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A study of acidic corrosion behavior of Furan-Derived schiff base for mild steel in hydrochloric acid environment: Experimental, and surface investigation
Abstract
The inhibitive of the mild steel corrosion in a corrosive environment by 2-(5-amino-1,3,4-thiadiazol-2-yl)-5-nitrofuran (ATFuran) has been investigated using gravimetric techniques. ATFuran as investigated corrosion inhibitor exhibited the highest inhibitive efficacy of 83.26% at the highest concentration of inhibitor of 0.005 M studied, for the immersion time of 5 h and a temperature of 30 °C from the gravimetric result. Moreover, the inhibition efficiency was increased with increasing ATFuran concentration and decreasing with exposure time or solution temperature. A reduction in inhibition efficacy with temperature increase is implied to the mechanism of physisorption and may be imputed to increase in the solubility of the precipitated ATFuran molecules on the surface of metal. The number of adsorbed molecules on the surface of the metal decreases regarding the temperature increases which resulted in a deficiency in inhibitive performance. The kinetic studies indicate that the adsorption of tested inhibitor on the metal surface both physical and chemical adsorption. ATFuran obeys the Langmuir adsorption isotherm equation.
... Inhibitors are natural or synthetic chemical compounds substances that are added to specific environments in small concentrations with the goal of slowing the rate of corrosion by increasing anodic or cathodic polarization behavior, reducing ion movement or diffusion to the metallic surface, and increasing the metallic surface's electrical resistance [9]. Corrosion inhibitors can be split into two categories, organic and inorganic, based on the chemical components of the inhibitors themselves [10]. ...
Metal corrosion has become a problem of worldwide significance due to its deleterious consequences where corrosive environments are employed in practically every industry and there are many techniques used to slow down or prevent it, but there are a several of restrictions that restrict the use of these methods and one of these restrictions is their impact on the environment one of these methods used to prevent corrosion are chemical inhibitors and they are split into two categories, organic and inorganic, based on the chemical components of the inhibitors. Inorganic inhibitors are used to prevent corrosion, but these are toxic, therefore, Inhibitors that are safe for the environment have gotten a lot of attention in recent years. Since they are affordable, renewable, biodegradable, and, most importantly, safe for both the environment and humans, plant extract corrosion inhibitors are the most intensively investigated. This review summarizes advances, opportunities, and recent progress in the use of different portions of palm oil as a corrosion inhibitor in various conditions and on various metals and evaluates the effectiveness using various methodologies. Palm oil is one of the common and abundant natural oils in Asian countries like Malaysia. These findings show that palm oil can be used to make green inhibitors, which is a great way to use palm oil in a way that is good for the environment.
... The mechanisms involved in the laser-solid interaction have been studied extensively, but they are still not fully understood. However it can be controlled and highly reproducible to enable analytical measurement capabilities [92,93]. Figures 1 and 2 represent SEM micrographs of St-37 surface corrosion with and without coherent shock wave treatment. ...
For a long period, there have been significant losses at high costs due to the corrosion and damage it causes in most industrial processes, especially in the oil and gas industries. Consequently, erosion represents a serious threat to humans and animals, as it has a catastrophic impact on the environment, which calls for permanent and final solutions to it, and therefore there is a lot of literature related to the issue of corrosion. Hence the importance of natural or synthetic organic corrosion inhibitors, as they are usually inexpensive and harmless because they biodegrade, as proven by previous studies. Organic molecules that contain a number of heterogeneous atoms and double and triple bonds in their molecular structures have a great ability to resist corrosion of metals in various corrosive solutions. Much research has been reported annually by many researchers related to corrosion inhibitors and their preparation or extraction as well as the mechanism of classification and inhibition. The current study represents the types of corrosion, types of inhibitors, mechanisms of action, measuring the corrosion inhibitor efficiency and a brief presentation of research articles that use manufactured or extracted coumarins as corrosion inhibitors, and a comparison between them in terms of
inhibition effectiveness has also been made.
The corrosion inhibition of Schiff base, namely 2-((2-hydroxy-5-methoxybenzylidene)amino)pyridine (HMAP), for mild steel (MS) in a 1 M hydrochloric acid environment was investigated by means of weight loss and scanning electron microscopy techniques. Quantum chemical calculation based on density functional theory (DFT) was carried out on HMAP. Results illustrated that HMAP is a superior inhibitor for the corrosion of MS in 1.0M hydrochloric acid environment, and inhibition efficiency is higher than 90.0% at 0.5 g/L HMAP. Inhibition performance increases with regard to concentration increase and inhibition performance decreases when raising temperature. Adsorption of the inhibitor on the MS surface followed Langmuir adsorption isotherm and the value of the free energy of adsorption; ΔGads indicated that the adsorption of HMAP was a physisorption/chemisorption process. The DFT refers to perfect correlation with methodological inhibition performance.
