Ti alloys were observed to behave similarly and ion release was sensitive to pH of the immersion solution. However, LPS significantly inhibited Ti release under the most acidic conditions (pH 2), which may develop in localized corrosion sites, but promoted dissolution at pH 4-7, which would be more commonly encountered physiologically. The observed pattern of sensitivity to environmental acidity of the effect of LPS on Ti corrosion has not previously been reported. LPS is found extensively on the surfaces of skin and mucosal penetrating Ti implants and the findings are therefore relevant when considering the chemical stability of Ti implant surfaces in vivo.

  5. Lipopolysaccharide inhibits or accelerates biomedical titanium corrosion depending on environmental acidity

    Institute of Scientific and Technical Information of China (English)

    Fei Yu; Owen Addison; Stephen J Baker; Alison J Davenport

    2015-01-01

    Titanium and its alloys are routinely used as biomedical implants and are usually considered to be corrosion resistant under physiological conditions. However, during inflammation, chemical modifications of the peri-implant environment including acidification occur. In addition certain biomolecules including lipopolysaccharide (LPS), a component of Gram-negative bacterial cell walls and driver of inflammation have been shown to interact strongly with Ti and modify its corrosion resistance. Gram-negative microbes are abundant in biofilms which form on dental implants. The objective was to investigate the influence of LPS on the corrosion properties of relevant biomedical Ti substrates as a function of environmental acidity. Inductively coupled plasma mass spectrometry was used to quantify Ti dissolution following immersion testing in physiological saline for three common biomedical grades of Ti (ASTM Grade 2, Grade 4 and Grade 5). Complementary electrochemical tests including anodic and cathodic polarisation experiments and potentiostatic measurements were also conducted. All three Ti alloys were observed to behave similarly and ion release was sensitive to pH of the immersion solution. However, LPS significantly inhibited Ti release under the most acidic conditions (pH 2), which may develop in localized corrosion sites, but promoted dissolution at pH 4–7, which would be more commonly encountered physiologically. The observed pattern of sensitivity to environmental acidity of the effect of LPS on Ti corrosion has not previously been reported. LPS is found extensively on the surfaces of skin and mucosal penetrating Ti implants and the findings are therefore relevant when considering the chemical stability of Ti implant surfaces in vivo.

  6. Inhibiting effects of some oxadiazole derivatives on the corrosion of mild steel in perchloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Lebrini, Mounim [Laboratoire de Cristallochimie et Physicochimie du Solide UMR 8012 ENSCL, BP. 108, F-59652 Villeneuve d' Ascq Cedex (France); Bentiss, Fouad [Laboratoire de Cristallochimie et Physicochimie du Solide UMR 8012 ENSCL, BP. 108, F-59652 Villeneuve d' Ascq Cedex (France); Laboratoire de Chimie de Coordination et d' Analytique, Universite Chouaib Doukkali, Faculte des Sciences, B.P. 20, El Jadida (Morocco); Vezin, Herve [Laboratoire de Chimie Organique et Macromoleculaire, CNRS UMR 8009, USTL Ba-hat t C4, F-59655 Villeneuve d' Ascq Cedex (France); Lagrenee, Michel [Laboratoire de Cristallochimie et Physicochimie du Solide UMR 8012 ENSCL, BP. 108, F-59652 Villeneuve d' Ascq Cedex (France)]. E-mail: michel.lagrenee@ensc-lille.fr

    2005-11-15

    The efficiency of 3,5-bis(n-pyridyl)-1,3,4-oxadiazole (n-POX, n = 1, 2, 3), as corrosion inhibitors for mild steel in 1 M perchloric acid (HClO{sub 4}) have been determined by weight loss measurements and electrochemical studies. The results show that these inhibitors revealed a good corrosion inhibition even at very low concentrations. Comparison of results among those obtained by the studied oxadiazoles shows that 3-POX was the best inhibitor. Polarisation curves indicate that n-pyridyl substituted-1,3,4-oxadiazoles are mixed type inhibitors in 1 M HClO{sub 4}. The adsorption of these inhibitors follows a Langmuir isotherm model. The electronic properties of n-POX, obtained using the AM1 semi-empirical quantum chemical approach, were correlated with their experimental efficiencies using the linear resistance model (LR)

  7. Infrared-visible sum frequency generation investigation of Cu corrosion inhibition with benzotriazole.

    Science.gov (United States)

    Schultz, Zachary D; Biggin, Mary Ellen; White, Jeffrey O; Gewirth, Andrew A

    2004-02-01

    Infrared-visible sum frequency generation spectroscopy is used to investigate the corrosion inhibitor benzotriazole (BTAH) adsorbed on Cu(100) and Cu(111) in acidic solution. Potential-dependent in situ spectra indicate that the adsorbed molecule is the benzotriazole anion (BTA-) at all potentials investigated. The Cu(100) surface is shown to form an ordered adlayer at all potentials probed, while the Cu(111) face is shown to be disordered at negative potentials, but to order with applied positive potential. The ordered adlayer is shown to consist of the BTA- in two configurations, one coordinated to the surface and Cu+ ions in solution and the other coordinated only to the surface. The BTA- coordinated to Cu+ is shown to be more stable with respect to Cl- addition than BTA- coordinated to only the surface. This study demonstrates the viability of using sum frequency generation to study corrosion inhibition in situ.

  8. [Influence of EPS on silicate corrosion inhibition for copper pipe in soft water].

    Science.gov (United States)

    Li, Shi-Yin

    2008-10-01

    The effects of sodium alginate on silicate corrosion inhibition for copper pipe in simulated soft water were investigated. The results showed that more soluble copper release was occurred when low concentration sodium alginate was in presence. The 1 a aged copper pipe released more soluble copper than the 3 a and 10 a aged copper pipe. The sequence of concentration of soluble copper release was c 1 a > c 3 a, > c 10 a. However, compared to the low concentration sodium alginate, soluble copper released from the 1 a aged copper pipe increased, and the 3 a and 10 a aged copper pipe were inverse when high level sodium alginate was in presence. These phenomena showed that the effect of silicate corrosion inhibition decreased when extracellular polymer substances was dissolved in soft water. Under the conditions of pH 7.5 and sodium alginate 16 mg/L, soluble copper release tend was gradually increase-decrease-gradually run-up which due to the absorption of sodium alginate on the surface of copper surface and the complex interaction between sodium alginate, silicate and copper ions. When the initial pH value was low, compared to the system of no sodium alginate, the soluble copper release distinctly increased in the presence of sodium alginate. The amount of soluble copper released from 1 a copper pipe is higher than that from 3 a and 10 a aged copper pipe, which due to the different components of copper corrosion by-products on the surface of different aged copper pipes and the different solubility of different corrosion by-products.

  9. Effect of Morinda Tinctoria Leaves Extract on the Corrosion Inhibition of Mild Steel in Acid Medium

    Institute of Scientific and Technical Information of China (English)

    K.Krishnaveni; J.Ravichandran; A.Selvaraj

    2013-01-01

    The Morinda tinctoria (MT) plant leaves extract was prepared in aqueous and hydrochloric acid media and was used as corrosion inhibitor for mild steel in hydrochloric acid medium.MT is found to be an efficient inhibitor at room temperature and the efficiency decreases with increase in temperature.Results from colorimetric studies predict the amount of iron present in the test solution and the percentage inhibition efficiency values calculated from this data fit well with the weight loss experiments.The AC impedance studies reveal that the mild steel surface is positively charged and the process of inhibition is through charge transfer.Polarisation studies indicate the mixed nature of the inhibitor.Thermodynamic parameters obtained predict that the process of inhibition is a spontaneous one.

  10. Corrosion inhibition of mild steel by amphoteric surfactants derived from aspartic acid

    Energy Technology Data Exchange (ETDEWEB)

    Morsi, M.S. (Cairo Univ., Faculty of Science, Chemistry Dept., Giza (Egypt)); Barakat, Y.F. (Cairo Univ., Faculty of Science, Chemistry Dept., Giza (Egypt)); El-Sheikh, R. (Cairo Univ., Faculty of Science, Chemistry Dept., Giza (Egypt)); Hassan, A.M. (Cairo Univ., Faculty of Science, Chemistry Dept., Giza (Egypt)); Baraka, A. (Cairo Univ., Faculty of Science, Chemistry Dept., Giza (Egypt))

    1993-07-01

    The inhibition of mild steel corrosion in 0.5 M HCl solution by amphoteric surfactants (which contain both an anionic and a cationic moiety in the same molecule) of general formula: NH[sub 2]-(CH[sub 2])[sub 2]-NH-CH(COOH)-CH[sub 2]-CO-NHR (R alkyl group of C[sub 10,] [sub 11,] [sub 12,] [sub 13,] [sub 15,] [sub and] [sub 17]) is shown to confirm Langmuir's absorption isotherms. At a given concentration of surfactants, the inhibiting action increases with the increase of carbon chain length. The influence of both inductive and steric hindrance effects of methylene groups in -R on the inhibition efficiency has also been mentioned. (orig.)

  11. ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY STUDY OF CORROSION INHIBITION OF MODIFIED LIGNOSULPHONATE FOR CARBON STEEL

    Institute of Scientific and Technical Information of China (English)

    C.H. Yi; X.Q. Qiu; D.J. Yang; H.M. Lou

    2005-01-01

    The corrosion inhibition for carbon steel in circulating cooling water by modified lignosulphonate has been investigated using electrochemical impedance spectroscopy technique. Results show that the inhibition efficiency of modified lignosulphonate GCL2 is a great improvement on that of lignosulphonate. The maximum inhibition efficiency of GCL2 reaches 99.21% at forming adsorption film on the metal surface for the electrochemical impedance spectroscopy in GCL2 solution shows more than one time-constant. Moreover, results also indicate that it is more efficient in stirring solution than in still solution for GCL2 because the constant of adsorption in stirring solution is much larger than that in still solution. The adsorption of inhibitor GCL2 follows Langmuir's adsorption isotherm.

  12. Corrosion Inhibition by Tithonia diversifolia (Hemsl) A. Gray leaves extract for 304 SS in hydrochloric acid solution

    Science.gov (United States)

    Firdausi, S.; Kurniawan, F.

    2016-04-01

    The inhibition effect of Tithonia diversifolia (Hemsl) A. Gray leaves extract on the corrosion phenomena of 304 SS in 1 M HCl has been studied by polarization potentiodynamic. The powder of T. diversifolia was extracted by demineralized water which was cultivated in East Java, Indonesia. The extract was characterized by FTIR spectrophotometer. The presence of T. diversifolia can inhibit the corrosion rate of 304 SS. The efficiency inhibition value of 2 g/L T. diversifolia leaves extract reached up to 77.27% at room temperature.

  13. A study of corrosion inhibition of steel AISI-SAE 1020 in CO2-brine using surfactant Tween 80

    Science.gov (United States)

    Cedeño, M. L.; L, E. Vera; Pineda T, Y.

    2017-01-01

    Surfactant inhibitors also called active surface agents are molecules composed of a polar hydrophilic group and a non-polar hydrophobic group, with characteristics of adsorption on metal surfaces, high efficiency of inhibiting, low price, low toxicity and easy production. In this work, the corrosion inhibition was study by CO2 steel AISI-SAE 1020 with the addition of 0.01M Tween 80 surfactant to a brine solution (3% NaCl). Electrochemical Impedance Spectroscopy and potentiodynamic polarization testing investigated the phenomenon. The results revealed that the surfactant studied acts as an excellent corrosion inhibitor and inhibition efficiency (E%) increases with increasing fluid velocity. The morphology of the steel surface after exposure to the solution of 3% NaCl with and without surfactant indicates the inhibition phenomenon is due to the adsorption of the surfactant molecules, which insulate the surface of the corrosive medium and reduces the attack surficial.

  14. Effect of molecular structure of aniline-formaldehyde copolymers on corrosion inhibition of mild steel in hydrochloric acid solution.

    Science.gov (United States)

    Zhang, Yan; Nie, Mengyan; Wang, Xiutong; Zhu, Yukun; Shi, Fuhua; Yu, Jianqiang; Hou, Baorong

    2015-05-30

    Aniline-formaldehyde copolymers with different molecular structures have been prepared and investigated for the purpose of corrosion control of mild steel in hydrochloric acid. The copolymers were synthesized by a condensation polymerization process with different ratios of aniline to formaldehyde in acidic precursor solutions. The corrosion inhibition efficiency of as-synthesized copolymers for Q235 mild steel was investigated in 1.0 mol L(-1) hydrochloric acid solution by weight loss measurement, potentiodynamic polarization, and electrochemical impedance spectroscopy, respectively. All the results demonstrate that as-prepared aniline-formaldehyde copolymers are efficient mixed-type corrosion inhibitors for mild steels in hydrochloric acid. The corrosion inhibition mechanism is discussed in terms of the role of molecular structure on adsorption of the copolymers onto the steel surface in acid solution.

  15. Inhibition effect of phosphorus-based chemicals on corrosion of carbon steel in secondary-treated municipal wastewater.

    Science.gov (United States)

    Shen, Zhanhui; Ren, Hongqiang; Xu, Ke; Geng, Jinju; Ding, Lili

    2013-01-01

    Secondary-treated municipal wastewater (MWW) could supply a viable alternative water resource for cooling water systems. Inorganic salts in the concentrated cooling water pose a great challenge to corrosion control chemicals. In this study, the inhibition effect of 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP), trimethylene phosphonic acid (ATMP) and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) on corrosion of carbon steel in secondary-treated MWW was investigated by the means of potentiodynamic polarization and electrochemical impedance spectroscopy. The inhibition effect increased with increasing concentration of inhibitors. The corrosion rates of carbon steel were 1.5, 0.8, 0.2 and 0.5 mm a(-1) for blank, HEDP, ATMP and PBTCA samples at 50 mg L(-1), respectively. The phosphorus-based chemicals could adsorb onto the surface of the carbon steel electrode, form a coat of protective film and then protect the carbon steel from corrosion in the test solution.

  16. Corrosion Inhibition of Sodium Phosphate for Coarse and Near Ultrafined-Grain Mild steel surface

    Directory of Open Access Journals (Sweden)

    Kazem Sabet Bokati

    2017-06-01

    Full Text Available An ultrafine grain surface layer with average crystallite size of 28 nm was produced on annealed mild steel through a wire brushing process. The effects of grain size reduction on the inhibition performance of sodium phosphate were investigated using polarization and electrochemical impedance spectroscopy (EIS measurements. The crystal grain size of wire brushed surface was analyzed by X-ray diffractometry (XRD and field emission scanning electron microscopy (FESEM. The electrochemical tests were conducted in artificial sea water (ASW in the presence and absence of 250 mg/lit sodium phosphate (SP. The wire brushed surface indicated considerable deformed plastic flows and high surface roughness. Due to the accumulated strains, a deformed layer with thickness of 20±5 μm was produced and the crystal grain size of severe deformed zone was about 28 nm. Wire brushed surface increased uniform corrosion rate of mild steel due to enhanced surface roughness and preferential sites to adsorption of corrosive ions. However, the wire brushed surface showed a positive effect on inhibition performance of sodium phosphate. The electrochemical results revealed that average inhibition efficiency increased from 65 to about 80 percent in ASW solution containing 1.5 mM Na3PO4 for coarse grained samples in comparison to that of ultra-fined grain samples respectively .The wire brushing process encouraged passivity on the surface in SP-containing solution due to a high density of nucleation sites which increased the adsorption of phosphate ions leading to a high fraction of passive layers and low corrosion rates.

  17. Electrochemical and spectroscopic evidences of corrosion inhibition of bronze by a triazole derivative

    Energy Technology Data Exchange (ETDEWEB)

    Dermaj, A. [Laboratoire Interfaces et Systemes Electrochimiques, UPR 15 du CNRS, Paris (France); Laboratoire Electrochimie, Corrosion et Environnement, Faculte des Sciences, Kenitra (Morocco); Hajjaji, N. [Laboratoire Electrochimie, Corrosion et Environnement, Faculte des Sciences, Kenitra (Morocco); Joiret, S. [Laboratoire Interfaces et Systemes Electrochimiques, UPR 15 du CNRS, Paris (France); Rahmouni, K. [Laboratoire Interfaces et Systemes Electrochimiques, UPR 15 du CNRS, Paris (France); Laboratoire Electrochimie, Corrosion et Environnement, Faculte des Sciences, Kenitra (Morocco); Srhiri, A. [Laboratoire Electrochimie, Corrosion et Environnement, Faculte des Sciences, Kenitra (Morocco); Takenouti, H. [Laboratoire Interfaces et Systemes Electrochimiques, UPR 15 du CNRS, Paris (France); Vivier, V. [Laboratoire Interfaces et Systemes Electrochimiques, UPR 15 du CNRS, Paris (France)]. E-mail: vivivier@ccr.jussieu.fr

    2007-04-01

    The electrochemical behavior of the bronze (Cu-8Sn in wt%) was investigated in 3% NaCl aqueous solution, in presence and in absence of a corrosion inhibitor, the 3-phenyl-1,2,4-triazole-5-thione (PTS). The inhibiting effect of the PTS was evidenced for concentrations higher than 1 mM for the cathodic process whereas its effect was clearly seen with a concentration as low as 0.1 mM for the anodic process. A significant positive shift of the corrosion potential was also observed, and its inhibiting effect increased with both its concentration and the immersion time of the sample. From voltammetry and electrochemical impedance spectroscopy experiments, the inhibiting efficiency of the PTS was found to be in the 94-99% range for 1 mM concentration. Scanning electron microscopy and X-ray energy dispersion analysis of the specimen surface show the presence of sulphur on the surface. Raman micro-spectrometry study confirms the protective effect of the PTS in aqueous solution through three types of interactions with the electrode, namely the adsorption of the inhibitor in a flat configuration, the formation of copper-thiol molecules, and when copper is released, the formation of a polymeric complex.

  18. Fabrication of Slippery Lubricant-Infused Porous Surface for Inhibition of Microbially Influenced Corrosion.

    Science.gov (United States)

    Wang, Peng; Zhang, Dun; Lu, Zhou; Sun, Shimei

    2016-01-20

    Microbially influenced corrosion (MIC) accelerates the failure of metal in a marine environment. In this research, slippery lubricant-infused porous surface (SLIPS) was designed on aluminum, and its great potential for inhibiting MIC induced by sulfate-reducing bacteria (SRB) was demonstrated in a simulated marine environment. The inhibition mechanism of SLIPS to MIC was proposed based on its effective roles in the suppression of SRB settlement and isolation effect to corrosive metabolites. The liquid-like property is demonstrated to be the major contributor to the suppression effect of SLIPS to SRB settlement. The effects of environmental factors (static and dynamic conditions) and lubricant type to SRB settlement over SLIPS were also investigated. It was indicated that the as-fabricated SLIPS can inhibit the SRB settlement in both static and dynamic marine conditions, and lubricant type presents a negligible effect on the SRB settlement. These results will provide a series of foundational data for the future practical application of SLIPS in the marine environment, and also a lubricant selecting instruction to construct SLIPS for MIC control.

  19. Synthesis, characterization and corrosion inhibition efficiency of N-(4-(Morpholinomethyl Carbamoyl Phenyl Furan-2-Carboxamide

    Directory of Open Access Journals (Sweden)

    N. Zulfareen

    2016-01-01

    Full Text Available A mannich base namely N-(4-(Morpholinomethyl Carbamoyl Phenyl Furan-2-Carboxamide (MFC was synthesized and characterized by FT-IR, 1H NMR, and 13C NMR. The molecular weight of MFC was confirmed by LC-MS. The inhibition effect of MFC on brass in 1 M HCl medium has been investigated by weight loss measurement, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS and cyclic voltametry (CV. Thermodynamic parameters such as free energy, entropy and enthalpy were calculated to describe the mechanism of corrosion inhibitor. The inhibition efficiency of MFC increases with increase in concentration and temperature ranges from 30 °C to 60 °C. Polarization measurements indicated that MFC acts as a mixed type corrosion inhibitor. AC impedance indicates that Rct value increases with increase in the concentration of inhibitor. CV reveals that the oxidation of the copper is controlled by the addition of inhibitor on the brass metal. Surface analysis using scanning electron microscope (SEM shows a significant morphological improvement on the brass surface with the addition of the inhibitor. The adsorption of MFC on brass obeys Langmuir adsorption isotherm. The molecular structure of MFC was distorted to quantum chemical indices using density functional theory (DFT which indicates that the inhibition efficiency of MFC is closely related to quantum parameters.

  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. Adsorption Behavior and Inhibition Corrosion Effect of Sodium Carboxymethyl Cellulose on Mild Steel in Acidic Medium

    Institute of Scientific and Technical Information of China (English)

    BAYOL E; G(U)RTEN A.A; DURSUN M.; KAYAK(I)R(I)LMAZ K.

    2008-01-01

    The effect of sodium carboxymethyl cellulose (Na-CMC) on the corrosion behavior of mild steel in 1.0 mol· L-1 HC1 solution has been investigated by using weight loss (WL) measurement, potentiodynamic polarization, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS) methods. These results showed that the inhibition efficiency of Na-CMC increased with increasing the inhibitor concentration. Potentiodynamic polarization studies revealed that the Na-CMC was a mixed type inhibitor in 1.0 mol·L-1 HC1. The adsorption of the inhibitor on mild steel surface has been found to obey the Langmuir isotherm. The effect of temperature on the corrosion behavior of mild steel in 1.0 mol ·L-1 HC1 with addition of 0.04% of Na-CMC has been studied in the temperature range of 298-328 K The associated apparent activation energy (E*a) of corrosion reaction has been determined. Scanning electron microscopy (SEM) has been applied to investigate the surface morphology of mild steel in the absence and presence of the inhibitor molecules.

  2. CORROSION INHIBITION OF X70 STEEL IN SALINE SOLUTION SATURATED WITH CO2 BY THIOUREA

    Institute of Scientific and Technical Information of China (English)

    X.Y. He; H.Y. Deng; R. Li; X.D. Fei; H.Y. Wang; Z.Y. Deng

    2008-01-01

    Corrosion monitoring techniques were performed on X70 steel in saline solution saturated with CO2 with and without thiourea additives within the concentration range 5-25 mg/L. It was found that when the concentration of the inhibitors were increased, the inhibitor efficiencies(IE) of thiourea varied with solution temperature and immersion time. The results indicated that thiourea had the highest inhibition efficiency. The potentiondynamic polarization studies revealed that thiourea are mixed-type inhibitor that mainly restrains the anodic process.

  3. Studies on Indian bentonite as the carrying medium in corrosion inhibitive compositions for ferrus metals

    Directory of Open Access Journals (Sweden)

    B. Sanyal

    1959-10-01

    Full Text Available A new type of preservative based on chemical inhibitive incorporated in a suspension of bentonite in water was developed by Sanyal &Preston which proved as efficacious as petroleum base compositions for protection of steel against corrosion during storage and promised to be useful in some fields where use of petroleum base compositions was not feasible. In the present investigation, the performance o f Indian bentonite as the carrying medium for a wide range of chemical inhibitors and their mixtures, ha8 been studied.

  4. Influence of poly(aminoquinone) on corrosion inhibition of iron in acid media

    Science.gov (United States)

    Jeyaprabha, C.; Sathiyanarayanan, S.; Phani, K. L. N.; Venkatachari, G.

    2005-11-01

    The inhibitor performance of chemically synthesized water soluble poly(aminoquinone) (PAQ) on iron corrosion in 0.5 M sulphuric acid was studied in relation to inhibitor concentration using potentiodynamic polarization and electrochemical impedance spectroscopy measurements. On comparing the inhibition performance of PAQ with that of the monomer o-phenylenediamine (OPD), the OPD gave an efficiency of 80% for 1000 ppm while it was 90% for 100 ppm of PAQ. PAQ was found to be a mixed inhibitor. Besides, PAQ was able to improve the passivation tendency of iron in 0.5 M H 2SO 4 markedly.

  5. Ph responsive capsules containing composite coatings for corrosion inhibition in metal alloys

    Science.gov (United States)

    Kashi, Kiran Bhat

    Hexavalent chromes have been used as effective corrosion inhibitors due to their high inhibitor efficiency and low cost for the protection of several metal alloys. However, owing to their toxicity federal legislations restrict the use and distribution of these highly toxic materials. The need for an environmentally friendly yet effective alternative to the chrome based corrosion inhibitors has led to the investigation of rare earth metals as potential candidates. Cerium is one such rare earth metal that has received considerable attention as an alternative to hexavalent chromes. However, the high water solubility of some of the cerium salts makes it difficult for the incorporation of such salts in coatings. In this work, pH responsive microcapsules containing cerium salts were synthesized using an internally phase separated emulsion polymerization technique. Core shell microcapsule consisting of a water core containing dissolved cerium salts were synthesized. The synthesized capsules were characterized using characterization techniques such as Fourier Transform Infrared (FTIR) spectroscopy, UV-vis spectroscopy, Dynamic Mechanical Analysis (DMA), Thermo-Gravimetric Analysis (TGA), and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The structure and morphology of the capsules were studied using electron microscopy techniques. The synthesized capsules were dispersed in 2K epoxy coatings and applied on aluminum alloy 2024 T-3 and cold rolled steel substrates. These coatings were exposed to salt spray (ASTM B117) and electrochemically evaluated using electrochemical impedance spectroscopy (EIS), potentio-dynamic(PD) polarization, cyclic voltammetry(CV), open circuit potential(OCP) measurements. Localized corrosion assessment was also performed on the coated metal alloys using Scanning electrochemical microscopy (SECM) to understand the mechanism of corrosion inhibition using cerium encapsulated microcapsules.

  6. 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

  7. 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.

  8. Corrosion inhibition and adsorption characteristics of Tridax Procumbens L leaves extract on mild steel immersed in 1M HCl solution

    Directory of Open Access Journals (Sweden)

    Kenneth Kanayo ALANEME

    2016-12-01

    Full Text Available The corrosion inhibition and adsorption mechanism of Tridax procumbens Linn leaves extract on mild steel immersed in 1M HCl solution was investigated. Mass loss, corrosion rate and inhibition efficiency from gravimetric and potentiodynamic polarization measurements, atomic adsorption spectroscopy (AAS, Fourier transform infra red spectroscopy (FTIR, and scanning electron microscopy; were used for the analysis. The results show that within the selected range of concentration of the extract and corrosion test temperatures, the inhibition efficiency obtained was within the range of 81 and 96 %. The efficiency values were observed to increase with increase in the extract concentration but decreased slightly with increase in temperature. The inhibitor molecules were noted to be physically adsorbed on the mild steel surface with OH, NH, and CO groups confirmed as the active phytochemical constituents in the extract responsible for the adsorption. The adsorption process fitted perfectly with the Langmuir adsorption isotherm indicating that the extract was strongly adsorbed on the mild steel surface.

  9. Corrosion inhibition of steel in sulfuric acidic solution by the Chenopodium Ambrosioides Extracts

    Directory of Open Access Journals (Sweden)

    L. Bammou

    2014-10-01

    Full Text Available The influence of natural occurring extract of Chenopodium Ambrosioides (CAE on the corrosion inhibition of carbon steel in sulfuric acid solution is studied by the weight loss method, potentiodynamic polarization and impedance spectroscopy (EIS measurements. The experimental results reveal that extract has a good inhibiting effect on the metal tested in 0.5 M H2SO4 solution. The protection efficiency increases with increasing inhibitor concentration to attain 94% at 4 g/l. Potentiodynamic polarization studies clearly reveal that it acts essentially as a cathodic inhibitor. EIS results show that the change in the impedance parameters (Rt and Cdl with concentration of extract of Chenopodium Ambrosioides is indicative of the adsorption of molecules leading to the formation of a protective layer on the surface of carbon steel. The efficiency decreases with temperature. The adsorption of Chenopodium Ambrosioides extract is found to obey the Langmuir adsorption isotherm. The activation energies and enthalpies of the corrosion process of carbon steel in acidic medium were determined.

  10. Synergistic Effect of Tungstate and Benzotriazole on Corrosion Inhibition of Carbon Steel in Solutions Containing Cl-

    Institute of Scientific and Technical Information of China (English)

    LI Yan; XI Dan-li; LU Zhu

    2004-01-01

    The corrosion inhibition of tungstate, benzotriazole (BTA) and their combination in solutions containing Cl- was studied by electrochemical techniques. The results indicated that the inhibition efficiency of tungstate was higher than that of BTA. The efficiency increased with increasing concentration of tungstate or BTA. In the studies of synergistic effect of tungstate and BTA, it had been found that in Ph 9.0 solution, the largest Rt could be obtained with the concentration ratio of tungstate / BTA being 1:1. Lowering the Ph value of solution would reduce the efficiency of inhibitors, especially in binary inhibitors. Increasing the concentration of Cl- accelerated the corrosion of carbon steel in the solutions with various inhibitors, but the influence of Cl- on corroding rate in binary inhibitors was not so strong as in single component. The results of surface analysis showed that W, C, N, O and Fe elements existed in the protecting film formed with binary inhibitors. The thickness of the film was about 12-15nm.

  11. Inhibition of microbial concrete corrosion by Acidithiobacillus thiooxidans with functionalised zeolite-A coating.

    Science.gov (United States)

    Haile, Tesfaalem; Nakhla, George

    2009-01-01

    The inhibition of the corrosive action of Acidithiobacillus thiooxidans on concrete specimens coated by functionalised zeolite-A containing 14% zinc and 5% silver by weight was studied. Uncoated concrete specimens, epoxy-coated concrete specimens (EP), and functionalised zeolite-A coated concrete specimens with epoxy to zeolite weight ratios of 3:1 (Z1), 2:2 (Z2) and 1:3 (Z3) were studied. Specimens were characterised by x-ray powder diffraction and field emission scanning electron microscopy for the identification of corrosion products and morphological changes. Biomass growth at the conclusion of the 32-day experiments was 4, 179 and 193 mg volatile suspended solids g(-1) sulphur for the uncoated, EP and Z1 specimens, whereas that of Z2 and Z3 were negligible. In the uncoated, EP and Z1 specimens, sulphate production rates were 0.83, 9.1 and 8.8 mM SO(4)(2-) day(-1) and the specific growth rates, mu, were 0.14, 0.57 and 0.47 day(-1), respectively. The corresponding values for Z2 and Z3 were negligible due to their bacterial inhibition characteristics.

  12. Electrochemical evaluation of inhibition efficiency of ciprofloxacin on the corrosion of copper in acid media

    Energy Technology Data Exchange (ETDEWEB)

    Thanapackiam, P. [Department of Chemistry, Coimbatore Institute of Technology, Coimbatore, Tamilnadu, 641 014 (India); Rameshkumar, Subramaniam [Department of Chemistry, Sri Vasavi College, Erode, Tamilnadu, 638 316 (India); Subramanian, S.S. [Department of Chemistry, PSG College of Technology, Coimbatore, Tamilnadu, 641 004 (India); Mallaiya, Kumaravel, E-mail: mkvteam.research@gmail.com [Department of Chemistry, PSG College of Technology, Coimbatore, Tamilnadu, 641 004 (India)

    2016-05-01

    The inhibition efficiency of ciprofloxacin on the corrosion of copper was studied in 1.0MHNO{sub 3} and 0.5MH{sub 2}SO{sub 4} solutions by electrochemical impedance spectroscopy and potentiodynamic polarization techniques. The corrosion inhibition action of ciprofloxacin was observed to be of mixed type in both the acid media, but with more of a cathodic nature. The experimental data were found to fit well with the Langmuir adsorption isotherm. The thermodynamic parameters such as adsorption equilibrium constant(K{sub ads}), free energy of adsorption(ΔG{sub ads}), activation energy(E{sub a}) and potential of zero charge(PZC) showed that the adsorption of ciprofloxacin onto copper surface involves both physisorption and chemisorption. - Highlights: • The inhibitor efficiency increases with increase in ciprofloxacin concentration. • Polarization measurements show that ciprofloxacin acts as a mixed type inhibitor. • The adsorption of the inhibitor on copper surface follows Langmuir adsorption isotherm. • The negative values of ΔG{sub ads} indicates that the adsorption is spontaneous and exothermic.

  13. The Inhibition Effect of Potassium Iodide on the Corrosion of Pure Iron in Sulphuric Acid

    Directory of Open Access Journals (Sweden)

    Tarik Attar

    2014-01-01

    Full Text Available The use of inorganic inhibitors as an alternative to organic compounds is based on the possibility of degradation of organic compounds with time and temperature. The inhibition effect of potassium iodide on the corrosion of pure iron in 0.5 M H2SO4 has been studied by weight loss. It has been observed from the results that the inhibition efficiency (IE% of KI increases from 82.17% to 97.51% with the increase in inhibitor concentration from 1·10−4 to 2·10−3 M. The apparent activation energy (Ea and the equilibrium constant of adsorption (Kads were calculated. The adsorption of the inhibitor on the pure iron surface is in agreement with Langmuir adsorption isotherm.

  14. Inhibition of corrosion of carbon steel by heptane sulphonic acid – Zn2+ system

    Directory of Open Access Journals (Sweden)

    C. MARY ANBARAS

    2012-03-01

    Full Text Available Corrosion inhibition of carbon steel in dam water by sodium heptane sulphonate (SHS and zinc ion system was investigated using weight loss and potentiodynamic polarization methods. Results of weight loss method indicated that inhibition efficiency (IE increased as the inhibitor concentration increased. A synergistic effect existed between SHS and Zn2+. The influence of sodium potassium tartrate (SPT on the IE of the SHS-Zn2+ system was evaluated. As the immersion period increased, the IE decreased. Polarization study revealed that SHS-Zn2+ system functioned as a cathodic inhibitor. AC impedance spectra revealed that a protective film was formed on the metal surface. The nature of the metal surface was analyzed by FTIR spectra, SEM and AFM analyses.

  15. Inhibition of corrosion of carbon steel in well water by arginine-Zn2+ system

    Directory of Open Access Journals (Sweden)

    ANTHONY SAMY SAHAYA RAJA

    2012-06-01

    Full Text Available The environmental friendly inhibitor system arginine-Zn2+, has been investigated by weight-loss method. A synergistic effect exists between arginine and Zn2+ system. The formulation consisting of 250 ppm of arginine and 5 ppm of Zn2+ offers good inhibition efficiency of 98 %. Polarization study reveals that this formulation functions as an anodic inhibitor. AC impedance spectra reveal that a protective film is formed on the metal sur­face. The FTIR spectral study leads to the conclusion that the Fe2+- DL-arginine complex, formed on anodic sites of the metal surface, controls the anodic reaction. Zn(OH2 formed on the cathodic sites of the metal surface controls the cathodic reaction. The surface morphology and the roughness of the metal surface were analyzed with Atomic Force Microscope. A suitable mechanism of corrosion inhibition is proposed based on the results obtained from weight loss study and surface analysis technique.

  16. Corrosion inhibition performance of different bark extracts on aluminium in alkaline solution

    Directory of Open Access Journals (Sweden)

    Namrata Chaubey

    2017-02-01

    Full Text Available The present work shows the effect of stem bark extracts of three trees namely Moringa oleifera (MO, Terminalia arjuna (TA and Mangifera indica (MI on the corrosion behaviour of Aluminium Alloy (AA in 1 M NaOH. The inhibition performance was studied by using gravimetric, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS measurements. Among these extracts, MO exhibited the maximum inhibition efficiency η (% of 85.3% at 0.6 g/L at 303 K. Polarization measurement showed that all the examined extracts are of mixed-type inhibitors. Langmuir’s adsorption isotherm was found to be best fit. Morphology of the surface was examined by scanning electron microscopy (SEM and atomic force microscopy (AFM which confirmed the existence of a protective film of inhibitor molecule on AA surface.

  17. Corrosion inhibition efficiency and surface activity of benzothiazol-3-ium cationic Schiff base derivatives in hydrochloric acid

    Energy Technology Data Exchange (ETDEWEB)

    Negm, N.A., E-mail: nabelnegm@hotmail.co [Petrochemicals Department, Egyptian Petroleum Research Institute, Nasr City, Cairo (Egypt); Elkholy, Y.M.; Zahran, M.K. [Chemistry Department, Faculty of Science, Helwan University, Helwan (Egypt); Tawfik, S.M. [Petrochemicals Department, Egyptian Petroleum Research Institute, Nasr City, Cairo (Egypt)

    2010-10-15

    Research highlights: {yields} Benzothiazolium inhibitors show high corrosion inhibition for carbon steel. {yields} Weight loss and corrosion rates decrease by increasing inhibitor dose. {yields} Inhibition mechanism suggested as physisorption mechanism supported by adsorption free energy values. {yields} The adsorption of the inhibitors obeys Langmuir isotherm. {yields} Side chains have ascending order on the corrosion inhibition of the different inhibitors. - Abstract: Two series of cationic Schiff base surfactants namely: 2-(benzylideneamino)-3-(2-oxo-2-alkoxyethyl)-1,3-benzothiazol-3-ium bromide and 2-[(4-methoxybenzylidene)amino]-3-(2-oxo-2-alkoxyethyl)-1, 3-benzothiazol-3-ium bromide were prepared and confirmed using elemental analysis, FTIR, and {sup 1}H NMR spectra. The surface activity of the synthesized Schiff bases showed their tendency towards adsorption at the interfaces. The prepared compounds were evaluated as corrosion inhibitors for carbon steel in 0.5 M HCl solution using gravimetric and polarization measurements. By fitting the gravimetric data, some thermodynamic and kinetic parameters were estimated. The adsorption of the inhibitors on the carbon steel surface obeyed Langmuir adsorption isotherm and had a physical mechanism. Polarization measurements showed that the synthesized inhibitors act as mixed inhibitors for carbon steel in the acidic media. The results of the corrosion inhibition using two different methods showed narrow differences in the obtained values between the two methods within 5%.

  18. Electrochemical and theoretical investigation on the corrosion inhibition of mild steel by thiosalicylaldehyde derivatives in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Behpour, M. [Department of Chemistry, Faculty of Science, University of Kashan, Kashan (Iran, Islamic Republic of)], E-mail: m.behpour@kashanu.ac.ir; Ghoreishi, S.M.; Soltani, N.; Salavati-Niasari, M.; Hamadanian, M.; Gandomi, A. [Department of Chemistry, Faculty of Science, University of Kashan, Kashan (Iran, Islamic Republic of)

    2008-08-15

    Inhibitory effect of three Schiff bases 2-{l_brace}[(2-sulfanylphenyl)imino]methyl{r_brace}]phenol (A), 2-{l_brace}[(2)-1-(4-methylphenyl)methylidene]amino{r_brace}-1-benznethiol (B), and 2-[(2-sulfanylphen-yl)ethanimidoyl)]phenol (C) on corrosion of mild steel in 15% HCl solution has been studied using weight loss measurements, polarization and electrochemical impedance spectroscopy (EIS) methods. The results of the investigation show that the compounds A and B with mean efficiency of 99% at 200 mg/L additive concentration have fairly good inhibiting properties for mild steel corrosion in hydrochloric acid, and they are as mixed inhibitor. All measurements show that inhibition efficiencies increase with increase in inhibitor concentration. This reveals that inhibitive actions of inhibitors were mainly due to adsorption on mild steel surface. Adsorption of these inhibitors follows the Langmuir adsorption isotherm. Thermodynamic adsorption parameters (K{sub ads}, {delta}G{sub ads}) of studied Schiff bases were calculated using the Langmuir adsorption isotherm. Activation parameters of the corrosion process such as activation energies, E{sub a}, activation enthalpies, {delta}H{sup *}, and activation entropies, {delta}S{sup *}, were calculated by the obtained corrosion currents at different temperatures. Obvious correlation was found between the corrosion inhibition efficiency and the calculated parameters. The obtained theoretical results have been adapted with the experimental data.

  19. Corrosion inhibition of Eleusine aegyptiaca and Croton rottleri leaf extracts on cast iron surface in 1 M HCl medium

    Energy Technology Data Exchange (ETDEWEB)

    Rajeswari, Velayutham [Department of Chemistry, Periyar University, Salem 636011 (India); Kesavan, Devarayan [Department of Chemistry, Dhirajlal Gandhi College of Technology, Salem 636309 (India); Gopiraman, Mayakrishnan [Department of Chemistry, National Institute of Technology, Tiruchirappalli 620015 (India); Viswanathamurthi, Periasamy, E-mail: viswanathamurthi72@gmail.com [Department of Chemistry, Periyar University, Salem 636011 (India); Poonkuzhali, Kaliyaperumal; Palvannan, Thayumanavan [Department of Bio-Chemistry, Periyar University, Salem 636011 (India)

    2014-09-30

    Graphical abstract: - Highlights: • Eleusine aegyptiaca and Croton rottleri are commonly available, less-toxic and eco-friendly inhibitors for cast iron corrosion. • The active constituents present in extracts adsorbed on the iron surface to inhibit the acidic corrosion. • The higher values of E{sub a} and ΔH{sup *} point out the higher inhibition efficiency noticed for the inhibitors. • Weight loss methods at various temperature and spectral data provides evidence for adsorption mechanism of inhibitors. - Abstract: The adsorption and corrosion inhibition activities of Eleusine aegyptiaca (E. aegyptiaca) and Croton rottleri (C. rottleri) leaf extracts on cast iron corrosion in 1 M hydrochloric acid solution were studied first time by weight loss and electrochemical techniques viz., Tafel polarization and electrochemical impedance spectroscopy. The results obtained from the weight loss and electrochemical methods showed that the inhibition efficiency increased with inhibitor concentrations. It was found that the extracts acted as mixed-type inhibitors. The addition of halide additives (KCl, KBr, and KI) on the inhibition efficiency has also been investigated. The adsorption of the inhibitors on cast iron surface both in the presence and absence of halides follows the Langmuir adsorption isotherm model. The inhibiting nature of the inhibitors was supported by FT-IR, UV–vis, Wide-angle X-ray diffraction and SEM methods.

  20. Corrosion Inhibition of Aluminum in 0.5 M HCl by Garlic aqueous extract

    Directory of Open Access Journals (Sweden)

    Saedah R. Al-Mhyawi

    2014-06-01

    Full Text Available The inhibition efficiency of extract of Garlic on aluminium in hydrochloric acid solutions has been evaluated by weight loss techniques. Values of inhibition efficiency obtained are dependent upon the concentration of inhibitor and temperature. Generally, inhibition was found to increase with inhibitor concentration, half-life, activation energy but decrease with temperature and first-order rate constant at the temperatures studied. Physical adsorption mechanism has been proposed for the inhibition and Langmuir , Temkin adsorption isotherm was obeyed. Garlic is an inhibitor of aluminium corrosion in 0.5 M hydrochloric acid solution.The values of standard free energy of adsorption suggest that the adsorption of inhibitor on aluminium surface occurred by physisorption mechanism. the negative sign of the Free Energy of adsorption indicates that the adsorption of the inhibitors on the aluminum surface was a spontaneous process.the negative values of enthalpy of adsorption (ΔH suggest that the chemical reaction involved in the adsorption of the inhibitors on the metal surface is an exothermic process, hence increase in the reaction temperature of the medium will decrease the inhibition efficiency.

  1. Thermodynamic, adsorption and corrosion inhibitive behaviour of benzyl nicotinate on cold rolled steel in sulphuric acid solution

    Directory of Open Access Journals (Sweden)

    Vinutha Rangaswamy Mutugadahalli

    2015-12-01

    Full Text Available The inhibition performance of benzyl nicotinate (BN on corrosion of cold rolled steel (CRS in 0.5 M H2SO4 solution has been investigated using weight loss, Tafel polarization and electrochemical impedance spectroscopy (EIS. The BN acts as mixed type inhibitor. The thermodynamic parameters indicate the comprehensive nature adsorption of BN on CRS which obey Langmuir isotherm. Morphological investigation of corrosion inhibition is carried out using AFM and optical microscopic studies support the formation of inhibitor film on CRS. There is a good agreement between the values of weight loss measurements and electrochemical studies. 

