共查询到20条相似文献,搜索用时 15 毫秒
1.
Ksenija Babić-Samardžija Norman Hackerman 《Journal of Solid State Electrochemistry》2005,9(7):483-497
The effect of a 1H-1,2,3-triazole, 1,2,3-benzotriazole and a number of substituted benzotriazoles, namely 1-hydroxybenzotriazole, 1H-benzotriazole-1-methanol and N-(1H-benzotriazol-1-ylmethyl)-formamide, have been investigated with respect to the corrosion of iron in 1 mol/l HCl and 1 mol/l HClO4. The Tafel extrapolation method, linear polarization resistance and electrochemical impedance spectroscopy illustrate the inhibiting effect of all of these compounds in both acids. They are better inhibitors in 1 mol/l HCl than in 1 mol/l HClO4. The changes of charge transfer resistance are also indicative for adsorption and inhibition of all of these compounds. This effect increases with time up to 16 h. An equivalent circuit is suggested as a model for the impedance. The adsorption of triazole-type of compounds in both acids follows a Langmuir isotherm. Molecular modeling was used to gain some insight, about structural and electronic effects in relation to the inhibiting efficiencies. 相似文献
2.
A. Zarrouk H. Zarrok R. Salghi B. Hammouti R. Touir I. Warad F. Bentiss H. Abou El Makarim N. Benchat 《Research on Chemical Intermediates》2013,39(3):1279-1289
The efficiency of 1H-1,2,4-triazol-3-amine (Tz1), 4-amino-3-hydrazino-4H-1,2,4-triazole-3-thiol (Tz2), and 1H-1,2,4-triazole-3,5-diamine (Tz3) as inhibitors of corrosion of copper in nitric acid was investigated by use of density functional theory (DFT). Quantum chemical data, for example energy of the highest occupied molecular orbital (E HOMO), energy of the lowest unoccupied molecular orbital (E LUMO), energy gap (ΔE), dipole moment (μ), electronegativity (χ), electron affinity (A), global hardness (η), softness (σ), ionization potential (I), fraction of electrons transferred from the inhibitor molecules to the metallic atom (ΔN), and total energy (TE), were calculated. All calculations were performed by use of DFT with Gaussian 03W software. A good correlation was found between theoretical data and experimental results. 相似文献
3.
A. S. Fouda T. F. Alsawy E. S. Ahmed B. S. Abou-elmagd 《Research on Chemical Intermediates》2013,39(6):2641-2661
The inhibitive effect of 2-cyano-3-hydroxy-4(Ar)-5-anilino thiophene derivatives on the corrosion of 304 stainless steel (SS) in 3 M HCl solution has been investigated by weight loss, galvanostatic polarization techniques, and potentiodynamic anodic polarization in 3.5 % NaCl. The results indicate that these compounds act as inhibitors retarding the anodic and cathodic corrosion reactions. The presence of inhibitors does not change the mechanism of either hydrogen evolution reaction or SS dissolution. The activation energy and some thermodynamic parameters are calculated and discussed. These compounds are mixed-type inhibitors in the acid solution, and their adsorption on the SS surface is found to obey the Temkin adsorption isotherm. The results suggest that the percentage inhibition of these thiophene derivatives increases with increasing inhibitor concentration and decreases with increasing temperature. The synergistic parameter (S) was calculated and found to have a value greater than unity, indicating that the enhanced inhibition efficiency caused by the addition of I?, SCN?, and Br? is only due to a synergistic effect. The relationship between molecular structure and inhibition efficiency was elucidated by quantum-chemical calculations using semi-empirical self-consistent field (SCF) methods. 相似文献
4.
A. A. Kostyaev A. V. Balmasov L. N. Inasaridze 《Russian Journal of General Chemistry》2016,86(2):429-433
The corrosion behavior of carbon steel in PO-6TS-M foaming solution was studied. Several kinds of inhibiting additives were tested for their ability to reduce the corrosion rate of steel. The antipyrene additive to the foaming solution was shown to be the most effective in reducing corrosion rate of carbon steel. The optimum concentration of the inhibitor additive was determined. 相似文献
5.
