The dissolution of carbon steel in 5% HCl in the temperature range of 30~90℃ was inhibited by two organic compounds having the general formula: ClR NH2(CH2)n NH2 RCl where R is a benzyl group. The behaviour of these ...The dissolution of carbon steel in 5% HCl in the temperature range of 30~90℃ was inhibited by two organic compounds having the general formula: ClR NH2(CH2)n NH2 RCl where R is a benzyl group. The behaviour of these inhibitors in acidic medium were investigated using weight loss method, open circuit potential and linear polarization technique. These inhibitors provided satisfactory corrosion inhibition for carbon steel in hydrochloric acid solutions even at higher temperature and acid concentration (10%). The electrochemical results showed that the polarization resistance (Rp) values increased with increasing inhibitor concentration, also the corrosion current decreased and a higher inhibition efficiency was obtained. The protective properties of these two organic inhibitors were attributed to the chemisorption mechanism展开更多
This study describes the adsorption behavior of three arylthiophene derivatives namely:2-(4-amidino-3-fluorophenyl)-5-[4-methoxy phenyl] thiophene dihydrochloride salt(MA-1217),2-(4-amidinophenyl)-5-[4-chlorophenyll t...This study describes the adsorption behavior of three arylthiophene derivatives namely:2-(4-amidino-3-fluorophenyl)-5-[4-methoxy phenyl] thiophene dihydrochloride salt(MA-1217),2-(4-amidinophenyl)-5-[4-chlorophenyll thiophene dihydrochloride salt(MA-1316) and 2-(4-amidino-3-fluorophenyl)-5-[4-ch lorophenyllthiophene dihydrochloride salt(MA-1312) at C-steel in 1.0 mol·L^(-1) HCl interface using experimental and theoretical studies.Electrochemical and mass loss measurements showed that the inhibition efficiency(IE) of the arylthiophene derivatives increases with increasing concentrations and exhibited maximum efficiency 89% at 21×10^(-6) mol·L^(-1)(MA-1217) by mass loss method.The investigated arylthiophene derivatives obey the Langmuir adsorption isotherm.From polarization studies the arylthiophene derivatives act as mixed-type inhibitors.Surface analysis were carried out and discussed.The mode of orientation and adsorption of inhibitor molecules on C-steel surface was studied using molecular dynamics(MD) simulations.Quantum chemical parameters as well as the radial distribution function indices and binding energies confirm the experimental results.展开更多
Green inhibitors are promising alternatives to toxic corrosion inhibitors as they are environmentally safe substances, ecologically acceptable and renewable. In this research, the effect of green henna as an inhibitor...Green inhibitors are promising alternatives to toxic corrosion inhibitors as they are environmentally safe substances, ecologically acceptable and renewable. In this research, the effect of green henna as an inhibitor existing in the coating of TMSM-PMMA and its electrochemical study were analyzed. The coating was produced by “sol-gel” method in order to protect the corrosion of low-carbon steel. TMSM hybrid cell was synthesized by hydrolysis and condensation, Metaacryloxypropyltrimethoxysilane and Tetraetylorthosilicate with 1:1 molar ratio and PMMA hybrid cell was produced by Methylmetaacrylate polymerization. Finally two cells were mixed in 1:1 weight ratio. The carbon steel substrates were prepared by dip coating method. SEM technique was applied for the microstructure evaluation of thin layers including different concentrations of henna extract. Adhesion of coating was analyzed by “Pull off” test. Additionally, the experimental results obtained in different concentrations of henna extract using electrochemical methods such as tafel polarization, electrochemical impedance spectroscopy indicating that coating with the concentration of 3% inhibitor had a high level of inhibition efficiency in 0.1 M HCL. The results of polarization tests signified that henna extract acts as a mixed inhibitor.展开更多