  2. Inhibition Effect of Glycerol on the Corrosion of Copper in NaCl Solutions at Different pH Values

    Directory of Open Access Journals (Sweden)

    Santos Lorenzo Chi-Ucán

    2014-01-01

    Full Text Available The inhibitory effect of glycerol on copper corrosion in aerated NaCl (0.5 M solutions at three pH values (4, 7, and 10 was evaluated. Inhibition efficiency was assessed with conventional electrochemical techniques: open circuit potential, potentiodynamic polarization, and electrochemical impedance analysis. Glycerol reduced the corrosion rate of copper in NaCl solutions. The best inhibition effect (η≈83% was produced in alkaline (pH 10 chloride media. This effect can be ascribed to increased viscosity and the presence of copper-glycerol complexes.

  3. Corrosion inhibition of low phosphonic multipolymer water treatment agent of industry circulating on brass in aqueous solution

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In response to environmental guidelines, a low phosphonic multipolymer was synthesized and its corrosion inhibition efficiency to brass in synthetic water was investigated through weight loss measurements and electrochemical tests.It showed that the synthesized inhibitor decreased corrosion under the conditions tested.Potentiodynamic polarization curves indicated that the new inhibitor acted as an anodic inhibitor, reducing metal dissolution.The composition of protective films formed on the brass was studied by energy-dispersive X-ray analysis (EDX).The inhibition effects were due to the formation of a protective film of the multipolymer inhibitor on the metal surface.

  4. Durability and synergistic effects of KI on the acid corrosion inhibition of mild steel by hydroxypropyl methylcellulose.

    Science.gov (United States)

    Arukalam, I O

    2014-11-04

    The performance of hydroxypropyl methylcellulose (HPMC) as safe corrosion inhibitor for mild steel in aerated 0.5M H2SO4 solution was appraised by weight loss, impedance and polarization measurements. Results indicate that HPMC functions as a good inhibitor in the studied environment and inhibition efficiency increased with increasing concentration of inhibitor and temperature. Time-dependent effect of the inhibition efficiency reveals that inhibition efficiency increased with time up to the fourth day after which it waned, but improved on addition of KI. The synergism parameter evaluated confirmed the synergistic effect of KI and HPMC. Impedance results clearly show that HPMC inhibited the corrosion reaction via adsorption onto the metal/solution interface following Freundlich adsorption isotherm. Polarization results indicate that HPMC acts as a mixed-type inhibitor with predominant cathodic effect. Theoretical study using density functional theory was employed to establish the correlation between the structure (molecular and electronic) and the inhibition efficiency.

  5. Quantum chemical study of the inhibition of the corrosion of mild steel in H2SO4 by some antibiotics.

    Science.gov (United States)

    Eddy, Nnabuk O; Ibok, Udo J; Ebenso, Eno E; El Nemr, Ahmed; El Ashry, El Sayed H

    2009-09-01

    The inhibition efficiency of some antibiotics against mild steel corrosion was studied using weight loss and quantum chemical techniques. Values of inhibition efficiency obtained from weight loss measurements correlated strongly with theoretical values obtained through semi empirical calculations. High correlation coefficients were also obtained between inhibition efficiency of the antibiotics and some quantum chemical parameters, including frontier orbital (E (HOMO) and E (LUMO)), dipole moment, log P, TNC and LSER parameters (critical volume and dipolar-polarisability factor), which indicated that these parameters affect the inhibition efficiency of the compounds. It was also found that quantitative structure activity relation can be used to adequately predict the inhibition effectiveness of these compounds.

  6. Investigating inhibition of microbes inducing microbiologically-influenced-corrosion by Tectona grandis based Fe-nanoparticle material

    Science.gov (United States)

    Okeniyi, Joshua Olusegun; Omotosho, Olugbenga Adeshola; Inyang, Michael Anietie; Okeniyi, Elizabeth Toyin; Nwaokorie, Ikechi Thaddeus; Adidi, Emmanuel Amanogho; Owoeye, Taiwo Felicia; Nwakudu, Kelechukwu Chinedu; Akinlabu, Deborah Kehinde; Gabriel, Olanrewaju Oyewale; Taiwo, Olugbenga Samson; Awotoye, Olufisayo Adebola

    2017-02-01

    In this paper, inhibition of microbes inducing microbiologically-influenced-corrosion (MIC) of metals by Tectona grandis based Fe (iron) Nanoparticle material was investigated. For this, extract was obtained from the leaf of Tectona grandis and this was employed as precursor for synthesizing the Fe-nanoparticle material. From this, the synthesized plant extract based nanoparticle material was characterized using scanning electron microscopy and energy dispersive spectroscopy (SEM+EDS) instrument. The developed Fe bio-nanoparticle material was then employed for sensitivity and/or resistance study application against different strains of microbes that are known to induce microbiologically-influenced-corrosion, in metallic materials, and for this, microbial growth inhibition effect was compared with that from a commercial antibiotic employed as control. Results showed that the Tectona grandis based Fe-nanoparticle exhibited good inhibition effects on the growth of many of the MIC inducing microbes investigated. Sensitivity measures of zone of inhibition against the growth of MIC inducing microbial strains either outperformed or compares well with that obtained from the commercial antibiotic control, in the study. These results indicate positive prospect on the suitability of Fe bio-nanoparticle for corrosion inhibition applications for the protection of metals against microbiological corrosion influencing environment.

  7. Studies on the inhibition of mild steel corrosion in hydrochloric acid solution by atenolol drug

    Directory of Open Access Journals (Sweden)

    G. Karthik

    2016-06-01

    Full Text Available The inhibition performance of atenolol on mild steel in 1 M hydrochloric acid solution was studied by weight loss and electrochemical methods. The results show the inhibition efficiency was found to increase with increasing the concentration of the inhibitor from 50 to 300 ppm. The maximum inhibition efficiency 93.8% was observed in the presence of 300 ppm inhibitor (in case of potentiodynamic polarization. The inhibition action of atenolol was explained in terms of adsorption on the mild steel surface. The adsorption process follows Langmuir isotherm via physical adsorption. Electrochemical Impedance spectroscopic technique (EIS exhibits one capacitive loop indicating that, the corrosion reaction is controlled by charge transfer process. Polarization measurements showed that the inhibitor is of a mixed type. The results obtained from the different methods are in good agreement. The surface morphologies of mild steel were examined by Fourier-transform infrared (FT-IR spectroscopy, scanning electron microscope (SEM. Further, the computational calculations are performed to find a relation between their electronic and structural properties.

  8. Application of Moessbauer spectroscopy to the study of tannins inhibition of iron and steel corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Jaen, Juan A., E-mail: jjaen@ancon.up.ac.pa [Universidad de Panama, CITEN, Depto. de Quimica Fisica (Panama); Obaldia, J. De; Rodriguez, M. V. [Universidad de Panama, Escuela de Quimica, Facultad de Ciencias Naturales, Exactas y Tecnologia (Panama)

    2011-11-15

    The inhibitory effect of tannins was investigated using, among others, potentiodynamic polarizations and Moessbauer spectroscopy. These techniques confirmed that the nature, pH and concentration of tannic solution are of upmost importance in the inhibitory properties of the solutions. It is observed that at low tannin concentration or pH, both, hydrolizable and condensed tannins, effectively inhibit iron corrosion, due to the redox properties of tannins. At pH Almost-Equal-To 0, Moessbauer spectra of the frozen aqueous solutions of iron(III) with the tannin solutions showed that iron is in the form of a monomeric species [Fe(H{sub 2}O){sub 6}]{sup 3 + }, without coordination with the functional hydroxyl groups of the tannins. The suspended material consisted of amorphous ferric oxide and oxyhydroxides, though with quebracho tannin partly resulted in complex formation and in an iron (II) species from a redox process. Other tannins, such as chestnut hydrolysable tannins, do not complex iron at this low pH. Tannins react at high concentrations or pH (3 and 5) to form insoluble blue-black amorphous complexes of mono-and bis-type tannate complexes, with a relative amount of the bis-ferric tannate generally increasing with pH. Some Fe{sup 2 + } in the form of hydrated polymeric ferrous tannate could be obtained. At pH 7, a partially hydrolyzed ferric tannate complex was also formed. The latter two phases do not provide corrosion protection. Tannin solutions at natural pH react with electrodeposited iron films (approx. 6 {mu}m) to obtain products consisting only on the catecholate mono-complex of ferric tannate. Some aspects of the mechanism of tannins protection against corrosion are discussed.

  9. The role of acid anion on the inhibition of the acidic corrosion of steel by lupine extract

    Energy Technology Data Exchange (ETDEWEB)

    Abdel-Gaber, A.M. [Chemistry Department, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt)], E-mail: ashrafmoustafa@yahoo.com; Abd-El-Nabey, B.A.; Saadawy, M. [Chemistry Department, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt)

    2009-05-15

    The inhibitive effect of lupine (Lupinous albus L.) extract on the corrosion of steel in aqueous solution of 1 M sulphuric and 2 M hydrochloric acids was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Potentiodynamic polarization curves indicated that the lupine extract acts as a mixed-type inhibitor. EIS measurements showed that the dissolution process is under activation control. The inhibition efficiency of the extract obtained from impedance and polarization measurements was in a good agreement and was found to increase with increasing concentration of the extract. The obtained results showed that, the lupine extract could serve as an effective inhibitor for the corrosion of steel in acid media and the extract was more effective in case of hydrochloric acid. Theoretical fitting of the corrosion data to the kinetic-thermodynamic model was tested to show the nature of adsorption.

  10. Corrosion inhibition properties of graphene oxide on mild steel in 3.5% NaCl

    Science.gov (United States)

    Anandh Senthilvasan, Prem; Rangarajan, Murali

    2016-09-01

    In this work the corrosion inhibition of mild steel in 3.5% Sodium chloride (NaCl) solution at ambient conditions by Graphene Oxide (GO) has been studied. Graphene oxide was prepared by Modified Hummers Method and characterized by Fourier Transform Infrared spectroscopy (FTIR), UV-Visible spectroscopy (UV-Vis), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Thermo-Gravimetric Analysis (TGA). The electrochemical corrosion behaviour of mild steel has been studied in the absence and presence of GO coatings by Tafel polarization and impedance analyses. The modified electrode has 44.8mV potential shift in the cathodic direction and reduction in current by 41.9 μA (61%). This indicates the strong protection offered by graphene oxide film. The obtained impedance spectra also clearly show that the charge transfer resistance of graphene oxide film is much higher than that of the uncoated steel electrode, demonstrating the strong protection offered by graphene oxide films for mild steel.

  11. Corrosion Inhibition Mechanism of Rare Earth Metal on LC4 Al Alloy with Spilt Cell Technique

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new method of studying the corrosion inhibition mechanism of rare earth metal(REM) on LC4 Al alloy with the spilt cell technique was studied. The principle and experimental method of the spilt cell technique were analyzed. By measuring the change of net-electric current between the two electrodes caused by the change of the amount of oxygen in the solution and the addition of CeCl3, the influence of corrosive performance of CeCl3 on LC4 super-power aluminum alloy in the 0.1 mol*L-1 NaCl solution was investigated. Meanwhile, the conditional changes of pH values, CeCl3 solution, additire and time of performance were also studied. Finally, the features of electrode surface were revealed by using SEM and X-ray energy-dispersive spectrometry (EDS). By combining these with other electric chemical techniques, such as potential-time curve, polarization curve et al.

  12. 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

  13. Corrosion Inhibition Performance of Triazole Derivatives on Copper-Nickel Alloy in 3.5 wt.% NaCl Solution

    Science.gov (United States)

    Jiang, B.; Jiang, S. L.; Liu, X.; Ma, A. L.; Zheng, Y. G.

    2015-12-01

    This study investigates the performance of three triazole derivatives with different molecular structures as corrosion inhibitors for the copper-nickel alloy CuNi 90/10 in 3.5 wt.% NaCl solution. Inhibition behavior was systematically determined through electrochemical measurements, scanning electron microscopy, energy-dispersive spectroscopy, and Fourier transform infrared spectroscopy. In addition, adsorption behavior and the inhibition mechanism were investigated via quantum chemical calculation and molecular dynamic simulation. Experimental results indicate that the three inhibitors with triazole rings and heteroatoms exhibited excellent corrosion inhibition capabilities on the copper-nickel alloy surface through physisorption and chemisorption. In particular, 3-amino-5-mercapto-1,2,4-triazole showed the best inhibition capability according to the concentration ranges considered in the experiments. The results of quantum chemical calculation agreed with the experimental findings.

  14. Corrosion inhibition of Eleusine aegyptiaca and Croton rottleri leaf extracts on cast iron surface in 1 M HCl medium

    Science.gov (United States)

    Rajeswari, Velayutham; Kesavan, Devarayan; Gopiraman, Mayakrishnan; Viswanathamurthi, Periasamy; Poonkuzhali, Kaliyaperumal; Palvannan, Thayumanavan

    2014-09-01

    The adsorption and corrosion inhibition activities of Eleusine aegyptiaca (E. aegyptiaca) and Croton rottleri (C. rottleri) leaf extracts on cast iron corrosion in 1 M hydrochloric acid solution were studied first time by weight loss and electrochemical techniques viz., Tafel polarization and electrochemical impedance spectroscopy. The results obtained from the weight loss and electrochemical methods showed that the inhibition efficiency increased with inhibitor concentrations. It was found that the extracts acted as mixed-type inhibitors. The addition of halide additives (KCl, KBr, and KI) on the inhibition efficiency has also been investigated. The adsorption of the inhibitors on cast iron surface both in the presence and absence of halides follows the Langmuir adsorption isotherm model. The inhibiting nature of the inhibitors was supported by FT-IR, UV-vis, Wide-angle X-ray diffraction and SEM methods.

  15. Inhibition of copper corrosion in aerated hydrochloric acid solution by heterocyclic compounds containing a mercapto group

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Daquan; Gao Lixin; Zhou Guoding

    2004-12-01

    Inhibition of copper corrosion by benzotriazole (BTA), 2-mercapto benzoxazole (MBO) and 2-mercapto benzimidazole (MBI) in 0.5 mol L{sup -1} HCl was investigated by weight-loss measurements, potentiodynamic polarization curves and electrochemical impedance spectroscopy. MBI was shown to be the most effective inhibitor among those tested. Potentiodynamic polarization results revealed that the three compounds acted as anodic inhibitors, particularly MBI strongly suppressed anodic current densities. Molecular structure parameters of BTA, MBO and MBI were obtained by using an MM2 forcefield program and PPP-SCF quantum chemical calculation. It was found that MBI has higher levels of HOMO and LUMO energy and the larger {pi}-electron density.

  16. Corrosion Inhibition Effect of Carbon Steel in Sea Water by L-Arginine-Zn2+ System

    Directory of Open Access Journals (Sweden)

    S. Gowri

    2014-01-01

    Full Text Available The inhibition efficiency of L-Arginine-Zn2+ system in controlling corrosion of carbon steel in sea water has been evaluated by the weight-loss method. The formulation consisting of 250 ppm of L-Arginine and 25 ppm of Zn2+ has 91% IE. A synergistic effect exists between L-Arginine and Zn2+. Polarization study reveals that the L-Arginine-Zn2+ system functions as an anodic inhibitor and the formulation controls the anodic reaction predominantly. AC impedance spectra reveal that protective film is formed on the metal surface. Cyclic voltammetry study reveals that the protective film is more compact and stable even in a 3.5% NaCl environment. The nature of the protective film on a metal surface has been analyzed by FTIR, SEM, and AFM analysis.

  17. Corrosion inhibition of mild steel in acidic media using newly synthesized heterocyclic organic molecules: Correlation between inhibition efficiency and chemical structure

    Energy Technology Data Exchange (ETDEWEB)

    Ouici, H. B., E-mail: ouici.houari@yahoo.fr; Guendouzi, A., E-mail: guendouzzi@yahoo.fr [Departement of Chimistry, Faculty of Sciences, University of Saïda (Algeria); Benali, O. [Department of Biology, Faculty of Science, University of Saida (Algeria)

    2015-03-30

    The corrosion inhibition of mild steel in 5% HCl solutions by some new synthesized organic compounds namely 3-(2-methoxyphenyl) 5-mercapto-1. 2. 4-triazole (2-MMT), 3-(3-methoxyphenyl) 5-mercapto-1. 2. 4-triazole (3-MMT) and 3-(2-hydroxyphenyl) 5-mercapto-1. 2. 4-triazole (2-HMT) was investigated using weight loss and potentiostatic polarization techniques. These measurements reveal that the inhibition efficiency obtained by these compounds increased by increasing their concentration. The inhibition efficiency follows the order 2-MMT >3-MMT >2-HMT. Polarization studies show that these compounds are of the mixed type but dominantly act as a cathodic inhibitors for mild steel in 5% HCl solutions. These inhibitors function through adsorption following Langmuir isotherm. Activation energy and Gibbs free energy for adsorption of inhibitors are calculated. Molecular modeling has been conducted to correlate the corrosion inhibition properties with the calculated quantum chemical parameters.

  18. C6H5NH2 effect on the corrosion inhibition of aluminium in 0.5 M HCl

    Science.gov (United States)

    Omotosho, Olugbenga Adeshola; Okeniyi, Joshua Olusegun; Loto, Cleophas Akintoye; Popoola, Abimbola Patricia Idowu; Fademi, Ekundayo Oluwademilade Jacob; Oladipupo, Segun Isaac; Alabi, Ayomide Samuel; Ajibola, Omokolade Bamidele; Emelieze, Alex Nwabunor

    2017-02-01

    In this paper, C6H6NH2 (aniline) effect on the corrosion of aluminium in 0.5 M (i.e. mol/L) HCl medium was studied using gravimetric method by weight loss measurements and electrochemical technique of corrosion potential and potentiodynamic polarization by cyclic voltamery (CV) instrumentation. By these techniques, corrosion rate obtained from aluminium specimens, in 0.5 HCl test-solution having different concentrations of the hydrogen-containing C6H6NH2 chemical, were requisitely analysed. Results showed that the potentiodynamic corrosion rate excellently correlated (R = 98.94%, Nash-Sutcliffe efficiency = 97.89% and ANOVA p-value = 0.0314) with function of the gravimetric corrosion rate and C6H5NH2 concentration. Both experimental and correlated prediction models identified 0.043 mol/L C6H5NH2 with optimal inhibition efficiency performance η = 84.11% by the experimental or η = 81.15% by the predicted models. Fittings of experimental and correlated data showed the data models followed the Langmuir adsorption isotherm from which favourable adsorption and prevalent physisorption were indicated as the C6H5NH2 corrosion-protection on aluminium metal in the 0.5 M HCl medium.

  19. Inhibition of acid corrosion of steel by some S-alkylisothiouronium iodides

    Energy Technology Data Exchange (ETDEWEB)

    Arab, S.T.; Noor, E.A. (Girl' s Coll. of Education, Jeddah (Saudi Arabia))

    1993-02-01

    Five selected S-alkylisothisothiouronium iodides have been studied as acid corrosion inhibitors at 30 C for steel in 0.5 M H[sub 2]SO[sub 4] using gasometry, mass loss, and direct current (DC) polarization techniques. All of the data reveal that the compounds act as inhibitors in the acid environments; furthermore, polarization curves show that the compounds act as mixed-type inhibitors. It was found that the inhibition efficiency increases with the increase of the length of the additive alkyl chain. Langmuir's adsorption isotherms fit the experimental data for the studied compounds. Thermodynamic parameter were obtained from experimental data of the temperature studies of the inhibition process at five temperatures ranging from 30 to 70 C. It was observed that the activation energy is slightly increased with the increase of the additive alkyl chain. On the other hand, the sudden large increase of the inhibition behavior of S-hexylisothiouronium iodide was attributed to a different adsorption process.

  20. Corrosion Inhibiting Mechanism of Nitrite Ion on the Passivation of Carbon Steel and Ductile Cast Iron for Nuclear Power Plants

    Directory of Open Access Journals (Sweden)

    K. T. Kim

    2015-01-01

    Full Text Available While NaNO2 addition can greatly inhibit the corrosion of carbon steel and ductile cast iron, in order to improve the similar corrosion resistance, ca. 100 times more NaNO2 addition is needed for ductile cast iron compared to carbon steel. A corrosion and inhibition mechanism is proposed whereby NO2- ion is added to oxidize. The NO2- ion can be reduced to nitrogen compounds and these compounds may be absorbed on the surface of graphite. Therefore, since nitrite ion needs to oxidize the surface of matrix and needs to passivate the galvanic corroded area and since it is absorbed on the surface of graphite, a greater amount of corrosion inhibitor needs to be added to ductile cast iron compared to carbon steel. The passive film of carbon steel and ductile cast iron, formed by NaNO2 addition showed N-type semiconductive properties and its resistance, is increased; the passive current density is thus decreased and the corrosion rate is then lowered. In addition, the film is mainly composed of iron oxide due to the oxidation by NO2- ion; however, regardless of the alloys, nitrogen compounds (not nitrite were detected at the outermost surface but were not incorporated in the inner oxide.

  1. 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.

  2. 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,…

  3. 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.

  4. Temperature dependence of corrosion inhibition of steels used in oil well stimulation using acetylenic compound and halide ion salt mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Menezes, M.A.M. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica], E-mail: marcom@eq.ufrj.br; Valle, M.L.M. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica. Dept. de Processos Organicos; Dweck, J. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica. Dept. de Processos Inorganicos; Queiroz Neto, J.C. [Petroleo Brasileiro S.A. (CENPES / PETROBRAS), Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

    2007-07-15

    Halogenated salt (HS)-acetylenic compound (AC) mixtures were tested as corrosion inhibitors of 13Cr and 22Cr stainless steel and N80 and P110 carbon steel when exposed to 15 wt.% HCl solutions, at 50 deg C, 80 deg C and 100 deg C. The best corrosion inhibition efficiency is obtained when the concentration of both AC and HS is 1.5 wt. %, which indicates the use of all tested steels in oil well stimulation operated at 50 deg C and the use of 13Cr, N80 and P110 steels in oil well processing temperatures up to 100 deg C. (author)

  5. Inhibitive effect of Xylopia ferruginea extract on the corrosion of mild steel in 1M HCl medium

    Science.gov (United States)

    Raja, Pandian Bothi; Rahim, Afidah Abdul; Osman, Hasnah; Awang, Khalijah

    2011-08-01

    The alkaloid content of the leaves and stem bark of Xylopia ferruginea plant was isolated and tested for its anticorrosion potential on mild steel corrosion in a hydrochloric acid medium by using electrochemical impedance spectroscopy, potentiodynamic polarization measurement, scanning electron microscopy (SEM), and Fourier transform infra red (FTIR) analysis. The experimental results reveal the effective anticorrosion potential of the plant extract. The mixed mode of action exhibited by the plant extract is evidenced from the polarization study. SEM images proof the formation of a protective layer over the mild steel surface, and this is supported by the FTIR study. The possible mode of the corrosion inhibition mechanism has also been discussed.

  6. Inhibition of La-Fe-Co-Si compound corrosion in distilled water by sodium molybdate and disodium hydrogen phosphate

    Institute of Scientific and Technical Information of China (English)

    ZHANG Min; YE Rongchang; LONG Yi; CHANG Yongqin

    2011-01-01

    A comparative study of Na2MoO4·2H2O and Na2HPO4·12H2O as inhibitors for magnetic refrigeration material La-Fe-Co-Si comments were applied to study the corrosion behavior of the compound in the absence or presence of different concentrations of these inhibitors studied compounds acted as anodic inhibitors. The potential of zero charge (PZC) of La-Fe-Co-Si compound was determined in distilled water in the absence of the studied inhibitors. Corrosion inhibition mechanisms for inhibitors were proposed in this work.

  7. Study on Corrosion Inhibition Efficiency of Stem Alkaloid Extract of Different Varieties of Holy Basil on Aluminium in HCl Solution

    Energy Technology Data Exchange (ETDEWEB)

    Kumpawat, Nutan; Chaturvedi, Alok; Upadhyay, R. K. [Synthetic and Surface Science Laboratory, Ajmer (India)

    2012-08-15

    Corrosion inhibition efficiencies of holy basil on Al in HCl solution were studied by weight loss and thermometric methods in presence and in absence of stem extract of three different varieties of holy basil viz. ocimum basilicum (E{sub B}), ocimum canum (E{sub C}) and ocimum sanctum (E{sub S}). Inhibition efficiency increases with the increasing concentration of stem extract and decreases with increases in acid strength. Results show that all varieties under study are good corrosion inhibitors, among which, E{sub B} is most effective. Maximum inhibition efficiency was found 97.09% in 0.5N HCl solution with 0.6% stem extract. The Langmuir adsorption isotherm indicates that surface coverage also increases with increasing in the concentration of extract of stem in HCl solution.

  8. Correlation between electronic parameters and corrosion inhibition of benzothiazole derivatives- NMR parameters as important and neglected descriptors

    Science.gov (United States)

    Behzadi, Hadi; Forghani, Ali

    2017-03-01

    The relation between electronic properties and corrosion inhibitive performance of three benzothiazole derivatives 1,3-benzothiazol-2-amine (BTA), 6-methyl-1,3-benzothiazol-2-amine (MBTA) and 2-amino-1,3-benzthiazole-6-thiol (TBTA) has been investigated by density functional theory. The electronic properties including EHOMO, ELUMO and related parameters were calculated at the B3LYP/6-311++G(d,p) level. The chemical shielding CS tensors were introduced as important and neglected descriptors to evaluate inhibitive efficiency of corrosion inhibitors. Nuclear independent chemical shift (NICS) components, as an aromaticity criterion, were also investigated as local descriptor. Polarizability and CS descriptors, as second rank tensors, show the best correlations with inhibition efficiencies of studied inhibitors.

  9. Branched Polymers and their Application in Corrosion Inhibition for mild steel in 1M H2SO4 medium

    Directory of Open Access Journals (Sweden)

    Sounthari. P

    2014-12-01

    Full Text Available The adsorption and corrosion inhibiting effect of branched polymers (BATP, BAAZ, BETP & BEAZ on mild steel in 1M H2SO4 at 30±1˚C was investigated using gravimetric, electrochemical impedance spectroscopy (EIS, and potentiodynamic polarization techniques. The experimental findings revealed that BATP inhibited the corrosion reaction in the acid environment to greater extend compared to BAAZ, BETP and BEAZ. Impedance results indicate that the polymers were adsorbed on the metal/solution interface, while polarization data showed that the polymers behaved mostly as mixed-type inhibitors. Kinetic parameters (activation energy, pre-exponential factor, enthalpy of activation and entropy of activation as well as thermodynamic parameters (enthalpy of adsorption, entropy of adsorption and Gibbs free energy were calculated and discussed. Scanning electron microscopy technique was used to confirm the effectiveness of inhibition of mild steel in sulphuric acid medium.

  10. Experimental and quantum chemical studies on corrosion inhibition performance of quinoline derivatives for MS in 1N HCl

    Indian Academy of Sciences (India)

    B M Mistry; N S Patel; S Sahoo; S Jauhari

    2012-06-01

    The corrosion inhibition effect of two quinoline derivatives, viz. 2-chloro quinoline 3-carbaldehyde (CQC) and (2-chloro-quinoline-3ylmethyl)--tolyl-amine (CQA) have been investigated against mild steel (MS) in 1N HCl solution using conventional weight loss, potentiodynamic polarization, linear polarization and electrochemical impedance spectroscopy. The losses in weights of MS samples have proved that both CQC and CQA are efficient inhibitors of corrosion. The mixed mode of inhibition was confirmed by electrochemical polarizations. The results of electrochemical impedance spectroscopy have showed changes in the impedance parameters like charge transfer resistance and double-layer capacitance that confirmed strong adsorption of inhibitors on the MS surface. The inhibition action of these compounds was assumed to occur via adsorption on the steel surface through the active centres contained in the molecules. Furthermore, quantum chemical calculations have been performed at B3LYP/6-31G( , ) level to complement the experimental evidence.

  11. Inhibition of copper corrosion in sodium chloride solution by the self-assembled monolayer of sodium diethyldithiocarbamate

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Q.Q., E-mail: liaoqq1971@yahoo.com.c [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Yue, Z.W.; Yang, D. [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Wang, Z.H. [Department of Chemistry, Tongji University, Shanghai 200092 (China); Li, Z.H. [Department of Chemistry, Fudan University, Shanghai 200433 (China); Ge, H.H. [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Li, Y.J. [Department of Chemistry, Tongji University, Shanghai 200092 (China)

    2011-05-15

    Research highlights: DDTC is of low toxicity. DDTC SAM had good corrosion inhibition effects on copper in 3% NaCl solution. DDTC SAM was chemisorbed on copper surface by its S atoms. - Abstract: Sodium diethyldithiocarbamate (DDTC) self-assembled monolayer (SAM) on copper surface has been investigated by SERS and EDS and the results show that DDTC SAM is chemisorbed on copper surface by its S atoms with tilted orientation. Corrosion inhibition ability of DDTC SAM was measured in 3% NaCl solution using electrochemical methods. The impedance results indicate that the maximum inhibition efficiency of DDTC SAM can reach 99%. Quantum chemical calculations show that DDTC has relatively small {Delta}E between HOMO and LUMO and large negative charge in its two sulfur atoms, which facilitates the formation of a DDTC SAM on copper surface.

  12. Inhibition of cold rolled steel corrosion by Tween-20 in sulfuric acid: weight loss, electrochemical and AFM approaches.

    Science.gov (United States)

    Mu, Guannan; Li, Xianghong

    2005-09-01

    The inhibiting action of a nonionic surfactant of Tween-20 on the corrosion of cold rolled steel (CRS) in 0.5-7.0 M sulfuric acid (H(2)SO(4)) was studied by weight loss and potentiodynamic polarization methods. Atomic force microscope (AFM) provided the surface conditions. The results show that inhibition efficiency increases with the inhibitor concentration, while it decreases with the sulfuric acid concentration. The adsorption of inhibitor on the cold rolled steel surface obeys the Langmuir adsorption isotherm equation. Effect of immersion time was studied and discussed. The effect of temperature on the corrosion behavior of cold rolled steel was also studied at four temperatures ranging from 30 to 60 degrees C, the thermodynamic parameters such as adsorption heat, adsorption free energy, and adsorption entropy were calculated. The results revealed that the adsorption was physisorption mechanism. A kinetic study of cold rolled steel in uninhibited and inhibited acid was also discussed. The kinetic parameters such as apparent activation energy, pre-exponential factor, rate constant, and reaction constant were calculated for the reactions of corrosion. The inhibition effect is satisfactorily explained by both thermodynamic and kinetic models. Polarization curves show that Tween-20 is a cathodic-type inhibitor in sulfuric acid. The results obtained from weight loss and potentiodynamic polarization are in good agreement, and the Tween-20 inhibition action could also be evidenced by surface AFM images.

  13. Inhibition of the corrosion of mild steel in hydrochloric acid by isatin and isatin glycine

    Directory of Open Access Journals (Sweden)

    B.I. Ita

    2006-12-01

    Full Text Available The inhibition of corrosion of mild steel in hydrochloric acid by isatin glycine (ING and isatin (IN at 30-60 oC and concentrations of 0.0001 M to 0.0005 M was studied via weight loss method. At the highest inhibitor concentration studied ING exhibited inhibition efficiency of 87% while IN exhibited 84% at 60 oC. A chemical adsorption mechanism was proposed on the basis of the temperature effect and obtained average activation energy values of 143.9 kJ/mol for ING and 118.5 kJ/mol for IN. The two inhibitors were confirmed to obey the Langmuir adsorption isotherm equation at the concentrations studied. Also a first-order type of mechanism was proposed from the kinetic treatment of the result. The difference in the inhibitory properties of the inhibitors was explained in terms of the difference in their molecular structures and solubility rather than difference in molecular weights alone.

  14. The inhibitive effect of bipyrazolic derivatives on the corrosion of steel in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Tebbji, K. [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); Oudda, H. [Laboratoire des Procedes de Separation, Faculte des Sciences, Kenitra (Morocco); Ramdani, A. [Laboratoire de Chimie Organique-Physique, Faculte des Sciences, B.P. 717, Oujda (Morocco); Benkadour, M. [Laboratoire de Chimie des Eaux et Corrosion, Faculte des Sciences, B.P. 717, Oujda (Morocco)

    2005-12-15

    The effect of two pyrazole-type organic compounds, namely ethyl 5,5'-dimethyl-1'H-1,3'-bipyrazole-3 carboxylate (P1) and 3,5,5'-trimethyl-1'H-1,3'-bipyrazole (P2) on the corrosion behaviour of steel in 1 M hydrochloric acid (HCl) solution is investigated at 308 K by weight loss measurements, potentiodynamic polarisation and impedance spectroscopy (EIS) methods. The inhibition efficiencies obtained from cathodic Tafel plots, gravimetric and EIS methods are in good agreement. Results obtained show that the compound P2 is the best inhibitor and its efficiency reaches 84% at 10{sup -3} M. Potentiodynamic polarisation studies show that pyrazolic derivatives are cathodic-type inhibitors and these compounds act on the cathodic reaction without changing the mechanism of the hydrogen evolution reaction. The inhibition efficiency of P2 is temperature-dependent in the range from 308 to 353 K and the associated activation energy has been determined. P2 adsorbs on the steel surface according to Langmuir adsorption model. The calculation of the total partial charge of inhibitor atoms is computed.

  15. Corrosion inhibition of carbon steel in the near neutral media by blends of tannin and calcium gluconate

    Energy Technology Data Exchange (ETDEWEB)

    Lahodny-Sarc, O.; Kapor, F. [Mining, Geology and Petrol. Eng. Dept., Univ. of Zagreb (Croatia)

    2002-04-01

    The efficiency of tannin/calcium gluconate blends, as corrosion inhibitors for carbon steel in near neutral water media, have been studied. Synergistic behaviour of two components blend of different concentrations has been demonstrated in solutions prepared with distilled and a tap water. The anodic character of the inhibitor was recognised by the shift of corrosion potential to more positive values and a decrease of the passivation current on potentiodynamic polarisation curves. The cathodic inhibition was also recognised by slowing down the cathodic current of the polarisation run. Soluble iron tannate chelate has been observed as a dark blue flux flowing down from the metal surface into solution of tannin in the tap water, resulting in a corrosion process. Tannin decreases the pH of tap water. Calcium gluconate added in tannin solutions increases the pH maintaining it in the near neutral region enabling the precipitation of a low soluble protective iron tannate and metal gluconate. (orig.)

  16. Adsorption and inhibitive properties of a Schiff base for the corrosion control of carbon steel in saline water.

    Science.gov (United States)

    Samide, Adriana; Tutunaru, Bogdan

    2011-01-01

    A Schiff base, namely N-(2-hydroxybenzylidene) thiosemicarbazide (HBTC), was investigated as inhibitor for carbon steel in saline water (SW) using electrochemical measurements such as: potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The morphology of the surfaces before and after corrosion was examined by Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy (SEM/EDS). The results showed that HBTC acts as corrosion inhibitor in SW by suppressing simultaneously the cathodic and anodic processes via adsorption on the surface which followed the Langmuir adsorption isotherm; the polarization resistance (R(p)) and inhibition efficiency (IE) increased with each HBTC concentration increase. SEM/EDS analysis showed at this stage that the main product of corrosion is a non-stoichiometric amorphous Fe(3+) oxyhydroxide, consisting of a mixture of Fe(3+) oxyhydroxides, α-FeOOH and/or γ-FeOOH, α-FeOOH/γ-FeOOH and Fe(OH)(3).

  17. Inhibition of Staphylococcus aureus biofilm by a copper-bearing 317L-Cu stainless steel and its corrosion resistance.

    Science.gov (United States)

    Sun, Da; Xu, Dake; Yang, Chunguang; Chen, Jia; Shahzad, M Babar; Sun, Ziqing; Zhao, Jinlong; Gu, Tingyue; Yang, Ke; Wang, Guixue

    2016-12-01

    The present study investigated the antibacterial performance, corrosion resistance and surface properties of antibacterial austenitic 317L-Cu stainless steel (317L-Cu SS). After 4.5wt% copper was added to 317L stainless steel (317L SS), the new alloy underwent solid solution and aging heat treatment. Fluorescent staining using 4',6-diamidino-2-phenylindole (DAPI) revealed that the 317L-Cu SS showed strong antibacterial efficacy, achieving a 99% inhibition rate of sessile Staphylococcus aureus cells after 5days. The corrosion data obtained by potentiodynamic polarization curves indicated that in comparison with 317L SS, the pitting potential and corrosion current density of 317L-Cu slightly decreased due to the addition of Cu. The 317L-Cu SS exhibited no cytotoxicity against zebrafish (Danio rerio) embryos. The experimental results in this study demonstrated that the new alloy has potential applications in medical and daily uses.

  18. Inhibitive Effect by Acid Extract of Ficus Exasperata Leaves on the Sulphuric Acid Corrosion of Mild Steel

    Directory of Open Access Journals (Sweden)

    N. S. Patel

    2009-01-01

    Full Text Available Extract of Ficus exasperata leaves was investigated as corrosion inhibitor of mild steel in 1 N H2SO4 using conventional weight loss, electrochemical polarizations, electrochemical impedance spectroscopy and scanning electron microscopic studies. The weight loss results showed that the extract of Ficus exasperata is excellent corrosion inhibitor. Electrochemical polarizations data revealed the mixed mode of inhibition. The results of electrochemical impedance spectroscopy shows that the change in the impedance parameters, charge transfer resistance and double layer capacitance, with the change in concentration of the extract is due to the adsorption of active molecules leading to the formation of a protective layer on the surface of mild steel. Scanning electron microscopic studies provided the confirmatory evidence of improved surface condition, due to the adsorption, for the corrosion protection.

  19. Study of Temperature Effect on the Corrosion Inhibition of C38 Carbon Steel Using Amino-tris(Methylenephosphonic Acid in Hydrochloric Acid Solution

    Directory of Open Access Journals (Sweden)

    Najoua Labjar

    2011-01-01

    Full Text Available Tafel polarization method was used to assess the corrosion inhibitive and adsorption behaviours of amino-tris(methylenephosphonic acid (ATMP for C38 carbon steel in 1 M HCl solution in the temperature range from 30 to 60∘C. It was shown that the corrosion inhibition efficiency was found to increase with increase in ATMP concentration but decreased with temperature, which is suggestive of physical adsorption mechanism. The adsorption of the ATMP onto the C38 steel surface was found to follow Langmuir adsorption isotherm model. The corrosion inhibition mechanism was further corroborated by the values of kinetic and thermodynamic parameters obtained from the experimental data.

  20. Inhibiting Effect of Indole and Some of Its Derivatives on Corrosion of C-Steel in HCl

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The Inhibiting effect of indole (A), indole acetic acid (B), indole buteric acid (C), and 3-acetyl indole (D), on the corrosion of three carbon steels in 10% HCl was investigated by using galvanostatic polarization method and open circuit potential measurements. It was observed that the inhibiting action of inhibitors increased with increasing inhibitor concentration. The best inhibiting effect obtained at the highest concentration (200×10-6 g/L) of the inhibitors for the three carbon steels. According to polarization and open circuit potential methods the inhibitors have effect on both anodic and cathodic area.

  1. Inhibition of Ce3+ on Stress Corrosion Crack of High Strength Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    LI Wen-ting

    2017-05-01

    Full Text Available The stress corrosion cracking (SCC susceptibility of 7A04 high strength aluminum alloy in 3.5% (mass fraction NaCl solution and the Ce3+ inhibition of SCC were investigated by slow stress rate test(SSRT, using constant current polarization, electrochemical noise (ECN and electrochemical impedance spectroscopy (EIS techniques. The inhibition mechanism of Ce3+ ions on the initiation and propagation of cracking was also analyzed. The results indicate that both anodic and cathodic galvanostatic polarizations can accelerate the SCC of 7A04, the former increases anodic dissolution but the latter accelerates hydrogen embrittlement of crack tip. SCC susceptibility of 7A04 can be reduced effectively by the addition of cerium ions, the fracture time is delayed and slowed down, but only during the initiation other than the propagation stage of cracking. Ce3+ ions can restrain the initiation of metastable pitting on the surface of 7A04 specimen, which therefore increase the induction time of the cracking since that the micro pits are usually the source of cracking.However, once the crack begins to propagate or the specimen is notched, the addition of cerium ions can rarely inhibit the cracking process. This is possibly attributed to that the radius of Ce3+ ion is too large to diffuse into the crack tip or it is hard to form protective CeO2 layer, Ce3+ ion therefore fails to rehabilitate the active alloy at the crack tip and further reduce the SCC developing rate of 7A04. SEM also indicates that the crack initiation of smooth 7A04 specimens is mainly induced by metastable or stable pits.

  2. Green corrosion inhibition of mild steel to aqueous sulfuric acid by the extract of Corchorus olitorius stems

    Science.gov (United States)

    Gobara, Mohamed; Zaghloul, Basem; Baraka, Ahmad; Elsayed, Mohamed; Zorainy, Mahmoud; Mokhtar Kotb, Mohamed; Elnabarawy, Hany

    2017-04-01

    Extract of Corchorus olitorius stems (ECS) was used as a green inhibitor for the inhibition of mild steel corrosion in 0.5 M H2SO4 solution. GC/MS was used for both qualitative and quantitative analysis of the extract. The corrosion performance of the extract was evaluated using electrochemical impedance spectroscopy, potentiodynamic polarization and weight loss. The results showed that ECS is a mixed-type inhibitor which reduces both anodic and cathodic reactions and the inhibition efficiency was reached up to 93%. Adsorption isotherm data was recorded at different temperatures and analyzed by selected adsorption isotherm models to reveal characteristics of inhibition. Thermodynamic calculations showed that the inhibition efficiency increases with increasing inhibitor concentration, and decreases with increasing temperature. Adsorption of ECS on the mild steel surface was found to be spontaneous and exothermic. Adsorption is suggested to be physisorption according to El-Awady isotherm model. Also, the scanning electron microscopy (SEM) was used to investigate the surface morphology to confirm the corrosion results.

  3. The effect of triphenylphosphane on corrosion inhibition of benzotriazole at Ag electrode monitored by SERS in nonaqueous solution

    Science.gov (United States)

    Yuan, Ya-Xian; Yang, Feng-Zhu; Morag, Clark-Heptinstall; Liu, Dong; Zhang, Yong; Gu, Ren-Ao; Yao, Jian-Lin

    2013-03-01

    The corrosion inhibition behavior of benzotriazole (BTAH) on Ag electrodes and the influence of triphenylphosphane (pph3) were investigated by electrochemical method, in situ surface-enhanced Raman spectroscopy (SERS) and direct electrochemical synthesis of surface complexes in nonaqueous solution. The results indicated that the BTA- ion was coordinated to the Ag surface to form a highly cross-linked surface polymer complex of [Ag(BTA)]n, which suppressed the dissolution and oxidation of Ag effectively. The introduction of a neutral ligand of pph3 blocked the surface coordination processes of BTAH with the Ag electrode. It resulted in a decrease of inhibition efficiency to Ag surface. The ligand of pph3 played a negative role on the corrosion inhibition of BTAH to the Ag electrode. The SERS results were well consistent with the cyclic voltammetry and polarization curves measurements. For modeling, two different surface complexes were prepared in acetonitrile with and without pph3 by direct electrochemical synthesis. A polymer-like complex of [Ag(BTA)]n attached to the Ag surface was obtained in the absence of pph3, which suppressed the dissolution and oxidation of Ag effectively. A new binuclear compound, Ag2(BTA)2(pph3)4, was produced in acetonitrile with pph3 and the final coordination process occurred in solution leading to difficulties in forming a compact surface film, thus decreasing the corrosion inhibition efficiency of BTAH. The role of pph3 and the mechanism were proposed.