4-Amino-3-(2-bromo-5-methoxyphenyl)-1H-1,2,4-triazole-5(4H)-thione (ATH) was synthesized and characterized by nuclear magnetic resonance and Fourier-transform infrared as spectroscopical techniques and elemental analysis. ATH was studied for corrosion inhibition of mild steel in corrosive environment by means of weight loss technique, scanning electron microscopy and the adsorption isotherm. ATH demonstrates a superior inhibition efficiency against corrosion of mild steel. Adsorption data fit well to a Langmuir isotherm model.
In this work, two new bis-Schiff bases, namely 2-bromoisophthalaldehyde-2-aminofluorene (M1) and glutaraldehyde 2-aminofluorene (M2), were synthesized, and their structures were characterized and confirmed by infrared spectroscopy, Fourier transform mass spectrometry and UV-visible spectroscopy. Their corrosion inhibition performance on carbon steel in simulated circulating cooling water was investigated by weight loss measurements and electrochemical measurements. The potentiodynamic polarization curves confirmed that two bis-Schiff bases are anode-type inhibitors; electrochemical impedance spectroscopy tests showed that M1 and M2 possess the best inhibition efficiencies of 96.25% and 99.15% at the optimal concentration of 2.50 mmol L⁻¹, respectively. The weight loss results showed that M1 and M2 exhibit maximum ηw values of 92.62% and 96.31%, respectively. Scanning electron microscopy showed that the inhibitors inhibited carbon steel corrosion. The adsorption isotherm measurements indicated that the two inhibitors exhibited physicochemisorption mechanisms and followed Langmuir adsorption isotherms. The relationships between the molecular structure and inhibition behavior of the inhibitors were explored by density functional theory, frontier molecular orbital studies, and Fukui index analysis, which affirmed that M2 possesses higher corrosion inhibition efficiency than M1.
The corrosion inhibition features of a new eco-friendly coumarin derivative, namely, 4-((4-((4-hydroxy-3-methoxybenzylidene)amino)-5-thioxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)-methyl)coumarin (HATC), for corrosion of the mild steel surface in an acidic environment was studied using gravimetric techniques and quantum chemical calculations. It was concluded that the tested coumarin derivative is an excellent corrosion inhibitor with high inhibition efficiency. The inhibition performance increases with increasing concentration of the investigated coumarin (HATC) and decreases with increasing temperature. The mechanism of adsorption includes a physical adsorption mechanism. Theoretical studies done on the new coumarin molecule using the density functional theory (DFT) have shown that the most likely entities in coumarin molecules to bond to the metal surface are nitrogen, sulfur and oxygen atoms.
New sulfanilamide derivative namely 4-((5,5-dimethyl-3-oxocyclohexenyl)amino)benzenesulfonamide (DOBF) was synthesized and the chemical structure was elucidate using Nuclear Magnetic Resonance (NMR) and elemental analysis (CHN). The inhibition effects of a studied DOBF on the corrosion of mild steel in 1 M hydrochloric acid environment were investigated using electrochemical impedance spectroscopy (EIS), weight loss method and scanning electron microscopy (SEM). The synthesized inhibitor concentrations were 0.1 mM to 0.5 mM and the temperatures ranging from 303-333 K. Results showed that the inhibition occurs through adsorption of the inhibitor molecules on the metal surface. Electrochemical and weight loss techniques revealed that the tested DOBF act as superior inhibitor for acidic corrosion of mild steel and the efficiency increase with increasing concentrations. EIS results revealed that DOBF demonstrate the highest inhibition efficiency of 93.70 %, at a concentration of 0.5 mM. The adsorption of the investigated inhibitor obeys Langmuir’s adsorption isotherm. Different thermodynamic parameters have been calculated and discussed. SEM confirmed the formation of a protective film on the surface. The investigated techniques are in good agreement to establish the using DOBF as corrosion inhibitor for mild steel in strong acid environment. It was found that the corrosion inhibition performance depends on the concentration of the DOBF and the solution temperature. Quantum chemical calculations have been done to correlate the electronic characteristics of the compounds with the corrosive inhibitive impact. The quantum calculations such as the HOMO, LUMO, energy gap (ΔE), atomic charges, dipole moment (μ), electron affinity (A), chemical hardness (η), softness (σ) electronegativity (χ), ionization potential (I), and fraction of electrons transferred (∆N), were used to explain the mechanism of inhibition of DOBF molecules on the mild steel surface. Experimental and theoretical results are in good agreement.