M. Abdallah I. Zaafarany S.O. Al-Karanee A.A. Abd El-Fattah 《Arabian Journal of Chemistry》2012,5(2):225-234
The corrosion behavior of aluminum and three aluminum–silicon alloys in different concentrations of HCl solutions and its inhibition by antihypertensive drugs was studied using potentiostatic polarization measurements. As the acid concentration increases, the rate of corrosion increases. Aluminum is less susceptible to corrosion than any of Al–Si alloys. The inhibition efficiency of the drug compounds increases with their concentration up to a critical value. At higher additive concentrations the inhibition efficiency starts to decrease. The inhibitive action of these compounds is due to their formation of insoluble complex adsorbed on the metal surface. The adsorption follows Langmuir adsorption isotherms. It was found that the drugs compounds provide protection to Al and Al–Si alloys against pitting corrosion by shifting the pitting potential to more positive direction until critical drug concentrations (250 ppm). After this critical concentration the inhibition against to pitting corrosion starts to decrease. 相似文献
6.
《Arabian Journal of Chemistry》2020,13(1):481-544
This review paper deals with corrosion of copper and its alloys in corrosive environments and their corrosion inhibitors. The main corrosion inhibitor groups for copper are introduced and a review of adsorption models is provided. The main part of this work is to investigate different corrosive environments for copper and its alloys and their corrosion inhibitors used in such environments to protect copper. According to the literature, the corrosion inhibition behavior of organic corrosion inhibitors and their derivatives in comparison with inorganic ones are further evaluated. Knowing maximum corrosion inhibition efficiency of a specific corrosion inhibitor in a specific corrosive environment is helpful to choose the most appropriate corrosion inhibitor compound. 相似文献
7.
《Green Chemistry Letters and Reviews》2013,6(3-4):17-29
ABSTRACTThe influence of extract of ceratonia siliqua extract on the corrosion of copper and brass in aqueous 1 M nitric acid was examined by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy and electrochemical frequency modulation techniques. The surface morphology was analyzed using scanning electron microscope and energy dispersive X-ray techniques. Potentiodynamic polarization curves indicated that the plant extract behaves as cathodic inhibitor. The results indicate that the extract solution of the plant could serve as an effective inhibitor for the corrosion of copper and brass in nitric acid media. As temperature increases, percentage of inhibition decreases. The degree of surface coverage of the adsorbed inhibitor was determined by weight-loss technique, and it was found that the results obeyed the Langmuir adsorption isotherm. 相似文献
8.
9.
N.A. Al-Mobarak K.F. Khaled Mohamed N.H. Hamed K.M. Abdel-Azim 《Arabian Journal of Chemistry》2011,4(2):185-193
The inhibition effect of 2-carboxymethylthio-4-(p-methoxyphenyl)-6-oxo-1,6-dihy-dropyrimidine-5-carbonitrile (CPD) towards the corrosion of copper was studied in aerated stagnant 3.5% NaCl at 25 °C using ac techniques include electrochemical frequency modulation and electrochemical impedance spectroscopy as well as potentiodynamic polarization measurements. Corrosion rates determined using electrochemical frequency modulation (EFM) which measures the non-linear behaviour of a corroding system are compared with corrosion rates obtained from traditional electrochemical techniques and show good agreement. Data obtained from EIS were analyzed to model the corrosion inhibition process through equivalent circuit. Polarization measurements showed that CPD acts as mixed-type inhibitor. The inhibition efficiency increases with an increase in the concentration of CPD. The adsorption of the inhibitor on the copper surface in the sodium chloride solution was found to obey Langmuir’s adsorption isotherm. A mixed inhibition mechanism is proposed for the inhibitive effects of CPD as revealed by potentiodynamic polarization technique. 相似文献
10.
《Journal of Saudi Chemical Society》2014,18(5):450-455
Quantum chemical calculations based on DFT method were performed on three quinoxalines compounds namely ethyl 2-(4-(2-ethoxy-2-oxoethyl)-2-p-tolylquinoxalin-1(4H)-yl)acetate (Q1), 1-[4-acetyl-2-(4-chlorophenyl)quinoxalin-1(4H)-yl]acetone (Q2) and 2-(4-methylphenyl)-1,4-dihydroquinoxaline (Q3), used as corrosion inhibitors for copper in nitric acid media to determine the relationship between the molecular structure of quinoxalines and inhibition efficiency. Quantum chemical parameters such as the highest occupied molecular orbital energy (EHOMO), the lowest unoccupied molecular orbital energy (ELUMO), energy gap (ΔE), dipole moment (μ), electronegativity (χ), electron affinity (A), global hardness (η), softness (σ), ionization potential (I), the fraction of electrons transferred (ΔN), and the total energy (TE), were calculated. The theoretically obtained results were found to be consistent with the experimental data reported. 相似文献
11.