The inhibition effect of dimethylethanolamine（DMEA） and its composite with carboxylic acid was studied with the electrochemical tests. The experimental results indicate that DMEA is not a good inhibitor but the comp...The inhibition effect of dimethylethanolamine（DMEA） and its composite with carboxylic acid was studied with the electrochemical tests. The experimental results indicate that DMEA is not a good inhibitor but the composite of DMEA with caprylic acid exhibits excellent inhibiting efficiency. The synergic mechanism of the organic corrosion inhibitors（OCIs） was studied with quantum chemical calculations. It is found that the DMEA forms a quaternary ammonium salt with the proton in carboxylic acid, and a cyclic complex formed between the salt and Fe may be responsible for the enhancement of inhibiting efficiency. The possible hydrogen bond formed between DMEA and carboxylic acid is not enough for the inhibiting effect. This work is helpful to proposing theoretical interpretation as well as developing a functional organic inhibitor to improve the durability of reinforced concrete contaminated with chloride.展开更多
An electrochemical investigation of the corrosion on AISI 316 austenitic stainless steel and AISI 1010 carbon steel in sodium chloride solution (3.0 wt.%) was performed in the absence and presence of imidazole and ben...An electrochemical investigation of the corrosion on AISI 316 austenitic stainless steel and AISI 1010 carbon steel in sodium chloride solution (3.0 wt.%) was performed in the absence and presence of imidazole and benzimidazole corrosion inhibitors. The results showed that at any inhibitor concentration (25 ppm to 1000 ppm), there was an increase in the polarisation resistance of both steels. The highest efficiency of corrosion inhibition was obtained using imidazole at a concentration of 50 ppm for both steels, with values of 96% for the AISI 316 stainless steel and 73% for the AISI 1010 carbon steel.展开更多
The chemical technique was used to investigate the inhibition and adsorption properties of L-proline for steel corrosion(weight loss method).As the concentration of L-proline increased,the inhibition efficiency increa...The chemical technique was used to investigate the inhibition and adsorption properties of L-proline for steel corrosion(weight loss method).As the concentration of L-proline increased,the inhibition efficiency increased,but decreased as the temperature increased,according to the findings.The inhibitor’s adsorption to the steel surface has been shown to be random,involving both electrostatic and chemisorptions.The Temkin adsorption isotherm governs the adsorption of L-proline to the steel surface.Thermodynamic parameters have been determined in some cases.展开更多
The corrosion inhibition efficiency (IE) of an aqueous extract Allium cepa (onion) in controlling the corrosion of carbon steel ground water in absence and presence of with Zn2+ has been studied by weight loss method....The corrosion inhibition efficiency (IE) of an aqueous extract Allium cepa (onion) in controlling the corrosion of carbon steel ground water in absence and presence of with Zn2+ has been studied by weight loss method. The formulation consisting of 3 mL Allium cepa extract, 50 ppm of Zn2+ and 50 ppm of sodium pattassium tartarate which offers 97% inhibition efficiency. The synergistic effect exists between onion-Zn2+-tartarate system. The addition of N-cetyl-N,N,N- trimethylammonium bromide on onion-Zn2+-tartarate system does not change the excellent inhibition efficiency. Polarization study shows that the onion-Zn2+-tartarate system functions as a cathodic inhibitor. AC impedance spectra reveals that a protective film is formed on the metal surface. The UV fluorescent spectra indicate the possibility of formation of Fe2+-onion complex and also Zn2+-onion complex in solution. Thus the protective film is found to be UV fluorescent.展开更多
In the process of exploration and development of oil and gas fields, the acidic environment of oil reservoir, production and transport processes cause corrosion of pipelines and equipment, resulting in huge economic l...In the process of exploration and development of oil and gas fields, the acidic environment of oil reservoir, production and transport processes cause corrosion of pipelines and equipment, resulting in huge economic losses and production safety risks. Corrosion inhibitors were widely used in oil industry because of simple operation process and economical. In this study, three environmentally friendly corrosion inhibitors were synthesized based on the natural polysaccharide chitosan. Corrosion inhibition of three dendritic chitosan derivatives (We