The inhibition efficiency of a new coumarin derivative, namely 2-(6-methylcoumarin-4-yl)-N´-(3-nitrobenzylidene)acetohydrazide (MCNAH), in controlling corrosion of mild steel in 1 M hydrochloric acid solution was investigated by gravimetric techniques at various temperatures (303, 313, 323 and 333 K). The impact of immersion time and temperature on inhibition performance of MCNAH was also studied. MCNAH was synthesized and the chemical structure was elucidated by magnetic resonance spectroscopy (MRS) and Fourier-transform infrared spectroscopy (FT-IR). The experimental results suggested that MCNAH is an excellent corrosion inhibitor for mild steel in 1 M hydrochloric acid environment. The synthesized inhibitor (MCNAH) has the ability to impede the corrosion of mild steel in 1 M hydrochloric acid environment at low and high concentrations. The inhibitive efficiency was found to increase with increasing concentration of MCNAH and decrease with increasing time and temperature. The thermodynamic parameters were estimated and discussed. The adsorption of the synthesized inhibitor on the surface of the tested mild steel in the presence of HCl obeyed the Langmuir adsorption isotherm. The relationship between the structure of the new synthesized inhibitor and its inhibitive effects was investigated using theoretical calculations. The experimental and density functional theory (DFT) calculation results are in good agreement. The results clearly show that the inhibition mechanism involves a blocking mechanism of action of the inhibitor.
A new ecofriendly coumarin derivative, namely 4-((4-amino-1H-1,2,4-triazole-5(4H)-thione-3-yl)methyl)coumarin (ATMC), was synthesized and the chemical structure was elucidated using Fourier Transform Infrared Spectroscopy (FT-IR), Nuclear Magnetic Resonance (NMR) and elemental analysis (CHN). ATMC was evaluated as a corrosion inhibitor and the concentrations were 0.1 mM to 0.5 mM for mild steel in 1 M hydrochloric acid in the temperature range of 303-333 K using gravimetric and surface analysis by means of scanning electron microscopy (SEM) techniques. The gravimetrical results show that ATMC inhibited the corrosion of mild steel in a strong acid solution with superior performance. It was found that the corrosion inhibition performance depends on the concentration of the studied inhibitor and the solution temperature. The inhibition efficiency increased with an increase in the concentration of the inhibitor and reached 96.5% at a concentration of 0.5 M and 303 K. Experimental and adsorption results are in good agreement.
A new benzylidene derivative, namely N-benzylidene-5-phenyl-1,3,4-thiadiazol-2-amine (BPTA), has been synthesized and instrumentally confirmed with Elemental Analysis (CHN), Nuclear Magnetic Resonance (NMR), and Fourier Transform Infrared Spectroscopy (FT-IR). Titanium Dioxide (TiO 2) nanoparticles (NPs) were synthesized and characterized by X-ray. The mutualistic complementary dependence of BPTA with TiO 2 nanoparticles as anti-corrosive inhibitor on mild steel (MS) in 1.0 M hydrochloric acid has been tested at various concentrations and various temperatures. The methodological work was achieved by gravimetric measurement methods complemented with surface analysis. The synthesized inhibitor concentrations were 0.1 mM to 0.5 mM and the temperatures ranging from 303-333 K. The BPTA with TiO 2-NP as a synergistic inhibitor becomes superior inhibitive effects with more than 96% inhibition competence of MS coupons in a harsh acidic medium. The efficiency of the inhibition improved with increasing BPTA content and also increase with the Synergistic effects of BPTA with TiO 2-NP. The excellent effectiveness was performed with the 0.5 mM concentration of BPTA and become higher with adding of TiO 2-NP rising to the maximum inhibition efficiency (IE). However, the inhibition efficacy declined as the temperature rises. Results of BPTA as corrosion inhibitor indicated the obedience of the adsorption of the inhibitor of mixed type on the surface of MS to Langmuir adsorption isotherm. It was found that the BPTA and performance depend on the Synergistic effects, concentrations of the TiO 2-NP and BPTA, in addition to the solution temperature. Nevertheless, the quantum calculations have confirmed the direct correlation of the electronic characteristics of BPTA with the corrosive inhibitive influence.