  4. The effect of triphenylphosphane on corrosion inhibition of benzotriazole at Ag electrode monitored by SERS in nonaqueous solution.

    Science.gov (United States)

    Yuan, Ya-Xian; Yang, Feng-Zhu; Morag, Clark-Heptinstall; Liu, Dong; Zhang, Yong; Gu, Ren-Ao; Yao, Jian-Lin

    2013-03-15

    The corrosion inhibition behavior of benzotriazole (BTAH) on Ag electrodes and the influence of triphenylphosphane (pph(3)) were investigated by electrochemical method, in situ surface-enhanced Raman spectroscopy (SERS) and direct electrochemical synthesis of surface complexes in nonaqueous solution. The results indicated that the BTA(-) ion was coordinated to the Ag surface to form a highly cross-linked surface polymer complex of [Ag(BTA)](n), which suppressed the dissolution and oxidation of Ag effectively. The introduction of a neutral ligand of pph(3) blocked the surface coordination processes of BTAH with the Ag electrode. It resulted in a decrease of inhibition efficiency to Ag surface. The ligand of pph(3) played a negative role on the corrosion inhibition of BTAH to the Ag electrode. The SERS results were well consistent with the cyclic voltammetry and polarization curves measurements. For modeling, two different surface complexes were prepared in acetonitrile with and without pph(3) by direct electrochemical synthesis. A polymer-like complex of [Ag(BTA)](n) attached to the Ag surface was obtained in the absence of pph(3), which suppressed the dissolution and oxidation of Ag effectively. A new binuclear compound, Ag(2)(BTA)(2)(pph(3))(4), was produced in acetonitrile with pph(3) and the final coordination process occurred in solution leading to difficulties in forming a compact surface film, thus decreasing the corrosion inhibition efficiency of BTAH. The role of pph(3) and the mechanism were proposed.

  5. Inhibitive Effect of Hydrofluoric Acid Doped Poly Aniline (HFPANI on Corrosion of Iron in 1N Phosphoric Acid Solution

    Directory of Open Access Journals (Sweden)

    G.Maheswari

    2015-03-01

    Full Text Available The inhibition effect of Hydrofluoric acid doped poly aniline HF-PANI on mild steel corrosion in 1N phosphoric acid has been studied by mass loss and polarization techniques and AC impedance measurements methods between 303 K and 333K.The inhibition efficiency increased with increase in concentration of HF PANI. The corrosion rate increased with increase in temperature and decreased with increase in concentration of inhibitor compared to blank. Potentiostatic polarization results revealed that HF-PANI act as mixed type inhibitor. The inhibitor of HF-PANI was chemically adsorbed and spontaneous adsorption on the mild steel surface .The values of activation energy (Ea, free energy of adsorption (ΔGads, heat of adsorption (Qads, enthalpy of adsorption (ΔH and entropy of adsorption (ΔS were calculated. The adsorption of inhibitor on mild steel surface has been found to obey Temkin’s adsorption isotherm. SEM analysis was agreed to establish the mechanism of corrosion inhibitor on mild steel corrosion in phosphoric acid medium.

  6. Effect of benzotriazole and phenyl-amino-triazine-dithiol on corrosion inhibition of copper in low-conductivity water

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, G.; Feng, Y. (Shanghai Inst. of Electric Power, Shanghai (People' s Republic of China)); Notoya, T. (Hokkaido Univ., Sapporo (Japan). Faculty of Engineering)

    1990-07-15

    Impedance measurements of copper electrodes in a low conductivity water (less than 10 {mu} S/cm) with the addition of either benzotriazole (BTA) or phenyl amino triazole dithiol (PTD) were performed. BTA inhibits copper corrosion better than PTD. Corrosion inhibition with PTD occurs only at concentrations above 10 ppm. A combination of BTA and PTD proved more effective than either used alone. The optimum ratio is 3 ppm BTA + 2 ppm PTD with the total amount of inhibitor 5 ppm. BTA may spread over the surface of copper electrodes and form a protective film consisting of a Cu BTA polymeric metwork. PTD may then plug the defects in the network on Cu/Cu {sub 2} O by forming the film. 12 refs, 8 figs.

  7. 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.

  8. 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.

  9. Superhydrophobic and superoleophobic surface by electrodeposition on magnesium alloy substrate: Wettability and corrosion inhibition.

    Science.gov (United States)

    Liu, Yan; Li, Shuyi; Wang, Yaming; Wang, Huiyuan; Gao, Ke; Han, Zhiwu; Ren, Luquan

    2016-09-15

    Superamphiphobic (both superhydrophobic and superoleophobic) surfaces have attracted great interests in the fundamental research and practical application. This research successfully fabricated the superamphiphobic surfaces by combining the nickel plating process and modification with perfluorocaprylic acid. The cooperation of hierarchical micro-nano structures and perfluorocaprylic acid with low surface energy plays an important role in the formation of superamphiphobic surfaces. The contact angles of water/oil have reached up to 160.2±1°/152.4±1°, respectively. Contrast with bare substrate, the electrochemical measurements of superamphiphobic surfaces, not only the EIS measurement, but also potentiodynamic polarization curves, all revealed that, the surface corrosion inhibition was improved significantly. Moreover, superamphiphobic surfaces exhibited superior stability in the solutions with a large pH range, also could maintain excellent performance after storing for a long time in the air. This method is easy, feasible and effective, and could be used to fabricate large-area mutli-functional surface. Such a technique will develop a new approach to fabricate superamphiphobic surfaces on different engineering materials.

  10. Corrosion Inhibition of Aluminium Using Exudate Gum from Pachylobus edulis in the Presence of Halide Ions in HCl

    Directory of Open Access Journals (Sweden)

    S. A. Umoren

    2008-01-01

    Full Text Available The anti-corrosive effect of Pachylobus edulis exudate gum in combination with halides ions (Cl–, Br– and I– for aluminium corrosion in HCl was studied at temperature range of 30-60°C using weight loss method. Results obtained showed that the naturally occurring exudate gum acts as an inhibitor for aluminium corrosion in acidic environment. Inhibition efficiency (%I increases with increase in concentration of the exudate gum and synergistically increased to a considerable extent on the addition of the halide ions. The increase in inhibition efficiency (%I and surface coverage (θ in the presence of the halides was found to be in the order I– > Br– > Cl– which indicates that the radii as well as electronegativity of the halide ions play a significant role in the adsorption process. Pachylobus edulis exudate gum obeys Temkin adsorption isotherm. Phenomenon of physical adsorption is proposed from the values of kinetic and thermodynamic parameters obtained. The values of synergism parameter (S1 obtained for the halides are greater than unity suggesting that the enhanced inhibition efficiency of the P. edulis caused by the addition of the halide ions is only due to synergistic effect.

  11. Quantum chemical studies on the corrosion inhibition of some hector bases on mild steel in acidic medium

    Directory of Open Access Journals (Sweden)

    Majid Khodaei-Tehrani

    2015-03-01

    Full Text Available The density functional theory (DFT at the B3LYP/6-31G (d,p basis set level method were performed on three hector bases used as corrosion inhibitors; namely, 3-anilino-5-imino-4-phenyl-1, 2,4-thiadiazoline (AIPT, 3-anilino-5-imino-4-tolyl-1, 2,4-thiadiazoline (AITT, and 4-(4-chlorophenyl-5-imino-N-phenyl-4,5-dihydro-1,2,4-thiadiazol-3-amine (AICT. They were used as corrosion inhibitors for mild steel in acidic medium in order to determine the relationship between molecular structure and their corresponding inhibition efficiency (%IE. The results of the quantum chemical calculations and experimental %IE were subjected to correlation analysis. This indicates that their inhibition effects are closely related to the highest occupied molecular orbital energy (EHOMO, the lowest unoccupied molecular orbital energy (ELUMO, the energy gap (ΔE, the hardness (η, the softness (σ, the electronegativity (χ, and the fraction of electrons transferred from the inhibitor molecule to the metal surface (ΔN. In addition, the local reactivity has been analyzed through the Fukui function. Two QSAR equations were developed and used to predict the corrosion inhibition efficiency for hector bases.

  12. Experimental and theoretical studies on inhibition of mild steel corrosion by some synthesized polyurethane tri-block co-polymers.

    Science.gov (United States)

    Kumar, Sudershan; Vashisht, Hemlata; Olasunkanmi, Lukman O; Bahadur, Indra; Verma, Hemant; Singh, Gurmeet; Obot, Ime B; Ebenso, Eno E

    2016-08-12

    Polyurethane based tri-block copolymers namely poly(N-vinylpyrrolidone)-b-polyurethane-b-poly(N-vinylpyrrolidone) (PNVP-PU) and poly(dimethylaminoethylmethacrylate)-b-polyurethane-b-poly(dimethylaminoethylmethacrylate) (PDMAEMA-PU) were synthesized through atom transfer radical polymerization (ATRP) mechanism. The synthesized polymers were characterized using nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC) methods. The corrosion inhibition performances of the compounds were investigated on mild steel (MS) in 0.5 M H2SO4 medium using electrochemical measurements, surface analysis, quantum chemical calculations and molecular dynamic simulations (MDS). Potentiodynamic polarization (PDP) measurements revealed that the polymers are mixed-type corrosion inhibitors. Electrochemical impedance spectroscopy (EIS) measurements showed that the polymers inhibit MS corrosion by adsorbing on MS surface to form pseudo-capacitive interface. The inhibitive effects of the polymers increase with increasing concentration and decrease with increasing temperature. The adsorption of both the polymers on MS surface obey the Langmuir adsorption isotherm and involves both physisorption and chemisorption mechanisms. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses showed that the polymers formed protective film on MS surface and shield it from direct acid attack. Quantum chemical calculations and molecular dynamic simulations studies corroborate experimental results.

  13. Inhibition of corrosion of mild steel in acid media by N′-benzylidene-3-(quinolin-4-ylthio)propanohydrazide

    Indian Academy of Sciences (India)

    V Ramesh Saliyan; Airody Vasudeva Adhikari

    2008-08-01

    In the present investigation a new corrosion inhibitor, N′-(3,4-dihydroxybenzylidene)-3-{[8-(trifluoromethyl) quinolin-4-yl]thio}propanohydrazide(DHBTPH) was synthesized, characterized and tested as a corrosion inhibitor for mild steel in HCl (1 M, 2 M) and H2SO4 (0.5 M, 1 M) solutions using weight-loss method, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization methods. The corrosion inhibition efficiency measured by all the above three techniques were in good agreement with each other. The results showed that DHBTPH is a very good inhibitor for mild steel in acidic media. The inhibition efficiency in different acid media was found to be in the decreasing order 0.5 M H2SO4 > 1 M HCl > 1 M H2SO4 > 2 M HCl. The inhibition efficiency increases with increasing inhibitor concentration and with increasing temperature. It acts as an anodic inhibitor. Thermodynamic and activation parameters are discussed. Adsorption of DHBTPH was found to follow the Langmuir’s adsorption isotherm. Chemisorption mechanism is proposed. The mild steel samples were also analysed by scanning electron microscopy (SEM).

  14. Experimental and theoretical studies on inhibition of mild steel corrosion by some synthesized polyurethane tri-block co-polymers

    Science.gov (United States)

    Kumar, Sudershan; Vashisht, Hemlata; Olasunkanmi, Lukman O.; Bahadur, Indra; Verma, Hemant; Singh, Gurmeet; Obot, Ime B.; Ebenso, Eno E.

    2016-01-01

    Polyurethane based tri-block copolymers namely poly(N-vinylpyrrolidone)-b-polyurethane-b-poly(N-vinylpyrrolidone) (PNVP-PU) and poly(dimethylaminoethylmethacrylate)-b-polyurethane-b-poly(dimethylaminoethylmethacrylate) (PDMAEMA-PU) were synthesized through atom transfer radical polymerization (ATRP) mechanism. The synthesized polymers were characterized using nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC) methods. The corrosion inhibition performances of the compounds were investigated on mild steel (MS) in 0.5 M H2SO4 medium using electrochemical measurements, surface analysis, quantum chemical calculations and molecular dynamic simulations (MDS). Potentiodynamic polarization (PDP) measurements revealed that the polymers are mixed-type corrosion inhibitors. Electrochemical impedance spectroscopy (EIS) measurements showed that the polymers inhibit MS corrosion by adsorbing on MS surface to form pseudo-capacitive interface. The inhibitive effects of the polymers increase with increasing concentration and decrease with increasing temperature. The adsorption of both the polymers on MS surface obey the Langmuir adsorption isotherm and involves both physisorption and chemisorption mechanisms. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses showed that the polymers formed protective film on MS surface and shield it from direct acid attack. Quantum chemical calculations and molecular dynamic simulations studies corroborate experimental results. PMID:27515383

  15. Experimental and theoretical studies on inhibition of mild steel corrosion by some synthesized polyurethane tri-block co-polymers

    Science.gov (United States)

    Kumar, Sudershan; Vashisht, Hemlata; Olasunkanmi, Lukman O.; Bahadur, Indra; Verma, Hemant; Singh, Gurmeet; Obot, Ime B.; Ebenso, Eno E.

    2016-08-01

    Polyurethane based tri-block copolymers namely poly(N-vinylpyrrolidone)-b-polyurethane-b-poly(N-vinylpyrrolidone) (PNVP-PU) and poly(dimethylaminoethylmethacrylate)-b-polyurethane-b-poly(dimethylaminoethylmethacrylate) (PDMAEMA-PU) were synthesized through atom transfer radical polymerization (ATRP) mechanism. The synthesized polymers were characterized using nuclear magnetic resonance (NMR) spectroscopy and gel permeation chromatography (GPC) methods. The corrosion inhibition performances of the compounds were investigated on mild steel (MS) in 0.5 M H2SO4 medium using electrochemical measurements, surface analysis, quantum chemical calculations and molecular dynamic simulations (MDS). Potentiodynamic polarization (PDP) measurements revealed that the polymers are mixed-type corrosion inhibitors. Electrochemical impedance spectroscopy (EIS) measurements showed that the polymers inhibit MS corrosion by adsorbing on MS surface to form pseudo-capacitive interface. The inhibitive effects of the polymers increase with increasing concentration and decrease with increasing temperature. The adsorption of both the polymers on MS surface obey the Langmuir adsorption isotherm and involves both physisorption and chemisorption mechanisms. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses showed that the polymers formed protective film on MS surface and shield it from direct acid attack. Quantum chemical calculations and molecular dynamic simulations studies corroborate experimental results.

  16. Corrosion Inhibition Performance of Lignin Extract of Sun Flower (Tithonia Diversifolia on Medium Carbon Low Alloy Steel Immersed in H2SO4 Solution

    Directory of Open Access Journals (Sweden)

    Kenneth K. ALANEME

    2012-08-01

    Full Text Available The inhibition potentials of lignin extract of sun flower was investigated by evaluating the corrosion behaviour of medium carbon low alloy steel immersed in 1M H2SO4 solution containing varied concentration of the extract. Mass loss, corrosion rate, and adsorption characterization were utilized to evaluate the corrosion inhibition and adsorption properties of the extract. The results revealed that the lignin extract is an efficient inhibitor of corrosion in mild steel immersed in 1M H2SO4. The corrosion rates were observed to decrease with increase in concentration of lignin extract but increase with temperature. The activation energies and the negative free energy of adsorption obtained from the adsorption studies indicate that the lignin extract is physically adsorbed on the surface of the steel and that the adsorption is strong, spontaneous and fit excellently with the assumptions of the Langmuir adsorption isotherm.

  17. Inhibition of pH fronts in corrosion cells due to the formation of cerium hydroxide

    NARCIS (Netherlands)

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

    2013-01-01

    The effect of cerium-based corrosion inhibitors on the pH front between the alkaline cathode and acidic anode in corrosion cells has been studied. The cerium component of these inhibitors can affect the pH front since it precipitates in an alkaline environment as cerium hydroxide, which is important

  18. Corrosion Inhibition on SAE 1010 Steel by Nanoscale Exopolysaccharides Coatings Determined by Electrochemical and Surface Characterization

    Science.gov (United States)

    Plating, painting and the application of enamel are the most common anti-corrosion treatments. They are effective by providing a barrier of corrosion resistant material between the damaging environment and the structural material. Coatings start failing rapidly if scratched or damaged because a co...

  19. Inhibiting effect of 2-mercaptobenzimidazole on the corrosion of Cu-30Ni alloy in aerated 3% NaCl in presence of ammonia

    Energy Technology Data Exchange (ETDEWEB)

    Benmessaoud, M. [Laboratoire d' Electrochimie, des Etudes de Corrosion et d' Environnement, Faculte des Sciences, BP 133 Kenitra (Morocco); Es-salah, K. [Laboratoire d' Electrochimie, des Etudes de Corrosion et d' Environnement, Faculte des Sciences, BP 133 Kenitra (Morocco); Laboratoire de Physique des Liquides et Electrochimie, UPR15 du CNRS, Universite Paris VI, 4 Place Jussieu, 75252 Paris, Cedex 05 (France); Hajjaji, N. [Laboratoire d' Electrochimie, des Etudes de Corrosion et d' Environnement, Faculte des Sciences, BP 133 Kenitra (Morocco); Takenouti, H. [Laboratoire de Physique des Liquides et Electrochimie, UPR15 du CNRS, Universite Paris VI, 4 Place Jussieu, 75252 Paris, Cedex 05 (France); Srhiri, A. [Laboratoire d' Electrochimie, des Etudes de Corrosion et d' Environnement, Faculte des Sciences, BP 133 Kenitra (Morocco)], E-mail: benmessaoud_mma@yahoo.fr; Ebentouhami, M. [Laboratoire d' Electrochimie, des Etudes de Corrosion et d' Environnement, Faculte des Sciences, BP 133 Kenitra (Morocco)

    2007-10-15

    The inhibiting effect of 2-mercaptobenzimidazole (MBI) against Cu-30Ni alloy corrosion in aerated 3% NaCl polluted by ammonia, has been developed. Potentiodynamic and electrochemical impedance spectroscopy (EIS) measurements have been applied to determine the corrosion rate. scanning electron microscopy (SEM) studied surface morphology has been used to characterise electrode surface. The obtained results indicate that MBI acts as a good mixed-type inhibitor retarding the anodic and cathodic reactions. An increase of MBI concentration leads to a decrease of corrosion rate and inhibition efficiency increase.

  20. Influence of silver additions to type 316 stainless steels on bacterial inhibition, mechanical properties, and corrosion resistance

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Tseng, I-Sheng; Møller, Per;

    2010-01-01

    techniques. The microstructure of these 316 stainless steels was examined, and the influences of silver additions to 316 stainless steels on bacterial inhibition, mechanical properties, and corrosion resistance were investigated. This study suggested that silver-bearing 316 stainless steels could be used......Bacterial contamination is a major concern in many areas. In this study, silver was added to type 316 stainless steels in order to obtain an expected bacteria inhibiting property to reduce the occurrence of bacterial contamination. Silver-bearing 316 stainless steels were prepared by vacuum melting...

  1. Corrosion behaviour of tinplate cans in contact with tomato purée and protective (inhibiting) substances.

    Science.gov (United States)

    Nincević Grassino, A; Grabarić, Z; Pezzani, A; Squitieri, G; Fasanaro, G; Impembo, M

    2009-11-01

    The dissolution of iron and tin from tinplate cans filled with tomato purée (pH 4.34) and dioctyl sebacate oil (DOS), essential onion oil (EOO) or potassium nitrate was studied using atomic absorption spectroscopy (AAS), while nitrate was determined using high-performance liquid chromatography (HPLC). The maximum values found in cans were up to 284 mg kg(-1) for tin and 513 mg kg(-1) for iron at elevated storage temperature. Results indicated that the addition of EOO to tomato purée prevents the corrosion process in the case of tin, where concentrations were lowered from 223 to 28 mg kg(-1) for cans with DOS oil and EOO at 20 degrees C, respectively (inhibition rate of 87%). On the other hand, the presence of EOO enhanced the corrosion process for iron increasing the concentration from 15 to 46 mg kg(-1) during 7 months of storage, although this value did not exceed maximum permitted value (50 mg kg(-1)). In cans with tomato purée and potassium nitrate, dissolution of tin started after 30 (36 degrees C) and 60 (20 degrees C) days of storage as a consequence of nitrate action, which act as a corrosion accelerator. Since the addition of EOO improves the taste of canned tomato purée, its potential use as a corrosion inhibitor would be of interest.

  2. Inhibition of acidic corrosion of carbon steel by some mono and bis azo dyes based on 1,5 dihydroxynaphihalene.

    Science.gov (United States)

    Abdallah, Metwally; Moustafa, Moustafa E

    2004-01-01

    Inhibition of the corrosion of carbon steel in hydrochloric acid solution by some mono- and bis-azo dyes based on 1,5-dihydroxynaphthalene was studied in relation to the concentration of inhibitors using weight loss and potentiostatic polarization techniques. The percentage inhibition efficiency calculated from two methods is in a good agreement with each other. The inhibition mechanism of the additives was ascribed to the formation of complex compound adsorbed on the metal surface. The adsorption process follows Freundlich adsorption isotherm. The formation of the complex compound was studied by conductometric and potentiometric titrations. The stability constants of the Fe-complexes were determined using the latter technique and related to the inhibition efficiency.

  3. Inhibition Behaviour of Some Isonicotinic Acid Hydrazides on the Corrosion of Mild Steel in Hydrochloric Acid Solution

    Directory of Open Access Journals (Sweden)

    M. P. Chakravarthy

    2013-01-01

    Full Text Available New corrosion inhibitors, namely, isonicotinic acid (1H-indol-3-yl-methylenehydrazide (INIMH and isonicotinic acid (1H-pyrrol-2-yl-methylenehydrazide (INPMH, have been synthesized, and their inhibitive characteristics for the corrosion of mild steel in 0.5 M HCl were investigated by mass loss and electrochemical techniques. The structures of the synthesized compounds were confirmed using spectral studies. Potentiodynamic polarization studies revealed that the investigated inhibitors are of mixed type. Various thermodynamic parameters were evaluated. Langmuir adsorption isotherm was found to be the best description for both inhibitors. FTIR spectra, energy dispersive X-ray spectroscopy (EDX, and scanning electron microscopy (SEM were performed to characterize the passive film on the metal surface.

  4. Utilization of Photo-Cross-Linkable Polymer for Mild Steel Corrosion Inhibition in 1.0 M HCl Medium

    Science.gov (United States)

    Baskar, R.; Gopiraman, M.; Kesavan, D.; Subramanian, K.; Gopalakrishnan, S.

    2015-08-01

    Novel biphenyl-based photo-cross-linkable polymers were synthesized and characterized by nuclear magnetic resonance and Fourier transform infrared spectroscopy. Upon UV irradiation, the polymers were cross-linked even in the absence of photo initiator or sensitizers, and the rate of photo-cross-linking was examined and discussed. The effectiveness of both virgin and cross-linked polymers for corrosion resistance on mild steel in 1.0 M hydrochloric acid medium was investigated, using polarization studies, electrochemical impedance measurements as well as by adsorption isotherm and surface analysis. The results clearly indicated a dramatic increase in the efficiency of inhibition of corrosion on mild steel by the photo-cross-linked polymer as compared to virgin polymers.

  5. Dual active ionic liquids and organic salts for inhibition of microbially influenced corrosion.

    Science.gov (United States)

    Seter, Marianne; Thomson, Melanie J; Stoimenovski, Jelena; MacFarlane, Douglas R; Forsyth, Maria

    2012-06-18

    We describe a series of novel compounds designed to combat the bacterial growth that leads to microbially induced corrosion on steel in the marine environment. A synergistic effect of the ionic components in these dual active organic salts is demonstrated.

  6. The Synergistic Effect of Iodide and Sodium Nitrite on the Corrosion Inhibition of Mild Steel in Bicarbonate–Chloride Solution

    Directory of Open Access Journals (Sweden)

    Gaius Debi Eyu

    2016-10-01

    Full Text Available The effect of potassium iodide (KI and sodium nitrite (NaNO2 inhibitor on the corrosion inhibition of mild steel in chloride bicarbonate solution has been studied using electrochemical techniques. Potentiodynamic polarisation data suggest that, when used in combination, KI and NaNO2 function together to inhibit reactions at both the anode and the cathode, but predominantly anodic. KI/NO2− concentration ratios varied from 2:1 to 2:5; inhibition efficiency was optimized for a ratio of 1:1. The surface morphology and corrosion products were analysed using scanning electron microscopy (SEM and X-ray diffractometry (XRD. The latter shows that the addition of I− to NO2 facilitates the formation of a passivating oxide (γ-Fe2O3 as compared to NO2− alone, decreasing the rate of metal dissolution observed in electrochemical testing. The synergistic effect of KI/NO2− inhibition was enhanced under the dynamic conditions associated with testing in a rotating disc electrode.

  7. Design of nanocoatings by in situ phosphatizing reagent catalyzed polysilsesquioxane for corrosion inhibition and adhesion promotion on metal alloys

    Science.gov (United States)

    Henderson, Kimberly B.

    When a metal reacts with oxygen and water, a redox reaction happens, which will cause corrosion. Current surface pretreatment for inhibiting corrosion on metal alloys is a phosphate conversion bath. The phosphate conversion bath will generate a phosphate-chromate layer to adhere strongly to a metal substrate. However, it is toxic and unfriendly to the environment. Our group proposed an innovative coating that contains a phosphate component (ISPR-In-situ Phosphatizing Reagent) within a protective coating. The ISPR coating will form a bound phosphate layer on the metal surface acting as the corrosion barrier and enhancing adhesion into the metal surface; moreover, it is low in cost and non-toxic. Within this dissertation, there are four projects that investigate design of ISPR nanocoatings for the use of corrosion inhibition and adhesion promotion. Surface modification and adjusting concentrations of materials with the different formulations are explored. The first project focuses on the adhesion enhancement of a coating created by modifying the surface of an aluminum panel. Secondly, the next project will discuss and present the use of three rare earth element formulations as a replacement for phosphate conversion coatings on magnesium alloy, AZ61. The third project is the design of a nanocoating by using heat dissipating materials to fill in small vacant spaces in the ISPR network coating on various metal alloys. The last project, studies the strategic selection of incorporating metal components into ISPR network by the reduction potential values on several different alloys. Many methods of analysis are used; SEM, TEM, ASTM B117, ASTM D1308, ASTM D3359, EIS, and thickness probe. It was found that the addition of ISPR in the nanocoatings dramatically improves the vitality of metal alloys and these results will be presented during this dissertation.

  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. Synergistic inhibition effect of L-phenylalanine and rare earth Ce(IV) ion on the corrosion of copper in hydrochloric acid solution

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Daquan, E-mail: zhangdaquan@shiep.edu.cn [Department of Environmental Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Wu Huan; Gao Lixin [Department of Environmental Engineering, Shanghai University of Electric Power, Shanghai 200090 (China)

    2012-04-16

    Highlights: Black-Right-Pointing-Pointer Synergistic effect of L-phenylalanine (L-Phe) and Ce(SO{sub 4}){sub 2} on the corrosion of copper on the corrosion inhibition of copper in 0.5 M HCl solution. Black-Right-Pointing-Pointer Structure of the complex film formed by the interaction of L-phenylalanine (L-Phe) and Ce(SO{sub 4}){sub 2} on the copper surface. Black-Right-Pointing-Pointer Mechanism of the improvement of the inhibition property of amino acids by the addition of rare earth compound. - Abstract: The synergistic inhibition effect of L-phenylalanine (L-Phe) and Ce(SO{sub 4}){sub 2} on the corrosion of copper in 0.5 M HCl solution was investigated by weight-loss, electrochemical methods and surface analysis. The electrochemical results showed that L-Phe has definite inhibition effects for copper, while Ce(IV) promoted the anodic process of copper corrosion. The combination L-Phe with Ce(IV) ion produced strong synergistic effect on corrosion inhibition for copper. The maximum inhibition efficiency was 82.7% for 5 mM L-Phe + 2 mM Ce(IV). The results of EIS and potentiodynamic polarization are in good agreement. SEM showed that L-Phe and Ce(IV) can form a dense protective film on the copper surface.

  10. Corrosion inhibition of carbon steel in tetra-n-butylammonium bromide aqueous solution by benzotriazole and Na{sub 3}PO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Liu Song [Department of Applied Chemistry, South China University of Technology, Wushan 1, Guangzhou 510640 (China)], E-mail: chsliu@scut.edu.cn; Xu Nannan; Duan Jinmei; Zeng Zhenou [Department of Applied Chemistry, South China University of Technology, Wushan 1, Guangzhou 510640 (China); Feng Ziping; Xiao Rui [Guangzhou Institute of Energy Conversion, CAS, Guangzhou 510640 (China)

    2009-06-15

    The corrosion inhibition behavior of benzotriazole, Na{sub 3}PO{sub 4} and their mixture on carbon steel in 20 wt.% (0.628 mol l{sup -1}) tetra-n-butylammonium bromide aerated aqueous solution was investigated by weight-loss test, potentiodynamic polarization measurement, electrochemical impedance spectroscopy and scanning electron microscope/energy dispersive X-ray techniques. The inhibition action of BTA or SP or inhibitors mixture on the corrosion of carbon steel is mainly due to the inhibition of anodic process of corrosion. The results revealed that inhibitors mixtures have shown synergistic effects at lower concentration of inhibitors. At 2 g l{sup -1} BTA and 2 g l{sup -1} SP showed optimum enhanced inhibition compared with their individual effects.

  11. 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.)

  12. RESEARCH AND DEVELOPMENT OF CORROSION INHIBITION TECHNOLOGY FOR STEELS%钢材阻锈技术的研究与发展

    Institute of Scientific and Technical Information of China (English)

    唐丹; 邢桂菊; 王开明; 姜效军

    2009-01-01

    Four corrosion inhibition technologies for steels,namely coating,corrosion inhibitor,steel bar in-hibitor and weathering steels are introduced based on the current knowledge in corrosion and protection of engineering steels.The status in research and application of these technologies and the problems existing in each technology are analyzed.The development trend of corrosion inhibition technology is put forword as a conclusion.%针对钢铁材料的锈蚀现状,介绍了涂层、缓蚀剂、钢筋阻锈剂、耐候钢等四种比较成型的钢材阻锈技术,分析了这几项技术的研究应用情况和目前存在的问题,指出了钢材阻锈技术未来的发展方向.

  13. Synthesis and characterization of a novel eco-friendly corrosion inhibition for mild steel in 1 M hydrochloric acid.

    Science.gov (United States)

    Al-Amiery, Ahmed A; Binti Kassim, Fatin A; Kadhum, Abdul Amir H; Mohamad, Abu Bakar

    2016-01-22

    The acid corrosion inhibition process of mild steel in 1 M HCl by azelaic acid dihydrazide has been investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). Azelaic acid dihydrazide was synthesized, and its chemical structure was elucidated and confirmed using spectroscopic techniques (infrared, nuclear magnetic resonance and mass spectroscopy). Potentiodynamic polarization studies indicate that azelaic acid dihydrazide is a mixed-type inhibitor. The inhibition efficiency increases with increased inhibitor concentration and reaches its maximum of 93% at 5 × 10(-3) M. The adsorption of the inhibitor on a mild steel surface obeys Langmuir's adsorption isotherm. The effect of te perature on corrosion behavior in the presence of 5 × 10(-3) M inhibitor was studied in the temperature range of 30-60 °C. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. To inspect the surface morphology of inhibitor film on the mild steel surface, scanning electron microscopy (SEM) was used before and after immersion in 1.0 M HCl.

  14. Experimental and theoretical investigation on corrosion inhibition of AA5052 aluminium alloy by L-cysteine in alkaline solution

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dapeng; Gao, Lixin [School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Zhang, Daquan, E-mail: zhangdaquan@shiep.edu.cn [School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Yang, Dong [School of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090 (China); Wang, Hongxia; Lin, Tong [Institute for Frontier Materials, Deakin University, Geelong, VIC 3216 (Australia)

    2016-02-01

    The corrosion inhibition of L-cysteine on AA5052 aluminium alloy in 4 mol/L NaOH solution was investigated by hydrogen gas evolution experiment, polarisation curve, galvanostatic discharge, electrochemical impedance spectroscopy measurements and quantum chemical calculations. The adsorption of L-cysteine on aluminium alloy surface obeyed the amended Langmuir's adsorption isotherm. The polarisation curves indicated that L-cysteine acted as a cathodic inhibitor to inhibit cathodic reaction. The inhibition mechanism was dominated by the geometric covering effect. The galvanostatic discharge shows that the additives restrain the hydrogen evolution and increase the anodic utilization rate. Quantum chemical calculations indicated that L-cysteine molecules mainly interacted with on the carboxyl groups on the aluminium alloy surface. A strong hybridization occurred between the s-orbital and p-orbital of reactive sites in the L-cysteine molecule and the sp-orbital of Aluminium. - Highlights: • L-cysteine was used as corrosion inhibitor for Al alloy in alkaline solution. • Adsorption of L-cysteine on Al alloy surface obeyed the amended Langmuir's isotherm. • L-cysteine molecules interacted with the carboxyl groups on the Al alloy surface. • A strong orbital hybridization occurred between the reactive sites in L-cysteine and Al.

  15. Corrosion inhibition of iron in 0.5 mol L-1 H2SO4 by halide ions

    Directory of Open Access Journals (Sweden)

    Jeyaprabha C.

    2006-01-01

    Full Text Available The inhibition effect of halide ions such as iodide, bromide and chloride ions on the corrosion of iron in 0.5 mol L-1 H2SO4 and the adsorption behaviour of these ions on the electrode surface have been studied by polarization and impedance methods. It has been found that the inhibition of nearly 90% has been observed for iodide ions at 2.5 10-3 mol L-1, for bromide ions at 10 10-3 mol L-1 and 80% for chloride ions at 2.5 10-3 mol L-1. The inhibition effect is increased with increase of halide ions concentration in the case of I- and Br- ions, whereas it has decreased in the case of Cl- ion at concentrations higher than 5 10-3 mol L-1. The double layer capacitance values have decreased considerably in the presence of halide ions which indicate that these anions are adsorbed on iron at the corrosion potential.

  16. The Inhibitive Potential of Arecaceae Extract on the Corrosivity of Aluminium based Matrix Composite and Medium Carbon Steel in Different Media

    Directory of Open Access Journals (Sweden)

    Paul Aondona IHOM

    2013-06-01

    Full Text Available In this research study, the inhibitive potential of Arecaceae extract on the corrosivity of aluminium based matrix composite and medium carbon steel in different media have been undertaken. The composite and the carbon steel were exposed in 0.5M NaOH and 0.5M HCl solutions as the control solutions. The Arecaceae extract from the fruit juice was added in volume percentages of 5%v/v and 10%v/v. The exposure time covered 12 days, and the monitored temperature range during the exposure time was 25-39°C. The result indicated that the most corrosive media were those without the Arecaceae inhibitor; where corrosion rate ranged from 0.106mpy to 0.409mpy. The medium carbon steel did not show any sign of corrosion in the 0.5M NaOH solution. Arecaceae inhibitor addition of 5%v/v gave optimum corrosion rate reduction; the corrosion rate was in the range of 0.018mpy to 0.199mpy. Although the lowest range of 0.013mpy to 0.192mpy was obtained with 10%v/v of Arecaceae, however on the overall performance the 5%v/v of Arecaceae was better. The inhibition of corrosion by Arecaceae was as a result of adsorption and phase layers on the surface of the metals.

  17. Copper corrosion inhibition in O{sub 2}-saturated H{sub 2}SO{sub 4} solutions

    Energy Technology Data Exchange (ETDEWEB)

    Amin, Mohammed A. [Materials and Corrosion Lab (MCL), Department of Chemistry, Faculty of Science, Taif University, 888 Hawiya, KSA (Egypt); Chemistry Department, Faculty of Science, Ain Shams University, Abbassia, Cairo (Egypt)], E-mail: maaismail@yahoo.com; Khaled, K.F. [Materials and Corrosion Lab (MCL), Department of Chemistry, Faculty of Science, Taif University, 888 Hawiya, KSA (Egypt); Electrochemistry Research Laboratory, Faculty of Education, Ain Shams University, Roxy, Cairo (Egypt)

    2010-04-15

    Corrosion inhibition of copper in O{sub 2}-saturated 0.50 M H{sub 2}SO{sub 4} solutions by four selected amino acids, namely glycine (Gly), alanine (Ala), valine (Val), or tyrosine (Tyr), was studied using Tafel polarization, linear polarization, impedance, and electrochemical frequency modulation (EFM) at 30 deg. C. Protection efficiencies of almost 98% and 91% were obtained with 50 mM Tyr and Gly, respectively. On the other hand, Ala and Val reached only about 75%. Corrosion rates determined by the Tafel extrapolation method were in good agreement with those obtained by EFM and an independent chemical (i.e., non-electrochemical) method. The chemical method of confirmation of the corrosion rates involved determination of the dissolved Cu{sup 2+}, using ICP-AES (inductively coupled plasma atomic emission spectrometry) method of chemical analysis. Nyquist plots exhibited a high frequency depressed semicircle followed by a straight line portion (Warburg diffusion tail) in the low-frequency region. The impedance data were interpreted according to two suitable equivalent circuits. The kinetics of dissolved O{sub 2} reduction and hydrogen evolution reactions on copper surface were also studied in O{sub 2}-saturated 0.50 M H{sub 2}SO{sub 4} solutions using polarization measurements combined with the rotating disc electrode (RDE). The Koutecky-Levich plot indicated that the dissolved O{sub 2} reduction at the copper electrode was an apparent 4-electron process.

  18. Synergistic effects of sodium lauroyl sarcosinate and glutamic acid in inhibition assembly against copper corrosion in acidic solution

    Science.gov (United States)

    Yu, Yinzhe; Zhang, Daquan; Zeng, Huijing; Xie, Bin; Gao, Lixin; Lin, Tong

    2015-11-01

    A self-assembled multilayer (SAM) from sodium lauroyl sarcosinate (SLS) and glutamic acid (GLU) is formed on copper surface. Its inhibition ability against copper corrosion is examined by electrochemical analysis and weight loss test. In comparison to SAM formed by just SLS or GLU, a synergistic effect is observed when the coexistence of SLS and GLU in SAM. The SLS/GLU SAM has an acicular multilayer structure, and SAM prepared under the condition of 5 mM SLS and 1 mM GLU shows the best protection efficiency. PM6 calculation reveals that the synergistic effect stems from interactions between SLS, GLU and cupric ions.

  19. Synergistic inhibition effect of benzotriazole (BTA) and oxalate ions on the corrosion of copper, zinc and brass in NaCl and HCl solutions

    Energy Technology Data Exchange (ETDEWEB)

    Yanardag, T.; Aksut, A.A. [Ankara Univ., Science Faculty, Dept. of Chemistry, Ankara (Turkey)

    2009-07-01

    Inhibition of corrosion is of high technological importance and progress made in this field has been phenomenal in recent years. Zinc is more active compared to copper. Copper is a valuable material, especially in electronics, solar cell fittings, household products, structural engineering, art and decoration, coinage and biomedical application. Even though copper is corrosion resistant due to its natural oxide film, it is prone to corrode in solutions that contain oxygen and high concentration of chloride, sulphate, sulphide and nitrate ions. A variety of potentially damaging environments require versatile inhibition actions. Although an inhibitor is sometimes added to avoid tarnishing, in the majority of cases the inhibitor's purpose is to prevent or postpone corrosion attack. The corrosion inhibition of copper, zinc and brass in 0.5 M NaCl and 0.5 M HCl solutions in the presence of BTA and sodium oxalate have been investigated using polarization, AC-impedance and current-potential methods. Inhibition effect depends to the pretreatment of electrode. For this reason, the electrodes were pretreated in 0.15 M HCl solution for 20 seconds in order to obtain better surface prone to form coatings on the electrode surface before immersing into the studied solutions. Results showed BTA and oxalate to have synergistic inhibition effect on the corrosion of copper and brass. All the methods employed showed good correlation between each other revealing a mean efficiency of 99% in neutral medium and 88% in acidic medium for brass. (authors)

  20. Investigation of adsorption and inhibitive effect of acid red GRE (183 dye on the corrosion of carbon steel in hydrochloric acid media

    Directory of Open Access Journals (Sweden)

    M. Abd El-raouf

    2015-09-01

    Full Text Available The adsorption and corrosion inhibitive effect of acid red GRE (183 dye on carbon steel alloy in 1 M HCl solutions was studied using various techniques. Results of weight loss, Tafel polarization measurements and electrochemical impedance spectroscopy (EIS techniques show that this compound has fairly good inhibiting properties for steel corrosion in acidic bath; with efficiency around 96% at a concentration of 50 ppm. The inhibition is of a mixed anodic–cathodic nature. Factors affecting the corrosion process have been calculated and discussed. Acid red GRE (183 dye was shown to be an inhibitor in the acidic corrosion. Inhibition efficiency increased with acid red GRE (183 dye concentration but decreased with rise in temperature, corrosion inhibition is attributed to the adsorption of acid red GRE (183 dye on the carbon steel surface via a physical adsorption mechanism. Langmuir isotherm is found to provide an accurate description of the adsorption behavior of the investigated azo compound. The nature of the protective film was investigated using SEM and EDX techniques.

  1. Corrosion inhibition of cobalt with a thin film of Cu-BTA

    Energy Technology Data Exchange (ETDEWEB)

    Brusic, V.; Frankel, G.S.; Schrott, A.G.; Petersen, T.A. (Thomas J. Watson Research Center, Yorktown Heights, NY (United States). IBM Research Division); Rush, B.M. (Univ. of California, Berkeley, CA (United States). Dept. of Chemical Engineering)

    1993-09-01

    Electrochemical techniques, ellipsometry and X-ray photoelectron spectroscopy were used to evaluate the use of benzotriazole, alone or in combination with boric acid/borate buffer and dilute copper sulfate for the protection of cobalt. The data indicate that in slightly alkaline solutions benzotriazole is a strong inhibitor for cobalt corrosion, whereas in water and neutral solutions it produces a barely measurable effect. In the presence of benzotriazole and Cu[sup +2] ions, spontaneous reduction of copper ions leads to the formation of a thin film of Cu-BTA on the cobalt surface. This film acts as a corrosion protector that is better than benzotriazole, with a significant reduction of the corrosion rate even during subsequent exposure to solutions without inhibitors.

  2. Principles of inhibiting of corrosion-static crack growth in constructional steels caused by hydrogen embrittlement

    Energy Technology Data Exchange (ETDEWEB)

    Romaniv, O.N.; Nikiforchin, G.N.; Tsirul' nik, A.T.

    1987-11-01

    The effectiveness of a range of organic and inorganic corrosion inhibitors was studied on a series of structural chromium steels--including 45KhN2MFA, 60KhS, and 30KhGSN2A--of different strength levels and certain principles are formulated for developing and selecting inhibitors based on the hydrogen mechanism of corrosive media. The inhibitors tested include monoethanol amine, urotropin, sodium benzoate, thiourea, sodium phosphates and chromates, various nitrates, and the IRT range of inhibitors.