Contact corrosion of a number of metals in aqueous-glycolic solutions of nitrites, borates, benzoates, and phosphates of alkali
metals was studied. 相似文献
12.
13.
Yan Zhao Xingbin Yang Ru Jiang Xiaoli Sun Wenmin Liu Shengyong Zhang 《Analytical sciences》2006,22(5):747-751
The investigation on capillary electrophoretic enantioseparation of six synthetic compounds containing vicinal diol groups has been undertaken to acquire the optimum conditions using native beta-cyclodextrin (beta-CD) as chiral selector and borate as a background electrolyte. The separation was carried out in an uncoated capillary (58.5 cm x 75 microm i.d., effective length 48.5 cm) and the effects of several important factors were investigated in detail. The results showed that beta-CD as a chiral selector exhibited good enantioselectivity and that the enantioseparation was greatly influenced by the structure of the diols, the borate concentration and the buffer pH. The optimum performance was obtained for the chiral vicinal diols under the conditions of 200 mM borate buffer of pH 9.8 containing 1.7% beta-CD at an applied voltage of 15 kV and a capillary temperature of 20 degrees C. Under the conditions, four diols were baseline separated with fast analysis time and the good theoretical plate numbers (above 10 x 10(4)) and favorable migration-time reproducibilities (RSDs below 3.0%) were obtained. The separation results were satisfactory. 相似文献
14.
《Chemical physics letters》1985,120(1):41-44
The Raman spectra of the liquid-solid interface recorded in situ show the formation of a salt complex of the inhibitor molecules and the copper ions. This suggests that this chemisorbed surface species produces the protective layer. 相似文献
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16.
The analytical properties of 5-chloro-, 5-bromo- and 5-methyl-2-thiophenealdehyde-2-benzothiazolylhydrazone (CTBH, BTBH and MTBH, respectively), are compared with those of 2-thiophenealdehyde-2-benzothiazolylhydrazone (TBH). The acid dissociation constants have been determined, and the 5-substituent effect is discussed. The complex formation of the reagents with several metal ions has been examined spectrophotometrically. Extraction—spectrophotometric determinations of traces of copper are proposed. The copper complexes can be extracted quantitatively into benzene over wide pH ranges (from weakly acidic to alkaline medium) and the molar absorptivities are high (4–5· 104 l mol-1 cm-1). The complexes formed are 1:2 (copper:ligand) in all cases. There are few interferences from common ions except silver(I), mercury(II), thiocyanate and citrate. 相似文献
17.
Alice Elia Karolien De Wael Mark Dowsett Annemie Adriaens 《Journal of Solid State Electrochemistry》2012,16(1):143-148
Carboxylic acids and sodium carboxylates are used to protect metals against aqueous and atmospheric corrosion. In this paper,
we describe the application of a layer of copper carboxylate on the surface of a copper electrode by means of cyclic voltammetry
technique and tests which measure the corresponding resistance to aqueous corrosion. Unlike the soaking process, which also
forms a film on the surface, the use of cyclic voltammetry allows one to follow the deposition process of the copper carboxylates
onto the electrode. The modified electrodes have been characterised with infrared spectroscopy. In addition, the corrosion
resistance of the film has been investigated using polarisation resistance and Tafel plot measurements. 相似文献
18.
The gas-phase adsorption of 1,2,3-triazole, benzotriazole, and naphthotriazole-considered as corrosion inhibitors-on copper surfaces was studied and characterized using density functional theory (DFT) calculations. We find that the molecule-surface bond strength increases with increasing molecular size, thus following the sequence: triazole相似文献
19.
Azorhodanine derivatives (HL1-HL5) were tested as corrosion inhibitors for nickel in 2M HNO3 solution using weight loss and galvanostatic polarization techniques. The results showed that these derivatives act as inhibitors for nickel in this medium. The inhibition was assumed to occur via adsorption of the inhibitor molecule on the metal surface. Polarization measurements indicated that these compounds act as mixed-type inhibitors, but the cathode is more polarized when an external current was applied. This means that these compounds retard the rate of hydrogen evolution and the rate of dissolution of the metal. Results showed that azorhodanine derivatives are adsorbed on the nickel surface following Temkin's adsorption isotherm. The activation energy and thermodynamic parameters were calculated and discussed at different temperatures (30-45 degrees C). 相似文献
20.