A new nicotinonitrile derivative, namely 4-methyl-2-(pyridin-3-yl)thiazole-5-carbohydrazide (MPTC), was synthesized and the chemical structure was elucidated using Fourier Transform Infrared Spectroscopy (FT-IR), Nuclear Magnetic Resonance (NMR) and elemental analysis (CHN). The anticorrosion properties of the new synthesized compound MPTC toward mild steel in 1M HCl solutions have been investigated using weight loss and scanning electron microscopy (SEM) techniques. The inhibitor concentrations were 0.1 mM to 0.5 mM and the temperatures ranged within 303 to 333 K. The inhibition efficiency increased with an increase in the inhibitor concentration and reached 95.1% at the concentration of 0.5 M and 303 K. Inhibition efficiency increased in parallel with increasing inhibitor concentration and decreased with rising temperature. The inhibition process was attributed to physical adsorption. The results obtained from the usage techniques show that new synthesized inhibitor could serve as an efficient corrosion inhibitor of mild steel in strong acid environment. The investigated inhibitor obeys the Langmuir adsorption isotherm equation. It was found that the corrosion inhibition performance depends on the concentration of the studied inhibitor and the solution temperature. Quantum chemical calculations have been done to correlate the electronic characteristics of the synthesized inhibitor with the corrosive inhibitive impact. Experimental and theoretical results are in good agreement.
Keywords: 4-hydroxyco
Corrosion of a material by reaction with a corrosive environment is a common problem across many industries. Iraq is an oil country and corrosion represents a large portion of the total costs for oil producing and a natural potential hazard associated with oil production and transportation. The synthesis of novel thiosemicarbazone, namely 2-(2,4-dimethoxybenzylidene)hydrazinecarbothioamide (DMBHC), was conducted and the chemical structure was elucidated via the 1H and 13C NMR (Nuclear magnetic resonance), and FT-IR (Fourier-transform infrared) spectroscopic spectroscopic techniques in addition to carbon, hydrogen, and nitrogen analyses (CHN analyses). The inhibition properties of the investigated thiosemicarbazone were evaluated for mild steel (MS) corrosion in 1N H2SO4 using electrochemical impedance spectroscopy (EIS), weight loss method, and scanning electron microscopy (SEM). Electrochemical and weight loss techniques revealed that the tested thiosemicarbazone acted as a superior inhibitor for the acidic corrosion of MS and the efficiency increased with increasing concentrations. The EIS results revealed that thiosemicarbazone demonstrated the highest inhibition efficiency of 94.86%, at a concentration of 0.5 mM. Results from the weight loss technique suggested that the thiosemicarbazone acted as a mixed type corrosion inhibitor. The impact of temperature on the mechanism of inhibition of the new synthesized inhibitor of the surface of MS in 1N H2SO4 was investigated at various temperatures (30–60 °C) where the inhibitive efficiency diminished with increasing temperatures. The mechanism of inhibition was additionally verified with the methodological data.
The optimal inhibition efficiency of DBTA (4-Dimethylamino-benzylidene)-[1, 3, 4]thiadiazol-2-yl-amine) for MS (mild steel) in 1.0 M hydrochloric acid solution was achieved through employing electrochemical impedance spectroscopy (EIS) and weight loss techniques in addition to Scanning Electron Microscopy (SEM). Theoretical calculations based on Density functional theory (DFT) method were carried out for DBTA. Investigations of the mechanism for the corrosion inhibition for MS with DBTA in acidic solution by molecular simulations were performed. The results demonstrated that DBTA is an excellent corrosion inhibitor for MS in corrosive solution, and the inhibitory effectiveness was 91%, much higher than that expected at the highest concentration of DBTA. Spontaneous process of adsorption of DBTA on the mild steel surface was proved based on Langmuir adsorption isotherm.
Iraq has been one of the most extensive oil and natural gas industries in the world. The corrosion of mild steel is costly and insufficiency process. It is responsible for great loss in manufacture and environment. Natural and organic inhibitors have been utilized for a long time to inhibit the corrosion. Selected thiadiazol derivative, namely 3-((5-(3,5-dinitrophenyl)-1,3,4-thiadiazol-2-yl)imino)indolin-2-one (TDIO) was investigated for it inhibitive impacts in 1 M HCl medium on corrosion of mild steel using weight loss and scanning electron microscope techniques. The maximum inhibition efficiency up to 90.7% at the maximum inhibitor concentration 0.5 mM. Surface morphology of results demonstrated that TDIO formed adsorbed film on surface of mild steel in hydrochloric acid solution. Give molecular based clarifications to the inhibitive impacts of the studied. The interactions between mild steel surface and the inhibitor molecules have been undertaken to further corroborate the methodological results. Keywords: Dinitrophenyl, Indolin, Morphology, Corrosion inhibitor
Mild steel is a metal which is commonly used in industrials and manufacturing of equipment for most industries round the world. It is cheaper cost compared with the other metals and its durable, hard and easy-to-wear physical properties make it a major choice in the manufacture of equipment parts. The main problem through the uses of mild steel in industry is its resistance against corrosion, especially in acidic solutions. This case led to raise the cost of maintenance of equipment that used mild steel and as a result increased costs for the company. Organic corrosive inhibitors that also act as green chemicals, 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol have been synthesized. This inhibitor is tested as corrosion inhibitor on a mild steel sample MS in 1 M hydrochloric acid solution (HCl) using electrochemical measurements test includes PD (Potentiodynamic), EIS (Electrochemical impedance spectroscopy), OCP (Open circuit potential) and EFM (electrochemical frequency modulation). The obtained results indicate that 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol acts as a good corrosion inhibitor for mild steel sample in HCl solution with efficiency above 90%. Changes in the impedance parameters postulated adsorption on the mild steel specimens' surfaces of, which it going to the formation of protective coating layer. It also shows that 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol corrosion inhibitors are effective in helping to reduce and slow down the corrosion process that occurs on mild steel surface in hydrochloric acid solution. Increase of corrosion inhibitor concentration provides a protective layer of mild steel. However, this protective layer becomes weak when the temperature of the solution increases.