  3. Inhibition of corrosion of zinc by Cr(VI)and Cr(III) treatments

    NARCIS (Netherlands)

    Zhang, X.; Bos, C. van den; Hovestad, A.; Terryn, H.; Wit, J.H.W. de

    2007-01-01

    The corrosion behavior of Cr(VI) and Cr(III) treated zinc has been studied using scanning Kelvin probe (SKP), potentiodynamic polarization and elctrochemical impedance spectroscopy (EIS). The Volta potentials measured on the Cr(VI) or the CR(III)-A treated zinc area by SKP in a humid chamber are

  4. Inhibition of corrosion of zinc by Cr(VI)and Cr(III) treatments

    NARCIS (Netherlands)

    Zhang, X.; Bos, C. van den; Hovestad, A.; Terryn, H.; Wit, J.H.W. de

    2007-01-01

    The corrosion behavior of Cr(VI) and Cr(III) treated zinc has been studied using scanning Kelvin probe (SKP), potentiodynamic polarization and elctrochemical impedance spectroscopy (EIS). The Volta potentials measured on the Cr(VI) or the CR(III)-A treated zinc area by SKP in a humid chamber are mor

  5. Intergranular stress corrosion cracking of type 304 stainless steels treated with inhibitive chemicals in high temperature pure water

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, T.K. [Nuclear Science and Technology Development Center, National Tsing-Hua Univ. Taiwan (China); Lee, M.Y.; Tsai, C.H. [Department of Engineering and System Science, National Tsing-Hua Univ. Taiwan (China)

    2002-07-01

    Electrochemical potentiodynamic polarizations, electrochemical corrosion potential (ECP) measurements and slow strain rate tensile (SSRT) tests were conducted to investigate the intergranular stress corrosion cracking (IGSCC) characteristics of Type 304 stainless steels treated with inhibitive chemicals in simulated boiling water reactor (BWR) environments. A number of thermally sensitized specimens were prepared and were pre-oxidized in a 288 C environment with the presence of 300 ppb dissolved oxygen for 360 hours. Most of the specimens were then treated with various chemicals including powdered zirconium oxide (ZrO{sub 2}), powdered titanium oxide (TiO{sub 2}), and zirconyl nitrate [ZrO(NO{sub 3}){sub 2}] via static immersion at 90 C, 150 C, and 200 C. Test environments were specifically designed in a circulation loop to create a dissolved oxygen concentration of 300 ppb. Test results showed that the corrosion current densities of all treated specimens were lower than that of the untreated, pre-oxidized specimen at ambient temperature in a solution mixed with 1 mM K{sub 3}Fe(CN){sub 6} and 1 mM K{sub 4}Fe(CN){sub 6}. The ECPs of the treated specimens could be lower or higher than that of the pre-oxidized one at 288 C, depending upon the type of treating chemical and the treating temperature. In addition, IGSCC was observed on all specimens (treated or untreated) in the same environment. However, the untreated specimen exhibited lower elongation, shorter failure time, and more secondary cracks on the side surfaces. It was therefore suggested that inhibitive chemicals such as ZrO{sub 2}, TiO{sub 2}, and ZrO(NO{sub 3}){sub 2} did provide a certain degree of enhancement in improving the mechanical behavior of the treated specimens and in prolonging the IGSCC initiation time. (authors)

  6. Inhibition effect of 2-amino-5-ethyl-1, 3, 4-thiadiazole on corrosion behaviour of austenitic stainless steel type 304 in dilute HCl solution

    Institute of Scientific and Technical Information of China (English)

    Roland T Loto; Cleophas A Loto; Abimbola P Popoola; Tatiana Fedotova

    2016-01-01

    The corrosion inhibition of type 304 austenitic stainless steel by 2-amino-5-ethyl-1, 3, 4-thiadiazole (TTD) compound and the electrochemical behaviour in dilute HCl solution were investigated through potentiodynamic polarization test, mass loss techniques and potential measurements. The results show that the organic derivative is highly effective with a maximum inhibition efficiency of 70.22% from mass loss analysis, while 74.2% is obtained from polarization tests. Observation of the scanning electron micrographs shows the absence of corrosion products due to electrochemical influence of TTD on the surface morphology of the steel. X-ray diffractometry reveals the absence of phase compounds and complexes on the steel samples after exposure. TTD adsorption on the steel surface obeys the Langmuir, Frumkin and Freundlich adsorption isotherms. Corrosion thermodynamic calculations reveal the inhibition mechanism occurs through chemisorption process and results from statistical analysis depict the strong influence of inhibitor concentration on the electrochemical performance of the TTD.

  7. Corrosion inhibition of aluminum with a series of aniline monomeric surfactants and their analog polymers in 0.5 M HCl solution

    Directory of Open Access Journals (Sweden)

    M.M. El-Deeb

    2015-07-01

    Full Text Available The inhibition effect of 3-(12-sodiumsulfonate dodecyloxy aniline monomeric surfactant (MC12 and its analog polymer Poly 3-(dodecyloxy sulfonic acid aniline (PC12 on the corrosion of aluminum in 0.5 M HCl solution was investigated using weight loss and potentiodynamic polarization techniques. The presence of these two compounds in 0.5 M HCl inhibits the corrosion of aluminum without modifying the mechanism of corrosion process. It was found that these inhibitors act as mixed-type inhibitors with anodic predominance as well as the inhibition efficiency increases with increasing inhibitor concentration, but decreases with raising temperature. Langmuir and Frumkin adsorption isotherms fit well with the experimental data. Thermodynamic functions for both dissolution and adsorption processes were determined. The obtained results from weight loss and potentiodynamic polarization techniques are in good agreement with contact angle measurements.

  8. Studies of the corrosion inhibition of copper in Na{sub 2}SO{sub 4} solution using polarization and electrochemical impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Hamed, E., E-mail: dr_science_7@hotmail.com [Chemistry Department, Faculty of Science, Ain Shams University, Abbassia 11566, Cairo (Egypt)

    2010-05-15

    Inhibition effect of different concentrations of potassium folate (green inhibitor) on copper corrosion in aerated Na{sub 2}SO{sub 4} solutions in the temperature range (15-55 deg. C) was investigated by using potentiodynamic polarization and electrochemical impedance spectroscopy technique. The polarization curves showed that the addition of potassium folate inhibits copper corrosion as a result of physical adsorption of folate anions on the copper surface. The folate anion acts as an anodic-type inhibitor. The inhibition efficiency increases with increasing the folate anion concentration but decreases with increasing Na{sub 2}SO{sub 4} concentration and temperature. The adsorption of folate anions on copper surface follows Flory-Huggins isotherm and kinetic-thermodynamic model. The thermodynamic parameters for corrosion and adsorption processes in the absence and presence of the inhibitor were calculated and discussed. Effect of immersion time on the performance of the inhibitor was also tested in this investigation.

  9. Corrosion Inhibition Effect of 4-(2-Diethylamino-Ethylsulfonyl-Phthalonitrile and 4,5-Bis(Hexylsulfonyl-Phthalonitrile

    Directory of Open Access Journals (Sweden)

    Esma Sezer

    2011-01-01

    Full Text Available Inhibition of stainless steel corrosion in a 3.0 M NaCl solution by 4-(2-diethylamino-ethylsulfanyl-phthalonitrile (DAESPN and 4,5-bis(hexylsulfonyl-phthalonitrile (Bis-HSPN was investigated by polarization and electrochemical impedance spectroscopy (EIS measurements. The values of cathodic (βc and anodic (βa Tafel slopes, corr, corr, corrosion rate (CR, and inhibition efficiences (IE% obtained from polarization curves and polarization resistance (P, double-layer capacitance (dl, specific capacitance (sp values were obtained from EIS. Double-layer capacitance differences in the presence and absence of inhibitors were also obtained from EIS measurements as suggested in the literature in order to investigate the interaction of them with metal surface. Results show that both DAESPN and Bis-HSPN are effective in cathodic reaction. Impedance measurements suggest higher surface coverage for DAESPN. The interaction between the inhibitor and the stainless steel was investigated by the adsorption isotherm. Langmuir adsorption isotherm ads was applied and Δ values were obtained and found as 4.32×10−4, 1.17×10−4 and 9.2 kJ, 12.5 kJ for DAESPN and Bis-HSPN, respectively, which suggests the electrostatic interaction between charged metal surface and charged organic molecules.

  10. The Inhibition of Aluminum Corrosion in Sulfuric Acid by Poly(1-vinyl-3-alkyl-imidazolium Hexafluorophosphate

    Directory of Open Access Journals (Sweden)

    Paulina Arellanes-Lozada

    2014-08-01

    Full Text Available Compounds of poly(ionic liquids (PILs, derived from imidazole with different alkylic chain lengths located in the third position of the imidazolium ring (poly(1-vinyl-3-dodecyl-imidazolium (PImC12, poly(1-vinyl-3-octylimidazolium (PImC8 and poly(1-vinyl-3-butylimidazolium (PImC4 hexafluorophosphate were synthesized. These compounds were tested as corrosion inhibitors on aluminum alloy AA6061 in diluted sulfuric acid (0.1–1 M H2SO4 by weight loss tests, polarization resistance measurements and inductively coupled plasma optical emission spectroscopy. Langmuir’s isotherms suggested film formation on bare alloy while standard free energy indicated inhibition by a physisorption process. However, compound efficiencies as inhibitors ranked low (PImC12 > PImC8 > PImC4 to reach 61% for PImC12 in highly diluted acidic solution. Apparently, the high mobility of sulfates favored their adsorption in comparison to PILs. The surface film displayed general corrosion, and pitting occurred as a consequence of PILs’ partial inhibition along with a continuous dissolution of defective patchy film on formation. A slight improvement in efficiency was displayed by compounds having high molecular weight and a long alkyl chain, as a consequence of steric hindrance and PIL interactions.

  11. Experimental and atomistic simulation studies of corrosion inhibition of copper by a new benzotriazole derivative in acid medium

    Energy Technology Data Exchange (ETDEWEB)

    Khaled, K.F. [Electrochemistry Research Laboratory, Chemistry Department, Ain Shams University, Roxy, Cairo 11711 (Egypt)], E-mail: khaledrice2003@yahoo.com

    2009-07-15

    The efficiency of N-(2-thiazolyl)-1H-benzotriazole-1-carbothioamide (TBC) as a non-toxic corrosion inhibitor for copper in 0.5 M HCl has been tested by weight loss and electrochemical techniques. Electrochemical techniques show that TBC is a mixed-type inhibitor and its inhibition mechanism on copper surface is adsorption assisted by H-bond formation. Impedance measurements show a wide peak presumably given by more than one time constant in the presence of TBC. Also, impedance results show that the values of CPEs (constant phase elements) tend to decrease and both polarization resistance and inhibition efficiency tend to increase with increasing of TBC concentration due to an increase in the electric double layer. Monte Carlo simulations incorporating molecular mechanics and molecular dynamics show that the TBC adsorb on the copper surface firmly through the thiazolyl and carbothioamide groups, the adsorption energy as well as hydrogen bond length have been calculated for both TBC and benzotriazole (BTA) for comparison. Quantum chemical calculations reveal that TBC has higher HOMO, lower LUMO, lower energy gap and lower dipole moment ({mu}) than BTA, which proves that TBC is better copper corrosion inhibitor compared with BTA in 0.5 M HCl.

  12. Synthesis of Four Triazole Compounds and Their Corrosion Inhibitive Effect on Carbon Steel in Hydrochloric Acid Medium

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiao-Ru; XU Min-Hua; ZHANG Shu-Sheng

    2008-01-01

    Four new 1,2,3-triazoles (3a, 3b, 4a and 4b) have been synthesized selectively via click chemistry approach and characterized by elemental analysis, IR, 1H NMR, 13C NMR and single crystal X-ray crystallographic analysis. The inhibiting action of these compounds against the corrosion of carbon steel in 1.0 mol/L HCI solution was investigated by electrochemical techniques including polarization and electrochemical impedance spectroscopy (EIS), both results of which indicate that these compounds act as good anodic inhibitors. The electrochemical study also shows that 4b is the best inhibitor among the four compounds in this work and its efficiency increases with concentration.The obtained highest IE (inhibition efficiency) of 4b is around 97%.

  13. Inhibition of Mild Steel Corrosion in 1M H2SO4 Medium by Benzimidazole Mannich bases

    Directory of Open Access Journals (Sweden)

    P. M. Dasami

    2015-03-01

    Full Text Available The corrosion inhibition behaviour of two synthesized Mannich bases has been investigated for mild steel in 1M H2SO4 by weight loss and electrochemical techniques.The inhibition efficiency depends on concentration of the inhibitor and temperature. The inhibitors function by adsorption on mild steel surface and obey Langmuir isotherm indicating monolayer adsorption on the surface. Thermodynamic parameters show that the adsorption of the inhibitors occurs through electrostatic interaction. Polarization studies reveal that the inhibitors behave as mixed type in 1M H2SO4 affecting both anodic metal dissolution and cathodic hydrogen evolution. SEM studies show the formation of surface adsorptive film of the Mannich bases on the mild steel surface.

  14. 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。

  15. Corrosion Inhibition Propargyl Alcohol on Low Alloy Cr Steel in 0.5 M H2SO4 in the Absence and Presence of Potassium Iodide

    OpenAIRE

    Baghaei Ravari, Fatemeh; Heydari, Mahdi; Dadgarineghad, Athareh

    2011-01-01

    The corrosion and inhibition behaviors of low alloy Cr steel in sulfuric acid in the presence of propargyl alcohol (PA) and potassium iodide (KI) have been studied using Electrochemical Impedance Spectroscopy (EIS) and Tafel polarization method. It was found that the inhibition efficiency increased with PA concentration. The addition of potassium iodide to propargyl alcohol in solution increased the inhibition efficiency of propargyl alcohol. A synergistic effect was observed between KI and P...

  16. Corrosion Inhibition Propargyl Alcohol on Low Alloy Cr Steel in 0.5 M H2SO4 in the Absence and Presence of Potassium Iodide

    OpenAIRE

    Baghaei Ravari, Fatemeh; Heydari, Mahdi; Dadgarineghad, Athareh

    2010-01-01

    The corrosion and inhibition behaviors of low alloy Cr steel in sulfuric acid in the presence of propargyl alcohol (PA) and potassium iodide (KI) have been studied using Electrochemical Impedance Spectroscopy (EIS) and Tafel polarization method. It was found that the inhibition efficiency increased with PA concentration. The addition of potassium iodide to propargyl alcohol in solution increased the inhibition efficiency of propargyl alcohol. A synergistic effect was observed between KI and P...

  17. An overview of NiTi shape memory alloy: Corrosion resistance and antibacterial inhibition for dental application

    Energy Technology Data Exchange (ETDEWEB)

    Fadlallah, Sahar A., E-mail: sahar.fadlallah@yahoo.com [Materials and Corrosion Lab. (MCL), Faculty of Science, Taif University, Taif (Saudi Arabia); Chemistry Department, Faculty of Science, Cairo University, Cairo (Egypt); El-Bagoury, Nader [Materials and Corrosion Lab. (MCL), Faculty of Science, Taif University, Taif (Saudi Arabia); Casting Technology Lab., Manufacturing Technology Dept., CMRDI, P.O. Box 87, Helwan, Cairo (Egypt); Gad El-Rab, Sanaa M.F. [Biotechnology Department, Faculty of Science, Taif University, Taif (Saudi Arabia); Botany Department, Faculty of Science, Asuit University, Asuit (Egypt); Ahmed, Rasha A. [Materials and Corrosion Lab. (MCL), Faculty of Science, Taif University, Taif (Saudi Arabia); Forensic Chemistry Laboratories, Medico Legal Department, Ministry of Justice, Cairo (Egypt); El-Ousamii, Ghaida [Materials and Corrosion Lab. (MCL), Faculty of Science, Taif University, Taif (Saudi Arabia)

    2014-01-15

    Highlights: • Evaluate the corrosion resistance of NiTi alloy by using electrochemical techniques. • Estimate the Antibacterial inhibition rate of NiTi alloy. • Assessment the mechanical properties of NiTi from the hardness measurements. • Comparsion the microstructures of cast NiTi with Ti, this indicate the role of Ni to change the behavior of alloy in oral environment. • Advise drinking green tea in small quantities in small quantities in the event of present NiTi alloy in the oral cavity. • Recommendation to use NiTi for dental application. -- Abstract: Nowadays, Nickel–titanium nearly equiatomic is considered as one of the best biomaterials. The aim of the present work deals with the evolution of the electrochemical behavior of NiTi in simulated oral environment. The hardness, microstructures corrosion resistance and antibacterial performance of NiTi alloy were compared with pure titanium. The hardness of NiTi is twice the hardness of pure titanium. Electrochemical techniques were used to detect the corrosion resistance of both biomaterials in Hank’s solution containing (−)-epigallocatechin gallate (EGCG) which used to simulate the oral environment. In the physiological solution selected for the present study, the impedance spectroscopy (EIS) results showed that EGCG sharply increase the corrosion resistance of NiTi from 129 kΩ cm{sup 2} to 1.10 T Ω cm{sup 2} while slowly increase the corrosion resistance of pure titanium from 9.4 kΩ cm{sup 2} to 11.3 kΩ cm{sup 2} during the duration time of immersion at 37 °C. The plate-counting method was used to evaluate the antibacterial performance against Staphylococcus aureus (ATCC 6538). Among the two specimens of biomaterials studied, the antibacterial performance results revealed that the NiTi alloy is better than the pure titanium. The morphology and chemical structure of NiTi and Ti samples were systematically investigated by scanning electron microscope (SEM) and energy dispersive X

  18. Inhibitive action of Cystine on the corrosion of low alloy steel ASTM A213 grade T22 in sulfamic acid solutions

    Directory of Open Access Journals (Sweden)

    Sayed S. Abd El Rehim

    2016-09-01

    Full Text Available The effect of Cystine on the corrosion behavior of low alloy steel ASTM A213 grade T22 in 0.5 M sulfamic acid solutions have been investigated by various electrochemical techniques. The study was performed using electrochemical impedance spectroscopy (EIS and the recent technique electrochemical frequency modulation (EFM. The results of the investigation show that the inhibition efficiency increased with increasing inhibitor concentration, but decreased with increasing the solution temperature and stirring velocity. All the collected results from the two techniques are in good agreements, which confirm the ability of EFM technique for monitoring the corrosion inhibition under the studied conditions.

  19. Sol-gel hybrid films based on organosilane and montmorillonite for corrosion inhibition of AA2024.

    Science.gov (United States)

    Dalmoro, V; dos Santos, J H Z; Armelin, E; Alemán, C; Azambuja, D S

    2014-07-15

    The present work reports the production of films on AA2024-T3 composed of vinyltrimethoxysilane (VTMS)/tetraethylorthosilicate (TEOS) with incorporation of montmorillonite (sodium montmorillonite and montmorillonite modified with quaternary ammonium salt, abbreviated Na and 30B, respectively), generated by the sol-gel process. According to FT-IR analyses the incorporation of montmorillonite does not affect silica network. Electrochemical characterization was performed by electrochemical impedance spectroscopy measurement in 0.05 mol L(-1) NaCl solution. Results indicate that montmorillonite incorporation improves the corrosion protection compared to the non-modified system. Scanning electron microscopy micrographs reveal that high concentrations of montmorillonite provide agglomerations on the metallic surface, which is in detriment of the anticorrosive performance. The VTMS/TEOS/30B films with the lowest concentration (22 mg L(-1)) of embedded clay provide the highest corrosion protection.

  20. Inhibition Effects of a Synthesized Novel 4-Aminoantipyrine Derivative on the Corrosion of Mild Steel in Hydrochloric Acid Solution together with Quantum Chemical Studies

    Directory of Open Access Journals (Sweden)

    Abu Bakar Mohamad

    2013-06-01

    Full Text Available 1,5-Dimethyl-4-((2-methylbenzylideneamino-2-phenyl-1H-pyrazol-3(2H-one (DMPO was synthesized to be evaluated as a corrosion inhibitor. The corrosion inhibitory effects of DMPO on mild steel in 1.0 M HCl were investigated using electrochemical impedance spectroscopy (EIS, potentiodynamic polarization, open circuit potential (OCP and electrochemical frequency modulation (EFM. The results showed that DMPO inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiency increased with increasing inhibitor concentration. Changes in the impedance parameters suggested an adsorption of DMPO onto the mild steel surface, leading to the formation of protective films. The novel synthesized corrosion inhibitor was characterized using UV-Vis, FT-IR and NMR spectral analyses. Electronic properties such as highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy (EHOMO and ELUMO, respectively and dipole moment (μ were calculated and discussed. The results showed that the corrosion inhibition efficiency increased with an increase in the EHOMO values but with a decrease in the ELUMO value.

  1. Experimental and theoretical investigations on the inhibition of mild steel corrosion in the ground water medium using newly synthesised bipodal and tripodal imidazole derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Gopi, D., E-mail: dhanaraj_gopi@yahoo.com [Department of Chemistry, Periyar University, Salem 636 011, Tamilnadu (India); Centre for Nanoscience and Nanotechnology, Periyar University, Salem 636 011, Tamilnadu (India); Sherif, El-Sayed M. [Center of Excellence for Research in Engineering Materials (CEREM), Advanced Manufacturing Institute, King Saud University, P.O. Box 800, Al-Riyadh 11421 (Saudi Arabia); Electrochemistry and Corrosion Laboratory, Department of Physical Chemistry, National Research Centre (NRC), Dokki, 12622 Cairo (Egypt); Surendiran, M. [Department of Chemistry, Periyar University, Salem 636 011, Tamilnadu (India); Jothi, M.; Kumaradhas, P. [Department of Physics, Periyar University, Salem 636 011, Tamilnadu (India); Kavitha, L. [Department of Physics, School of Basic and Applied Sciences, Central University of Tamilnadu, Thiruvarur 610 101, Tamilnadu (India)

    2014-10-15

    Two new imidazole derivatives, namely 1,4-bis(N-imidazolylmethyl)-2-5-dimethoxybenzene (BIDM) and 1,3,5-tris(N-imidazolylmethyl)-2,4,6-trimethoxybenzene (TITM), were synthesised and their effects on the inhibition of mild steel corrosion in ground water medium are reported. The study was carried out using gravimetric and electrochemical techniques in order to determine the corrosion inhibition efficiencies of the bipodal and tripodal structured imidazoles. Further, the quantum chemical calculations using density functional theory (DFT) gave a profound insight into the inhibitory action mechanism of BIDM and TITM and their calculation parameters, such as E{sub HOMO}, E{sub LUMO} and ΔE were in good agreement with the results of the experimental studies. BIDM and TITM exhibited lowest corrosion current densities of circa 7.5 μA cm{sup −2} and 4.1 μAcm{sup −2} at the optimum concentrations of 0.67 and 0.49 mM, respectively. All measurements thus confirmed that both BIDM and TITM behaved as good inhibitors for mild steel corrosion in ground water medium. - Highlights: • Synthesis of new imidazole derivatives-BIDM(bipodal) and TITM(tripodal) inhibitors. • Gravimetric analysis to investigate mild steel corrosion inhibition in ground water. • Electrochemical characterizations to substantiate results of weight loss method. • Quantum studies to analyse the chemical behavior, structure and substituent effect.

  2. Inhibition effects of a synthesized novel 4-aminoantipyrine derivative on the corrosion of mild steel in hydrochloric acid solution together with quantum chemical studies.

    Science.gov (United States)

    Junaedi, Sutiana; Al-Amiery, Ahmed A; Kadihum, Abdulhadi; Kadhum, Abdul Amir H; Mohamad, Abu Bakar

    2013-06-04

    1,5-Dimethyl-4-((2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-one (DMPO) was synthesized to be evaluated as a corrosion inhibitor. The corrosion inhibitory effects of DMPO on mild steel in 1.0 M HCl were investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). The results showed that DMPO inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiency increased with increasing inhibitor concentration. Changes in the impedance parameters suggested an adsorption of DMPO onto the mild steel surface, leading to the formation of protective films. The novel synthesized corrosion inhibitor was characterized using UV-Vis, FT-IR and NMR spectral analyses. Electronic properties such as highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy (EHOMO and ELUMO, respectively) and dipole moment (μ) were calculated and discussed. The results showed that the corrosion inhibition efficiency increased with an increase in the EHOMO values but with a decrease in the ELUMO value.

  3. Modeling corrosion inhibition efficacy of small organic molecules as non-toxic chromate alternatives using comparative molecular surface analysis (CoMSA).

    Science.gov (United States)

    Fernandez, Michael; Breedon, Michael; Cole, Ivan S; Barnard, Amanda S

    2016-10-01

    Traditionally many structural alloys are protected by primer coatings loaded with corrosion inhibiting additives. Strontium Chromate (or other chromates) have been shown to be extremely effectively inhibitors, and find extensive use in protective primer formulations. Unfortunately, hexavalent chromium which imbues these coatings with their corrosion inhibiting properties is also highly toxic, and their use is being increasingly restricted by legislation. In this work we explore a novel tridimensional Quantitative-Structure Property Relationship (3D-QSPR) approach, comparative molecular surface analysis (CoMSA), which was developed to recognize "high-performing" corrosion inhibitor candidates from the distributions of electronegativity, polarizability and van der Waals volume on the molecular surfaces of 28 small organic molecules. Multivariate statistical analysis identified five prototypes molecules, which are capable of explaining 71% of the variance within the inhibitor data set; whilst a further five molecules were also identified as archetypes, describing 75% of data variance. All active corrosion inhibitors, at a 80% threshold, were successfully recognized by the CoMSA model with adequate specificity and precision higher than 70% and 60%, respectively. The model was also capable of identifying structural patterns, that revealed reasonable starting points for where structural changes may augment corrosion inhibition efficacy. The presented methodology can be applied to other functional molecules and extended to cover structure-activity studies in a diverse range of areas such as drug design and novel material discovery. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Application of Mössbauer spectroscopy to the study of tannins inhibition of iron and steel corrosion

    Science.gov (United States)

    Jaén, Juan A.; de Obaldía, J.; Rodríguez, M. V.

    2011-11-01

    The inhibitory effect of tannins was investigated using, among others, potentiodynamic polarizations and Mössbauer spectroscopy. These techniques confirmed that the nature, pH and concentration of tannic solution are of upmost importance in the inhibitory properties of the solutions. It is observed that at low tannin concentration or pH, both, hydrolizable and condensed tannins, effectively inhibit iron corrosion, due to the redox properties of tannins. At pH ≈ 0, Mössbauer spectra of the frozen aqueous solutions of iron(III) with the tannin solutions showed that iron is in the form of a monomeric species [Fe(H2O)6]3 + , without coordination with the functional hydroxyl groups of the tannins. The suspended material consisted of amorphous ferric oxide and oxyhydroxides, though with quebracho tannin partly resulted in complex formation and in an iron (II) species from a redox process. Other tannins, such as chestnut hydrolysable tannins, do not complex iron at this low pH. Tannins react at high concentrations or pH (3 and 5) to form insoluble blue-black amorphous complexes of mono-and bis-type tannate complexes, with a relative amount of the bis-ferric tannate generally increasing with pH. Some Fe2 + in the form of hydrated polymeric ferrous tannate could be obtained. At pH 7, a partially hydrolyzed ferric tannate complex was also formed. The latter two phases do not provide corrosion protection. Tannin solutions at natural pH react with electrodeposited iron films (approx. 6 μm) to obtain products consisting only on the catecholate mono-complex of ferric tannate. Some aspects of the mechanism of tannins protection against corrosion are discussed.

  5. Corrosion inhibition of carbon steel pipelines by some novel Schiff base compounds during acidizing treatment of oil wells studied by electrochemical and quantum chemical methods

    Science.gov (United States)

    Abd El-Lateef, Hany M.; Abu-Dief, Ahmed M.; Mohamed, Mounir A. A.

    2017-02-01

    Three novel Schiff bases compounds were prepared and their structures were characterized by X-ray, 13C-NMR, 1H-NMR, mass, UV-Vis, FT-IR, spectral data and elemental analyses. The corrosion inhibition of the investigated inhibitors towards carbon steel in 15% HCl was investigated by using electrochemical measurements (EIS, LPR corrosion rate and Tafel plots), SEM, EDX and quantum chemical methods. The results showed that, the inhibitors are efficient mixed type corrosion inhibitors, and their inhibition performance increased with the rise of inhibitor concentration and temperature. The adsorption of the inhibitors on steel surface was found to obey Langmuir's adsorption isotherm and chemisorption. Quantum chemical calculations provide good support to empirical results.

  6. Physicochemical Characterization and Corrosion Inhibition Potential of Ficus benjamina (FB Gum for Aluminum in 0.1 M HCl

    Directory of Open Access Journals (Sweden)

    Nnabuk Okon EDDY

    2014-09-01

    Full Text Available Examination of the physical (colour, odour, pH, solubility in various solvent and chemical (GCMS and FTIR characteristics of Ficus benjamina gum revealed that the gum is yellowish in colour, mildly acidic and ionic in nature. Major constituents of the gums were found to be sucrose and d-glucose, which constituted 60.92 % of its chemical constituents while various carboxylic acids (albietic acid (1.00 %; hexadecanoic acid (4.41 %; 9-octadecanoic acid (1.00 %, stearic acid (3.01 %; oleic acid (0.10 %; octadecanoic acid (9.12 % and 6,13-pentacenequinone (20.43 % accounted for the remaining constituents. Functional groups identified in the gum were found to be those typical for other carbohydrates. From the knowledge of the chemical structures of compounds that constitutes the gum, the corrosion inhibition potentials of the gum was ascertained and from weight loss analysis, the gum was found to be an active inhibitor against the corrosion of aluminum in solutions of tetraoxosulphate (VI acid. The gum acted as an adsorption inhibitor that favours the mechanism of chemical adsorption and supported the Frumkin and Dubinin-Radushkevich adsorption models.

  7. Use of chlorine dioxide in a secondary recovery process to inhibit bacterial fouling and corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Knickrehm, M.; Caballero, E.; Romualdo, P.; Sandidge, J.

    1987-01-01

    A major oil company operates a secondary recovery waterflood in Inglewood, California. The waterflood currently processes 250,000 bbls. per day of produced fluid. The major economic and operational problems associated with a secondary recovery waterflood are: 1) corrosion due to oxygen, carbon dioxide, hydrogen sulfide, and bacteria (sulfate reducers and slime biomass), 2) plugging from deposits due to salts, sulfides, and biofilms. These problems lead to deterioration of water handling equipment, injection lines (surface and subsurface), and decreased water quality resulting in the plugging of injection wells. During the last 8 years the operator has used varying mechanical and chemical technology to solve these problems. From 1978 to 1982 traditional chemical programs were in effect. Over this time period there was a continuing decline in water quality, and a substantial increase in chemical and operational costs. It was determined at that time that the major reason for this was due to microbiological activity. With this in mind, the operator proceeded to test the effects of using Aqueous Chlorine Dioxide in one portion of their water handling facilities. Due to the success of the program it was applied field wide. Presently, the primary problems associated with bacteria have been arrested. Solving one corrosion problem can lead to the onset of another. The operator is now in the process of making a concentrated effort to eliminate the other synergistically related corrosive and plugging agents (O/sub 2/, CO/sub 2/, H/sub 2/S). A field history of the problems, findings, and solutions, are discussed along with an overview of our present direction.

  8. INHIBITION OF STRESS CORROSION CRACKING OF CARBON STEEL STORAGE TANKS AT HANFORD

    Energy Technology Data Exchange (ETDEWEB)

    BOOMER, K.D.

    2007-01-31

    The stress corrosion cracking (SCC) behavior of A537 tank steel was investigated in a series of environments designed to simulate the chemistry of legacy nuclear weapons production waste. Tests consisted of both slow strain rate tests using tensile specimens and constant load tests using compact tension specimens. Based on the tests conducted, nitrite was found to be a strong SCC inhibitor. Based on the test performed and the tank waste chemistry changes that are predicted to occur over time, the risk for SCC appears to be decreasing since the concentration of nitrate will decrease and nitrite will increase.

  9. Benzimidazole ligands in the corrosion inhibition for carbon steel in acid medium: DFT study of its interaction on Fe30 surface

    Science.gov (United States)

    Garcia-Ochoa, E.; Guzmán-Jiménez, S. J.; Hernández, J. Guadalupe; Pandiyan, Thangarasu; Vásquez-Pérez, José M.; Cruz-Borbolla, Julián

    2016-09-01

    The corrosion inhibition of N,N‧-bis(benzimidazole-2-yl-methyl)amine (L1) and N, N‧-bis(benzimidazole-2-yl-methyl)hydroxyethylamine (L2) was analyzed by electrochemical and theoretical methods. The data show that ligands form an adsorption layer over an iron surface, obeying the Langmuir isotherm (Δ Gads° of -32.96 kJ mol-1); the value are higher than -20 kJ mol-1 but less than -40 kJ mol-1, belonging to a conversion stage of physical adsorption to chemical adsorption or a comprehensive adsorption. This is consistent with fractal dimension of the electrode surface, estimated by an impedance depression angle of a semicircle that the surface is homogeneously covered by the formation of an inhibitor film. Furthermore, the electronic parameters of the ligands were analyzed by DFT, showing that L1 and L2 possesses corrosion inhibition properties that give up its p orbital electron density through its HOMO orbital to the metal LUMO to form an adsorption layer, and this has been proved theoretically by the interaction of ligands with Fe30. In addition, we have collected corrosion inhibition data for around 70 organic compounds reported in the literature, and the inhibition data plotted against different inhibitors, showing that amine ligands are good corrosion inhibitors.

  10. QSAR, DFT and quantum chemical studies on the inhibition potentials of some carbozones for the corrosion of mild steel in HCl.

    Science.gov (United States)

    Eddy, Nnabuk O; Ita, Benedict I

    2011-02-01

    Experimental aspects of the inhibition of the corrosion of mild steel in HCl solutions by some carbozones were studied using gravimetric, thermometric and gasometric methods, while a theoretical study was carried out using density functional theory, a quantitative structure-activity relation, and quantum chemical principles. The results obtained indicated that the studied carbozones are good adsorption inhibitors for the corrosion of mild steel in HCl. The inhibition efficiencies of the studied carbozones were found to increase with increasing concentration of the respective inhibitor. A strong correlation was found between the average inhibition efficiency and some quantum chemical parameters, and also between the experimental and theoretical inhibition efficiencies (obtained from the quantitative structure-activity relation).

  11. Investigation of the Corrosion Inhibition of CTAB and SDS on Carbon Steel Using an Experimental Design Strategy

    Science.gov (United States)

    Arjmand, Farzin; Wang, Jiamei; Zhang, Lefu

    2016-03-01

    The corrosion inhibition performance of sodium dodecyl sulfate (SDS) and cetyltrimethyl ammonium bromide (CTAB) on carbon steel was investigated in sodium chloride solutions. Using an experimental design strategy pH, chloride concentration, SDS/CTAB concentrations, and temperature were optimized by conducting only 30 experiments. The optimum value of each factor was obtained from the designed matrix of the experiments based on the lowest log I corr value calculated for each experimental condition. The 3D surface plots of the electrochemical response (log I corr) against each factor were constructed. The optimum conditions in which the lowest log I corr can be achieved were found as follows: pH 12, [Cl-] ≈ 1 M, [SDS] ≈ 200 ppm, [CTAB] ≈ 20 ppm, and T ≈ 10 °C.

  12. Computational study of some triazole derivatives (un- and protonated forms) and their copper complexes in corrosion inhibition process

    Science.gov (United States)

    El Ibrahimi, Brahim; Soumoue, Aziza; Jmiai, Aziz; Bourzi, Hassan; Oukhrib, Rachid; El Mouaden, Khadija; El Issami, Souad; Bazzi, Lahcen

    2016-12-01

    Three triazoles compounds used as corrosion inhibitors for copper in acidic medium, namely: 1,2,4 triazole (TR), 3-amino 1,2,4 triazole (3 ATR) and 3,5-diamino 1,2,4 triazole (3,5 DATR) have been studied theoretically in aim to investigate the correlation between its molecular reactivity indicators and the corresponding inhibition efficiency. All quantum chemical calculations at the B3LYP/6-31+G(d,p) method were performed with and without solvent effect. In the present paper, not only the neutral inhibitors has been studied, but also the first and the second protonation forms. A good correlation between theoretical and experimental data has been obtained both in gas and aqueous phases, notably for unprotonated inhibitors. Also, the interaction energy between inhibitors and copper has been calculated.

  13. THERMODYNAMIC PROPERTIES AND CHARACTERIZATIONS OF CHITOSAN NANO-PARTICLES CORROSION INHIBITION ON THE SURFACE OF MILD STEELIN PEAT WATER MEDIA

    Directory of Open Access Journals (Sweden)

    Maria Erna

    2016-03-01

    Full Text Available The thermodynamic properties and characterizations of corrosion inhibition of chitosan nano-particles on the surface of mild steel in peat water media had been studied using weight loss method at temperatures of 30 - 50 oC. Steel surfaces were characterized by FT-IR spectra and SEM-EDS morphology photos. The research found that the value of DGo approaching -40 kJmol-1. The negative value of Gibbs free energy shows that the adsorption of inhibitor molecules on the surface of mild steel was achemisorption and it occurred spontaneously. Meanwhile, the values of DHo is also negative confirming that the adsoprtion of inhibitor molecules is an exothermic process. The value of DSo obtained is positive, it indicates hat the inhibitor molecules were adsorbed spontaneously on the mild steel surface. The analysis on mild steel surfaces hows that the nano-particle chitosan was adsorbed on the steel surface to form the complex compounds.

  14. 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.

  15. 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.

  16. Corrosion inhibition in sputter-deposited thin-film systems using an intermediary layer of palladium

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, D.J.

    1979-03-01

    Accelerated and long term corrosion data are presented for the Ti--Ag and Cr--Au thin film metallization systems deposited by sputter deposition. The Ti--Ag conductor system is used as an electrode for high intensity silicon solar cells, and it has been found that an intermediate layer of 1500 A of palladium greatly improves the environmental stability of the metallization. The Cr--Au system has been used as an electrical circuit pattern, and thin films of palladium (100--300 A) have been incorporated to improve storage, processing, and service stability. A 100 A palladium intermediary did not affect the etch patterning of the Cr--Au metallization. It is observed that the introduction of palladium modifies the anodic potential of the active metal producing a passive oxide when exposed to an electrolytic environment. It is proposed that this modified oxide, at exposed pinhole sites, is responsible for the increased corrosion resistance when palladium is present as an intermediate layer for either the Ti--Ag or Cr--Au metallization systems.

  17. Adsorption of alginate and albumin on aluminum coatings inhibits adhesion of Escherichia coli and enhances the anti-corrosion performances of the coatings

    Energy Technology Data Exchange (ETDEWEB)

    He, Xiaoyan; Liu, Yi; Huang, Jing; Chen, Xiuyong; Ren, Kun; Li, Hua, E-mail: lihua@nimte.ac.cn

    2015-03-30

    Graphical abstract: - Highlights: • Adsorption behaviors of alginate and albumin on Al coatings were investigated at molecular level. • The adsorption inhibits effectively the colonization of Escherichia coli bacteria. • The adsorption alters the wettability of the Al coatings. • The conditioning layer enhances anti-corrosion performances of the Al coatings. - Abstract: Thermal-sprayed aluminum coatings have been extensively used as protective layers against corrosion for steel structures in the marine environment. The corrosion usually deteriorates from marine biofouling, yet the mechanism of accelerated corrosion of the coatings remains elusive. As the first stage participating in biofouling process, adsorption of molecules plays critical roles in mediating formation of biofilm. Here, we report at molecular level the adsorption behaviors of albumin and marine polysaccharide on arc-sprayed aluminum coatings and their influence on adhesion of Escherichia coli. The adsorption of alginate and albumin was characterized by infrared spectra analyses and atomic force microscopic observation. The adsorption inhibits effectively adhesion of the bacteria. Further investigation indicates that alginate/albumin altered the hydrophilicity/hydrophobicity of the coatings instead of impacting the survival of the bacteria to decline their adhesion. The conditioning layer composed of the molecules enhances anti-corrosion performances of the coatings.

  18. Corrosion inhibition of mild steel in 1 M HCl solution by henna extract: A comparative study of the inhibition by henna and its constituents (Lawsone, Gallic acid, {alpha}-D-Glucose and Tannic acid)

    Energy Technology Data Exchange (ETDEWEB)

    Ostovari, A. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of)], E-mail: A.Ostovari@gmail.com; Hoseinieh, S.M.; Peikari, M. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of); Shadizadeh, S.R. [Petroleum Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of); Hashemi, S.J. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of)

    2009-09-15

    The inhibitive action of henna extract (Lawsonia inermis) and its main constituents (lawsone, gallic acid, {alpha}-D-Glucose and tannic acid) on corrosion of mild steel in 1 M HCl solution was investigated through electrochemical techniques and surface analysis (SEM/EDS). Polarization measurements indicate that all the examined compounds act as a mixed inhibitor and inhibition efficiency increases with inhibitor concentration. Maximum inhibition efficiency (92.06%) is obtained at 1.2 g/l henna extract. Inhibition efficiency increases in the order: lawsone > henna extract > gallic acid > {alpha}-D-Glucose > tannic acid. Also, inhibition mechanism and thermodynamic parameters are discussed.

  19. Panel report on corrosion in energy systems

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-06-01

    Corrosion problems in high-temperature (non aqueous) energy systems, corrosion in aqueous energy systems and institutional problems inhibiting the development of corrosion science and engineering are discussed. (FS)

  20. Panel report on corrosion in energy systems

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-06-01

    Corrosion problems in high-temperature (non aqueous) energy systems, corrosion in aqueous energy systems and institutional problems inhibiting the development of corrosion science and engineering are discussed. (FS)

  1. Adsorption and inhibitive properties of a new heterocyclic furan Schiff base on corrosion of copper in HCl 1 M: Experimental and theoretical investigation

    Energy Technology Data Exchange (ETDEWEB)

    Issaadi, S., E-mail: issaadi-s@univ-setif.dz; Douadi, T.; Chafaa, S.

    2014-10-15

    Highlights: • The new Schiff base is a good corrosion inhibitor for copper in 1 M HCl. • SEM and FT-IR analysis indicates that copper corrosion can be inhibited due to the adsorption of Schiff base on copper surface. • Quantum chemical calculations reveal O and N atoms are proper adsorption sites. - Abstract: A new corrosion inhibitor namely (NE)-N-(furan-2-ylmethylidene)-4-({4-[E)-(furan-2-ylmethylidene) amino] phenyl} ethyl) aniline (SB)has been synthesized and its influence on corrosion inhibition of copper in 1 M hydrochloric acid solution has been studied by both electrochemical impedance spectroscopy (EIS) and Tafel polarization measurements. The investigated inhibitor has shown good inhibition efficiency in 1 M HCl. Adsorption of SB on copper surface follows the Langmuir isotherm. Copper surface characterization was performed using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Quantum chemical calculations show that SB has large negative charge in nitrogen and oxygen atoms, which facilitates the adsorption of SB on the copper surface.

  2. Experimental and theoretical study on the inhibition performance of triazole compounds for mild steel corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Musa, Ahmed Y., E-mail: ahmed.musa@ymail.co [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)

    2010-10-15

    A relationship between quantum chemical parameters for three triazole compounds and their inhibition ability was studied using electrochemical measurements (potentiodynamic polarization and EIS), molecular dynamic method and quantum chemical calculations. Electrochemical measurements results revealed that the inhibition efficiencies increased with the concentration of inhibitors. The molecular dynamic method results showed that the higher interaction potential between the inhibitor and metal surface, the higher the inhibition efficiency. The quantum chemical calculation results showed that the triazole ring is the active site in these inhibitors and they can absorb on Fe surface by donating electrons to Fe d-orbital.