name them BH, CH and DH) on mild steel in 1 mol/L HCl solution with natural ventilation system was evaluated by weight loss experiment, electrochemical analysis and surface morphology characterization. The experimental results showed that when the three dendritic chitosan derivatives added in the corrosive medium were 500 mg L^(−1), the corrosion inhibition efficiencies were all more than 80%. Based on quantum chemical calculation, inhibition mechanisms of three dendritic chitosan derivatives were investigated according to molecular structures. The results showed that the benzene ring, Schiff base and N atom contained in the molecule were the active centers of electron exchange, which were more likely to form a film on the carbon steel surface, thereby slowing or inhibiting corrosion. The results also predicted the corrosion inhibition effect BH > DH > CH, which was consistent with the experimental conclusion.展开更多
文摘The dissolution of carbon steel in 5% HCl in the temperature range of 30~90℃ was inhibited by two organic compounds having the general formula: ClR NH2(CH2)n NH2 RCl where R is a benzyl group. The behaviour of these inhibitors in acidic medium were investigated using weight loss method, open circuit potential and linear polarization technique. These inhibitors provided satisfactory corrosion inhibition for carbon steel in hydrochloric acid solutions even at higher temperature and acid concentration (10%). The electrochemical results showed that the polarization resistance (Rp) values increased with increasing inhibitor concentration, also the corrosion current decreased and a higher inhibition efficiency was obtained. The protective properties of these two organic inhibitors were attributed to the chemisorption mechanism
基金financial support provided by the Ministry of Higher Education&Scientific Research of Yemen。
文摘This study describes the adsorption behavior of three arylthiophene derivatives namely:2-(4-amidino-3-fluorophenyl)-5-[4-methoxy phenyl] thiophene dihydrochloride salt(MA-1217),2-(4-amidinophenyl)-5-[4-chlorophenyll thiophene dihydrochloride salt(MA-1316) and 2-(4-amidino-3-fluorophenyl)-5-[4-ch lorophenyllthiophene dihydrochloride salt(MA-1312) at C-steel in 1.0 mol·L^(-1) HCl interface using experimental and theoretical studies.Electrochemical and mass loss measurements showed that the inhibition efficiency(IE) of the arylthiophene derivatives increases with increasing concentrations and exhibited maximum efficiency 89% at 21×10^(-6) mol·L^(-1)(MA-1217) by mass loss method.The investigated arylthiophene derivatives obey the Langmuir adsorption isotherm.From polarization studies the arylthiophene derivatives act as mixed-type inhibitors.Surface analysis were carried out and discussed.The mode of orientation and adsorption of inhibitor molecules on C-steel surface was studied using molecular dynamics(MD) simulations.Quantum chemical parameters as well as the radial distribution function indices and binding energies confirm the experimental results.
文摘Green inhibitors are promising alternatives to toxic corrosion inhibitors as they are environmentally safe substances, ecologically acceptable and renewable. In this research, the effect of green henna as an inhibitor existing in the coating of TMSM-PMMA and its electrochemical study were analyzed. The coating was produced by “sol-gel” method in order to protect the corrosion of low-carbon steel. TMSM hybrid cell was synthesized by hydrolysis and condensation, Metaacryloxypropyltrimethoxysilane and Tetraetylorthosilicate with 1:1 molar ratio and PMMA hybrid cell was produced by Methylmetaacrylate polymerization. Finally two cells were mixed in 1:1 weight ratio. The carbon steel substrates were prepared by dip coating method. SEM technique was applied for the microstructure evaluation of thin layers including different concentrations of henna extract. Adhesion of coating was analyzed by “Pull off” test. Additionally, the experimental results obtained in different concentrations of henna extract using electrochemical methods such as tafel polarization, electrochemical impedance spectroscopy indicating that coating with the concentration of 3% inhibitor had a high level of inhibition efficiency in 0.1 M HCL. The results of polarization tests signified that henna extract acts as a mixed inhibitor.