The corrosion inhibition effectiveness of thiosemicarbazide compound, namely 3-nitro-5-(2-amino-1,3,4-thiadiazolyl)nitrobenzene (NATN), on mild steel in 1 M hydrochloric acid media has been investigated by weight loss technique. The results exhibit that the corrosion ratio of mild steel was reduced regarding to adding NATN. The corrosion inhibition rate for the NATN was 92.3% at the highest investigated NATN concentration. From the weight loss results it could be concluded that NATN with sulfur, nitrogen and oxygen atoms has clarified best corrosion inhibition achievement comparing to 3,5-dinitrobenzoic acid. Regarding to theoretical studies, DFT was employee to figured geometrical structure and electronic characteristics on NATN. The investigation have been extensive to the HOMO and LUMO analysis to evaluate the energy gap, Ionization potential, Electron Affinity, Global Hardness, Chemical Potential, Electrophilicity, Electronegativity and Polarizability.
Background
Relatively inexpensive, stable Schiff bases, namely 3-((4-hydroxybenzylidene)amino)-2-methylquinazolin-4(3H)-one (BZ3) and 3-((4-(dimethylamino)benzylidene)amino)-2-methylquinazolin-4(3H)-one (BZ4), were employed as highly efficient inhibitors of mild steel corrosion by corrosive acid. FindingsThe inhibition efficiencies were estimated based on weight loss method. Moreover, scanning electron microscopy was used to investigate the inhibition mechanism. The synthesized Schiff bases were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy and micro-elemental analysis. The inhibition efficiency depends on three factors: the amount of nitrogen in the inhibitor, the inhibitor concentration and the inhibitor molecular weight. Conclusions
Inhibition efficiencies of 96 and 92% were achieved with BZ4 and BZ3, respectively, at the maximum tested concentration. Density functional theory calculations of BZ3 and BZ4 were performed to compare the effects of hydroxyl and N,N-dimethylamino substituents on the inhibition efficiency, providing insight for designing new molecular structures that exhibit enhanced inhibition efficiencies.
Abstract
The synthesis and characterization of a novel organic corrosion inhibitor (4-(3-mercapto-5,6,7,8-tetrahydro-[1]; [2] ; [4]triazolo[4,3-b][1]; [2]; [4] ; [5]tetrazin-6-yl)phenol), for mild steel in 1M hydrochloric acid (HCl) has been successfully reported for the first time. The inhibitor evaluated as corrosion inhibitor for mild steel in 1M of Hydrochloric acid solution using Electrochemical Impedance Spectroscopy (EIS), and electrochemical frequency modulation (EFM) measurement techniques. Changes in the impedance parameters suggested an adsorption of the inhibitor onto the mild steel surface, leading to the formation of protective films. The results show that the inhibition efficiencies increased with increasing the concentrations of the inhibitors and decreased with increasing temperature. The maximum inhibition efficiency up to 67% at the maximum concentration 0.5 mM. This shows that those inhibitors are effective in helping to reduce and slowing down the corrosion process that occurs to mild steel with a hydrochloric acid solution by providing an organic inhibitor for the mild steel that can be weakened by increasing the temperature. The adsorption process of the synthesized organic inhibitor depends on its electronic characteristics in addition to steric effects and the nature of metal surface, temperature degree and the varying degrees of surface-site activity. The synthesized inhibitor molecules were absorbed by metal surface and follow Langmuir isotherms.