  3. Experimental and theoretical study for corrosion inhibition of mild steel in normal hydrochloric acid solution by some new macrocyclic polyether compounds

    Energy Technology Data Exchange (ETDEWEB)

    Lebrini, M. [Unite de Catalyse et de Chimie du Solide, CNRS UMR 8181, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Lagrenee, M. [Unite de Catalyse et de Chimie du Solide, CNRS UMR 8181, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Vezin, H. [Laboratoire de Chimie Organique et Macromoleculaire, CNRS UMR 8009, USTL Bat C4, F-59655 Villeneuve d' Ascq Cedex (France); Traisnel, M. [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, PERF UMR 8008, ENSCL, BP 90108, F-59652 Villeneuve d' Ascq Cedex (France); Bentiss, F. [Laboratoire de Chimie de Coordination et d' Analytique, Faculte des Sciences, Universite Chouaib Doukkali, BP 20, M-24000 El Jadida (Morocco)]. E-mail: f.bentiss@pop.ensc-lille.fr

    2007-05-15

    New macrocyclic polyether compounds containing a 1,3,4-thiadiazole moiety have been prepared to study the corrosion inhibitive effect of mild steel in normal hydrochloric acid solutions. The salient features obtained from weight loss and electrochemical impedance spectroscopy (EIS) have been discussed. The results of these investigations have shown enhancement in inhibition efficiencies with the extent of the polyethylene glycol unit that forms a cavity. Data obtained from EIS show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. Display Omitted Adsorption of n-MCTH was found to follow the Langmuir's adsorption isotherm. The thermodynamic functions of adsorption process were calculated from experimental ac impedance data and the interpretation of the results are given. Molecular modelling has been conducted in an attempt to correlate the corrosion inhibition properties with the calculated quantum chemical parameters.

  4. Theoretical and experimental studies on the inhibition potentials of aromatic oxaldehydes for the corrosion of mild steel in 0.1 M HCl.

    Science.gov (United States)

    Eddy, Nnabuk Okon; Ita, Benedict I

    2011-04-01

    Experimental aspect of the inhibition of the corrosion of mild steel by oxaldehydes was carried out using gravimetric, gasometric and thermometric methods while the theoretical studies were carried out using quantum chemical principle and quantitative structure activity relation (QSAR) approaches. The results obtained indicated that the studied oxaldehydes are good inhibitors for the corrosion of mild steel in HCl solutions. The adsorption of the inhibitors on mild steel surface is spontaneous, exothermic and is consistent with the assumptions of Langmuir adsorption isotherm. Excellent correlations were found between the calculated quantum chemical parameters and experimental inhibition efficiencies of the studied compounds. Correlations between theoretical and experimental inhibition efficiencies (for the different Hamiltonians, namely, PM6, PM3, AM1, RM1 and MNDO) were very close to unity. Condensed Fukui function and condensed softness have been used to determine the sites for electrophilic and nucleophilic attacks on each of the inhibitors.

  5. Synergistic effect of iodide ions on the corrosion inhibition of steel in 0.5 M H 2SO 4 by new chalcone derivatives

    Science.gov (United States)

    Bouklah, M.; Hammouti, B.; Aouniti, A.; Benkaddour, M.; Bouyanzer, A.

    2006-07-01

    The effect of addition of 4',4-dihydroxychalcone (P 1), 4-aminochalcone (P 2) and 4-bromo, 4'-methoxychalcone (P 3) on the corrosion of steel in 0.5 M sulphuric acid has been studied by weight loss measurements, potentiodynamic and EIS measurements. We investigate the synergistic effect of iodide ions on the corrosion inhibition of steel in the presence of chalcone derivatives. The corrosion rates of the steel decrease with the increase of the chalcones concentration, while the inhibition efficiencies increase. The addition of iodide ions enhances the inhibition efficiency considerably. The presence of iodide ions increases the degree of surface coverage. The synergism parameters SΘ and SI, calculated from surface coverage and the values of inhibition efficiency, in the case of chalcone derivatives are found to be larger than unity. The enhanced inhibition efficiency in the presence of iodide ions is only due to synergism and there is a definite contribution from the inhibitors molecules. E (%) obtained from the various methods is in good agreement. Polarisation measurements show also that the compounds act as cathodic inhibitors.

  6. Corrosion control in mining technology

    Energy Technology Data Exchange (ETDEWEB)

    Telekesi, J.

    1985-01-01

    An overview of corrosion effects in mining technology and the importance of protection is presented. The most common corrosion processes and effects are summarized and the system and criteria of their avoidance are discussed in detail. Preventive measures are recommended to decrease possible corrosion effects including the selection of corrosion-resistive constructions, to use protective coatings and inhibition techniques and some other protection possibilities where applicable. The organization aspects and the economic impact of corrosion control in mining are discussed.

  7. Inhibition of corrosion of carbon steel in well water by L-Lysine – Zn2+system

    Directory of Open Access Journals (Sweden)

    J.AngelinThangakani

    2016-08-01

    Full Text Available The environmental friendly inhibitor system L-Lysine-Zn2+, has been investigated by weight loss method. A synergistic effect exists between L-Lysine and Zn2+ system. The formulation consisting of 250 ppm of L-Lysine and 50 ppm of Zn2+ offers good inhibition efficiency of 98%.Polarization study reveals that this formulation functions as anodic inhibitor. AC impedance spectra reveal that a protective film is formed on the metal surface. The FTIR spectra study leads to the conclusion that the Fe2+ - L-Lysine complex formed on anodic sites of the metal surface controlled the anodic reaction and Zn(OH2 formed on the cathodic sites of the metal surface controlling the cathodic reaction. UV and Fluorescence spectrum study reveals the metal film formed on the solution containing 250 ppm of L-Cysteine and 50 ppm of Zn2+.The morphology of the metal is studied by AFM images. A suitable mechanism of corrosion inhibition is proposed based on the results obtained from weight loss study and surface analysis technique. Synergism parameters have been calculated. They are found to be greater than 1 suggesting that a synergistic effect exists between L-Lysine and –Zn2+

  8. Effect of Piperidin-4-ones on the Corrosion Inhibition of Mild Steel in 1 N H2SO4

    Directory of Open Access Journals (Sweden)

    Glory Tharial Xavier

    2015-01-01

    Full Text Available The corrosion inhibition of mild steel in 1 N sulphuric acid solution by 2,6-diphenylpiperidin-4-ones with various substituents at 3- and 3,5-positions (01–06 has been tested by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopic methods, and FTIR and UV absorption spectra. The surface morphology of the mild steel specimen has been analyzed by SEM. The effect of temperature (300 to 323 ± 1 K on the corrosion behavior of mild steel in the presence of the inhibitors (01–06 was studied using weight loss techniques. The effect of anions (Cl−, Br−, and I− on the corrosion behavior of mild steel in the presence of the same inhibitors was also studied by weight loss method and the synergism parameters were calculated. The adsorption characteristics of the inhibitors have been determined from the results.

  9. Electrochemical Study on Corrosion Inhibition of Copper in Hydrochloric Acid Medium and the Rotating Ring-Disc Voltammetry for Studying the Dissolution

    Directory of Open Access Journals (Sweden)

    A. K. Satpati

    2011-01-01

    Full Text Available Dissolution characteristics of copper in hydrochloric acid medium and the effect of 4-amino 1,2,4-triazole (ATA on the corrosion process have been studied using conventional electrochemical techniques and rotating ring-disc electrodes (RRDEs. Corrosion potential (corr and corrosion current density (corr were obtained by Tafel extrapolation methods. Charge transfer resistance (ct and double-layer capacitance (dl were obtained from the electrochemical impedance spectroscopy (EIS. ATA was shown to be an effective inhibitor for the copper-corrosion inhibition in acid medium. The corrosion rate was retarded in presence of inhibitors mainly because of the adsorption of the inhibitor on the electrode surface. Adsorption of the inhibitor on the metal surface was found to follow the Langmuir adsorption isotherm. Standard free energy change of the adsorption process (Δ0ad was calculated to be −54.3 kJ mol−1; such a large negative value of Δ0ad suggests the prescence of a chemisorption process.

  10. Inhibitive effect by Psidium guajava leaf extract on the corrosion of Al-Si-Mg (SSM-HPDC alloy in simulated seawater environment

    Directory of Open Access Journals (Sweden)

    M. Abdulwahab

    2015-12-01

    Full Text Available The assessment of Psidium guajava leaf extract as corrosion inhibitor for Al-Si- Mg (SSM-HPDC alloy in 3.5%wt NaCl solution using the gravimetric based-mass loss and potentiodynamic polarization techniques was investigated. The gravimetric based mass loss test was carried out at different inhibitor concentration, time and temperature ranges of 0.1-0.5%v/v, 1-5 hrs and 30-70oC, respectively, the results revealed that Psidium guajava leaf extract in 3.5%wt NaCl solution-aluminium environment decreased the corrosion rate at various concentrations considered. Inhibition efficiency (IE as high as 63.17% at 0.5% v/v Psidium guajava leaf extract addition using the gravimetric method was demonstrated in 3.5%wt NaCl solution. The IE of 90.48% was obtained at 0.5%v/v using the potentiodynamic polarization method. The additions of Psidium guajava leaf extract as corrosion inhibitor in the solution indicate higher potential value, IE and polarization resistance with decrease in current density. The two methods used for assessment of the aluminium alloy corrosion behaviour were in agreement and mixed-type corrosion exists which obeyed the Langmuir adsorption isotherm.

  11. Inhibition of Brass Corrosion by 2-Mercapto-1-methylimidazole in Weakly Alkaline Solution

    Science.gov (United States)

    Radovanovic, Milan B.; Antonijevic, Milan M.

    2016-03-01

    The electrochemical behavior of brass and anticorrosion effect of 2-mercapto-1-methylimidazole (2-MMI) in weakly alkaline solution with and without presence of chloride ions was investigated using electrochemical techniques in addition to SEM-EDS analysis. Results show that inhibition efficiency depended on inhibitor concentration and immersion time of brass electrode in inhibitor solution. Inhibition mechanism of 2-mercapto-1-methylimidazole includes adsorption of inhibitor on active sites on electrode surface which was confirmed by SEM-EDS analysis of the brass. Adsorption of the 2-MMI in sodium tetraborate solution obeys Flory-Huggins adsorption isotherm, while in the presence of chloride, ions adsorption of inhibitor obeys Langmuir adsorption isotherm.

  12. Inhibition of carbon steel corrosion in CO{sub 2}-saturated brine using some newly surfactants based on palm oil: Experimental and theoretical investigations

    Energy Technology Data Exchange (ETDEWEB)

    Abd El-Lateef, Hany M., E-mail: Hany_shubra@yahoo.co.uk [Chemistry Department, Faculty of Science, Sohag University, Sohag (Egypt); Abbasov, V.M.; Aliyeva, L.I.; Qasimov, E.E.; Ismayilov, I.T. [Mamedaliev Institute of Petrochemical Processes, National Academy of Sciences of Azerbaijan, AZ1025 Baku (Azerbaijan)

    2013-11-01

    New surfactants from the type of fatty acids derivatives were synthesized based on palm oil and their inhibitive action against the corrosion of carbon steel in CO{sub 2}-saturated 1% NaCl solution were investigated at 50 °C. The detailed study of surfactants as corrosion inhibitors is given using polarization curves and electrochemical impedance spectroscopy methods. The inhibition efficiencies obtained from the two employed methods are nearly closed. Results show that, the investigated surfactants are good inhibitors and its inhibition efficiency reaches to 98.95% at 100 ppm for inhibitor V. The high inhibition efficiencies were attributed to the simple blocking effect by adsorption of inhibitor molecules on the steel surface. The surface activity of the synthesized surfactant solutions was determined using surface tension measurements at 25 °C. Adsorption of the inhibitors on the carbon steel surface was found to obey Langmuir's adsorption isotherm and chemisorption. The correlation between the inhibition efficiencies of the studied surfactants and their molecular structures has been investigated using quantum chemical calculations. The obtained theoretical results have been supported our experimental data. - Graphical abstract: To investigate the relationship between molecular structures of the studied surfactants and their inhibition effect; Quantum chemical molecular calculations were performed. The following quantum chemical indices such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO), energy gap ΔE = E{sub HOMO} − E{sub LUMO}, and dipole moment (μ) were considered. The relation between these parameters and the inhibition efficiencies was explained. The obtained theoretical results have been supported our experimental data. - Highlights: • Effect of surfactants on carbon steel corrosion in CO{sub 2}-saturted brine was investigated. • The high inhibition efficiency attributed to the adherent adsorption

  13. Green approach to corrosion inhibition of mild steel in two acidic solutions by the extract of Punica granatum peel and main constituents

    Energy Technology Data Exchange (ETDEWEB)

    Behpour, M., E-mail: m.behpour@kashanu.ac.ir [Department of Analytical Chemistry, Faculty of Chemistry, University of Kashan, Kashan, I.R. 87317-51167 (Iran, Islamic Republic of); Ghoreishi, S.M.; Khayatkashani, M. [Department of Analytical Chemistry, Faculty of Chemistry, University of Kashan, Kashan, I.R. 87317-51167 (Iran, Islamic Republic of); Soltani, N. [Department of Chemistry, Payame Noor University (PNU), 19395-4697 Tehran (Iran, Islamic Republic of)

    2012-01-05

    Graphical abstract: Ellagic acid (EA) and tannic acid (TA) were studied as corrosion inhibitors. The electron density HOMO and LUMO of EA and TA were used to explain difference in behavior of them. Highlights: Black-Right-Pointing-Pointer The extract of Punica granatum (PG) and their main constituent (ellagic acid (EA)) are found to be good inhibitors for the corrosion of mild steel in 1 M H{sub 2}SO{sub 4} and 2 M HCl. Black-Right-Pointing-Pointer The electrochemical inhibitive mechanism is explained by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) results. Black-Right-Pointing-Pointer The adsorption of ALLOX on mild steel surface was found to accord with the Temkin adsorption isotherm. Black-Right-Pointing-Pointer The effect of temperature on the corrosion behavior of mild steel in 2 M HCl and 1 M H{sub 2}SO{sub 4} without and with the PG extract was studied. - Abstract: The effect of the extract of Punica granatum (PG) and their main constituents involve ellagic acid (EA) and tannic acid (TA), as mild steel corrosion inhibitor in 2 M HCl and 1 M H{sub 2}SO{sub 4} solutions was investigated by weight loss measurements. The results obtained from the weight loss measurements show that the inhibition efficiency of TA even in high concentration is very low. Thus, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) investigations were used for different concentrations of PG and EA and best concentration of TA. Potentiodynamic polarization curves indicated that PG and EA behave as mixed-type inhibitors. EIS measurements show an increase of the transfer resistance with increasing inhibitor concentration. The temperature effect on the corrosion behavior of steel without and with the PG extract was studied. The inhibition action of the extract was discussed in view of Langmuir adsorption isotherm.

  14. Adsorption properties and inhibition of mild steel corrosion in hydrochloric solution by some newly synthesized diamine derivatives: Experimental and theoretical investigations

    Energy Technology Data Exchange (ETDEWEB)

    Herrag, L.; Hammouti, B.; Elkadiri, S.; Aouniti, A. [Laboratoire de Chimie Appliquee et Environnement, LCAE-URAC18, Faculte des Sciences, Universite Mohammed Premier, B.P. 717, M-6000 Oujda (Morocco); Jama, C. [Unite Materiaux et Transformations (UMET), Ingenierie des Systemes Polymeres, CNRS UMR 8207, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Vezin, H. [Laboratoire de Spectrochimie Infrarouge et Raman (LASIR), UMR-CNRS 8516, Universite des Sciences et Technologies de Lille, Batiment C5, F-59655 Villeneuve d' Ascq Cedex (France); Bentiss, F., E-mail: fbentiss@enscl.f [Laboratoire de Chimie de Coordination et d' Analytique (LCCA), Faculte des Sciences, Universite Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco)

    2010-09-15

    New diamine derivatives, namely 2-[{l_brace}2-[bis-(2-hydroxyethyl)amino]ethyl{r_brace}(2-hydroxyethyl)amino]ethanol (DAME) and 2-[{l_brace}2-[bis-(2-hydroxyethyl)amino]ethyl{r_brace}(2-hydroxyethyl)amino]propanol (DAMP) were synthesised and their inhibitive action against the corrosion of mild steel in 1 M HCl solution were investigated at 308 K. The detailed study of DAME is given using gravimetric measurements and polarization curves method. Results show that DAME is a good inhibitor and inhibition efficiency reaches 91.7% at 10{sup -3} M. Tafel polarization study revealed that DAME acts as a mixed-type inhibitor. The inhibitor adsorption process in mild steel/DAME/hydrochloric acid system was studied at different temperatures (308-353 K) by means of weight loss measurements. The adsorption of DAME on steel surface obeyed Langmuir's adsorption isotherm. The kinetic and thermodynamic parameters for mild steel corrosion and inhibitor adsorption, respectively, were determined and discussed. The comparative study of inhibitive performance of the two diamine derivatives revealed that DAME is more effective than DAMP. Quantitative Structure-Activity Relationship (QSAR) approach has been conducted in attempt to correlate the corrosion inhibition properties of these diamine derivatives with their calculated quantum chemical parameters.

  15. The isoxazolidines: the effects of steric factor and hydrophobic chain length on the corrosion inhibition of mild steel in acidic medium

    Energy Technology Data Exchange (ETDEWEB)

    Ali, S.A. [Chemistry Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)]. E-mail: shaikh@kfupm.edu.sa; El-Shareef, A.M. [Chemistry Department, Dammam Girl' s College, Dammam 31113 (Saudi Arabia); Al-Ghamdi, R.F. [Chemistry Department, Dammam Girl' s College, Dammam 31113 (Saudi Arabia); Saeed, M.T. [Chemistry Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2005-11-01

    Several new isoxazolidines having varying degree of steric environment and hydrophobic chain length, prepared efficiently using single-step nitrone cycloaddition reactions, are tested for corrosion inhibition of mild steel in 1M and 5M HCl at 50-70{sup o}C range by gravimetric and electrochemical methods. All compounds have shown very good corrosion inhibition efficiency (IE%) in acidic solution. Steric crowding around the nitrogen centres and hydrophobic chain lengths as well as increase in temperature (in the presence of the inhibitor in the higher concentration range 100-400ppm) are found to increase the inhibition efficiency of the isoxazolidines. Thermodynamic parameters ({delta}G{sup o}{sub ads}, {delta}H{sup o}{sub ads}, {delta}S{sup o}{sub ads}) for the adsorption process and kinetic parameters for the metal dissolution (or hydrogen evolution) reaction in the presence of one of the isoxazolidines were determined. Experimental results agree with the Temkin adsorption isotherm. The inhibition of corrosion in 1M HCl, influenced by both physi- and chemi-sorption, was found to be under mixed control, but predominantly under cathodic control.

  16. Inhibitive action of some bipyrazolic compounds on the corrosion of steel in 1 M HCl

    Energy Technology Data Exchange (ETDEWEB)

    Benabdellah, M. [Laboratoire de Chimie Appliquee et Environnement, Faculte des Sciences, 60000 Oujda (Morocco); Touzani, R. [Laboratoire de Chimie Appliquee et Environnement, Faculte des Sciences, 60000 Oujda (Morocco); Faculte Pluridisciplinaire de Nador, Universite Mohammed 1er, B.P. 300, 62700 Selouane, Nador (Morocco); Aouniti, A.; Dafali, A.; El Kadiri, S. [Laboratoire de Chimie Appliquee et Environnement, Faculte des Sciences, 60000 Oujda (Morocco); Hammouti, B. [Laboratoire de Chimie Appliquee et Environnement, Faculte des Sciences, 60000 Oujda (Morocco)], E-mail: hammoutib@yahoo.fr; Benkaddour, M. [Laboratoire d' Analyse et de Caracterisation des Materiaux, Faculte des Sciences, 60000 Oujda (Morocco)

    2007-10-15

    Potentiodynamic polarisation, electrochemical impedance spectroscopy and weight loss studies were carried out on the inhibition of carbon steel in 1 M hydrochloric acid solution by three bipyrazolic compounds. The examined inhibitors are 5,5'-dipropyl-1H,1'H-[3,3']bipyrazolyl (Bp1), 5,5'-diphenyl-1H,1'H-[3,3']bipyrazolyl (Bp2) and 5,5'-bis-(4-chloro-phenyl)-1H,1'H-[3,3']bipyrazolyl (Bp3). All measurements show that inhibition efficiency increases with increase in inhibitor concentration and the variation in inhibitive efficiency mainly depends on the type and nature of the substituents present in the inhibitor molecule to attain 98% for chloro derivative (Bp3) at 10{sup -3} M. This reveals that inhibitive actions of bipyrazolic compounds were mainly due to adsorption on steel surface. Adsorption of these inhibitors follows Langmuir adsorption isotherm. Electrochemical impedance spectroscopy (EIS) measurements showed that the dissolution process of steel occurred under activation control. The curves of polarisation indicated that the examined inhibitors act primarily as cathodic inhibitors. From the adsorption isotherm, thermodynamic data for the adsorption process (K, {delta}G{sub ads}{sup o}) are calculated and discussed. Some quantum parameters (highest occupied molecular orbital (HOMO) energy, lowest unoccupied molecular orbital (LUMO) energy and total partial charge of inhibitors atoms) are computed.

  17. Inhibition of copper corrosion by the formation of Schiff base self-assembled monolayers

    Science.gov (United States)

    Zhang, Jing; Liu, Zheng; Han, Guo-Cheng; Chen, Shi-Liang; Chen, Zhencheng

    2016-12-01

    Self-assembled monolayers (SAMs) of 4-((2-thiophenecarboxylic acid hydrazide) methylene) benzoic acid (HD2) (denoted as HD2-SAMs) were formed on copper surface. The SAMs were characterized by scanning electron microscopy and X-ray photoelectron spectroscopy. Polarization curve and weight loss methods indicated that the highest inhibition efficiency was 93.9% for CO2-saturated simulative oilfield water at a self-assembled time of 3 h. Potential-time curve, electrochemical impedance tests showed that HD2-SAMs on copper surface exhibited excellent inhibition effect at 30 °C. The adsorption behavior of HD2-SAMs on the copper surface followed the Langmuir adsorption isotherm, which was indicative of typically chemical adsorption. Quantum chemistry calculation showed that O and N atoms can interact with Cu atoms by coordination bonds which were the mainly active area of the adsorption of HD2 molecules.

  18. The Inhibitive Effect of 2-Phenyl-3-nitroso-imidazo [1, 2-a]pyridine on the Corrosion of Steel in 0.5 M HCl Acid Solution

    Directory of Open Access Journals (Sweden)

    K. Bouhrira

    2010-01-01

    Full Text Available The effect of 2-phenyl-3-nitroso-imidazo[1,2-a]pyridine (PNIP on the corrosion inhibition of carbon-steel in 0.5 M HCl was studied by weight loss and different electrochemical techniques such as electrochemical impedance spectroscopy (EIS, potentiodynamic polarization. The obtained results showed that PNIP effectively reduces the corrosion rate of carbon steel. Inhibition efficiency (E% increases with inhibitor concentration to attain 88% at 10-3 M. Adsorption of that PNIP on the carbon steel surface in 0.5 M HCl follows the Langmuir isotherm model. E% values obtained from various methods used are in good agreement. SEM characterization of the steel surface is made.

  19. Synergistic of a coumarin derivative with potassium iodide on the corrosion inhibition of aluminum alloy in 1.0 M H2SO4

    Science.gov (United States)

    Mohamad, Abu Bakar; Kadhum, Abdul Amir H.; Al-Amiery, Ahmed A.; Ying, Lim Chai; Musa, Ahmed Y.

    2014-05-01

    Synergistic effects of the addition of KI on the corrosion inhibitive performance of a coumarin derivative on an aluminum alloy in 1.0 M H2SO4 at different temperatures were studied using various electrochemical measurements. Density functional theory was used to calculate the quantum chemical parameters of the coumarin derivative. The experimental results showed that the coumarin derivative is considered as a mixedtype inhibitor. The corrosion potential values were almost unchanged upon the addition of PBBC to the acidic solution. The inhibition efficiency increases with increasing inhibitor concentration and increases further in the presence of 6.02 mM KI but decreases significantly at higher temperature. The adsorption of PBBC obeyed the Langmuir isotherm, and being chemically adsorbed at lower temperatures, while physical adsorption is favoured at higher temperature. The theoretical results indicated that the coumarin derivative was adsorbed onto the surface of Al2024 through the sulfur, oxygen and nitrogen atoms.

  20. Study on the inhibition of mild steel corrosion by 1,3-bis-(morpholin-4-yl-phenyl-methyl-thiourea in hydrochloric acid medium

    Directory of Open Access Journals (Sweden)

    Devaraj Karthik

    2014-12-01

    Full Text Available 1,3-Bis-(morpholin-4-yl-phenyl-methyl-thiourea (MBT was synthesized and their influence on the inhibition of corrosion on mild steel in various hydrochloric acid concentrations has been investigated by weight loss, potentiodynamic polarization, electrochemical impedance (EI, Tafel polarization, scanning electron microscope (SEM and FT-IR methods. The result of weight loss study shows that the corrosion inhibition efficiency (IE is directly proportional to the concentration of the inhibitor and inversely proportional to the temperature. Electrochemical study proved that the inhibitor acts as a mixed type inhibitor. SEM shows the formation of a protective film of the inhibitor on the mild steel. The IR data also provide evidence for the anticorrosion effect of the inhibitor.

  1. Adsorption Properties and Inhibition of C38 Steel Corrosion in Hydrochloric Solution by Some Indole Derivates: Temperature Effect, Activation Energies, and Thermodynamics of Adsorption

    Directory of Open Access Journals (Sweden)

    M. Lebrini

    2013-01-01

    Full Text Available The corrosion rates in the presence of some indole derivates, namely, 9H-pyrido[3,4-b]indole (norharmane and 1-methyl-9H-pyrido[3,4-b]indole (harmane, as inhibitors of C38 steel corrosion inhibitor in 1 M HCl solution, were measured by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS techniques, in the range of temperatures from 25 to 55∘C. Results obtained revealed that the organic compounds investigated have inhibiting properties for all temperatures. The inhibition was assumed to occur via adsorption of the indole molecules on the metal surface. Adsorption of indole derivates was found to follow the Langmuir isotherm. The apparent activation energies, enthalpies, and entropies of the dissolution process and the free energies and enthalpies for the adsorption process were determined by potentiodynamic polarization and electrochemical impedance. The fundamental thermodynamic functions were used to collect important information about indole inhibitory behaviour.

  2. Synergistic effect of tartaric acid with 2,6-diaminopyridine on the corrosion inhibition of mild steel in 0.5 M HCl

    Science.gov (United States)

    Qiang, Yujie; Guo, Lei; Zhang, Shengtao; Li, Wenpo; Yu, Shanshan; Tan, Jianhong

    2016-09-01

    The inhibitive ability of 2,6-diaminopyridine, tartaric acid and their synergistic effect towards mild steel corrosion in 0.5 M HCl solution was evaluated at various concentrations using potentiodynamic polarization measurements, electrochemical impedance spectroscopy (EIS), and weight loss experiments. Corresponding surfaces of mild steel were examined by atomic force microscope (AFM), field emission scanning electron microscope (FE-SEM), energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS) analysis. The experimental results are in good agreement and reveal a favorable synergistic effect of 2,6-diaminopyridine with tartaric acid, which could protect mild steel from corrosion effectively. Besides, quantum chemical calculations and Monte Carlo simulation were used to clarify the inhibition mechanism of the synergistic effect.

  3. Adsorption and inhibitive properties of a new heterocyclic furan Schiff base on corrosion of copper in HCl 1 M: Experimental and theoretical investigation

    Science.gov (United States)

    Issaadi, S.; Douadi, T.; Chafaa, S.

    2014-10-01

    A new corrosion inhibitor namely (NE)-N-(furan-2-ylmethylidene)-4-({4-[E)-(furan-2-ylmethylidene) amino] phenyl} ethyl) aniline (SB)has been synthesized and its influence on corrosion inhibition of copper in 1 M hydrochloric acid solution has been studied by both electrochemical impedance spectroscopy (EIS) and Tafel polarization measurements. The investigated inhibitor has shown good inhibition efficiency in 1 M HCl. Adsorption of SB on copper surface follows the Langmuir isotherm. Copper surface characterization was performed using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Quantum chemical calculations show that SB has large negative charge in nitrogen and oxygen atoms, which facilitates the adsorption of SB on the copper surface.

  4. Corrosion inhibition of 6061 Al-15 vol. pct. SiC(p) composite and its base alloy in a mixture of sulphuric acid and hydrochloric acid by 4-(N,N-dimethyl amino) benzaldehyde thiosemicarbazone

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Geetha Mable [Department of Chemistry, National Institute of Technology Karnataka, Surathkal, Srinivasnagar 575 025, Mangalore, Karnataka (India); Nayak, Jagannath [Department of Metallurgical and Materials Engineering, National Institute of Technology Karnataka, Surathkal, Srinivasnagar 575 025, Karnataka (India); Shetty, A. Nityananda, E-mail: nityashreya@gmail.com [Department of Chemistry, National Institute of Technology Karnataka, Surathkal, Srinivasnagar 575 025, Mangalore, Karnataka (India)

    2011-02-15

    Research highlights: {yields} Corrosion inhibition of Al-SiC composite. {yields} DMABT as corrosion inhibitor. {yields} Inhibition through physisorption of DMABT. - Abstract: The corrosion inhibition characteristics of 4-(N,N-dimethylamino) benzaldehyde thiosemicarbazone (DMABT) on the corrosion behavior of 6061 Al-15 vol. pct. SiC(p) composite and its base alloy were studied at different temperatures in acid mixture medium containing varying concentrations of hydrochloric acid and sulphuric acid using Tafel extrapolation technique and ac impedance spectroscopy (EIS). The effect of inhibitor concentration, temperature and concentration of the acid mixture media on the inhibitor action was investigated. It was found that inhibition efficiencies increase with the increase in inhibitor concentration, but decrease with the increase in temperature and with the increase in concentration of the acid media. Thermodynamic parameters for dissolution process were determined. The adsorption of DMABT on both the composite and base alloy was found to be through physisorption obeying Freundlich adsorption isotherm.

  5. Inhibition of the corrosion process of alloy AA5083 (Al-Mg) in seawater by cerium cations. An EIS study

    Energy Technology Data Exchange (ETDEWEB)

    Aballe, A.; Bethencourt, M.; Botana, F.J.; Cano, M.J. [Cadiz Univ. (Spain). Dept. de Ciencia de los Materiales e Ingenieria Metalurgica y Quimica Inorganica; Marcos, M. [Cadiz Univ. (Spain). Dept. de Ingenieria Mecanica y Diseno Industrial

    2001-05-01

    The principal corrosion process of the alloy AA5083 in aerated NaCl solutions mainly affects the zones occupied by Al(Mn,Fe,Cr) cathodic precipitates, over which the oxygen reduction reaction takes place. Thus, the design of an effective protection system could be based on the use of cathodic inhibitors. In previous papers, the inhibition efficiency of various lanthanide chlorides, particularly CeCl{sub 3}, has been proved. These compounds act as cathodic inhibitors, blocking these cathodic sites by means of the precipitation of a lanthanide oxide or hydroxide film. In this paper, EIS has been used to detect the blocking effect of the cathodic sites. This fact is reflected in the electrical response of the system through the minimisation of the values of those elements of the electrical loop that are related to the response of the cathodic intermetallics. In addition, the dielectric properties of the anodic film have been evaluated by measuring the value of the associated capacitance. From these values, it can be concluded that the thickness of the film produced over the matrix when the inhibitor is added is much lower than that produced in the bare solution. This finding is in good agreement with the results obtained with other techniques and may be related to the minimisation of the anodic reaction as a consequence of the decrease in the intensity of the cathodic process by the action of CeCl{sub 3}. (orig.)

  6. A novel triazole-based cationic gemini surfactant: synthesis and effect on corrosion inhibition of carbon steel in hydrochloric acid

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Lingguang [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China)]. E-mail: lgahu@163.com; Xie Anjian [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China); Shen Yuhua [School of Chemistry and Chemical Engineering, Anhui University, Hefei 230039 (China)

    2005-06-15

    A triazole-based cationic gemini surfactant, 3,5-bis(methylene octadecyl dimethylammonium chloride)-1,2,4-triazole (18-triazole-18) has been synthesized, and its effect on corrosion inhibition of A{sub 3} steel in 1 M HCl has been studied using the weight-loss method. The result showed that 18-triazole-18 acted as an excellent inhibitor in 1 M HCl. It was found that the adsorption mechanism of 18-triazole-18 on the steel surface in acid medium was quite different from that of cationic gemini surfactants containing dimethylene as a spacer, as well as that of conventional cationic single-chained surfactants, which is due to unique molecular structure of 18-triazole-18. 18-Triazole-18 may be adsorbed on the steel surface in acid medium through a maximum of four atoms or groups, i.e., the two nitrogen atoms of triazole ring and two quaternary ammonium head groups. Four regions of surfactant concentration could be divided to illustrate the adsorption of 18-triazole-18 on the steel surface, and four different adsorption mechanisms may take place in different regions of surfactant concentration.

  7. Adsorption and corrosion inhibition behavior of hydroxyethyl cellulose and synergistic surfactants additives for carbon steel in 1M HCl.

    Science.gov (United States)

    Mobin, Mohammad; Rizvi, Marziya

    2017-01-20

    The inhibitory effect of hydroxyethylcellulose (HEC) on A1020 carbon steel corrosion in 1M HCl solution was evaluated at different concentrations and temperatures using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), UV-vis spectrophotometry, scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDX), atomic force microscopy (AFM) and quantum chemical analysis. Inhibition efficiency was found to increase with increase in concentration of HEC but decreased with increasing temperature. Inhibitory effect of HEC mixed with minimal concentration of surfactants, triton X 100 (TX), cetyl pyridinium chloride (CPC) and sodium dodecyl sulfate (SDS) was also evaluated. HEC gets adsorbed onto the mild steel surface via mixed type adsorption. Ea, ΔH, ΔS and ΔG⁰ads, the thermodynamic and activation parameters, were calculated and discussed. Adsorption of inhibitor on the steel/solution interface follows Langmuir adsorption isotherm. EIS suggests formation of protective layer over the carbon steel surface. Results of different experimental techniques pertaining to the inhibitory effect of HEC and HEC mixed with surfactants are in good agreement with theoretical quantum chemical investigation.

  8. Synthesis and characterization of an effective organic/inorganic hybrid green corrosion inhibitive complex based on zinc acetate/Urtica Dioica

    Science.gov (United States)

    Salehi, E.; Naderi, Reza; Ramezanzadeh, B.

    2017-02-01

    This study aims at synthesis and characterization of an effective corrosion inhibitive complex based on zinc acetate/Urtica Dioica (ZnA-U.D) for corrosion protection of mild steel in chloride solution. The chemical structure and morphology of the complex were characterized by Fourier transform infrared spectroscopy (FT-IR), UV-vis, thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The corrosion protection performance of the mild steel samples dipped in 3.5 wt.% NaCl solutions with and without ZnA-U.D extract was investigated by visual observations, open circuit potential (OCP) measurements, electrochemical impedance spectroscopy (EIS) and polarization test. Results revealed that the ZnA successfully chelated with organic inhibitive compounds (i.e Quercetin, Quinic acid, Caffeic acid, Hystamine and Serotonin) present in the U.D extract. The electrochemical measurements revealed the effective inhibition action of ZnA-U.D complex in the sodium chloride solution on the mild steel. The synergistic effect between Zn2+ and organic compounds present in the U.D extract resulted in protective film deposition on the steel surface, which was proved by SEM and XPS analyses.

  9. Influence of surfactants on the corrosion inhibition behaviour of 2-aminophenyl-5-mercapto-1-oxa-3,4-diazole (AMOD) on mild steel

    Energy Technology Data Exchange (ETDEWEB)

    Rafiquee, M.Z.A. [Department of Applied Chemistry, Corrosion Research Laboratory, Faculty of Engineering and Technology, Aligarh Muslim University, Aligarh 202002 (India)], E-mail: drrafiquee@gmail.com; Saxena, Nidhi; Khan, Sadaf [Department of Applied Chemistry, Corrosion Research Laboratory, Faculty of Engineering and Technology, Aligarh Muslim University, Aligarh 202002 (India); Quraishi, M.A. [Department of Applied Chemistry, IT-BHU Banaras Hindu University (India)

    2008-02-15

    The corrosion inhibition characteristics of 2-aminophenyl-5-mercapto-1-oxa-3,4-diazole (AMOD) on mild steel in HCl solution have been studied by weight loss studies and potentiodynamic polarization. AMOD is a good corrosion inhibitor in HCl solution and its inhibition efficiency is increased markedly in presence of surfactants (SDS, CTAB, TX-100). TX-100 is found to be most effective among the tested surfactants. Weight loss measurements showed that the inhibition efficiency increased with the increasing surfactant concentration and attained a maximum value around 0.2 mol dm{sup -3}. In presence of surfactant, the adsorption of AMOD on the mild steel surface obeyed Langmuir's adsorption isotherm. The influence of inhibitor concentration, solution temperature, and acid concentration on the corrosion rate of mild steel has also been investigated. The deduced thermodynamic parameters for adsorption reveal a strong interaction between the inhibitor and mild steel surface. The negative values of G{sub ads} indicate the spontaneous adsorption of inhibitors on the mild steel surface. Potentiodynamic polarization studies show that these surfactants are mixed-type inhibitors.

  10. Comparative Corrosion Inhibition Effect of Imidazole Compounds and of Trichodesma indicum (Linn R. Br. on C38 Steel in 1 M HCl Medium

    Directory of Open Access Journals (Sweden)

    S. Alarmal Mangai

    2013-01-01

    Full Text Available Corrosion inhibition effect of alkaloid extract part of the plant Trichodesma indicum (Linn R. Br. of Boraginaceae family was studied and compared with that of imidazole compounds (imidazole, benzimidazole on C38 steel in 1 M HCl solution by weight loss method at various temperatures. The study showed that the alkaloid part of the plant extract acts as a better inhibitor in comparison to the selected organic inhibitors. The maximum inhibition efficiency of the extract of Trichodesma indicum R. Br. was found to be 94.5% at a concentration of 75 mg/L at 30°C.

  11. Quantum chemical studies on the inhibition potentials of some Penicillin compounds for the corrosion of mild steel in 0.1 M HCl.

    Science.gov (United States)

    Eddy, Nnabuk Okon; Ebenso, Eno E

    2010-07-01

    Inhibitive and adsorption properties of Penicillin G, Amoxicillin and Penicillin V potassium were studied using gravimetric, gasometric and quantum chemical methods. The results obtained indicate that these compounds are good adsorption inhibitors for the corrosion of mild steel in HCl solution. The adsorption of the inhibitors on mild steel surface is spontaneous, exothermic and supports the mechanism of physical adsorption. From DFT results, the sites for nucleophilic attacks in the inhibitors are the carboxylic acid functional group while the sites for electrophilic attacks are in the phenyl ring. There was a strong correlation between theoretical and experimental inhibition efficiencies.

  12. Experimental and theoretical studies on the corrosion inhibition of copper by two indazole derivatives in 3.0% NaCl solution.

    Science.gov (United States)

    Qiang, Yujie; Zhang, Shengtao; Xu, Shenying; Li, Wenpo

    2016-06-15

    Corrosion experiments and theoretical calculations were performed to investigate the inhibition mechanism of indazole (IA) and 5-aminoindazole (AIA) for copper in NaCl solution. The results obtained from weight loss and electrochemical experiments are in good agreement, and reveal that these compounds are high-efficiency inhibitors with inhibition efficiency order: AIA>IA, which was further confirmed by field emission scanning electronic microscope (FESEM) observation. Besides, the quantum chemical calculations and molecular dynamics (MD) simulation showed that both studied inhibitors are adsorbed strongly on the copper surface in parallel mode. The adsorption of these molecules on copper substrate was found to obey Langmuir isotherm.

  13. 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.

  14. Investigation of the inhibitive effect of N-phosphono-methyl-glycine on the corrosion of carbon steel in neutral solutions by electrochemical techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pech-Canul, M.A.; Chi-Canul, L.P. [CHINVESTAV-IPN-Merida (Mexico). Dept. de Fisica Aplicada

    1998-12-31

    Steady-state current-voltage curves for various disk rotation rates were combined with electrochemical impedance measurements in order to investigate the corrosion inhibition of carbon steel by N-phosphono-methyl-glycine (NPMG)/Zn{sup 2+} mixtures with a concentration ratio of 1:1 between NPMG and zinc cations, in a model water. The efficiency of the NPMG/Zn{sup 2+} combination increases with concentration in the range 10--100 ppm, and it acts as a mixed type inhibitor, affecting both the anodic and cathodic reactions. The corrosion behavior in all the metal/environments investigated is characterized by the formation of a 3-D porous layer which tends to hinder the diffusion of oxygen. Such layer consists of corrosion products in the blank solution and of corrosion products and/or inhibitors in the presence of the NPMG/Zn{sup 2+} mixture. The impedance response of such layers depends on inhibitor concentration, exposure time and rotation rate of the disk. From electrochemical impedance measurements it was found that the oxygen reduction reaction is under mixed activation diffusion control. It was shown by both steady-state and impedance measurements that there is a significant effect of rotation speed on the anodic reaction.

  15. DFT and QSAR study of corrosion inhibition on 3,5-di-substituted pyrazole derivatives with heteroatom on position one

    Directory of Open Access Journals (Sweden)

    Mariam Olayemi Abdulazeez

    2016-12-01

    Full Text Available Abdulazeez, M.O., Oyabamiji, A.K. and Semire, B. 2016. DFT and QSAR study of corrosion inhibition on 3,5-di-substituted pyrazole derivatives with heteroatom on position one. Lebanese Science Journal, 17(2: 217-232. A class of organic corrosion inhibitors namely; 2,5-bis(4-dimethylaminophenyl-1,3,4-thiadiazole (DAPT, 2,5-bis(4-dimethylaminophenyl-1,3,4-oxadiazole (DAPO, 3,5-diphenyl-4H-1,2,4-triazole (DHT, 3,5-di(4-pyridyl-4H-1,2,4-triazole (PHT, 2,5-bis(4-aminophenyl-1,3,4-oxadiazole (PAOX, 3,5-di(4-methylthiophenyl-4H-1,2,4-triazole (4-MTHT were investigated at density functional theory (DFT B3LYP/6-31G** (d,p level. The calculated molecular descriptors such as the HOMO, LUMO, the dipole moment, chemical potential (μ, chemical hardness (ղ, softness (s, global nucleophilicity (N and average Mulliken charges on nitrogen atoms are discussed in relation to the observed inhibitory efficiency for the compounds. The developed qualitative structural activity relationship (QSAR models relate the calculated molecular descriptors to the corrosion efficiency; thus QSAR model predicted the experimental corrosion efficiencies. The possible sites for nucleophilic and electrophilic attacks on the compounds were analyzed through the Fukui functions.

  16. Adsorption isotherm and inhibition effect of a synthesized di-(m-Formylphenol)-1,2-cyclohexandiimine on corrosion of steel X52 in HCl solution

    Institute of Scientific and Technical Information of China (English)

    A karimi; I Danaee; H Eskandari; M RashvanAvei

    2016-01-01

    The potential of di-(m-Formylphenol)-1,2-cyclohexandiimine as an environmentally friendly corrosion inhibitor for steel was investigated in 1 mol/L HCl using potentiodynamic polarization, electrochemical impedance spectroscopy and chronoamperometry measurements. All electrochemical measurements suggest that this compound is an excellent corrosion inhibitor for mild steel and the inhibition efficiency increases with the increase in inhibitor concentration. The effect of temperature on the corrosion behavior of mild steel with the addition of the Schiff base was studied in the temperature range from 25 °C to 65 °C. It is found that the adsorption of this inhibitor follows the Langmuir adsorption isotherms. The value of activation energy and the thermodynamic parameters such asΔHads,ΔSads,Kads andΔGads were calculated by the corrosion currents at different temperatures using the adsorption isotherm. The morphology of mild steel surface in the absence and presence of inhibitor was examined by scanning electron microscopy (SEM) images.