基金Funded by the National Natural Science Foundation of China(No.51278443)the Shandong Province Natural Science Foundation(ZR2011EEM006)
文摘The inhibition effect of dimethylethanolamine（DMEA） and its composite with carboxylic acid was studied with the electrochemical tests. The experimental results indicate that DMEA is not a good inhibitor but the composite of DMEA with caprylic acid exhibits excellent inhibiting efficiency. The synergic mechanism of the organic corrosion inhibitors（OCIs） was studied with quantum chemical calculations. It is found that the DMEA forms a quaternary ammonium salt with the proton in carboxylic acid, and a cyclic complex formed between the salt and Fe may be responsible for the enhancement of inhibiting efficiency. The possible hydrogen bond formed between DMEA and carboxylic acid is not enough for the inhibiting effect. This work is helpful to proposing theoretical interpretation as well as developing a functional organic inhibitor to improve the durability of reinforced concrete contaminated with chloride.
文摘An electrochemical investigation of the corrosion on AISI 316 austenitic stainless steel and AISI 1010 carbon steel in sodium chloride solution (3.0 wt.%) was performed in the absence and presence of imidazole and benzimidazole corrosion inhibitors. The results showed that at any inhibitor concentration (25 ppm to 1000 ppm), there was an increase in the polarisation resistance of both steels. The highest efficiency of corrosion inhibition was obtained using imidazole at a concentration of 50 ppm for both steels, with values of 96% for the AISI 316 stainless steel and 73% for the AISI 1010 carbon steel.
文摘The chemical technique was used to investigate the inhibition and adsorption properties of L-proline for steel corrosion(weight loss method).As the concentration of L-proline increased,the inhibition efficiency increased,but decreased as the temperature increased,according to the findings.The inhibitor’s adsorption to the steel surface has been shown to be random,involving both electrostatic and chemisorptions.The Temkin adsorption isotherm governs the adsorption of L-proline to the steel surface.Thermodynamic parameters have been determined in some cases.
文摘The corrosion inhibition efficiency (IE) of an aqueous extract Allium cepa (onion) in controlling the corrosion of carbon steel ground water in absence and presence of with Zn2+ has been studied by weight loss method. The formulation consisting of 3 mL Allium cepa extract, 50 ppm of Zn2+ and 50 ppm of sodium pattassium tartarate which offers 97% inhibition efficiency. The synergistic effect exists between onion-Zn2+-tartarate system. The addition of N-cetyl-N,N,N- trimethylammonium bromide on onion-Zn2+-tartarate system does not change the excellent inhibition efficiency. Polarization study shows that the onion-Zn2+-tartarate system functions as a cathodic inhibitor. AC impedance spectra reveals that a protective film is formed on the metal surface. The UV fluorescent spectra indicate the possibility of formation of Fe2+-onion complex and also Zn2+-onion complex in solution. Thus the protective film is found to be UV fluorescent.
文摘In the process of exploration and development of oil and gas fields, the acidic environment of oil reservoir, production and transport processes cause corrosion of pipelines and equipment, resulting in huge economic losses and production safety risks. Corrosion inhibitors were widely used in oil industry because of simple operation process and economical. In this study, three environmentally friendly corrosion inhibitors were synthesized based on the natural polysaccharide chitosan. Corrosion inhibition of three dendritic chitosan derivatives (We name them BH, CH and DH) on mild steel in 1 mol/L HCl solution with natural ventilation system was evaluated by weight loss experiment, electrochemical analysis and surface morphology characterization. The experimental results showed that when the three dendritic chitosan derivatives added in the corrosive medium were 500 mg L^(−1), the corrosion inhibition efficiencies were all more than 80%. Based on quantum chemical calculation, inhibition mechanisms of three dendritic chitosan derivatives were investigated according to molecular structures. The results showed that the benzene ring, Schiff base and N atom contained in the molecule were the active centers of electron exchange, which were more likely to form a film on the carbon steel surface, thereby slowing or inhibiting corrosion. The results also predicted the corrosion inhibition effect BH > DH > CH, which was consistent with the experimental conclusion.