2-Methyl-4H-benzo[d][1,3]oxazin-4-one (BZ1) and 3-amino-2-methylquinazolin-4(3H)-one (BZ2) were evaluated for their corrosion inhibition properties on mild steel (MS) in hydrochloric acid solution by weight loss technique and scanning electron microscopy. Results show the inhibition efficiency values depend on the amount of nitrogen in the inhibitor, the inhibitor concentration and the inhibitor molecular weight with maximum inhibition efficiency of 89% and 65% for BZ2 and BZ1 at highest concentration of the compounds.
A nanohybrid waterborne binder was synthesized by miniemulsion polymerization with the incorporation of ZnO nanoparticles in order to increase the corrosion protection capability. This system was compared to a neat waterborne binder and to a physical blend of the binder with an aqueous ZnO nanoparticles dispersion. The hybrid dispersion was characterized by SEM and TEM, while the corrosion behavior of these latexes was investigated by electrochemical measurements (open circuit potential and electrochemical impedance spectroscopy in 3.5 wt% NaCl solution), evaluating the effect of the incorporation of these nanoparticles into the polymeric matrix. The incorporation of ZnO nanoparticles by blending showed similar behavior to the neat coating despite flash rust reduction on the metal surface. In contrast, the hybrid binder prepared by miniemulsion polymerization has shown the best performance according to the values of pore resistance (R i ) and coating ca
The arc thermal metal spraying method (ATMSM) provides proven long-term protective coating systems using zinc, aluminum and their alloys for steel work in a marine environment. This paper focuses on studying experimentally the anti-corrosion criteria of ATMSM on steel specimens. The effects of the types of spraying metal and the presence or absence of sealing treatment from the thermal spraying of film on the anti-corrosion performance of TMSM were quantitatively evaluated by electrochemical techniques. The results showed that ATMSM represented a sufficient corrosion resistance with the driving force based on the potential difference of more than approximately 0.60 V between the thermal spraying layer and the base substrate steel. Furthermore, it was found that the sealing treatment of specimens had suppressed the dissolution of metals, increased the corrosion potential, decreased the corrosion current density and increased the polarization resistance. Metal alloy Al-Mg (95%:5%) by mass with epoxy sealing coating led to the most successful anti-corrosion performance in these electrochemical experiments.
The paper proposes an approach to the assessment of the economic efficiency of innovative anti-corrosion coatings for sectors of the national economy of the Russian Federation on the basis of a synthesis of strategic sectoral and cost analysis, field research methods. According to the authors, a comparative analysis of composite polymeric anticorrosion protecting coatings with similar products, estimating of direct and indirect economic effect and prognosis of implementation, forms a deeper understanding of the role of innovative technologies in the Russian state development of import substitution, the investment attractiveness of Russian industries in the new part technologies, applied research activities of private companies. Metal consumption sectors of the economy were chosen as an object of research, as they are characterized by the use of the following products: industrial construction and reconstruction, nuclear and thermal power, chemical, oil and gas, utilities, food processing, automotive, shipbuilding, aviation and rocket science, other industry. Basic modeling of implementation of anticorrosion protecting coatings in industrial enterprises was carried out on the basis of generating energy enterprises as one of the main end-users of anti-corrosive materials that also issue accurate statements.
A new coumarin derivative, N,N'-((2E,2'E)-2,2'-(1,4-phenylenebis (methanylylidene)) bis(hydrazinecarbonothioyl)) bis(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, H-1-NMR and carbon-13 nuclear magnetic resonance C-13-NMR). The corrosion inhibition effect of PMBH on mild steel in 1.0 M HCl was investigated using corrosion potential (E-CORR), 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.
The power of Creatinine as inhibitor, for metals in 1 Molar corrosive acid solution (hydrochloric acid) has been investigated utilizing a weight loss technique. Impact of temperature and thermodynamic parameters were explored. Results demonstrated that the inhibition happens through adsorption of the creatinine molecules on the surface of the metal and the efficiencies were improved with an increment in creatinine concentration and diminished at higher temperature degrees. Scanning electron microscopy was done for the metal surface to examine it. The highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy and dipole moment was theoretically calculated utilizing Density Function theory.
The anticorrosion ability of a synthesized coumarin, namely 2-(coumarin-4-yloxy)acetohydrazide (EFCI), for mild steel (MS) in 1 M hydrochloric acid solution has been studied using a weight loss method. The effect of temperature on the corrosion rate was investigated, and some thermodynamic parameters were calculated. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. The IE value reaches 94.7% at the highest used concentration of the new eco-friendly inhibitor. The adsorption of inhibitor on MS surface was found to obey a Langmuir adsorption isotherm. Scanning electron microscopy (SEM) was performed on inhibited and uninhibited mild steel samples to characterize the surface. The Density Function theory (DFT) was employed for quantum-chemical calculations such as EHOMO (highest occupied molecular orbital energy), ELUMO (lowest unoccupied molecular orbital energy) and μ (dipole moment), and the obtained results were found to be consistent with the experimental findings. The synthesized inhibitor was characterized by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopic studies.