  17. Adsorption and corrosion inhibition effect of Schiff base molecules on the mild steel surface in 1 M HCl medium: a combined experimental and theoretical approach.

    Science.gov (United States)

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

    2015-02-28

    Corrosion inhibition performance of 2-(2-hydroxybenzylideneamino)phenol (L(1)), 2-(5-chloro-2-hydroxybenzylideneamino)phenol (L(2)) and 2-(2-hydroxy-5-nitrobenzylideneamino)phenol (L(3)) on the corrosion behaviour of mild steel surface in a 1 M hydrochloric acid (HCl) solution is investigated by sophisticated analytical methods like potentiodynamic polarization, electrochemical impedance spectroscopy and weight loss measurements. Polarization studies showed that all the compounds are mixed type (cathodic and anodic) inhibitors and the inhibition efficiency (η%) increased with increasing inhibitor concentration. The inhibition actions of these Schiff base molecules are discussed in view of blocking the electrode surface by means of adsorption of the inhibitor molecule obeying the Langmuir adsorption isotherm. Scanning electron microscopy (SEM) studies of the metal surfaces confirmed the existence of an adsorbed film. Density functional theory (DFT) and molecular dynamics (MD) simulation have been used to determine the relationship between molecular configuration and their inhibition efficiencies. The order of inhibition performance obtained from experimental results is successfully verified by DFT and MD simulation.

  18. BTA Film Growth on Copper and Its Corrosion Inhibition Investigated by UHV-STM and LEED

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Kye Hyun [School of Metallurgy and Materials Engineering College of Engineering, Yeungnam University, Kyungbook (Korea, Republic of)

    1996-12-25

    The adsorption and film growth of the organic inhibitor(Benzotriazole: BTA) on the copper single crystal were investigated by the UHV-STM(Scanning Tunnelling Microscope) and LEED. The BTA adsorbed structure on the clean Cu(110)-1*1 surface exhibited well-ordered c(4*2) structure by STM image and LEED pattern. Further deposition of BTA on monolayer film, BTA film growth on the clean surface exhibited 2-dimensional growth mode with commensurate growth film. On the other hand, the BTA adsorbed structure on oxygen induced Cu(110)-2*1 surface was a fully-disordered cluster-like structure. For the multilayer film on the oxygen induced Cu(110)-2*1 surface, the BTA film was grown by 3-dimensional growth mode. BTA preferential adsorption was seen the oxygen induced Cu(110)-2*1 surface. The inhibition mechanism of the BTA on copper single crystal on both the clean Cu(110)-1*1 surface and the oxygen induced Cu(110)-2*1 surface was exerted by the complete blocking of the polymerized multi-layer film. (author). 24 refs., 4 figs.

  19. Corrosion inhibition performance of 2,5-bis(4-dimethylaminophenyl)-1,3,4-oxadiazole for carbon steel in HCl solution: Gravimetric, electrochemical and XPS studies

    Science.gov (United States)

    Bouanis, M.; Tourabi, M.; Nyassi, A.; Zarrouk, A.; Jama, C.; Bentiss, F.

    2016-12-01

    Corrosion inhibition of carbon steel in normal hydrochloric acid solution at 30 °C by 2,5-bis(4-dimethylaminophenyl)-1,3,4-oxadiazole (DAPO) has been studied by weight loss measurements and electrochemical techniques (polarization and AC impedance). The experimental results showed that DAPO acted as an efficient inhibitor against the carbon steel corrosion in 1 M HCl, and its inhibition efficiency increased with the inhibitor concentration reaching a value up to 93% at 1 mM. Polarization studies showed that the DAPO was a mixed-type inhibitor. The adsorption of this 1,3,4-oxadiazole derivative on the carbon steel surface in 1 M HCl solution followed the Langmuir adsorption isotherm and the corresponding value of the standard Gibbs free energy of adsorption (ΔG°ads) is associated to a chemisorption mechanism. Scanning Electron Microscopy (SEM) and X-Ray Photoelectron Spectroscopy (XPS) analyses were carried out to characterize the chemical composition of the inhibitive film formed on the steel surface. The surfaces studies showed that the inhibitive layer is composed of an iron oxide/hydroxide mixture where DAPO molecules are incorporated. The cytotoxicity of DAPO was also determined using cell culture system.

  20. 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)

  1. Corrosion-resistant metallic coatings

    OpenAIRE

    F. Presuel-Moreno; M.A. Jakab; N. Tailleart; Goldman, M.; J. R. Scully

    2008-01-01

    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 i...

  2. Synthesis, Characterization, Antimicrobial Studies and Corrosion Inhibition Potential of 1,8-dimethyl-1,3,6,8,10,13-hexaazacyclotetradecane: Experimental and Quantum Chemical Studies

    Directory of Open Access Journals (Sweden)

    Henry U. Nwankwo

    2016-02-01

    Full Text Available The macrocylic ligand, 1,8-dimethyl-1,3,6,8,10,13-hexaazacyclotetradecane (MHACD was synthesized by the demetallation of its freshly synthesized Ni(II complex (NiMHACD. Successful synthesis of NiMHACD and the free ligand (MHACD was confirmed by various characterization techniques, including Fourier transform infra-red (FT-IR, proton nuclear magnetic resonance (1H-NMR, carbon-13 nuclear magnetic resonance (13C-NMR, ultraviolet-visible (UV-vis, and energy dispersive x-ray (EDX spectroscopic techniques. The anti-bacteria activities of MHACD were investigated against Staphylococcus aureus and Enterococcus species and the results showed that MHACD possesses a spectrum of activity against the two bacteria. The electrochemical cyclic voltammetry study on MHACD revealed that it is a redox active compound with promising catalytic properties in electrochemical applications. The inhibition potential of MHACD for mild steel corrosion in 1 M HCl was investigated using potentiodynamic polarization method. The results showed that MHACD inhibits steel corrosion as a mixed-type inhibitor, and the inhibition efficiency increases with increasing concentration of MHACD. The adsorption of MHACD obeys the Langmuir adsorption isotherm; it is spontaneous and involves competitive physisorption and chemisorption mechanisms. Quantum chemical calculations revealed that the energy of the highest occupied molecular orbital (HOMO of MHACD is high enough to favor forward donation of charges to the metal during adsorption and corrosion inhibition. Natural bond orbital (NBO analysis revealed the presence of various orbitals in the MHACD that are capable of donating or accepting electrons under favorable conditions.

  3. Structure effect of some amine derivatives on corrosion inhibition efficiency for carbon steel in acidic media using electrochemical and Quantum Theory Methods

    Directory of Open Access Journals (Sweden)

    Ahmed M. Al-Sabagh

    2013-06-01

    Full Text Available The structure effect on corrosion inhibition of two amines and their derivatives is the main object of this article. The first amine was 1,8-diaminooctane and its ethoxylated (50 e.o. 1,8-diaminooctane and propoxylated (50 p.o. 1,8-diaminooctane. The second amine is the tetraethylenepentamine and its ethoxylated (50 e.o. and propoxylated (50 p.o. derivatives. The investigations were carried out by open circuit potential, potentiodynamic polarization, electrochemical impedance, quantum calculations and SEM measurements. The data obtained for the first amine showed the minimum inhibition efficiency (65.5%, meanwhile the maximum inhibition efficiency was 78.9% for its propoxylated derivative. On the other hand the maximium inhibition efficiency was 91% for the second propoxylated amine. The electronic properties; HOMO and LUMO energy levels, energy gap, dipole moment, polarizability, log P, total energy, charge densities, area/molecule and hydration energy have been calculated. The inhibition efficiency was calculated theoretically using the electronic parameters. From the obtained results, there is a significant difference between the inhibition efficiency of the electronic and the inhibition efficiency experimentally. The results were discussed on the light of the chemical structure of the used inhibitors. In general, the inhibition efficiency is affected by the shape and structure of the molecule.

  4. 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,

  5. Corrosion Inhibition Of Mild Steel In 0.5 M H2so4 By 1-(2- Methyl-4-(2-Methylphenyldiazenyl Phenyl Azonapthalen-2-Ol

    Directory of Open Access Journals (Sweden)

    S.ANANTH KUMAR

    2013-09-01

    Full Text Available The effect of addition of1-(2-methyl-4-(2-methylphenyldiazenyl phenyl azonapthalen-2-ol on the corrosion of steel in 0.5M H2SO4 acid has been studied by weight loss measurements, potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS measurements. The inhibition efficiency was found to increase with inhibitors content to attain 61.00% and 79.66% 1-(2-methyl-4-(2-methylphenyldiazenyl phenyl azonapthalen-2-ol and 25ppm(Tetra butyl ammonium bromideTBAB respectively. Data obtained from EIS studies were analyzed to determinate the model inhibition process through appropriate equivalent circuit models. Inhibition efficiency E (% obtained from the various methods is in good agreement.

  6. Novel cationic surfactants from fatty acids and their corrosion inhibition efficiency for carbon steel pipelines in 1 M HCl

    Directory of Open Access Journals (Sweden)

    A.M. Al-Sabagh

    2011-06-01

    Full Text Available Four fatty acids were used as a source of alkyl halides. Untraditionally tertiary amines were prepared by ethoxylation of aromatic and aliphatic fatty amines. These alkyl halide and tertiary amines were used to prepare 20 cationic quaternary ammonium surfactants (QASS. Their chemical structures were characterized and they tested as corrosion inhibitors for carbon steel in 1 M HCl solution. The corrosion inhibition efficiency was measured using, weight loss and potentiodynamic polarization methods. The inhibition efficiencies obtained from the two employed methods are nearly closed. From the obtained data it was found that, the inhibition efficiency increases with increasing the inhibitor concentration until the optimum one. Also, it was found that the inhibition efficiency of QASs which based on ethoxylated aromatic tertiary amine is greater than the obtained efficiencies by the QASs which based on ethoxylated aliphatic tertiary amines. The QASs based on alkyl halide C16 exhibited the maximum inhibition efficiency 98.8%. Adsorption of the inhibitors on the carbon steel surface was found to obey Langmuir’s adsorption isotherm. The quantum chemical calculations were done for some selected quaternary ammonium compounds based on their chemical structures QL1,4,5–QP3,4,5. The following quantum chemical indices such as the bond length, bond angle, charge density distribution, highest occupied molecular orbital (HOMO, lowest unoccupied molecular orbital (LUMO, energy gap ΔE = HOMO − LUMO, and dipole moment (u were considered. The relation between these parameters and the inhibition efficiencies was explained on the light of the chemical structure of the used inhibitors.

  7. Synthesis and characterization of a novel eco-friendly corrosion inhibition for mild steel in 1 M hydrochloric acid

    Science.gov (United States)

    Al-Amiery, Ahmed A.; Binti Kassim, Fatin A.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar

    2016-01-01

    The acid corrosion inhibition process of mild steel in 1 M HCl by azelaic acid dihydrazide has been investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). Azelaic acid dihydrazide was synthesized, and its chemical structure was elucidated and confirmed using spectroscopic techniques (infrared, nuclear magnetic resonance and mass spectroscopy). Potentiodynamic polarization studies indicate that azelaic acid dihydrazide is a mixed-type inhibitor. The inhibition efficiency increases with increased inhibitor concentration and reaches its maximum of 93% at 5 × 10−3 M. The adsorption of the inhibitor on a mild steel surface obeys Langmuir’s adsorption isotherm. The effect of temperature on corrosion behavior in the presence of 5 × 10−3 M inhibitor was studied in the temperature range of 30–60 °C. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. To inspect the surface morphology of inhibitor film on the mild steel surface, scanning electron microscopy (SEM) was used before and after immersion in 1.0 M HCl. PMID:26795066

  8. Synthesis and characterization of a novel eco-friendly corrosion inhibition for mild steel in 1 M hydrochloric acid

    Science.gov (United States)

    Al-Amiery, Ahmed A.; Binti Kassim, Fatin A.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar

    2016-01-01

    The acid corrosion inhibition process of mild steel in 1 M HCl by azelaic acid dihydrazide has been investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). Azelaic acid dihydrazide was synthesized, and its chemical structure was elucidated and confirmed using spectroscopic techniques (infrared, nuclear magnetic resonance and mass spectroscopy). Potentiodynamic polarization studies indicate that azelaic acid dihydrazide is a mixed-type inhibitor. The inhibition efficiency increases with increased inhibitor concentration and reaches its maximum of 93% at 5 × 10-3 M. The adsorption of the inhibitor on a mild steel surface obeys Langmuir’s adsorption isotherm. The effect of temperature on corrosion behavior in the presence of 5 × 10-3 M inhibitor was studied in the temperature range of 30-60 °C. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. To inspect the surface morphology of inhibitor film on the mild steel surface, scanning electron microscopy (SEM) was used before and after immersion in 1.0 M HCl.

  9. Adsorption and quantum chemical studies on the inhibition potentials of some thiosemicarbazides for the corrosion of mild steel in acidic medium.

    Science.gov (United States)

    Ebenso, Eno E; Isabirye, David A; Eddy, Nnabuk O

    2010-06-15

    Three thiosemicarbazides, namely 2-(2-aminophenyl)-N phenylhydrazinecarbothioamide (AP4PT), N,2-diphenylhydrazinecarbothioamide (D4PT) and 2-(2-hydroxyphenyl)-N-phenyl hydrazinecarbothioamide (HP4PT), were investigated as corrosion inhibitors for mild steel in H(2)SO(4) solution using gravimetric and gasometric methods. The results revealed that they all inhibit corrosion and their % inhibition efficiencies (%IE) follow the order: AP4PT > HP4PT > D4PT. The %IE obtained from the gravimetric and gasometric experiments were in good agreement. The thermodynamic parameters obtained support a physical adsorption mechanism and the adsorption followed the Langmuir adsorption isotherm. Some quantum chemical parameters were calculated using different methods and correlated with the experimental %IE. Quantitative structure activity relationship (QSAR) approach was used on a composite index of some quantum chemical parameters to characterize the inhibition performance of the studied molecules. The results showed that the %IE were closely related to some of the quantum chemical parameters, but with varying degrees. The calculated/theoretical %IE of the molecules were found to be close to their experimental %IE. The local reactivity has been studied through the Fukui and condensed softness indices in order to predict both the reactive centers and to know the possible sites of nucleophilic and electrophilic attacks.

  10. Corrosion Inhibition Effect of Furfural on Carbon Steel%糠醛对碳钢缓蚀性能的研究

    Institute of Scientific and Technical Information of China (English)

    刘峥

    2001-01-01

    The corrosion inhibition effect of furfural on the carbon steel was studied by weightloss method. It was shown that the furfural had strong corrosion inhibition effect on carbon steel in 5% HCl solution at 30 ℃. A strong synergistic effect was observed while using both furfural and sexamethyltetraamine as inhibitors. The inhibition mechanism was discussed by the authors.%采用失重法研究了糠醛对碳钢的缓蚀性能。实验表明30 ℃,4 h条件下,在5% 的盐酸中,糠醛具有较强的缓蚀作用,与六次甲基四胺复配缓蚀效果增强。通过研究找到了糠醛在碳钢上的吸附等温式,计算出碳钢溶解的表观活化能,研究了糠醛在碳钢上的吸附机理。研究表明糠醛为混合控制型缓蚀剂。

  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. Inhibition of Steel Corrosion and Alkaline Zinc Oxide Dissolution by Dicarboxylate Bola-Amphiphiles: Self-Assembly Supersedes Host-Guest Conception.

    Science.gov (United States)

    Schmelter, Dirk; Langry, Arthur; Koenig, Andrej; Keil, Patrick; Leroux, Fabrice; Hintze-Bruening, Horst

    2017-06-05

    For many decorative applications like industrial and architectural paints, prevention of metal substrates from corrosion is a primary function of organic coatings. Triggered release of inhibitor species is generally accepted as a remedy for starting corrosion in case of coatings damage. A polyurethane based coating, doped with bola-amphiphiles of varying molecular weight but with a common head group motif that stems from ring-opened alkenyl succinic anhydride, enables passivation of the defect and mitigates cathodic delamination, if applied on cold rolled steel. An antagonistic effect results from the intercalation of the bola-amphiphiles into layered double hydroxide Zn2Al(OH)6 and subsequent incorporation of the hybrid phase into the organic matrix. In particular higher molecular weight bola-amphiphiles get immobilized through alkaline degradation of the layered framework in the basic milieu at the cathode. By means of sediments from colloidal states it is demonstrated that in-situ formed zinc oxide encapsulates the hybrid phase, evidenced by impeded dissolution of the ZnO based shell into caustic soda. While inhibition of steel corrosion results from a Donnan barrier layer, impeded zinc oxide dissolution is rooted in zinc catalyzed bola-amphiphile hydrolysis and layered deposition of the crystalline spacer diol hydrogenated bisphenol-A.

  13. Electrochemical, quantum chemical and SEM investigation of the inhibiting effect and mechanism of ciprofloxacin, norfloxacin and ofloxacin on the corrosion for mild steel in hydrochloric acid

    Institute of Scientific and Technical Information of China (English)

    PANG XueHui; GUO Wenduan; LI WeiHua; XIE dianDong; HOU BaoRong

    2008-01-01

    The inhibiting effect and mechanism of 1-cyclopropyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylicacid(ciprofloxacin), 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid (norfloxacin) and (-)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7oxo-7 H-pyrido(1,2,3-de)-1,4-benzoxazine-6 carboxylic acid (ofloxacin) on the corrosion of mild steel in 1 mol/L HCl have been studied using electrochemical method, quantum chemical method and SEM at 303 K. The potentiodynamic results showed that these compounds suppressed both cathodic and anodic processes of mild steel corrosion in 1 mol/L HCl. The impedance spectroscopy showed that Rp values increased, and Cdl values decreased with the rising of the working concentration. Quantum chemical calculation showed that there was a positive correlation between some inhibitors structure properties and the inhibitory efficiency. The inhibitors function through adsorption followed Langmuir isotherm, and chemisorption made more contribution to the adsorption of the inhibitors on the steel surface compared with physical adsorption. SEM analysis suggested that the metal had been protected from aggressive corrosion because of the addition of the inhibitors.

  14. Effect of three 2-allyl-p-mentha-6,8-dien-2-ols on inhibition of mild steel corrosion in 1 M HCl

    Directory of Open Access Journals (Sweden)

    S. Kharchouf

    2014-11-01

    Full Text Available 2-Allyl-p-mentha-6,8-dien-2-ols P1−P3 synthesized from carvone P are tested as corrosion inhibitors of steel in 1 M HCl using weight loss measurements, potentiodynamic polarisation and impedance spectroscopy (EIS methods. The addition of 2-allyl-p-mentha-6,8-dien-2-ols reduced the corrosion rate. Potentiodynamic polarisation studies clearly reveal that the presence of inhibitors does not change the mechanism of hydrogen evolution and that they act essentially as cathodic inhibitors. 2-Allyl-p-mentha-6,8-dien-2-ols tested adsorb on the steel surface according to Langmuir isotherm. From the adsorption isotherm some thermodynamic data for the adsorption process are calculated and discussed. EIS measurements show the increase of the charge-transfer resistance with the inhibitor concentration. The highest inhibition efficiency (92% is obtained for P1 at 3 g/L. The corrosion rate decreases with the rise of temperature. The corresponding activation energies are determined.

  15. Electrochemical, quantum chemical and SEM investigation of the inhibiting effect and mechanism of ciprofloxacin, norfloxacin and ofloxacin on the corrosion for mild steel in hydrochloric acid

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The inhibiting effect and mechanism of 1-cyclopropyl-6-fluoro-1,4-dihydro -4-oxo-7-(1-piperazinyl) -3- quinoline carboxylicacid(ciprofloxacin), 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(1-piperazinyl)-3-quinoline carboxylic acid (norfloxacin) and (?)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7- oxo-7 H-pyrido(1,2,3-de)-1,4- benzoxazine-6 carboxylic acid (ofloxacin) on the corrosion of mild steel in 1 mol/L HCl have been studied using electrochemical method, quantum chemical method and SEM at 303 K. The potentiodynamic results showed that these compounds suppressed both cathodic and an-odic processes of mild steel corrosion in 1 mol/L HCl. The impedance spectroscopy showed that Rp values increased, and Cdl values decreased with the rising of the working concentration. Quantum chemical calculation showed that there was a positive correlation between some inhibitors structure properties and the inhibitory efficiency. The inhibitors function through adsorption followed Langmuir isotherm, and chemisorption made more contribution to the adsorption of the inhibitors on the steel surface compared with physical adsorption. SEM analysis suggested that the metal had been protected from aggressive corrosion because of the addition of the inhibitors.

  16. 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.

  17. Corrosion of low Si-alloyed steels in aqueous solution at 90 deg. C. Inhibitive action of silicates; Corrosion d'aciers faiblement allies au silicium en solution aqueuse a 90 deg. C. Action inhibitrice des silicates

    Energy Technology Data Exchange (ETDEWEB)

    Giordana, S

    2002-02-01

    Low-Si alloyed steels, with Si content ranging from 0.25 to 3.2 wt%, as potential candidate materials for high-level nuclear waste disposal containers, have been studied four the point of view of their corrosion behaviour at 90 deg C in an aqueous solution simulating groundwater (0.1 M NaCl borate-buffered solution with a pH of 8.5) both in reducing and in aerated conditions. The influence of silicate addition to the solution is examined so as to represent the silicon of groundwater, coming from the clay dissolution. When no silicate was added to the solution, silicon as an alloying element was proved to degrade in the first moments the steel ability to passivate. For longer immersion times, protective effects developed most efficiently on the steel containing 3.2 wt% silicon both in reducing an in aerating conditions, Infrared spectroscopy, EDSX, XRD and Raman microprobe were applied to characterise the oxide layer composition, which was found to be a mixture of magnetite and maghemite. In the presence of silicate in the solution, clay-like iron silicates appeared in the corrosion layer. Electrochemical tests results show that adding silicate into solution resulted in increasing the steel ability to passivate. In the short term, the inhibiting effect of silicate was confirmed by mass loss tests, but the tendency was inverse in the long term. Silicate iron layers were eventually less protective than the magnetite layers formed in the absence of silicate. (author)

  18. The synergistic effect of Na{sub 3}PO{sub 4} and benzotriazole on the inhibition of copper corrosion in tetra-n-butylammonium bromide aerated aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Liu, S.; Dong, J.; Guan, W.W.; Duan, J.M.; Jiang, R.Y. [Department of Applied Chemistry, South China University of Technology, Guangzhou 510640 (China); Feng, Z.P.; Song, W.J. [Guangzhou Institute of Energy Conversion, CAS, Guangzhou 510640 (China)

    2012-11-15

    The effect of Na{sub 3}PO{sub 4} and the mixture of benzotriazole (BTA) and Na{sub 3}PO{sub 4} (SP) on the corrosion of copper in 17 wt% (0.534 mol/L) tetra-n-butylammonium bromide (TBAB) aerated aqueous solution has been investigated by means of weight-loss test, potentiodynamic polarization test, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy/energy dispersive X-ray techniques. The experimental results showed that a dosage of Na{sub 3}PO{sub 4} stimulated the copper corrosion, and the corrosion rate increased with increasing Na{sub 3}PO{sub 4} concentration, whereas the mixture of BTA and Na{sub 3}PO{sub 4} could protect copper in aqueous TBAB solution. The inhibition action of the mixture of BTA and Na{sub 3}PO{sub 4} on the corrosion of copper is mainly due to the inhibition of the anodic process of corrosion. The inhibition efficiency of a mixture consisting of 2 g/L BTA and 1 g/L Na{sub 3}PO{sub 4} was about 96%. The mixture of BTA and Na{sub 3}PO{sub 4} inhibits the corrosion of copper better than BTA by itself, indicating that Na{sub 3}PO{sub 4} has a synergistic role with BTA on the corrosion inhibition of copper in TBAB aqueous solution. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. One-step fabrication of biomimetic superhydrophobic surface by electrodeposition on magnesium alloy and its corrosion inhibition.

    Science.gov (United States)

    Liu, Yan; Xue, Jingze; Luo, Dan; Wang, Huiyuan; Gong, Xu; Han, Zhiwu; Ren, Luquan

    2017-04-01

    A facile, rapid and one-step electrodeposition process has been employed to construct a superhydrophobic surface with micro/nano scale structure on a Mg-Sn-Zn (TZ51) alloy, which is expected to be applied as a biodegradable biomedical implant materials. By changing the electrodeposition time, the maximum contact angle of the droplet was observed as high as 160.4°±0.7°. The characteristics of the as-prepared surface were conducted by field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR). Besides, the anti-corrosion performance of the coatings in stimulated body fluid (SBF) solution were investigated by electrochemical measurement. The results demonstrated that the anti-corrosion property of superhydrophobic surface was greatly improved. This method show beneficial effects on the wettability and corrosion behavior, and therefore provides a efficient route to mitigate the undesirable rapid corrosion of magnesium alloy in favor of application for clinical field. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Corrosion inhibition by leaves and stem extracts of Sida acuta for mild steel in 1 M H2SO4 solutions investigated by chemical and spectroscopic techniques

    Directory of Open Access Journals (Sweden)

    S.A. Umoren

    2016-09-01

    Full Text Available Corrosion inhibition of mild steel in 1 M H2SO4 by leaves and stem extracts of Sida acuta was studied using chemical (weight loss and hydrogen evolution and spectroscopic (AAS, FTIR and UV-V techniques at 30–60 °C. It was found that the leaves and stem extracts of S. acuta inhibited the acid induced corrosion of mild steel. The inhibition efficiency increases with increase in concentration of the extracts but decrease with rise in temperature. Inhibitive effect was afforded by adsorption of the extracts’ components which was approximated by Freundlich adsorption isotherm. Inhibition mechanism is deduced from the temperature dependence of the inhibition efficiency and also from spectroscopic results.

  1. Investigation of the inhibitive effect of N-phosphono-methyl-glycine on the corrosion of carbon steel in neutral solutions by electrochemical techniques

    Energy Technology Data Exchange (ETDEWEB)

    Pech-Canul, M.A.; Chi-Canul, L.P.

    1999-10-01

    Steady-state current-voltage curves for various disk rotation rates were combined with electrochemical impedance measurements to investigate the corrosion inhibition of carbon steel by N-phosphono-methyl-glycine (NPMG)/Zn{sup 2+} mixtures with a concentration ratio of 1:1 between NPMG and zinc cations in a model water. Efficiency of the NPMG/Zn{sup 2+} formulation increased with concentration in the range from 10 ppm to 100 ppm, and it performed as a mixed type inhibitor, retarding the rate of the anodic and cathodic reactions. Analysis of impedance measurements by means of a simple model suggested that the oxygen reduction reaction was under mixed activation-diffusion control in blank solutions and nearly under diffusion control in the inhibited solutions. Results showed that with increasing rotation speeds, the rate of oxygen diffusion through the porous layer covering the electrode surface increased and the anodic dissolution reaction became slower.

  2. Effect of optimized structure and electronic properties of some benzimidazole derivatives on corrosion inhibition of mild steel in hydrochloric acid medium: Electrochemical and theoretical studies

    Indian Academy of Sciences (India)

    Alokdut Dutta; Sujit Sankar Panja; M M Nandi; Dipankar Sukul

    2015-05-01

    The corrosion inhibitive action of a few benzimidazole derivatives namely 2-(benzamido) ethylbenzimidazole (BAEBI), 2-(-benzenesulphonamido) ethylbenzimidazole (BSAEBI), 2-(benzamido) methylbenzimidazole (BAMBI) and 2-(-benzenesulphonamido) methylbenzimidazole (BSAMBI), towards mild steel in hydrochloric acid has been studied using potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) methods. The results show that these compounds get adsorbed on the mild steel surface following Temkin adsorption isotherm, and act as mixed-type inhibitors. The inhibition efficiencies are found to follow the order, BAEBI > BSAEBI > BAMBI > BSAMBI. This observation is explained in terms of chain length, relative effects of amido and sulphonamido groups, possible structural factors, spatial orientations, energy gap between the frontier molecular orbitals, different intrinsic molecular parameters, like, global hardness and softness, and number of electrons transferred.

  3. 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.

  4. 化学镀镍层缓蚀工艺研究%Study on Corrosion Inhibition Process of Electroless Nickel Coating

    Institute of Scientific and Technical Information of China (English)

    周慧云; 李继红; 刘斌; 曹祖军; 刘光明

    2014-01-01

    Objective To improve the corrosion resistance of electroless Ni-P coating. Methods Passivation treatment for corro-sion inhibition was conducted with phytic acid, sodium silicate, ammonium molybdate and hydrogen peroxide on the electroless Ni-P coating prepared on the steel substrate. The variation of corrosion resistance was investigated by dropping test and filter paper method. The optimal compositions of passivation solution were obtained by orthogonal experiments. Results The results showed that the complex inhibitor solution composed of phytic acid, sodium silicate, ammonium molybdate and hydrogen peroxide had good cor-rosion resistance in nitric acid dropping test. The electrochemical test showed that the corrosion current density of the composite passivation coating decreased and the impedance values increased by more than one order of magnitude. Conclusion The synergis-tic effect among the components in the passivation solution was observed. The optimized compositions of passivation solution were 6 g/ L of phytic acid, 6 g/ L of sodium silicate, 4 g/ L of ammonium molybdate, and 30 mL/ L of hydrogen peroxide.%目的:提高化学镀 Ni-P 镀层的耐蚀性能。方法在钢铁基体表面化学镀 Ni-P 镀层,采用植酸、硅酸钠、钼酸铵和双氧水中的一种或多种复配对镀层进行钝化处理。通过硝酸点滴法、贴滤纸法分析镀层耐蚀性的变化,并通过正交实验确定四种物质复配的最佳浓度。结果以植酸、硅酸钠、钼酸铵和双氧水为主要成分配制的复合缓蚀剂能使镀层耐硝酸效果良好,电化学实验表明,复合钝化膜的腐蚀电流密度降低和阻抗值增加都超过1个数量级。结论所研究的复合缓蚀剂各组分间存在协同效应,最佳配方为:6 g / L 植酸,6 g / L 硅酸钠,4 g / L 钼酸铵,30 mL/ L 双氧水。

  5. 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.

  6. 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.

  7. 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.

  8. Theoretical and experimental studies on the corrosion inhibition potentials of some purines for aluminum in 0.1 M HCl

    Directory of Open Access Journals (Sweden)

    Nnabuk O. Eddy

    2015-03-01

    Full Text Available Experimental aspect of the corrosion inhibition potential of adenine (AD, guanine (GU and, hypoxanthine (HYP was carried out using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS methods while the theoretical aspect of the work was carried out by calculations of semi-empirical parameters (for AM1, MNDO, CNDO, PM3 and RM1 Hamiltonians, Fukui functions and inhibitor–metal interaction energies. Results obtained from the experimental studies were in good agreement and indicated that adenine (AD, guanine (GU and hypoxanthine (HYP are good adsorption inhibitors for the corrosion of aluminum in solutions of HCl. Data obtained from electrochemical experiment revealed that the studied purines functioned by adsorption on the aluminum/HCl interface and inhibited the cathodic half reaction to a greater extent and anodic half reaction to a lesser extent. The adsorption of the purines on the metal surface was found to be exothermic and spontaneous. Deviation of the adsorption characteristics of the studied purines from the Langmuir adsorption model was compensated by the fitness of Flory Huggins and El Awardy et al. adsorption models. Quantum chemical studies revealed that the experimental inhibition efficiencies of the studied purines are functions of some quantum chemical parameters including total energy of the molecules (TE, energy gap (EL–H, electronic energy of the molecule (EE, dipole moment and core–core repulsion energy (CCR. Fukui functions analysis through DFT and MP2 theories indicated slight complications and unphysical results. However, results obtained from calculated Huckel charges, molecular orbital and interaction energies, the adsorption of the inhibitors proceeded through the imine nitrogen (N5 in GU, emanine nitrogen (N7 in AD and the pyridine nitrogen (N5 in HPY.

  9. Theoretical and experimental studies on the corrosion inhibition potentials of some purines for aluminum in 0.1 M HCl.

    Science.gov (United States)

    Eddy, Nnabuk O; Momoh-Yahaya, H; Oguzie, Emeka E

    2015-03-01

    Experimental aspect of the corrosion inhibition potential of adenine (AD), guanine (GU) and, hypoxanthine (HYP) was carried out using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods while the theoretical aspect of the work was carried out by calculations of semi-empirical parameters (for AM1, MNDO, CNDO, PM3 and RM1 Hamiltonians), Fukui functions and inhibitor-metal interaction energies. Results obtained from the experimental studies were in good agreement and indicated that adenine (AD), guanine (GU) and hypoxanthine (HYP) are good adsorption inhibitors for the corrosion of aluminum in solutions of HCl. Data obtained from electrochemical experiment revealed that the studied purines functioned by adsorption on the aluminum/HCl interface and inhibited the cathodic half reaction to a greater extent and anodic half reaction to a lesser extent. The adsorption of the purines on the metal surface was found to be exothermic and spontaneous. Deviation of the adsorption characteristics of the studied purines from the Langmuir adsorption model was compensated by the fitness of Flory Huggins and El Awardy et al. adsorption models. Quantum chemical studies revealed that the experimental inhibition efficiencies of the studied purines are functions of some quantum chemical parameters including total energy of the molecules (TE), energy gap (E L-H), electronic energy of the molecule (EE), dipole moment and core-core repulsion energy (CCR). Fukui functions analysis through DFT and MP2 theories indicated slight complications and unphysical results. However, results obtained from calculated Huckel charges, molecular orbital and interaction energies, the adsorption of the inhibitors proceeded through the imine nitrogen (N5) in GU, emanine nitrogen (N7) in AD and the pyridine nitrogen (N5) in HPY.

  10. Synergistic inhibition effect of 5-aminotetrazole and 4,6-dihydroxypyrimidine on the corrosion of cold rolled steel in H{sub 3}PO{sub 4} solution

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xianghong, E-mail: xianghong-li@163.com [Yunnan Key Laboratory of Wood Adhesives and Glue Products, Southwest Forestry University, Kunming 650224 (China); Faculty of Science, Southwest Forestry University, Kunming 650224 (China); Deng, Shuduan [Yunnan Key Laboratory of Wood Adhesives and Glue Products, Southwest Forestry University, Kunming 650224 (China); Xie, Xiaoguang [School of Chemical Science and Technology, Yunnan University, Kunming 650091 (China); Du, Guanben [Yunnan Key Laboratory of Wood Adhesives and Glue Products, Southwest Forestry University, Kunming 650224 (China)

    2016-09-15

    The synergistic inhibition effect of 5-aminotetrazole (AT) and 4,6-dihydroxypyrimidine (DHP) on the corrosion of cold rolled steel (CRS) in H{sub 3}PO{sub 4} solution was studied by weight loss, potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), quantum chemical calculation and molecular dynamics (MD) methods. The results show that AT exhibits a moderate inhibitive effect, and DHP has a poor effect. However, incorporation AT with DHP significantly improves the inhibitive performance, and yields synergism. The adsorption of AT in the absence and presence of DHP obeys Langmuir adsorption isotherm. AT/DHP mixture acts as a mixed-type inhibitor. The combined AT and DHP molecules co-adsorb on the Fe (001) surface in the nearly flat manner, and the adsorption energy is larger than individual AT or DHP. - Highlights: • There is a synergistic inhibition effect of AT and DHP for steel in H{sub 3}PO{sub 4} solution. • The adsorption of AT whether it is mixed with DHP or not obeys Langmuir isotherm. • The AT/DHP mixture behaves as a mixed-type inhibitor. • E{sub HOMO} increases and E{sub LUMO} decreases in the combined AT and DHP. • AT and DHP co-adsorb on Fe (001) surface with the nearly flat manner.

  11. 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

  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. 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%.

  14. Synergistic effect of sodium dodecyl sulfate and cetyltrimethyl ammonium bromide on the corrosion inhibition behavior of l-methionine on mild steel in acidic medium

    Directory of Open Access Journals (Sweden)

    M. Mobin

    2017-02-01

    Full Text Available The corrosion inhibition behavior of amino acid l-methionine (LMT separately and in combination with very low concentration of surfactants sodium dodecyl sulfate (SDS and cetyltrimethyl ammonium bromide (CTAB on mild steel in 0.1 M H2SO4 solution was studied, using weight loss and potentiodynamic polarization measurement techniques. The studies were carried out in the temperature range of 30–60 °C. The surface morphology of the corroded steel samples was studied by scanning electron microscopy (SEM and atomic force microscopy (AFM.The results show that LMT is an effective inhibitor for mild steel corrosion in 0.1 M H2SO4 which is synergistically improved in the presence of SDS and CTAB. The mixed LMT and CTAB is more effective as an inhibitor than mixture of LMT and SDS. The SEM and AFM photographs show a clearly different surface morphology in the presence of additives. LMT alone and in combination with surfactants obeys Langmuir adsorption isotherm from the fit of the experimental data of all concentrations and temperatures studied. Phenomenon of physical adsorption is proposed from the trend of the IE with temperature and also the values of activation energy (Ea, standard enthalpy of adsorption (ΔHads, and standard free energy of adsorption (ΔGads obtained. The results obtained by potentiodynamic polarization measurements are consistent with the results of the weight loss measurements. LMT acts as a mixed type inhibitor.

  15. Synthesis and study of the mechanisms of action of biodegradable additives for corrosion and scale inhibition in industrial cooling water systems; Mise au point et etude des mecanismes d'action d'additifs biodegradables pour l'inhibition du pouvoir entartrant et corrosif des eaux de refroidissement industrielles

    Energy Technology Data Exchange (ETDEWEB)

    Estievenart, C.

    2003-11-01

    Industrial cooling water systems undergo more and more environmental constraints. The recycling of water increases the risks of scale deposition and corrosion. The use of chemical additives to inhibit these phenomena is necessary. Poly-aspartates are proposed as green multi-functional inhibitors. Polymers of different characteristics have been synthesized by different ways. Their efficiency towards scale deposition and corrosion is determined by electrochemical techniques in different test conditions (composition of the test water, temperature, flow rate, concentration of additive...). Their biodegradability is also evaluated. These poly-aspartates inhibit both nucleation and growth of calcium carbonate crystals, but also corrosion. Their efficiency depends on the characteristics of the polymers and their way of synthesis. The morphology of scale and corrosion deposits is modified in the presence of poly-aspartate. The mechanism of action of poly-aspartates combines adsorption, dispersion, complexation with both iron and calcium ions and insertion in the crystal lattice. (author)

  16. The Inhibition of Aluminum Corrosion in Sulfuric Acid by Poly(1-vinyl-3-alkyl-imidazolium Hexafluorophosphate)

    OpenAIRE

    Paulina Arellanes-Lozada; Octavio Olivares-Xometl; Diego Guzmán-Lucero; Natalya V. Likhanova; Marco A. Domínguez-Aguilar; Irina V. Lijanova; Elsa Arce-Estrada

    2014-01-01

    Compounds of poly(ionic liquid)s (PILs), derived from imidazole with different alkylic chain lengths located in the third position of the imidazolium ring (poly(1-vinyl-3-dodecyl-imidazolium) (PImC12), poly(1-vinyl-3-octylimidazolium) (PImC8) and poly(1-vinyl-3-butylimidazolium) (PImC4) hexafluorophosphate) were synthesized. These compounds were tested as corrosion inhibitors on aluminum alloy AA6061 in diluted sulfuric acid (0.1–1 M H2SO4) by weight loss tests, polarization resistance meas...

  17. Inhibition Behaviour of 2-butine1, 4diol and Tartrate Salt, and Their Synergistic Effects on Corrosion of AA3003 Aluminium Alloy in 0.5% NaCl Solution

    Institute of Scientific and Technical Information of China (English)

    Taghi Shahrabi; Alireza Yazdzad; Mirghasem Hosseini

    2008-01-01

    This work intends to investigate the inhibition behaviour of 2-butine 1, 4diol and potassium sodium tartrate and their synergistic effects on 3003 aluminium alloy corrosion in 0.5% NaCl solution. Experiments were carried out by electrochemical impedance spectroscopy (EIS) and Tafel polarization method in a three-electrode cell. It was concluded that the inhibition efficiencies increased with an increase in the concentrations of inhibitors. For 2-butinel, 4diol and tartrate salt, the optimum in the inhibition efficiency, at room temperature and neutral pH, was observed for concentrations close to 10-3 mol/L and 1.5×10-3mol/L, respectively. The electrochemical results illustrated that 2-butine1, 4diol and tartrate salt, have significant synergistic inhibition effects on corrosion of 3003 aluminium alloy in 0.5% NaCl solution. The optimum ratio of concentrations for tartrate to alcohol was 2:1.

  18. Electrochemical measurements for the corrosion inhibition of mild steel in 1 M hydrochloric acid by using an aromatic hydrazide derivative

    Directory of Open Access Journals (Sweden)

    P. Preethi Kumari

    2017-07-01

    Full Text Available The influence of an aromatic hydrazide derivative, 2-(3,4,5-trimethoxybenzylidene hydrazinecarbothioamide (TMBHC as corrosion inhibitor on mild steel in 1 M hydrochloric acid was studied by Tafel polarization and electrochemical impedance spectroscopy (EIS technique. The results showed that the inhibition efficiency (% IE of TMBHC increased with increasing inhibitor concentrations and also with increase in temperatures. TMBHC acted as a mixed type of inhibitor and its adsorption on mild steel surface was found to follow Langmuir’s adsorption isotherm. The evaluation of thermodynamic and activation parameters indicated that the adsorption of TMBHC takes place through chemisorption. The formation of protective film was further confirmed by scanning electron microscopy (SEM.

  19. Density Functional Theory (DFT) modeling and Monte Carlo simulation assessment of inhibition performance of some carbohydrazide Schiff bases for steel corrosion

    Science.gov (United States)

    Obot, I. B.; Kaya, Savaş; Kaya, Cemal; Tüzün, Burak

    2016-06-01

    DFT and Monte Carlo simulation were performed on three Schiff bases namely, 4-(4-bromophenyl)-N‧-(4-methoxybenzylidene)thiazole-2-carbohydrazide (BMTC), 4-(4-bromophenyl)-N‧-(2,4-dimethoxybenzylidene)thiazole-2-carbohydrazide (BDTC), 4-(4-bromophenyl)-N‧-(4-hydroxybenzylidene)thiazole-2-carbohydrazide (BHTC) recently studied as corrosion inhibitor for steel in acid medium. Electronic parameters relevant to their inhibition activity such as EHOMO, ELUMO, Energy gap (ΔE), hardness (η), softness (σ), the absolute electronegativity (χ), proton affinity (PA) and nucleophilicity (ω) etc., were computed and discussed. Monte Carlo simulations were applied to search for the most stable configuration and adsorption energies for the interaction of the inhibitors with Fe (110) surface. The theoretical data obtained are in most cases in agreement with experimental results.

  20. The inhibitive mechanisms of nitrite and molybdate anions on initiation and propagation of pitting corrosion for mild steel in chloride solution

    Science.gov (United States)

    Zhou, Yong; Zuo, Yu

    2015-10-01

    The inhibitive mechanism of NO2- and MoO42- on the initiation and propagation of pitting corrosion for mild steel in chloride solution was studied with electrochemical methods and X-ray photoelectron spectroscopy (XPS). In 0.1 M NaCl solution both the addition of 0.2 M NaNO2 and 0.2 M Na2MoO4 effectively promoted passivation of mild steel. The passive film on the steel surface formed in NaCl + NO2- solution was composed of mainly γ-Fe2O3, and the film formed in NaCl + MoO42- solution was composed of two components: one is Fe2(MoO4)3 and the other is an oxide composed of Fe and O. The film formed in NaNO2 solution has lower oxygen vacancies and larger impedance than the film formed in Na2MoO4 solution. NO2- shows better inhibition to the initiation of pitting corrosion than MoO42-, which is attributed to its strong oxidability that results in the formation of a stable γ-Fe2O3 film. However, in NaNO2 solution, once a pit forms, it is more difficult to get repassivated than the situation in Na2MoO4 solution. The main reason is due to that in a propagating pit MoO42- anions result in increased solution pH value, but conversely NO2- anions lead to a decreased solution pH value within a pit.