A new curcumin derivative, i.e., (1E,4Z,6E)-5-chloro-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,4,6-trien-3-one(chlorocurcumin), was prepared starting with the natural compound curcumin. The newly synthesized compound was characterized by elemental analysis and spectral studies (IR, H-1-NMR and C-13-NMR). The corrosion inhibition of mild steel in 1 M HCl by chlorocurcumin has been studied using potentiodynamic polarization (PDP) measurements and electrochemical impedance spectroscopy (EIS). The inhibition efficiency increases with the concentration of the inhibitor but decreases with increases in temperature. The potentiodynamic polarization reveals that chlorocurcumin is a mixed-type inhibitor. The kinetic parameters for mild steel corrosion were determined and discussed.
2-(1-methyl-4-((E)-(2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-ylidene)-hydrazineecarbothioamide (HCB) was synthesized as a corrosion inhibitor from the reaction of 4-aminoantipyrine, thiosemicarbazide and 2-methylbenzaldehyde. The corrosion inhibitory effects of HCB on mild steel in 1.0 M HCl were investigated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS). The results showed that HCB inhibited mild steel corrosion in acidic solution and inhibition efficiency increased with an increase in the concentration of the inhibitor. The inhibition efficiency was up to 96.5% at 5.0 mM. Changes in the impedance parameters suggested that HCB adsorbed on the surface of mild steel, leading to the formation of a protective film. The novel corrosion inhibitor synthesized in the present study was characterized using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) spectral data.
Inhibition of C-steel corrosion by some thiadiazole derivatives (I–VI) in 1 M H2SO4 was investigated by weight loss, potentiodynamic polarization, linear polarization resistance (LPR) and electrochemical impedance
spectroscopy (EIS) techniques. The presence of these compounds in the solution decreases the double layer capacitance, increases
the charge transfer resistance and increase of linear polarization. Polarization studies were carried out at room temperature,
and showed that all the compounds studied are mixed type inhibitors with a slight predominance of cathodic character. The
effect of temperature on corrosion inhibition has been studied and the thermodynamic activation and adsorption parameters
were calculated and discussed. Electrochemical impedance was used to investigate the mechanism of corrosion inhibition. The
adsorption of the compounds on C-steel was found to obey Langmuir’s adsorption isotherm. The synergistic effect brought about
by combination of the inhibitors and KSCN, KI and KBr was examined and explained. The mechanism of inhibition process was
discussed in the light of the chemical structure and quantum-chemical calculations of the investigated inhibitors.
The bi-functional conjugates comprise of 4-aminoquinoline and 1,3,5-triazine was synthesized through facile synthetic routes. These compounds were rigorously screened for determination of antimalarial activity against wild and mutant cultured Plasmodium falciparum. Results disclosed that, conjugates have considerable antimalarial activity against both wild and mutant parasites with marked variation on changing the pattern of substitutions. The observed activity profiles were additionally substantiated by docking studies on both wild and qradruple mutant P. falciparum dihydrofolate reductase thymidylate synthase (pf-DHFR-TS).
Adsorption of four derivatives of piperidinylmethylindoline-2-one on mild steel surface in 1 M HCl solution and its corrosion inhibition properties has been studied by a series of techniques, such as polarization, electrochemical impedance spectroscopy (EIS), weight loss and quantum chemical calculation methods. The values of activation energy (Ea) for mild steel corrosion and various thermodynamic parameters were calculated and discussed. Potentiodynamic polarization measurements showed that all inhibitors are mixed type. The degree of surface coverage was determined by using weight loss measurements and it was found that adsorption process of studied inhibitors on mild steel surface obeys Langmuir adsorption isotherm.
This review article provides critical analysis of literature data regarding the heterocyclization reactions of compounds containing alk-2-en-4-yn-1-one and alk-1-en-4-yn-3-one moieties. We discuss the reactions leading to the formation of furans, 2,3-dihydropyrans, 1,2,3-triazoles, 4,5-dihydro-1Н-pyrazoles, pyrazoles, isoxazoles, pyrimidines, aziridines, as well as a range of more complex fused ringsystems. The biological activity and photophysical properties of the obtained heterocyclic compounds are described. The attention ismainly focused on the studies published during the last 5 years. A total of 87 references are given.