  1. Extending surface Raman spectroscopy to transition metals for practical applications IV. A study on corrosion inhibition of benzotriazole on bare Fe electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Yao, J.L.; Ren, B.; Huang, Z.F.; Cao, P.G.; Gu, R.A.; Tian, Z.-Q

    2003-04-20

    The emphasis in the present study was placed on developing Raman spectroscopy into a versatile technique, which offers an opportunity for investigating the inhibition effect on the corrosion process of bare Fe surfaces. Several surface pretreatments have been developed to bare Fe electrodes in order to obtain a surface of optimal surface-enhanced Raman scattering (SERS). It has been shown that the surface enhancement factor (SEF) of a bare Fe electrode can reach about two to three orders, depending on the roughening procedure. Therefore, SERS can be extended successfully to study some Fe electrode systems of practical importance. Here we present a study on the film formation process and inhibition effect of benzotriazole (BTA) on Fe surfaces. The results show that BTA interacts with Fe surface through its two N atoms of the triazole ring and surface complex polymer of [Fe{sub n}(BTA){sub p}]{sub m} is formed, which may suppress the dissolution and oxidation of Fe effectively. In addition, the solution pH, the synergetic effect of I{sup -} with BTA was revealed to have a significant influence on the inhibition efficiency.

  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. 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. %.

  4. Conceptual DFT Descriptors of Amino Acids with Potential Corrosion Inhibition Properties Calculated with the Latest Minnesota Density Functionals

    Science.gov (United States)

    Frau, Juan; Glossman-Mitnik, Daniel

    2017-01-01

    Amino acids and peptides have the potential to perform as corrosion inhibitors. The chemical reactivity descriptors that arise from Conceptual DFT for the twenty natural amino acids have been calculated by using the latest Minnesota family of density functionals. In order to verify the validity of the calculation of the descriptors directly from the HOMO and LUMO, a comparison has been performed with those obtained through ΔSCF results. Moreover, the active sites for nucleophilic and electrophilic attacks have been identified through Fukui function indices, the dual descriptor Δf(r) and the electrophilic and nucleophilic Parr functions. The results could be of interest as a starting point for the study of large peptides where the calculation of the radical cation and anion of each system may be computationally harder and costly. PMID:28361050

  5. Studies on adsorption and corrosion inhibitive properties of quinoline derivatives on N80 steel in 15% hydrochloric acid

    Directory of Open Access Journals (Sweden)

    K.R. Ansari

    2016-12-01

    Full Text Available This paper deals with the N80 steel corrosion protection study in 15% HCl which was carried by three quinoline derivatives namely 3-acetyl-1-(4-methylbenzylideneamino quinolin-2-one (AQ-1, 3-acetyl-1-(4 hydroxy benzylideneamino quinolin-2-one (AQ-2, 3-acetyl-1-(3-nitrobenzylideneamino quinolin-2(1H-one (AQ-3 using gravimetric, electrochemical, and quantum chemical studies. Tafel polarization showed that AQs are mixed type inhibitors but dominantly affect cathodic reaction more. The observed results reveal that AQ-1 is the best inhibitor. All the three inhibitors were found to obey the Langmuir adsorption isotherm. Scanning electron microscopy (SEM micrographs supports the protection of the N80 steel by AQs. Quantum chemical study reveals that the inhibitors have a tendency to get protonated and this protonated form has greater tendency to get adsorbed onto the N80 steel surface.

  6. Conceptual DFT Descriptors of Amino Acids with Potential Corrosion Inhibition Properties Calculated with the Latest Minnesota Density Functionals.

    Science.gov (United States)

    Frau, Juan; Glossman-Mitnik, Daniel

    2017-01-01

    Amino acids and peptides have the potential to perform as corrosion inhibitors. The chemical reactivity descriptors that arise from Conceptual DFT for the twenty natural amino acids have been calculated by using the latest Minnesota family of density functionals. In order to verify the validity of the calculation of the descriptors directly from the HOMO and LUMO, a comparison has been performed with those obtained through ΔSCF results. Moreover, the active sites for nucleophilic and electrophilic attacks have been identified through Fukui function indices, the dual descriptor Δf(r) and the electrophilic and nucleophilic Parr functions. The results could be of interest as a starting point for the study of large peptides where the calculation of the radical cation and anion of each system may be computationally harder and costly.

  7. Inhibitive effect of Ce(III) and La(III) cations for AA2219 aluminium alloy corrosion in sodium chloride medium

    Energy Technology Data Exchange (ETDEWEB)

    Venkatasubramanian, G., E-mail: venkatguru_1966@yahoo.co.in [Department of Chemistry, Sathyabama University, Jeppiaar Nagar, Chennai 600119 (India); Sheik Mideen, A. [Department of Chemistry, Sathyabama University, Jeppiaar Nagar, Chennai 600119 (India); Jha, Abhay K. [Materials Processing Division, Vikram Sarabhai Space Centre, Indian Space Research Organisation, Thiruvananthapuram 695022 (India); Kulandainathan, M. Anbu [Electro Organic Chemistry Division, Central Electrochemical Research Institute, Karaikudi 630006 (India)

    2014-11-14

    In this paper, the rare earth chlorides were used to mitigate the dealloying of Al{sub 2}Cu intermetallic particles in aluminium alloy 2219-T87 plate exposed to 0.6 M NaCl solution. The negative shift of cathodic branches of potentiodynamic polarisation curves revealed the cathodic inhibition towards intermetallic dealloying. The low and high frequency time constants obtained from electrochemical impedance spectra revealed an increase in the corrosion resistance due to precipitation of rare earth oxides/hydroxides on the porous surface of native oxide film of aluminium alloy. Scanning electron microscopy coupled with energy dispersive X-ray analysis and atomic force microscopy revealed that intermetallic inclusions are the sites for the formation of cerium and lanthanum deposits which suppress copper redeposition and minimise galvanic interactions between the matrix and Al{sub 2}Cu particles. - Graphical abstract: Scanning electron microscopy and atomic force microscopy reveal the intermetallic inclusions, the sites for the formation of cerium and lanthanum oxide/hydroxide precipitates which prevent intermetallic de-alloying, suppress copper redeposition and minimise galvanic interactions in aluminium alloy 2219-T87 plate. - Highlights: • Ce{sup 3+} and La{sup 3+} act as cathodic inhibitors for AA2219-T87 aluminium alloy in 0.6 M NaCl. • Al{sub 2}Cu intermetallic particles are the sites for the formation of Ce and La precipitates. • The decrease in surface potential by rare earth chlorides confirms their inhibition.

  8. Inhibition by Ginkgo leaves extract of the corrosion of steel in HCl and H{sub 2}SO{sub 4} solutions

    Energy Technology Data Exchange (ETDEWEB)

    Deng Shuduan, E-mail: dengshuduan@163.com [Faculty of Materials Engineering, Southwest Forestry University, Kunming 650224 (China); Li Xianghong [Faculty of Science, Southwest Forestry University, Kunming 650224 (China)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Ginkgo leaves extract (GLE) acts as a good inhibitor for steel in HCl and H{sub 2}SO{sub 4} media. Black-Right-Pointing-Pointer The inhibition efficiency follows the order: HCl > H{sub 2}SO{sub 4}. Black-Right-Pointing-Pointer The adsorption of GLE on steel surface obeys Langmuir adsorption isotherm. Black-Right-Pointing-Pointer GLE behaves as a mixed-type inhibitor in 1.0 M HCl, while cathodic inhibitor in 0.5 M H{sub 2}SO{sub 4}. - Abstract: The inhibition effect of Ginkgo leaves extract (GLE) on the corrosion of cold rolled steel (CRS) in 1.0-5.0 M HCl and 0.5-2.5 M H{sub 2}SO{sub 4} solutions was investigated for the first time by weight loss, potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) methods. The results show that GLE is a good inhibitor, and exhibits more efficient in 1.0 M HCl than 0.5 M H{sub 2}SO{sub 4}. The adsorption of GLE on CRS surface obeys Langmuir adsorption isotherm. GLE acts as a mixed-type inhibitor in 1.0 M HCl, while a cathodic inhibitor in 0.5 M H{sub 2}SO{sub 4}.

  9. Inhibition of mild steel corrosion by 1,4,6-trimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile and synergistic effect of halide ion in 0.5 M H{sub 2}SO{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Mourya, Punita, E-mail: mouryapunita025@gmail.com [Department of Chemistry, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India); Singh, Praveen [Department of Chemistry, Banaras Hindu University, Varanasi 221005 (India); Rastogi, R.B.; Singh, M.M. [Department of Chemistry, Indian Institute of Technology (Banaras Hindu University), Varanasi 221005 (India)

    2016-09-01

    Highlights: • TODPCN is a good corrosion inhibitor for mild steel in 0.5 M H{sub 2}SO{sub 4} solution. • Addition of iodide ion increases the inhibition efficiency of the studied nitrile derivative. • Inhibition efficiency successively increases with concentration. • XPS study has revealed the chemical composition of the protective film. - Abstract: The effect of iodide ions on inhibitive performance of 1,4,6-trimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile (TODPCN) on mild steel (MS) corrosion in 0.5 M H{sub 2}SO{sub 4} was studied using gravimetric and electrochemical measurements. TODPCN inhibits the corrosion of MS to the extent of 62.3% at its lowest concentration (0.5 mM) and its inhibition efficiency (η) further increases on increasing concentration at 298 K. The adsorption of TODPCN on MS was found to follow the Langmuir adsorption isotherm. The value of η increased on the addition of 2.0 mM KI. The value of synergism parameter being more than unity indicates that the enhanced η value in the presence of iodide ions is only due to synergism. Thus, a cooperative mechanism of inhibition exists between the iodide anion and TODPCN cations. The increase in surface coverage in the presence of KI indicates that iodide ions enhance the adsorption of TODPCN. The surface morphology of corroded/inhibited MS was studied by atomic force microscopy. X-ray photoelectron spectroscopy of inhibited MS surface was carried out to determine the composition of the adsorbed film. Some quantum chemical parameters and the Mulliken charge densities for TODPCN calculated by density functional theory provided further insight into the mechanism of inhibition.

  10. 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

  11. Influence of silver additions to type 316 stainless steels on bacterial inhibition, mechanical properties, and corrosion resistance

    DEFF Research Database (Denmark)

    Chiang, Wen-Chi; Tseng, I-Sheng; Møller, Per;

    2010-01-01

    Bacterial contamination is a major concern in many areas. In this study, silver was added to type 316 stainless steels in order to obtain an expected bacteria inhibiting property to reduce the occurrence of bacterial contamination. Silver-bearing 316 stainless steels were prepared by vacuum melti...

  12. Inhibition de la corrosion d'acier au carbone en milieu H3PO4 2M par des composés organiques de type ``triazine''

    Science.gov (United States)

    Bekkouch, K.; Aouniti, A.; Hammouti, B.; Kertit, S.

    1999-05-01

    The effect of addition of some triazine compounds on the corrosion behaviour of steel in 2M H3PO4 has been studied by weight loss and electrochemical polarisation methods. Both methods showed that the dissolution rate was dependent on the chemical properties and concentration of the product. From comparison of results, it was found that 6-azathymine (T6) is the best inhibitor and its inhibition efficiency reaches a maximum value of 86% at 10-3 M. Polarisation measurements indicated that T6 acts as cathodic inhibitor by merely blocking the reaction sites without changing the mechanism of the hydrogen evolution reaction. It was found that T6 was adsorbed on steel surface according to a Langmuir isotherm model. The effect of temperature indicated that inhibition efficiency of T6 is dependent on the temperature in the range 25-50 circC. L'effet de l'addition de certains composés organiques de type triazine sur la corrosion d'un acier en milieu H3PO4 2M a été étudié à l'aide des méthodes électrochimiques et gravimétriques. Les résultats obtenus ont montré que la vitesse de dissolution de l'acier dépend de la structure moléculaire et de la concentration du produit. La comparaison des efficacités inhibitrices montre que le 6-azathymine (T6) est le meilleur inhibiteur de la série des triazines testés. L'efficacité inhibitrice du T6 atteint une valeur maximale de 86 % à 10-3 M. L'allure des courbes de polarisation indique que le T6 agit essentiellement comme inhibiteur de type cathodique par adsorption à la surface de l'acier selon le modèle de l'isotherme de Langmuir. L'efficacité inhibitrice du T6 dépend de la température dans le domaine allant de 25 à 50 circC.

  13. Inhibition of mild steel corrosion by 1,4,6-trimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile and synergistic effect of halide ion in 0.5 M H2SO4

    Science.gov (United States)

    Mourya, Punita; Singh, Praveen; Rastogi, R. B.; Singh, M. M.

    2016-09-01

    The effect of iodide ions on inhibitive performance of 1,4,6-trimethyl-2-oxo-1,2-dihydropyridine-3-carbonitrile (TODPCN) on mild steel (MS) corrosion in 0.5 M H2SO4 was studied using gravimetric and electrochemical measurements. TODPCN inhibits the corrosion of MS to the extent of 62.3% at its lowest concentration (0.5 mM) and its inhibition efficiency (η) further increases on increasing concentration at 298 K. The adsorption of TODPCN on MS was found to follow the Langmuir adsorption isotherm. The value of η increased on the addition of 2.0 mM KI. The value of synergism parameter being more than unity indicates that the enhanced η value in the presence of iodide ions is only due to synergism. Thus, a cooperative mechanism of inhibition exists between the iodide anion and TODPCN cations. The increase in surface coverage in the presence of KI indicates that iodide ions enhance the adsorption of TODPCN. The surface morphology of corroded/inhibited MS was studied by atomic force microscopy. X-ray photoelectron spectroscopy of inhibited MS surface was carried out to determine the composition of the adsorbed film. Some quantum chemical parameters and the Mulliken charge densities for TODPCN calculated by density functional theory provided further insight into the mechanism of inhibition.

  14. 异恶唑衍生物缓蚀剂缓蚀性能的理论评价%THEORETICAL EVALUATION OF CORROSION INHIBITION PERFORMANCE OF ISOXAZOLIDINES DERIVATIVES

    Institute of Scientific and Technical Information of China (English)

    吴刚; 耿玉凤; 贾晓林; 孙霜青; 胡松青

    2012-01-01

    The corrosion resisting property of four corrosion inhibitors in HC1 on mild steel, including 2-methyl-5-hexylisoxazolidine (A), 2-methyl-5-dodecylisoxazolidine (B), 2-isopropyl-5-dodecylisoxazolidine (C) and 2-tert-butyl-5-dodecylisoxazolidine (D), was theoretically evaluated using quantum chemistry calculations and molecular dynamics simulations. The corrosion inhibition mechanism was analyzed. The quantum chemical calculations indicated that the frontier orbitals of four molecules were located in the isoxazole ring and side chain of the molecules. The electrophilic attack centers of the inhibitors were on the N and O atoms. Molecular dynamics calculation shows that under liquid conditions the polarity head group of isoxazolidine corrosion inhibitors priority adsorbed in the metal surface, while the alkyl chain stayed in the water phase with distortion. The strength of molecules adsorbed on the surface enhanced with increasing the number of methyl in the molecular heads. The theoretical evaluation was shown to be in complete accord with experiment results.%采用量子化学计算和分子动力学模拟相结合的方法,对盐酸溶液中2-甲基-5-己基异恶唑、2-甲基-5-十二烷基异恶唑、2-异丙基.5-十二烷基异恶唑和2-叔丁基-5-十二烷基异恶唑4种异恶唑衍生物缓蚀剂抑制低碳钢腐蚀的缓蚀性能进行理论评价,并对其缓蚀机理进行分析。量子化学计算表明,4种缓蚀剂分子的前线轨道主要离域在分子头部的异恶唑环和侧链上,亲电反应活性中心为分子中的N、O原子。分子动力学模拟结果表明,液相条件下,异恶唑衍生物缓蚀剂的极性头部优先吸附于金属表面,而烷基长链在溶剂水的作用下背离金属表面,分子在表面的吸附强度随着头基侧链中甲基个数的增加而增强。理论评价结论与实验结果完全一致。

  15. 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

  16. 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.

  17. 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.

  18. Analysis of electrochemical noise (ECN) data in time and frequency domain for comparison corrosion inhibition of some azole compounds on Cu in 1.0 M H2SO4 solution

    Science.gov (United States)

    Ramezanzadeh, B.; Arman, S. Y.; Mehdipour, M.; Markhali, B. P.

    2014-01-01

    In this study, the corrosion inhibition properties of two similar heterocyclic compounds namely benzotriazole (BTA) and benzothiazole (BNS) inhibitors on copper in 1.0 M H2SO4 solution were studied by electrochemical techniques as well as surface analysis. The results showed that corrosion inhibition of copper largely depends on the molecular structure and concentration of the inhibitors. The effect of DC trend on the interpretation of electrochemical noise (ECN) results in time domain was evaluated by moving average removal (MAR) method. Accordingly, the impact of square and Hanning window functions as drift removal methods in frequency domain was studied. After DC trend removal, a good trend was observed between electrochemical noise (ECN) data and the results obtained from EIS and potentiodynamic polarization. Furthermore, the shot noise theory in frequency domain was applied to approach the charge of each electrochemical event (q) from the potential and current noise signals.

  19. The dual role of microbes in corrosion.

    Science.gov (United States)

    Kip, Nardy; van Veen, Johannes A

    2015-03-01

    Corrosion is the result of a series of chemical, physical and (micro) biological processes leading to the deterioration of materials such as steel and stone. It is a world-wide problem with great societal and economic consequences. Current corrosion control strategies based on chemically produced products are under increasing pressure of stringent environmental regulations. Furthermore, they are rather inefficient. Therefore, there is an urgent need for environmentally friendly and sustainable corrosion control strategies. The mechanisms of microbially influenced corrosion and microbially influenced corrosion inhibition are not completely understood, because they cannot be linked to a single biochemical reaction or specific microbial species or groups. Corrosion is influenced by the complex processes of different microorganisms performing different electrochemical reactions and secreting proteins and metabolites that can have secondary effects. Information on the identity and role of microbial communities that are related to corrosion and corrosion inhibition in different materials and in different environments is scarce. As some microorganisms are able to both cause and inhibit corrosion, we pay particular interest to their potential role as corrosion-controlling agents. We show interesting interfaces in which scientists from different disciplines such as microbiology, engineering and art conservation can collaborate to find solutions to the problems caused by corrosion.

  20. The dual role of microbes in corrosion

    Science.gov (United States)

    Kip, Nardy; van Veen, Johannes A

    2015-01-01

    Corrosion is the result of a series of chemical, physical and (micro) biological processes leading to the deterioration of materials such as steel and stone. It is a world-wide problem with great societal and economic consequences. Current corrosion control strategies based on chemically produced products are under increasing pressure of stringent environmental regulations. Furthermore, they are rather inefficient. Therefore, there is an urgent need for environmentally friendly and sustainable corrosion control strategies. The mechanisms of microbially influenced corrosion and microbially influenced corrosion inhibition are not completely understood, because they cannot be linked to a single biochemical reaction or specific microbial species or groups. Corrosion is influenced by the complex processes of different microorganisms performing different electrochemical reactions and secreting proteins and metabolites that can have secondary effects. Information on the identity and role of microbial communities that are related to corrosion and corrosion inhibition in different materials and in different environments is scarce. As some microorganisms are able to both cause and inhibit corrosion, we pay particular interest to their potential role as corrosion-controlling agents. We show interesting interfaces in which scientists from different disciplines such as microbiology, engineering and art conservation can collaborate to find solutions to the problems caused by corrosion. PMID:25259571

  1. 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

  2. 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…

  3. 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.

  4. An atomic emission spectroelectrochemical study of corrosion inhibition: The effect of hexamethylenetetramine on the reaction of mild steel in HCl

    Energy Technology Data Exchange (ETDEWEB)

    Volovitch, P., E-mail: polina-volovitch@enscp.f [Laboratoire de Physicochimie des Surfaces, UMR7045, Ecole Nationale Superieure de Chimie de Paris, Chmie ParisTech, 11, rue Pierre et Marie Curie, Paris (France); Gazizzullin, I.; Ruel, F. [Laboratoire de Physicochimie des Surfaces, UMR7045, Ecole Nationale Superieure de Chimie de Paris, Chmie ParisTech, 11, rue Pierre et Marie Curie, Paris (France); Ogle, K., E-mail: kevin-ogle@enscp.f [Laboratoire de Physicochimie des Surfaces, UMR7045, Ecole Nationale Superieure de Chimie de Paris, Chmie ParisTech, 11, rue Pierre et Marie Curie, Paris (France)

    2011-04-15

    Research highlights: Time resolved elemental dissolution rates on time scales typical for pickling lines. Segregated impurities dissolve selectively at early stages. At high HMTA concentration the dissolution rate is the same for different steels. Several mechanisms of HMTA inhibition are discussed. - Abstract: The dissolution of low carbon steel in hydrochloric acid has been investigated by atomic emission spectroelectrochemistry. The rate of Mn, Fe and P dissolution was measured as a function of time for steels of variable Mn and P composition and as a function of HMTA concentration. Regardless of the reactivity of the steel in uninhibited solutions, at high concentration of HMTA, all steel grades show a nearly identical dissolution rate. The effect is selective for Fe; the dissolution of segregated Mn is not affected by HMTA.

  5. 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.

  6. Corrosion Inhibition Performance of Composite Dopamine/BSA Film on Medical 316 L Stainless Steel Surface%医用316 L不锈钢表面多巴胺/BSA复合膜缓蚀性能研究

    Institute of Scientific and Technical Information of China (English)

    陈玉林; 屈钧娥; 王海人; 曹志勇

    2015-01-01

    ABSTRACT:Objective To study the corrosion inhibition performance of composite dopamine ( DP )/bovine serum albumin (BSA) film on the medical 316L stainless steel surface. Methods The dopamine/BSA composite self-assembled bilayer film was prepared by soaking method on the surface of 316L stainless steel (316L SS) by using DP as the bridge layer. The effect of BSA mass concentration on the adsorption behavior and the corrosion inhibition performance of the bilayer film was studied by potentiody-namic scanning, electrochemical impedance spectroscopy ( EIS) , scanning electron microscopy ( SEM) and energy dispersive X-ray detection ( EDX) . Results The composite self-assembled bilayer film showed corrosion inhibition effect in the appropriate con-dition. Too high and too low BSA mass concentrations were both unfavorable for the corrosion inhibition performance of the film. The optimum corrosion inhibition efficiency for 316L SS in physiological saline environment was obtained at the BSA mass concen-tration of 40 g/L, and the corrosion inhibition efficiency increased form 62. 4% of the single DP film to 83. 9% of the DP/BSA bi-layer film. Conclusion The results show that DP molecules successfully graft BSA onto the surface of 316L stainless steel and the adsorption capacity is great improved compared with the single BSA film. It shows that the modified 316L SS surface with good cor-rosion resistance and biocompatibility can be obtained by using dopamine as the adhesive layer to graft BSA onto the substrate.%目的:研究医用316 L不锈钢表面组装多巴胺/牛血清白蛋白分子( BSA )复合膜的缓蚀性能。方法采用浸泡法在医用316 L不锈钢表面制备以多巴胺自组装膜为桥接层的多巴胺/BSA复合双层自组装膜,通过动电位扫描、交流阻抗测试,SEM,EDX等手段分析BSA组装液质量浓度对复合双层自组装膜吸附行为及耐蚀性能的影响。结果在合适的自组装条件下可获得具有缓蚀效果的

  7. 两种席夫碱缓蚀剂对碳钢材料的缓蚀性能探究%Investigation of corrosion inhibition to carbon steel by Schiff base compounds

    Institute of Scientific and Technical Information of China (English)

    陈瑶; 陈嫚丽; 张玲; 刘传银

    2012-01-01

    Two Schiff bases 2-( 2-hydroxybenzylideneamino) benzoic acid ( SB-I) and 2, 2 '-( 1 , 2-phenylenebis ( azan-1-yl-1-yli-dene) )bis(methan-l-yl-l-ylidene)diphenol(SB-II)have been investigated for its corrosion inhibition properties on the corrosion of carbon steels by polarization curve and electrochemical impedance spectroscopy. The experiment results indicate that the Schiff bases show its favorable corrosion inhibition properties with about maximum inhibition efficiency value of 83%. The adsorption model of Schiff base on carbon steel has also been investigated, the experimental results indicate that the Schiff bases are mixed corrosion inhibitor with standard free Gibbs energy of adsorption-30 kj/mol,which also shows that Schiff base corrosion inhibitors are adhered on the surface of the carbon steel through the model between physical adsorption and chemical adsorption, the corrosion inhibition properties of Schiff bases are performed by inhibiting and delaying the electrochemical process of metal corrosion. And the electrochemical and theoretical investigations also verify that SB-I has stronger inhibiting properties than that of SB-II.%采用了电化学方法研究了2种席夫碱缓蚀剂水杨醛基邻苯甲酸亚胺(SB-Ⅰ)和N,N’-二水杨醛基-1,2-邻苯二亚胺( SB-Ⅱ)在1 mol/L盐酸溶液中对20#碳钢的缓蚀性能.通过极化曲线和交流阻抗谱研究该席夫碱对碳钢的缓蚀效果表明:席夫碱对碳钢材料具有良好的缓蚀作用,其最大缓蚀率可达到83%.研究了席夫碱在碳钢表面的吸附模式,结果表明,席夫碱在碳钢表面上的吸附吉布斯自由能在-30 kJ/mol之间,表现为混合型缓蚀剂,即通过化学吸附和物理吸附之间的一种混合吸附在碳钢工作电极的表面,通过抑制、阻止延缓金属的电化学过程而起到缓蚀的作用.另外,实验还发现,SB-Ⅰ比SB-Ⅱ具有更好的缓蚀性能,该实验结果与理论计算结果相符合.

  8. On the relationship between corrosion inhibiting effect and molecular structure of 2,5-bis(n-pyridyl)-1,3,4-thiadiazole derivatives in acidic media: Ac impedance and DFT studies

    Energy Technology Data Exchange (ETDEWEB)

    Bentiss, F., E-mail: fbentiss@enscl.f [Laboratoire de Chimie de Coordination et d' Analytique (LCCA), Faculte des Sciences, Universite Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Mernari, B. [Laboratoire de Chimie de Coordination et d' Analytique (LCCA), Faculte des Sciences, Universite Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Traisnel, M. [Unite Materiaux et Transformations (UMET), Ingenierie des Systemes Polymeres, CNRS UMR 8207, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Vezin, H. [Laboratoire de Spectrochimie Infrarouge et Raman (LASIR), UMR-CNRS 8516, Universite des Sciences et Technologies de Lille, Batiment C5, F-59655 Villeneuve d' Ascq Cedex (France); Lagrenee, M., E-mail: michel.lagrenee@ensc-lille.f [Unite de Catalyse et de Chimie du Solide (UCCS), UMR-CNRS 8181, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France)

    2011-01-15

    Research highlights: {yields}2,5-Bis(n-pyridyl)-1,3,4-thiadiazoles (n-PTH) act as good inhibitors for the mild steel in acidic media. {yields}The inhibiting protection depends on the position of the nitrogen on the pyridinium substituent according to order 3-PTH > 2-PTH > 4-PTH. {yields}The adsorption of n-PTH is found to follow the Langmuir's adsorption isotherm. {yields}Data obtained from quantum chemical calculations using DFT method were correlated to the experimentally obtained inhibition efficiencies. - Abstract: The inhibition properties of 2,5-bis(n-pyridyl)-1,3,4-thiadiazoles (n-PTH) on corrosion of mild steel in different acidic media (1 M HCl, 0.5 M H{sub 2}SO{sub 4} and 1 M HClO{sub 4}) were analyzed by electrochemical impedance spectroscopy (EIS). The n-PTH derivatives exhibit good inhibition properties in different acidic solutions and the calculated values of {Delta}G{sub ads}{sup 0} revealed that the adsorption mechanism of n-PTH on steel surface is mainly due to chemisorption. While in 1 M HClO{sub 4}, both 2-PTH and 4-PTH isomers stimulate the corrosion process especially at low concentrations. Quantum chemical calculations using the density functional theory (DFT) were performed on n-PTH 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 the inhibition effects of n-PTH may be explained in terms of electronic properties.

  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. 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...

  11. 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...

  12. Corrosion protection by anaerobiosis.

    Science.gov (United States)

    Volkland, H P; Harms, H; Wanner; Zehnder, A J

    2001-01-01

    Biofilm-forming bacteria can protect mild (unalloyed) steel from corrosion. Mild steel coupons incubated with Rhodoccocus sp. strain C125 and Pseudomonas putida mt2 in an aerobic phosphate-buffered medium containing benzoate as carbon and energy source, underwent a surface reaction leading to the formation of a corrosion-inhibiting vivianite layer [Fe3(PO4)2]. Electrochemical potential (E) measurements allowed us to follow the buildup of the vivianite cover. The presence of sufficient metabolically active bacteria at the steel surface resulted in an E decrease to -510 mV, the potential of free iron, and a continuous release of ferrous iron. Part of the dissolved iron precipitated as vivianite in a compact layer of two to three microns in thickness. This layer prevented corrosion of mild steel for over two weeks, even in a highly corrosive medium. A concentration of 20 mM phosphate in the medium was found to be a prerequisite for the formation of the vivianite layer.

  13. Study of the inhibiting properties of fatty amines in association with phosphono-carboxylic acid salts for the corrosion protection of a carbon steel. Influence of flow on the inhibition mechanism; proprietes inhibitrices d'un melange d'amines grasses et de sels d'acide phosphonocarboxyliques vis-a-vis de la corrosion d'un acier au carbone. Influence des conditiions hydrodynamiques sur le mecanisme d'inhibition

    Energy Technology Data Exchange (ETDEWEB)

    Ochoa de Echevarrieta, N.

    2004-02-01

    This work is devoted to the corrosion inhibition of a carbon steel in a 200 mg l{sup -1} NaCl solution by a non-toxic multicomponent inhibitor used for water treatment in cooling circuits. It was composed of fatty amines (FA) associated with phosphono-carboxylic acid salts (PCAS). Steady-state current-voltage curves were combined with electrochemical impedance measurements to characterise the inhibitive properties of each compound and to optimize the concentration of the compounds in the mixture. Maximum efficiency was reached for the mixture containing 50 mg l{sup -1} FA +200 mg l{sup -1} PCAS. A competitive adsorption mechanism was proposed to account for the synergistic effect. The inhibitive film was composed of an iron oxide/hydroxide mixture incorporating the organic molecules. The properties of the protective layer were dependent on the electrode rotation rate and on the immersion time. This behaviour is related to the influence of flow on the anodic kinetics. (author)

  14. Biobased polymers for corrosion protection of metals

    Science.gov (United States)

    Anticorrosive biobased polymers were developed in our lab. We isolated an exopolysaccharide produced by a microbe that, when coated on metal substrates, exhibited unique corrosion inhibition. Corrosion is a worldwide problem and impacts the economy, jeopardizes human health and safety, and impedes t...

  15. 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

  16. 烟柴杆提取物与碘化钾的缓蚀协同效应%Synergistic effect of corrosion inhibition of tobacco rob extract and potassium iodide

    Institute of Scientific and Technical Information of China (English)

    郭勇; 高美丹; 王艳; 王荷芳; 胡荣彬

    2015-01-01

    The corrosion i nhibition capacity of tobacco rob extract for N80 steel in hydrochloride solutions and its synergistic effect with potassium iodide are investigated. The results show that tobacco rob extract has excellent corrosion inhibition efficiency,and the inhibition efficiency increases further when tobacco rob extract combines with potassium iodide. From the electrochemical polarization curve,before and after the combination,the tobacco rob extract are both a kind of mixed-type corrosion inhibitor and the inhibition mechanism is geometric covering effect. By fitting the weight loss data,the result shows that after the combination of tobacco rob extract with potassium iodide,the adsorption on the surface of N80 steel obeys the Langmuir’s adsorption isotherm equation.%研究了烟柴杆提取物在盐酸介质中对N80钢的缓蚀性能及其与碘化钾复配的协同效应。结果表明,烟柴杆提取物具有良好的缓蚀性能,与碘化钾复配后缓蚀性能进一步提高。电化学极化曲线表明,复配前后烟柴杆提取物均为混合型缓蚀剂,其作用机理为几何覆盖效应。对失重数据进行拟合,结果表明烟柴杆提取物与碘化钾复配后在N80钢表面的吸附服从Langmuir吸附等温方程。

  17. 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.

  18. Modelling aqueous corrosion of nuclear waste phosphate glass

    Science.gov (United States)

    Poluektov, Pavel P.; Schmidt, Olga V.; Kascheev, Vladimir A.; Ojovan, Michael I.

    2017-02-01

    A model is presented on nuclear sodium alumina phosphate (NAP) glass aqueous corrosion accounting for dissolution of radioactive glass and formation of corrosion products surface layer on the glass contacting ground water of a disposal environment. Modelling is used to process available experimental data demonstrating the generic inhibiting role of corrosion products on the NAP glass surface.

  19. Synthesis, characterization and corrosion inhibition efficiency of 2-(6-methylpyridin-2-yl)-1H-imidazo[4,5-f][1,10] phenanthroline on mild steel in sulphuric acid

    OpenAIRE

    Obi-Egbedi, N. O.; I. B. Obot; A.O. Eseola

    2014-01-01

    Phenanthroline derivative, 2-(6-methylpyridin-2-yl)-1H-imidazo[4,5-f][1,10] phenanthroline (MIP) was synthesized and characterized by elemental analysis, FT-IR, 1H NMR, 13C NMR, and single crystal X-ray diffraction study. MIP was evaluated as corrosion inhibitor for mild steel in 0.5 M H2SO4 solution using gravimetric and UV–Visible spectrophotometric methods at 303–333 K. Results obtained show that MIP acts as inhibitor for mild steel in H2SO4 solution. The inhibition efficiency was found to...

  20. Exopolysaccharide hydrogels for corrosion inhibition

    Science.gov (United States)

    Exopolysaccharide production by micro-organisms have several industrial applications in food, pharmaceuticals, or other industries. Lactic acid bacteria such as Leuconostoc mesenteroides (LM) are endemic to the environment and produce extracellular polymeric glucans such as dextran. Dextrans cause s...

  1. Corrosion resistance of monolayer hexagonal boron nitride on copper

    Science.gov (United States)

    Mahvash, F.; Eissa, S.; Bordjiba, T.; Tavares, A. C.; Szkopek, T.; Siaj, M.

    2017-02-01

    Hexagonal boron nitride (hBN) is a layered material with high thermal and chemical stability ideal for ultrathin corrosion resistant coatings. Here, we report the corrosion resistance of Cu with hBN grown by chemical vapor deposition (CVD). Cyclic voltammetry measurements reveal that hBN layers inhibit Cu corrosion and oxygen reduction. We find that CVD grown hBN reduces the Cu corrosion rate by one order of magnitude compared to bare Cu, suggesting that this ultrathin layer can be employed as an atomically thin corrosion-inhibition coating.

  2. 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.

  3. 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.

  4. Corrosivity of paper mill effluent and corrosion performance of stainless steel.

    Science.gov (United States)

    Ram, Chhotu; Sharma, Chhaya; Singh, A K

    2015-01-01

    Present study relates to the corrosivity of paper mill effluent and corrosion performance of stainless steel (SS) as a construction material for the effluent treatment plant (ETP). Accordingly, immersion test and electrochemical polarization tests were performed on SS 304 L, 316 L and duplex 2205 in paper mill effluent and synthetic effluent. This paper presents electrochemical polarization measurements, performed for the first time to the best of the authors' information, to see the influence of chlorophenols on the corrosivity of effluents. The corrosivity of the effluent was observed to increase with the decrease in pH and increase in Cl- content while the addition of SO4- tends to inhibit corrosion. Mill effluent was found to be more corrosive as compared to synthetic effluent and has been attributed to the presence of various chlorophenols. Corrosion performance of SS was observed to govern by the presence of Cr, Mo and N contents.

  5. 二氧化氯杀菌剂配伍羧酸水处理剂的缓蚀性能%Corrosion Inhibition of Chlorine Dioxide with Carboxylic Acid Water Treatment Agents

    Institute of Scientific and Technical Information of China (English)

    朱小梅; 朱明新; 周桃玉; 徐炎华

    2012-01-01

    投加二氧化氯可以有效地控制冷却水中的微生物。采用旋转挂片腐蚀试验和电化学试验研究了二氧化氯对金属的腐蚀问题,并研究了二氧化氯溶液中配伍羧酸类水处理剂PBTCA(2-膦酸基丁烷-1,2,4-三羧酸)、PESA(聚环氧琥珀酸)、TH-628(有机羧酸复合药剂)的缓蚀性能。结果表明,二氧化氯浓度为0.8mg/L时,碳钢的腐蚀率最低。三种药剂在二氧化氯的体系中均有一定的缓蚀作用,PESA的缓蚀效果最好。在碳钢的腐蚀过程中,复合药剂TH-628对电极的阳极和阴极过程均具有抑制作用,属于混合型缓蚀剂。%Microorganisms in circulating cooling water can be effectively controlled by injecting chlorine dioxide. The metal corrosion due to chlorine dioxide and the corrosion inhibition property of PBTCA (2-phosphonobutane-1, 2, 4- tricarboxylic acid), PESA (polyepoxysuccinic acid) and TH-628(organic carboxylic acid complex reagent) in chlorine dioxide solution were investigated by rotary weight-loss measurement and electrochemical testing. The results indicated that the concentration of 0. 8 mg/L chlorine dioxide resulted in the lowest corrosive rate of carbon steel. Complex drugs TH-628, PBTCA and PESA had good inhibition effects. In the process of corrosion of carbon steel, complex reagent TH-628 has inhibition effect on the reactions of both anode and cathode. So it is a mixed inhibitor.

  6. Comparison Between the Inhibition Efficiencies of Two Modification Processes with PEG-Ceria Based Layers Against Corrosion of Mild Steel in Chloride and Sulfate Media

    Science.gov (United States)

    Boudellioua, H.; Hamlaoui, Y.; Tifouti, L.; Pedraza, F.

    2017-08-01

    Cerium (III) and polyethylene glycol (PEG) combinations were employed to enhance the corrosion resistance of ASTM A915 mild steel in 0.1 M NaCl and in 0.1 M Na2SO4 media. One of the combinations consisted in dipping the steel in a bath mixture of PEG and cerium nitrate for 60 min. In the second combination, the steel was first immersed in the PEG solution for 30 min, then in cerium nitrate for 30 additional minutes. The corrosion protective capabilities of the superficially modified steels were evaluated through cyclic voltammetry, linear polarization resistance (R p), polarization measurements (Tafel) and electrochemical impedance spectroscopy. The composition and structure of the surface products were analyzed through Raman spectroscopy and scanning electron microscopy coupled to chemical EDS analysis. The mixture of PEG and cerium nitrate hindered the development of corrosion products on the mild steel surface. However, the subsequent immersion of the steel first in PEG then in cerium nitrate was not efficient to slow down corrosion.

  7. Underground pipeline corrosion

    CERN Document Server

    Orazem, Mark

    2014-01-01

    Underground pipelines transporting liquid petroleum products and natural gas are critical components of civil infrastructure, making corrosion prevention an essential part of asset-protection strategy. Underground Pipeline Corrosion provides a basic understanding of the problems associated with corrosion detection and mitigation, and of the state of the art in corrosion prevention. The topics covered in part one include: basic principles for corrosion in underground pipelines, AC-induced corrosion of underground pipelines, significance of corrosion in onshore oil and gas pipelines, n

  8. 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.

  9. 金竹竹叶提取物在HCl中对铝的缓蚀作用研究%Corrosion Inhibition of Extracts from Phyllostachy sulphurea Leaves for Aluminum in HCl Solution

    Institute of Scientific and Technical Information of China (English)

    刘建祥; 王瑞苓; 付惠; 李向红

    2013-01-01

    Fourier transform infrared( FT-IR) spectroscopy was employed to characterize the main functional groups of extracts from Phyllostachy sulphured leaves (PSLE). The inhibition effect of PSLE on the corrosion of aluminum in 1. 0 mol/L HC1 was studied by mass loss and electrochemical impedance spectroscopy (EIS). The results showed that the PSLE was a good inhibitor in hydrochloric acid for aluminum, and the maximum inhibition efficiency was 77.7 %. The corrosion inhibition of bamboo leaves was good at 20℃ and 30℃. The adsorption of PSLE on the aluminum surface obeys the Langmuir adsorption isotherm equation. Adsorption heat △Hads was calculated by Van't Hoff, and the inhibition mechanism was discussed in detail according to the parameters. All EIS exhibited that corrosion inhibitor at the aluminum surface had good are resistance. PSLE was a mix-type inhibition.%通过红外光谱(FT-IR)分析,表征了金竹竹叶提取物(PSLE)的主要官能团,利用失重法、电化学阻抗谱研究了PSLE在1.0 mol/L (')HCl介质中对铝的缓蚀作用.结果表明,PSLE具有较好的缓蚀作用,最大缓蚀率达77.7%,竹叶提取物的缓蚀率在20和30℃时效果较好,在铝表面的吸附符合Langmuir吸附校正模型,通过Van't Hoff方程求出吸附热(△Hads),讨论了缓蚀作用机理,吸附过程是一个自发放热的过程.通过电化学阻抗谱,表明缓蚀剂在铝表面发生吸附后使电荷传递明显抑制,PSLE为混合抑制型缓蚀剂.

  10. Corrosion Inhibition Effect of Aliphatic Amines on Aluminum in HCl Solution%盐酸介质中脂肪胺类化合物对铝材的缓蚀作用

    Institute of Scientific and Technical Information of China (English)

    帅长庚; 邓淑珍; 宋玉苏; 银继伟

    2001-01-01

    用失重法和电化学方法研究了正丁胺、二乙胺、乌洛托品在1.0 mol/L HCl中对铝的缓蚀作用,并对其机理进行了探讨。研究结果表明:起初,3种化合物对铝均具有缓蚀作用,缓蚀效果:乌洛托品>二乙胺>正丁胺,随着时间的延长,缓蚀效率逐渐降低;3种化合物均为吸附型缓蚀剂,对铝腐蚀的阴极过程和阳极过程都有一定的抑制作用,其吸附符合兰格缪尔等温吸附方程。%The corrosion inhibition effect of aliphatic amines on industrial pure aluminum in 1.0 mol/L HCl solution was investigated by weightloss and electrochemical methods. The inhibition efficiency was found to decrease in following order hexamethylenetetramine >diethylamine>nbutylamine. The thermodynamic functions of adsorption ΔG0am and corrosion potential Ek were evaluated. The authors pointed out that the adsorption of amines followed Langmuir isothermal equation.

  11. 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.

  12. Preparation of HA/P(AM-SAS) blend and their inhibition performance of scale and corrosion%改性腐植酸新型阻垢缓蚀剂的制备及应用

    Institute of Scientific and Technical Information of China (English)

    邱广明; 邱广亮

    2001-01-01

    The blends [HA/P(AM-SAS)]of humic acids(HA)and copolymer P(AM-SAS) of acrylamide(AM) and sodium allylsulfonate(SAS) have been prepared by solution blend. Their inhibition performance of scale and corrosion and dispersion performance have been studied and compared with HA and P(AM-SAS). Experimental results indicates that their scale and corrosion inhibition rates and dispersing Fe2O3 capability increase with the increasing of their concentration. Compared with HA and P(AM-SAS),HA/P(AM-SAS)blends have better scale and corrosion inhibition performance and dispersion capability. During the blending of HA and P(AM-SAS),HA and P(AM-SAS)have synergistic effects for CaCO3 and Ca3(PO4)2 scale inhibition when HA/P(AM-SAS)mass ratio is above 1 and 2.Under the condition:ρ(Ca2+)=250 mg/L、ρ(HCO3-)=250 mg/L、ρ(CO32-)=85 mg/L、ρ(PO43-)=5 mg/L、pH=8.5、T=80 ℃、t=10 h,the inhibition rates of HA/P(AM-SAS)blends on the CaCO3 and Ca3(PO4)2 scale are up to 98.9%and 97.2%respectively. When the dosage ofHA/P(AM-SAS)blends is beyond 20 mg/L,the corrosion inhibition rate on mild steel reaches 95.0%.%采用溶液共混技术,制备了腐植酸钠(HA)和丙烯酰胺—烯丙基磺酸钠(SAS)共聚物[P(AM-SAS)]的共混物[HA/P(AM-SAS)],研究了共混物[HA/P(AM-SAS)]的阻垢、缓蚀和分散性能,并与HA和P(AM-SAS)做了对比分析。实验表明,HA/P(AM-SAS)共混物、HA和P(AM-SAS)的阻垢、缓蚀和分散能力随着使用浓度的增加而提高。与HA和P(AM-SAS)相比,HA/P(AM-SAS)共混物具有更好的阻垢、缓蚀和分散能力。当HA/P(AM-SAS)质量比超过1或2时,HA和P(AM-SAS)的共混对于CaCO3和Ca3(PO4)2的阻垢作用表现出了明显的协同效应。当ρ(Ca2+)=250 mg/L、ρ(HCO3-)=250 mg/L、ρ(CO32-)=85 mg/L、ρ(PO43-)=5 mg/L、pH=8.5、T=80 ℃、t=10 h时,HA/P(AM-SAS)共混物对CaCO3和Ca3(PO4)2的阻垢率分别达到了98.9%和97.2%。当HA/P(AM-SAS)共混物的使用浓度超过20 mg/L,共混物

  13. Corrosion protection of steel in ammonia/water heat pumps

    Science.gov (United States)

    Mansfeld, Florian B.; Sun, Zhaoli

    2003-10-14

    Corrosion of steel surfaces in a heat pump is inhibited by adding a rare earth metal salt to the heat pump's ammonia/water working fluid. In preferred embodiments, the rare earth metal salt includes cerium, and the steel surfaces are cerated to enhance the corrosion-inhibiting effects.

  14. Corrosion Testing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Corrosion Testing Facility is part of the Army Corrosion Office (ACO). It is a fully functional atmospheric exposure site, called the Corrosion Instrumented Test...

  15. 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.

  16. 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.

  17. Corrosion protection of low-carbon steel using exopolysaccharide coatings from Leuconostoc mesenteroides

    Science.gov (United States)

    Corrosion is one of the most serious and challenging problems faced worldwide by industry. This research investigates the inhibition of corrosive behavior of SAE1010 steel by bacterial exopolysaccharides. Electrochemical Impedance Spectroscopy was used to evaluate the corrosion inhibition of diffe...

  18. Corrosion inhibition of copper in aqueous chloride solution by 1H-1,2,3-triazole and 1,2,4-triazole and their combinations: electrochemical, Raman and theoretical studies.

    Science.gov (United States)

    Ofoegbu, Stanley Udochukwu; Galvão, Tiago L P; Gomes, José R B; Tedim, João; Nogueira, Helena I S; Ferreira, M G S; Zheludkevich, M L

    2017-02-22

    Triazoles are well-known organic corrosion inhibitors of copper. 1H-1,2,3-Triazole and 1,2,4-triazole, two very simple molecules with the only difference being the positions of the nitrogen atoms in the triazole ring, were studied in this work as corrosion inhibitors of copper in 50 mM NaCl solution using a set of electrochemical and analytical techniques. The results of electrochemical tests indicate that 1H-1,2,3-triazole exhibited superior inhibitor properties but could not suppress anodic copper dissolution at moderate anodic potentials (>+300 mV SCE), while 1,2,4-triazole, although it exhibited higher anodic currents, suppressed anodic copper dissolution at very anodic potentials. Density functional theory calculations were also performed to interpret the measured data and trends observed in the electrochemical studies. The computational studies considered either the inhibitors isolated in the gaseous phase or adsorbed onto Cu(111) surface models. From the calculations, the mechanisms of the inhibitive effects of both triazoles were established and plausible mechanisms of formation of the protective films on the Cu surface were proposed. The results of this study hold positive implications for research in the areas of catalysis, and copper content control in water purification systems.

  19. Recent Developments on Microencapsulation for Autonomous Corrosion Protection

    Science.gov (United States)

    Calle, Luz M.; Li, Wenyan; Buhrow, Jerry W.; Fitzpatrick, Lilliana; Jolley, Scott T.; Surma, Jan M.; Pearman, Benjamin P.; Zhang, Xuejun

    2014-01-01

    This work concerns recent progress in the development of a multifunctional smart coating based on microencapsulation for the autonomous control of corrosion. Microencapsulation allows the incorporation of desired corrosion control functionalities, such as early corrosion detection and inhibition through corrosion controlled release of corrosion indicators and inhibitors, as well as self-healing agent release when mechanical damage occurs.While proof-of-concept results have been reported previously, more recent efforts have been concentrated in technical developments to improve coating compatibility, synthesis procedure scalability, as well as fine tuning the release property of encapsulated active agents.

  20. Stifling of Crevice Corrosion in Alloy 22

    Energy Technology Data Exchange (ETDEWEB)

    Mon, K G; Gordon, G M; Rebak, R B

    2005-06-08

    Artificially creviced Alloy 22 (N06022) specimens may be susceptible to crevice corrosion in presence of hot chloride containing solutions. The presence of oxyanions in the electrolyte, especially nitrate, may inhibit the nucleation and growth of crevice corrosion. Constant potential tests were performed using tightly creviced specimens of Alloy 22. It was found that crevice corrosion may initiate when a constant potential above the crevice repassivation potential is applied. It was found that as the crevice corrosion nucleated, the current initially increased but later decreased. The net measured current can be converted into penetration following a power law fit of the experimental data. The average power law coefficient ''n'' was found to be 0.439, suggesting that even under constant applied potential crevice corrosion penetration is diffusion controlled.

  1. STIFLING OF CREVICE CORROSION IN ALLOY 22

    Energy Technology Data Exchange (ETDEWEB)

    K.G. Mon; G.M. Gordon; R.B. Rebak

    2005-07-01

    Artificially creviced Alloy 22 (N06022) specimens may be susceptible to crevice corrosion in presence of hot chloride containing solutions. The presence of oxyanions in the electrolyte, especially nitrate, may inhibit the nucleation and growth of crevice corrosion. Constant potential tests were performed using tightly creviced specimens of Alloy 22. It was found that crevice corrosion may initiate when a constant potential above the crevice repassivation potential is applied. It was found that as the crevice corrosion nucleated, the current initially increased but later decreased. The net measured current can be converted into penetration following a power law fit of the experimental data. The average power law coefficient ''n'' was found to be 0.439, suggesting that even under constant applied potential, crevice corrosion penetration is diffusion controlled.

  2. Aircraft Corrosion

    Science.gov (United States)

    1981-08-01

    allowed to dry. The area is then checked for the golden brown color which is produced by the chemical conversion material. If the work area requires...Materials, pp. 258-3074 1968. 41. W. IH. Ailor, "Seven-year exposure at Point leyes , California," "Corrosion in Natural Environments, ASTM STP 558," American... Color Units 3 Turbidity Units 0.7 pH Units 7.6 Temperature OF 76 Sp. Conductivity MMhos 425 B.O.D. (5 days at 206C) 0.2 SjV i;~-- 1201 A .9 8 ~ 8 kl

  3. 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.

  4. Synthesis, characterization and corrosion inhibition efficiency of 2-(6-methylpyridin-2-yl-1H-imidazo[4,5-f][1,10] phenanthroline on mild steel in sulphuric acid

    Directory of Open Access Journals (Sweden)

    N.O. Obi-Egbedi

    2014-04-01

    Full Text Available Phenanthroline derivative, 2-(6-methylpyridin-2-yl-1H-imidazo[4,5-f][1,10] phenanthroline (MIP was synthesized and characterized by elemental analysis, FT-IR, 1H NMR, 13C NMR, and single crystal X-ray diffraction study. MIP was evaluated as corrosion inhibitor for mild steel in 0.5 M H2SO4 solution using gravimetric and UV–Visible spectrophotometric methods at 303–333 K. Results obtained show that MIP acts as inhibitor for mild steel in H2SO4 solution. The inhibition efficiency was found to increase with increase in MIP concentration but decreased with temperature. Activation parameters and Gibbs free energy for the adsorption process using statistical physics were calculated and discussed. The UV–Visible absorption spectra of the solution containing the inhibitor after the immersion of mild steel specimen indicate the formation of a MIP-Fe complex.

  5. USE OF COUPLED MULTI-ELECTRODE ARRAYS TO ADVANCE THE UNDERSTANDING OF SELECTED CORROSION PHENOMENA

    Energy Technology Data Exchange (ETDEWEB)

    N.D. Budiansky; F. Bocher; H. Cong; M.F. Hurley; J.R. Scully

    2006-02-23

    The use of multi-coupled electrode arrays in various corrosion applications is discussed with the main goal of advancing the understanding of various corrosion phenomena. Both close packed and far spaced electrode configurations are discussed. Far spaced electrode arrays are optimized for high throughput experiments capable of elucidating the effects of various variables on corrosion properties. For instance the effects of a statistical distribution of flaws on corrosion properties can be examined. Close packed arrays enable unprecedented spatial and temporal information on the behavior of local anodes and cathodes. Interactions between corrosion sites can trigger or inhibit corrosion phenomena and affect corrosion damage evolution.

  6. Corrosion Inhibition of Yushania Polytricha Leaves Extract for Aluminum in Hydrochloric Acid Media%滑竹叶提取物在盐酸介质中对铝的缓蚀性能

    Institute of Scientific and Technical Information of China (English)

    李向红; 邓书端; 付惠

    2012-01-01

    The inhibition effect of Yushania polytricha leaves extract (YPLE) on the corrosion of aluminum in 1.0 mol/L HC1 media was studied by mass loss, potentiodynamic polarization curves, electrochemical impedance spectroscopy, Fourier transform infrared spectroscopy, ultraviolet spectrophotometry and scanning electron microscope methods. The results show that YPLE is a good inhibitor, and the inhibition efficiency increases with the inhibitor concentration. The adsorption of YPLE on aluminum surface obeys Langmuir adsorption isotherm. YPLE behaves as a cathodic inhibitor. EIS spectra exhibit one capacitive loop at high frequencies followed by an inductive one at low frequency values, and the impedance value increases with the inhibitor concentration. SEM results confirm the corrosion of aluminum is retarded remarkably by the addition of YPLE.%采用失重法、动电位极化曲线、电化学阻抗谱、红外光谱、紫外光谱和扫描电子显微镜研究了滑竹叶提取物(YPLE)在1.0mol/L HCl介质中对铝的缓蚀作用.结果表明,YPLE对铝具有良好的缓蚀作用,缓蚀率随其浓度的增加而增大,且在铝表面的吸附符合Langmuir吸附等温式.YPLE为阴极抑制型缓蚀剂;电化学阻抗谱在高频区呈容抗弧,在低频区呈感抗弧,添加YPLE后,阻抗值显著增大.SEM表明,添加YPLE对铝的腐蚀产生了明显的抑制作用.

  7. Corrosion inhibition of mild steel in 1M HCl by D-glucose derivatives of dihydropyrido [2,3-d:6,5-d′] dipyrimidine-2, 4, 6, 8(1H,3H, 5H,7H)-tetraone

    Science.gov (United States)

    Verma, Chandrabhan; Quraishi, M. A.; Kluza, K.; Makowska-Janusik, M.; Olasunkanmi, Lukman O.; Ebenso, Eno E.

    2017-01-01

    D-glucose derivatives of dihydropyrido-[2,3-d:6,5-d′]-dipyrimidine-2, 4, 6, 8(1H,3H, 5H,7H)-tetraone (GPHs) have been synthesized and investigated as corrosion inhibitors for mild steel in 1M HCl solution using gravimetric, electrochemical, surface, quantum chemical calculations and Monte Carlo simulations methods. The order of inhibition efficiencies is GPH-3 > GPH-2 > GPH-1. The results further showed that the inhibitor molecules with electron releasing (-OH, -OCH3) substituents exhibit higher efficiency than the parent molecule without any substituents. Polarization study suggests that the studied compounds are mixed-type but exhibited predominantly cathodic inhibitive effect. The adsorption of these compounds on mild steel surface obeyed the Langmuir adsorption isotherm. SEM, EDX and AFM analyses were used to confirm the inhibitive actions of the molecules on mild steel surface. Quantum chemical (QC) calculations and Monte Carlo (MC) simulations studies were undertaken to further corroborate the experimental results. PMID:28317849

  8. Corrosion inhibition of mild steel in 1M HCl by D-glucose derivatives of dihydropyrido [2,3-d:6,5-d‧] dipyrimidine-2, 4, 6, 8(1H,3H, 5H,7H)-tetraone

    Science.gov (United States)

    Verma, Chandrabhan; Quraishi, M. A.; Kluza, K.; Makowska-Janusik, M.; Olasunkanmi, Lukman O.; Ebenso, Eno E.

    2017-03-01

    D-glucose derivatives of dihydropyrido-[2,3-d:6,5-d‧]-dipyrimidine-2, 4, 6, 8(1H,3H, 5H,7H)-tetraone (GPHs) have been synthesized and investigated as corrosion inhibitors for mild steel in 1M HCl solution using gravimetric, electrochemical, surface, quantum chemical calculations and Monte Carlo simulations methods. The order of inhibition efficiencies is GPH-3 > GPH-2 > GPH-1. The results further showed that the inhibitor molecules with electron releasing (-OH, -OCH3) substituents exhibit higher efficiency than the parent molecule without any substituents. Polarization study suggests that the studied compounds are mixed-type but exhibited predominantly cathodic inhibitive effect. The adsorption of these compounds on mild steel surface obeyed the Langmuir adsorption isotherm. SEM, EDX and AFM analyses were used to confirm the inhibitive actions of the molecules on mild steel surface. Quantum chemical (QC) calculations and Monte Carlo (MC) simulations studies were undertaken to further corroborate the experimental results.

  9. The inhibition of mild steel corrosion in acidic solutions by 2,5-bis(4-pyridyl)-1,3,4-thiadiazole: Structure-activity correlation

    Energy Technology Data Exchange (ETDEWEB)

    Lebrini, M. [Laboratoire de Cristallochimie et Physicochimie du Solide, UMR 8012 ENSCL, BP. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Bentiss, F. [Laboratoire de Cristallochimie et Physicochimie du Solide, UMR 8012 ENSCL, BP. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Laboratoire de Chimie de Coordination et d' Analytique, Universite Chouaib Doukkali, Faculte des Sciences, B.P. 20, El Jadida (Morocco); Vezin, H. [Laboratoire de Chimie Organique et Macromoleculaire, CNRS UMR 8009, USTL Bat C4, F-59655 Villeneuve d' Ascq Cedex (France); Lagrenee, M. [Laboratoire de Cristallochimie et Physicochimie du Solide, UMR 8012 ENSCL, BP. 90108, F-59652 Villeneuve d' Ascq Cedex (France)]. E-mail: michel.lagrenee@ensc-lille.fr

    2006-05-15

    The effect of 2,5-bis(4-pyridyl)-1,3,4-thiadiazole (4-PTH) on the corrosion of mild steel in acidic media (1 M HCl, 0.5 M H{sub 2}SO{sub 4}, 1 M HClO{sub 4}) has been investigated using weight loss measurements, electrochemical impedance spectroscopy and potentiodynamic polarisation. These studies have shown that 2,5-bis(4-pyridyl)-1,3,4-thiadiazole is good inhibitor for mild steel in 1 M HCl, 0.5 M H{sub 2}SO{sub 4} and 1 M HClO{sub 4} solutions, the better performances are seen in the case of 1 M HCl solutions. But in 1 M HClO{sub 4}, the 4-PTH stimulates corrosion at low concentrations. Polarisation curves indicate that the 4-PTH is a mixed-type inhibitor in all acidic media and E (%) is temperature-dependent. Adsorption on the mild steel surface follows the Langmuir isotherm model in all acidic media. The electronic properties obtained using the Hartree-Fock AB initio 3-21G quantum chemical approach, were correlated with the experimental efficiencies.

  10. Application of a quartz crystal microbalance to the study of copper corrosion in acid solution inhibited by triazole-iodide protective films

    Energy Technology Data Exchange (ETDEWEB)

    Jope, D.; Sell, J.; Pickering, H.W.; Weil, K.G. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering

    1995-07-01

    When one uses one side of a quartz crystal microbalance as the working electrode in electrochemical experiments, mass changes can be monitored continuously with a sensitivity of a few nanograms per square centimeter. In this study the working electrode consisted of electrolytically deposited copper, exposed to 0.1M sodium sulfate at pH 3, open to the atmosphere and in some cases containing H{sub 2}O{sub 2}. Upon addition of one of the inhibitors, benzotriazole (BTA), tolyltriazole (TTA), carboxy-benzotriazole (CBT), or these inhibitors plus potassium iodide, the rate of frequency change decreases markedly. After removal of the inhibitors from the corrosive medium by fast solution exchange there is a marked continuing protective effect of the inhibitor films in the cases of BTA + KI and TTA + KI with the latter being the most stable and protective of all of the films. The results were qualitatively the same in the more corrosive solution containing H{sub 2}O{sub 2}.

  11. T551金属减活剂对变压器油中铜腐蚀抑制作用研究%STUDY ON THE INHIBITION OF COPPER CORROSION WITH METAL PASSIVATOR T551 IN TRANSFORMER OIL

    Institute of Scientific and Technical Information of China (English)

    万涛; 钱晖; 徐松; 冯兵

    2012-01-01

    通过变压器油添加苯三唑型T551金属减活剂的腐蚀性硫试验和减活剂添加量试验,确定了T551具有抑制铜腐蚀和油品老化的作用.油质影响试验结果表明,T551能够将介质损耗因素从0.21%降低至0.08%,体积电阻率从5.97×1012Ω·cm提高至7.05×1012Ω·cm.采用飞行时间二次离子质谱对铜片表面进行分析,证实T551与铜发生螯合作用,苯三唑环上与氮原子相连的支链发生断裂,在铜表面形成苯三唑-铜的配位化合物.%The corrosion inhibition function of benzotriazole (BTA) type metal passivator T551 in transformer oil was investigated based on corrosive sulfur test (ASTM D1275B),the related properties of transformer oil were tested and the copper strip samples were analyzed by SEM and TOF-SIMS. Test results showed that T551 metal passivator exhibited good inhibition function of copper corrosion and aging of transformer oil. Adding T551 metal passivator in transformer oil,the dielectric loss of transformer oil could be reduced from 0. 21% to 0. 08% and the volume resistivity improved from 5. 97×1012Ω · cm to 7. 05×1012Ω · cm. The test results of copper strip surface indicated that chelation happened between T551 passivator and copper,the branch chain was broken from the nitrogen atom of BTA ring to form coordination compounds containing BTA and Cu on the copper surface.

  12. Corrosion behavior of corrosion resistant alloys in stimulation acids

    Energy Technology Data Exchange (ETDEWEB)

    Cheldi, Tiziana [ENI E and P Division, 20097 San Donato Milanese Milano (Italy); Piccolo, Eugenio Lo; Scoppio, Lucrezia [Centro Sviluppo Materiali, via Castel Romano 100, 00128 Rome (Italy)

    2004-07-01

    In the oil and gas industry, selection of CRAs for downhole tubulars is generally based on resistance to corrosive species in the production environment containing CO{sub 2}, H{sub 2}S, chloride and in some case elemental sulphur. However, there are non-production environments to which these materials must also be resistant for either short term or prolonged duration; these environments include stimulation acids, brine and completion fluids. This paper reports the main results of a laboratory study performed to evaluate the corrosion and stress corrosion behaviour to the acidizing treatments of the most used CRAs for production tubing and casing. Laboratory tests were performed to simulate both 'active' and 'spent' acids operative phases, selecting various environmental conditions. The selected steel pipes were a low alloyed steel, martensitic, super-martensitic, duplex 22 Cr, superduplex 25 Cr and super-austenitic stainless steels (25 Cr 35 Ni). Results obtained in the 'active' acid environments over the temperature range of 100-140 deg. C, showed that the blend acids with HCl at high concentration and HCl + HF represented too much severe conditions, where preventing high general corrosion and heavy localised corrosion by inhibition package becomes very difficult, especially for duplex steel pipe, where, in some case, the specimens were completely dissolved into the solution. On the contrary, all steels pipes were successfully protected by inhibitor when organic acid solution (HCOOH + CH{sub 3}COOH) were used. Furthermore, different effectiveness on corrosion protection was showed by the tested inhibitors packages: e.g. in the 90% HCl at 12% + 10 CH{sub 3}COOH acid blend. In 'spent' acid environments, all steel pipes showed to be less susceptible to the localised and general corrosion attack. Moreover, no Sulphide Stress Corrosion Cracking (SSC) was observed. Only one super-austenitic stainless steel U-bend specimen showed

  13. Launch Pad Coatings for Smart Corrosion Control

    Science.gov (United States)

    Calle, Luz M.; Hintze, Paul E.; Bucherl, Cori N.; Li, Wenyan; Buhrow, Jerry W.; Curran, Jerome P.; Whitten, Mary C.

    2010-01-01

    . Researchers at NASA's Corrosion Technology Laboratory at KSC are developing a smart, environmentally friendly coating system for early corrosion detection, inhibition, and self healing of mechanical damage without external intervention. This smart coating will detect and respond actively to corrosion and mechanical damage such as abrasion and scratches, in a functional and predictable manner, and will be capable of adapting its properties dynamically. This coating is being developed using corrosion sensitive microcapsules that deliver the contents of their core (corrosion inhibiting compounds, corrosion indicators, and self healing agents) on demand when corrosion or mechanical damage to the coating occurs.

  14. Factors affecting the corrosivity of pulping liquors

    Science.gov (United States)

    Hazlewood, Patrick Evan

    Increased equipment failures and the resultant increase in unplanned downtime as the result of process optimization programs continue to plague pulp mills. The failures are a result of a lack of understanding of corrosion in the different pulping liquors, specifically the parameters responsible for its adjustment such as the role and identification of inorganic and organic species. The current work investigates the role of inorganic species, namely sodium hydroxide and sodium sulfide, on liquor corrosivity at a range of process conditions beyond those currently experienced in literature. The role of sulfur species, in the activation of corrosion and the ability of hydroxide to passivate carbon steel A516-Gr70, is evaluated with gravimetric and electrochemical methods. The impact of wood chip weathering on process corrosion was also evaluated. Results were used to identify black liquor components, depending on the wood species, which play a significant role in the activation and inhibition of corrosion for carbon steel A516-Gr70 process equipment. Further, the effect of black liquor oxidation on liquor corrosivity was evaluated. Corrosion and stress corrosion cracking performance of selected materials provided information on classes of materials that may be reliably used in aggressive pulping environments.

  15. Controlling Corrosion in Defence Equipment - Technical Meeting,

    Science.gov (United States)

    1985-10-01

    corrosion of Ni/Al bronze in neutral solution, (2) the inhibited corrosion of mild steel in sulphuric acid, (3) comparison and ranking of a number of... electropolish : alkaline clean: pumice scrub: anodic etch: chromium plate. It must be remembered that mild steel is not being used, but a low alloy steel ...Wolsley shows no such damage. After all they are both made - from similar steels and both have been exposed to the two essential ingredients required

  16. 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.

  17. Microbiologically Influenced Corrosion: an Update

    Science.gov (United States)

    2014-01-01

    the material that failed was carbon steel and the electrolyte were saline waters, but the microorgan- isms, the environments and the corrosion...different salinities . Martin et al.42 demonstrated that Ecorr ennoblement was site specific, varying 100 mV versus SCE between locations, with higher...microbial consortium of the fungus Aspergillus niger and bacteria influenced the corrosion–inhibiting effectiveness of Crz6 leached from chromate (CrO{24

  18. 苯并三氮唑和磷酸钠对锌的协同缓蚀%Synergistic Inhibition of Zinc Corrosion by Benzotriazole in Combination with Sodium Phosphate

    Institute of Scientific and Technical Information of China (English)

    柳松; 钟燕; 蒋荣英; 冯自平; 肖睿

    2011-01-01

    The inhibition behaviors of benzotriazole (BTA), sodium phosphate (SP) and their mixture on zinc corrosion in 17% (0. 534 mol/L) aqueous tetra-n-butylammonium bromide (TBAB) solution were investigated by means of static weight-loss test, potentiodynamic polarization curve method, electrochemical impedance spectroscopy (EIS), SEM and XPS. The results indicate that BTA, SP and their mixture all protect zinc from corrosion in aqueous TBAB solution, with an inhibition efficiency increasing with BTA or SP content, and that the mixture consisting of 0. 1 g/L BTA and 1 g/L SP is of an inhibition efficiency higher than 93%. Moreover, according to the results of SEM and XPS, it is found that the synergistic inhibition of zinc corrosion by benzotriazole in combination with SP is due to not only the formation of the protective film containing ZnO, Zn ( OH ) 2 and Zn3 ( PO4 ) 2 on the electrode surface but also the adsorption of BTA on the film surface or the inserting of BTA in the film.%采用静态失重法、动电位极化曲线法、电化学交流阻抗法、扫描电镜和X射线光电子能谱等方法,研究了在质量分数为17%(0.534mol/L)的四丁基溴化铵(TBAB)溶液中,苯并三氮唑(BTA)和Na3PO4(SP)单独和复配使用对锌腐蚀的抑制作用.结果表明,BTA和Na3PO4及其复配物对TBAB溶液中的锌具有缓蚀作用,BTA和Na3PO4对锌的缓蚀效率随缓蚀剂质量浓度的增大而提高;0.1g/L的BTA和1g/L的Na3PO4的复配物的缓蚀效率高于93%.文中还结合扫描电镜和X射线光电子能谱的结果对复配物的缓蚀机理进行了讨论,二者的协同效应在于Na3PO4在锌的表面形成含有ZnO、Zn(OH)2和Zn3(PO4)2的保护层,BTA吸附在该保护层的表面或者是镶嵌在保护层的内部.

  19. Environmentally Friendly Coating Technology for Autonomous Corrosion Control

    Science.gov (United States)

    Calle, Luz M.; Li, Wenyan; Buhrow, Jerry W.; Johnsey, Marissa N.; Jolley, Scott T.; Pearman, Benjamin P.; Zhang, Xuejun; Fitzpatrick, Lilliana; Gillis, Mathew; Blanton, Michael; Hanna, Joshua S.; Rawlins, James W.

    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.

  20. A comparative study of the inhibition effects of benzotriazole and 6-aniline-1,3,5-triazine-2,4-dithiol monosodium salt on the corrosion of copper by potentiodynamic polarization, AC impedance and surface-enhanced Raman spectroscopic techniques

    Science.gov (United States)

    Zhou, Guoding; Cai, Shengmin; Song, Liqun; Yang, Huaquan; Fujishima, A.; Ibrahim, A.; Lee, Y. G.; Loo, B. H.

    1991-11-01

    The inhibition effects of benzotriazole (BTA) and 6-aniline-1,3,5-triazine-2,4-dithiol (ATD) monosodium salt on copper corrosion have been studied by the potentiodynamic polarization, AC impedance and surface-enhanced Raman spectroscopic techniques. The polarization resistance Rp increases with the concentration of either BTA or ATD. From the plots of the phase shift θ versus logarithm of the frequency, it is found that θ is close to 90° after the copper electrode is immersed for a long period of time in BTA-containing solution which indicates the behavior of an ideal capacitor. In ATD-containing solutions, θ is close to 45 ° which shows the appearance of a Warburg impedance for a diffusion process. Surface-enhanced Raman spectroscopic studies of the competitive adsorption of BTA and ATD on copper surfaces indicate that BTA adsorbs better than ATD. Based on these results, it is concluded that the inhibition action of BTA is better than that of ATD.

  1. Smart Coating for Corrosion Indication and Prevention: Recent Progress

    Science.gov (United States)

    Li, Wenyan; Hintze, Paul; Calle, Luz M.; Buhrow, Jerry; Curran, Jerry; Muehlberg, A. J.; Gelling, V. J.; Webster, D. C.; Croll, S. G.; Contu, F.; Taylor, S. R.

    2009-01-01

    The authors are developing a smart coating system based on pH-triggered release microcapsules. These microcapsules can be incorporated into various coating systems for corrosion detection, protection and self-repair of mechanical coating damage. This paper will present the results from progress made to date in the controlled release properties of these microcapsules as well as in their corrosion indication and corrosion inhibition function.

  2. Combinatorial materials research applied to the development of new surface coatings X: a high-throughput electrochemical impedance spectroscopy method for screening organic coatings for corrosion inhibition.

    Science.gov (United States)

    He, Jie; Bahr, James; Chisholm, Bret J; Li, Jun; Chen, Zhigang; Balbyshev, Séva N; Bonitz, Verena; Bierwagen, Gordon P

    2008-01-01

    The objective of the study was to develop a high-throughput electrochemical impedance spectroscopy (HT-EIS) method for rapid and quantitative evaluation of corrosion protective coatings. A 12-element, spatially addressable electrochemical platform was designed, fabricated, and validated. This platform was interfaced to a commercial EIS instrument through an automated electronic switching unit. The HT-EIS system enables four parallel EIS measurements to be run simultaneously, which significantly reduces characterization time compared to that of serial EIS measurements using a multiplexer. The performance of the HT-EIS system was validated using a series of model systems, including a Randles equivalent circuit, an electrochemical reaction (Ti/K4FeCN6, K3FeCN6), a highly uniform polymer film, and several polymer coatings. The results of the validation studies showed that the HT-EIS system enables a major reduction in characterization time and provides high quality data comparable to data obtained with conventional, single-cell EIS measurement systems.

  3. Synthetic seawater as stress-corrosion test medium

    Science.gov (United States)

    Humphries, T. S.; Nelson, E. E.

    1980-01-01

    Seawater minimizes pitting corrosion of aluminum-alloy test samples. Of three corrosion-inhibiting methods evaluated using (a) chromate inhibitors in saltwater, (b) surface treating sample via anodizing or alodine treatment, and (c) synthetic seawater, synthetic seawater was most effective test medium, since it is more uniform than fresh seawater.

  4. 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.

  5. Corrosion Behavior of S450EW Low-alloy Weathering Steel in Cyclically Alternate Corrosion Environments

    Institute of Scientific and Technical Information of China (English)

    Jun-shan WANG; Pei-yang SHI; Cheng-jun LIU; Mao-fa JIANG

    2015-01-01

    Weathering steel is widely used in various ifelds due to its excellent mechanical properties and high corrosion resistance. The effect of chromium content on the S450EW weathering steel in cyclic immersion test was studied. The results indicated that the corrosion resistance of S450EW weathering steel is closely related to chromium content. The addition of chromium signiif-cantly inhibited the weathering steel corrosion. The corrosion rate of experimental steel after 96 h immersion was 1.101 g·m−2·h−1. The rust of S450EW weathering steel was mainly constituted of FeOOH and Fe3O4 phase, and the elevation of chromium content promoted the formation of α-FeOOH. The ifne precipitates of the two phases contributed to the formation of dense dust layer of test steel. Furthermore, the increase of chromium is beneifcial for the cure of original defects and cracks of the rust layer via the enrich-ment of chromium. The corrosion potential and the resistance of corrosion process were thus increased, protecting the experimental steel from further corrosion. A S450EW steel with corrosion resistance more than 1.5 times of Q450NQR1 steel was prepared.

  6. Modelling of Corrosion Cracks

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    Modelling of corrosion cracking of reinforced concrete structures is complicated as a great number of uncertain factors are involved. To get a reliable modelling a physical and mechanical understanding of the process behind corrosion in needed.......Modelling of corrosion cracking of reinforced concrete structures is complicated as a great number of uncertain factors are involved. To get a reliable modelling a physical and mechanical understanding of the process behind corrosion in needed....

  7. Management of Reinforcement Corrosion

    DEFF Research Database (Denmark)

    Küter, André; Geiker, Mette Rica; Møller, Per

    Reinforcement corrosion is the most important cause for deterioration of reinforced concrete structures, both with regard to costs and consequences. Thermodynamically consistent descriptions of corrosion mechanisms are expected to allow the development of innovative concepts for the management...... of reinforcement corrosion....

  8. Elucidation of the Corrosion Inhibition of Mild Steel in 1.0 M HCl by Catechin Monomers from Commercial Green Tea Extracts

    Science.gov (United States)

    Nofrizal, S.; Rahim, Afidah A.; Saad, Bahruddin; Bothi Raja, P.; Shah, Affaizza M.; Yahya, S.

    2012-04-01

    The inhibitive action of commercial green tea extracts on mild steel (MS) in a 1.0 M hydrochloric acid solution was investigated by weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). A high-performance liquid chromatographic (HPLC) analysis showed conclusively that of the eight catechin monomers and caffeine found in the original extracts, only four components were responsible for the inhibition of MS. The decreasing adsorption capacity of monomers on MS is related to the stereochemistry of molecules and the number of phenolic groups, and it is as follows: epigallocatechin gallate > epicatechin gallate > epigallocatechin > epicatechin. Adsorption of green tea extract constituent was found to follow Langmuir adsorption isotherm and the calculated Gibb's free energy values indicated the physisorption of inhibitor over MS surface. Physisorption was supported well by the potential zero charge (PZC) and molecular surface energy-level calculations.

  9. The Inhibitive Effect of para-Amino Benzoic Acid and Its Polymer on Corrosion of Iron in 1 mol/L HCl Solution

    Institute of Scientific and Technical Information of China (English)

    P. Manivel; G. Venkatachari

    2006-01-01

    Poly p-aminobenzoic acid has been synthesized by chemical oxidation method. The inhibitive effect of poly p-aminobenzoic acid on iron in 1 mol/l HCl solution was investigated by polarization and electrochemical impedance spectroscopy and compared with that of monomer p-aminobenzoic acid. The effectiveness of poly p-aminobenzoic acid is very high in comparison with that of monomer. The results show that both cathodic and anodic processes were suppressed by p-aminobenzoic acid and poly p-aminobenzoic acid of iron dissolution in 1 mol/L HCl by their adsorption on the iron surface. The inhibition efficiency of both p-aminobenzoic acid and poly p-aminobenzoic acid were found to increase with the inhibitor concentrations. Ultraviolet (UV)reflectance studies of the iron surface after exposure to inhibitor acid show that poly p-aminobenzoic acid is strongly adsorbed on iron surface.

  10. 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.

  11. Synthesis, structures, spectral properties and DFT quantum chemical calculations of (E)-4-(((4-propylphenyl)imino)methyl)phenol and (E)-4-((2-tolylimino)methyl)phenol; their corrosion inhibition studies of mild steel in aqueous HCl

    Science.gov (United States)

    Elemike, Elias E.; Nwankwo, Henry U.; Onwudiwe, Damian C.; Hosten, Eric C.

    2017-08-01

    Two Schiff base compounds with similar backbone, but different positions and lengths of alkyl groups, (E)-4-(((4-propylphenyl)imino)methyl)phenol (PMP) and (E)-4-((2-tolylimino)methyl)phenol (TMP) have been synthesized. Their structures were established by spectroscopic techniques which include FTIR, 1H and 13C NMR, relative molecular mass (mass spect.), and single crystal X-ray crystallography. The spectroscopic methods revealed the characteristic imine functional groups and the exact molecular masses of the compounds. Single crystal analysis revealed an orthorhombic crystal system with Pca21 space group for the two compounds; and the structure of PMP reveal that the propyl group is disordered over two positions in 0.79:0.21 ratio. The corrosion inhibition behaviour of the two Schiff bases were studied by electrochemical measurements. The results suggest that the two derivatives adsorbed onto the mild steel surface and formed hydrophobic films, which to an appreciable extent, protected the surface of the mild steel. Potentiodynamic polarization results strongly suggested that the investigated Schiff bases behave as mixed-type inhibitors with a more pronounced cathodic nature, and the adsorption isotherm basically obeys the Langmuir isotherm. Quantum chemical computations were also employed to provide further explanations on the adsorption mode, and the theoretical predictions conformed to the experimental results.

  12. CORROSION INHIBITION OF 6-NITROBENZIMIDAZOLE IN KOH SOLUTION FOR ZINC%6-硝基苯并咪唑在KOH溶液中对锌的缓蚀性能

    Institute of Scientific and Technical Information of China (English)

    胡莲跃; 张胜涛; 黄小红; 吴永英

    2012-01-01

    采用失重法、电化学测试以及量子化学计算方法研究6-硝基苯并咪唑在KOH(0.1mol/L)溶液中对Zn的缓蚀性能。结果表明,6-硝基苯并咪唑能有效抑制锌的阳极氧化,从而抑制Zn在碱液中的自腐蚀,属于阳极型缓蚀剂;当6-硝基苯并咪唑浓度为5mmol/L时缓蚀效果最佳,其效率达到96.8%;6.硝基苯并咪唑在锌表面的吸附符合Langmuir等温式。%The effect of 6-nitrobenzimidazole on the zinc corrosion in 0.1 mol/L KOH solution has been studied by electrochemical, weight loss measurements and quantum chemical calculations. It has been shown that 6-nitrobenzimidazole act as an anodic inhibitor, can effectively restrain the process of the anodic oxidation of zinc. The highest value of inhibition efficiency is 96.8% at 5 mmol/L concentration. Thermodynamic calculation suggests that the adsorption of 6-nitrobenzimidazole follows Langmuir adsorption isotherm.

  13. 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.

  14. 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.

  15. Corrosion Inhibition of 316L Steel Using Sodium Diethyl Dithiocarbamate in Simulated Crude Oil Solution%二乙基二硫代氨基甲酸钠在原油模拟液中对316L钢的缓蚀作用

    Institute of Scientific and Technical Information of China (English)

    任晓光; 杨杰

    2012-01-01

    The corrosion inhibition behaviors of 316L steel using the sodium diethyl dithiocarbamate(SDDTC) compound in simulated crude oil solution were studied in the absence and presence of zinc sulfate or sodium chromate with different combinations.Experiment results showed that in the environments of high acidity and high concentrations of chloride ions the SDDTC compound could well inhibit the corrosion of 316L steel.The good synergic effects on the corrosion inhibition of 316L steel by additions of either zinc sulfate or sodium chromate into SDDTC compound were indicated in this study,which is of great significance and importance in practical applications.%配制原油模拟液,研究了二乙基二硫代氨基甲酸钠(SDDTC)于模拟液中单独使用以及分别与硫酸锌,铬酸钠的复配对316L钢的缓蚀效果.实验表明:在高酸高氯环境下,SDDTC能够很好地抑制316L钢的腐蚀;而且SDDTC与硫酸锌、铬酸钠之复配缓蚀剂具有很好的协同增效作用.这一相关研究具有重要的实际应用意义.

  16. 聚天冬氨酸与十四烷基二甲基苄基氯化铵等复配物的缓蚀阻垢杀菌性能%Scale, Corrosion Inhibitions and Anti-Bacterial Performances of the Combinations of Polyaspartic Acid and Tetradecyl Dimethyl Benzyl Ammonium Chloride

    Institute of Scientific and Technical Information of China (English)

    刘芳; 常新; 董文文; 姜慧超; 张玉娇

    2013-01-01

    采用旋转挂片法、碳酸钙沉积法和平板计数法,分别考察了十四烷基二甲基苄基氯化铵(1427)、聚天冬氨酸(PASP)和氨基三亚甲基膦酸(ATMP)水处理剂在循环冷却水中的缓蚀、阻垢和杀菌性能,并将它们与锌盐复配使用,通过正交实验筛选出具有良好缓蚀、阻垢和杀菌性能的复合配方.结果表明,当循环冷却水中ATMP、PASP、1427和锌盐的质量浓度分别为40、20、80、2 mg/L时,该复配剂可获得最佳性能,对碳钢的缓蚀率和相应的阻垢率均高于91%,杀菌率可达98%以上,实现了缓蚀、阻垢和杀菌3种功效.%The corrosion, scale inhibitions and anti-bacterial performances of tetradecyl dimethyl benzyl ammonium chloride(1427) , polyaspartic acid (PASP) , amino trimethylene phosphonic acid (ATMP) water treatment chemicals in circulating cooling water were investigated by using rotary coupon corrosion test, carbonate precipitation process and flat colony counting method. A combination formula composed of 1427, PASP, ATMP and zinc salt with high performances of corrosion, scale inhibitions and anti-bacterial was screened by orthogonal experiment. The results showed that when the combination water treatment agent composed of 40 mg/L ATMP, 20 mg/L PASP, 80 mg/L 1427 and 2 mg/L zinc salt was used in circulating cooling water, the corrosion inhibition rate for carbon steel exceeded 91%, the corresponding scale inhibition rate exceeded 91% , and the bactericidal rate reached above 98%. The multi-function of corrosion inhibition, scale inhibition and sterilization was achieved.

  17. 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.

  18. Anti-Corrosive Effect of Tridax Procumbens – Zn2+ System Controlling the Corrosion of Carbon Steel

    OpenAIRE

    Kumar, C.; Mohan, R

    2014-01-01

    The corrosion inhibition efficiency (IE) of an aqueous extract Tridax Procumbens(TP) in controlling the corrosion of carbon steel aqueous medium containing 60 ppm of chloride ions in absence and presence of Zn2+ has been studied by weight loss method. The formulation consisting of 1 ml of Tridax Procumbens extract and 150 ppm of Zn2+ offers 96% inhibition efficiency. The synergistic effect exists between Tridax Procumbens and Zn2+ system. Polarization study shows that the Trida...

  19. Thin Metal Films as Corrosion Indicators

    Science.gov (United States)

    1960-03-01

    used during the preceding two years were replaced by quart glass jars with gasket sealed lids. All electric lead- in entrances were sealed with beeswax ...rinse, and the excess lanolin could be seen to dissolve quite rapidly. Apparently, however, a corrosion inhibiting layer of lanolin remained. At the 40

  20. The corrosion behaviour of brass in acid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Zoran, Avramovic [TiR, Copper Smelter and Electrolysis Plant, Bor (Serbia); Milan, Antonijevic [Belgrade Univ., Technical Faculty, Bor (Serbia)

    2009-07-01

    The corrosion behaviour of brass was studied in acid sulphate solution at pH-value 2 with additional chloride ions and five organic inhibitors namely: thiourea (TU), benzotriazole (BTA), ethylene diamine tetraacetic acid (EDTA), hydrazine sulphate (HS) and 2-butin-1,4 diole (DS-3) using potentiodynamic polarization techniques. Increase of a concentration of the Cl{sup -} ions, except for value of 5*10{sup -2} moldm{sup -3}, resulted in a significant increase of value for corrosion current densities. Polarization measurements showed that the organic compounds investigated are mixed type inhibitors, inhibiting the corrosion of brass by blocking the active sites of the metal surface. The results of studies show that only thiourea, in concentration of 10{sup -2}%, inhibit the corrosion of brass in chloride solutions. Inhibitor benzotriazole in concentration of 10{sup -1}% inhibit the corrosion of brass with inhibition efficiency more then 94%. The film improved significantly the protecting ability of brass surface to corrosion in chloride solutions. When the films were modified with benzotriazole the quality and corrosion protection of films improved rapidly. (authors)