Two new benzohydrazide Schiff bases, (Z)-2-hydroxy-N′-(2-hydroxy-1,2-diphenylethylidene) benzohydrazide (B1) and (Z)-2-hydroxy-N′-(2-oxo-1,2-diphenylethylidene) benzohydrazide (B2) were synthesized and examined as carbon steel corrosion inhibitors in 1.0 mol L−1 HCl using weight loss (WL) method, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), Quantum chemical calculations (QCC) and molecular dynamics (MD) simulations. Results showed that both studied Schiff bases are adsorptive corrosion inhibitors, which obeys Langmuir adsorption with predominantly chemisorption. The maximum inhibition efficiencies (based on WL results) were obtained 94.0% and 96.5% for B1 and B2, respectively. Thermodynamics of the adsorption process was studied and the activation parameters of the corrosion reaction were also calculated and discussed. The calculated electronic parameters, EHOMO, ELUMO, the energy gap between HOMO-LUMO and dipole moment could well explain the order of inhibition efficiencies. Molecular dynamic simulations revealed that the inhibitors adsorbed in an almost planar manner, leading to a more efficient adsorption and inhibition.
We studied the inhibition performances of IMB (imidazoline quaternary salt (IM) and benzotriazole (BTAH)) and IMO (IM and octyl phenol ethoxylates (OP)) mixtures as inhibitors of L245 steel placed in 10 vol% HCl solution at 298 K using experimental methods and theoretical calculations. We found that the mixtures adsorb on the steel by an endothermic spontaneous process, and the adsorption model follows Langmuir isotherm. The mixtures exhibit good synergistic inhibition effect, and the inhibition efficiency enhanced in turn (IMB < IMO). The relationship between synergistic effect of organic inhibitors and their energetic position of molecular frontier orbitals was discussed.
The corrosion characteristics of L245 steel were analyzed under H2S atmosphere in stratum water with imidazoline quaternary ammonium salt (IM), and IM mixed with octylphenol polyoxyethene ether (OP). L245 suffered pitting corrosion in solutions with only IM, but pitting corrosion was inhibited in solutions with IM and OP. Local damages of the adsorbed IM film appeared on the steel surface in solutions with only IM. While Cl− accumulated on these areas, surface potentials were lower than surrounding areas, and a small anode/large cathode galvanic corrosion system was formed. The influence of inhibitor on pitting corrosion for L245 steel was discussed.
Scanning electrochemical microscopy was employed to characterize the local surface activity of an AA2024-T3 coated with sol-gel. Corrosion inhibitors were added to the sol-gel either as soluble chemical species, namely 1,2,3-benzotriazole, Na‐(diethyl(dithiocarbamate)), and piperazine, or using Ce(III)-montmorillonite containers. The Scanning electrochemical microscopy was operated in the feedback mode by using ferrocene-methanol as redox mediator. This experimental procedure allowed evaluation of the coating behaviour in damaged and non-damaged areas from the analysis of Z‐approach curves and 2D maps. The results evidence differences in the local electrochemical activity of the modified coatings that correlate well with averaging electrochemical measurements using electrochemical impedance spectroscopy.
A technique for calculation of coefficients in the power-linear function for long-term prediction of corrosion losses of structural metals is presented. The formula consists of a power function at the initial corrosion stage and a linear function at the stationary stage. Conditions for application of the power and power-linear functions for long-term prediction of corrosion losses of technically important metals in various regions of the world are shown. A comparative estimate of predicted corrosion losses of metals based on the equations provided in this study and in ISO CORRAG 9224:2012(E) standard is given.
Steel rebars attain passivity in concrete environment. Passive film can be destroyed by acidification through carbonation and chloride ions from NaCl in concrete. There are different techniques have been employed to mitigate the corrosion problem of steel rebars embedded in concrete. Among different methods inhibitors are very popular and frequently used. Commercially available N, N′-Dimethyl ethanol amine (DMEA) inhibitor is studied in different concentrations of NaCl in saturated Ca(OH)2 solution. The performance of inhibitor was evaluated by potential time, electrochemical impedance spectroscopy and potentiodynamic techniques. DMEA inhibitor is showing 63–74% efficiency and effectively reduces the corrosion rate.
Novel corrosion inhibitor as a green chemical product namely derivative, 2-amino 5-oleyl-1,3,4-thiadiazol (AOT) was synthesized by cyclization of oleic acid. The new corrosion inhibitor was characterized by FT-IR and NMR spectroscopical methods. AOT was evaluated as corrosion inhibitor for mild steel in 1M of Hydrochloric acid solution using Potentiodynamic and Electrochemistry Impedance Spectroscopy (EIS) technique. Results obtained show that AOT acts as a good corrosion inhibitor for mild steel in HCl solution. Theoretical studies were also done for the novel compound AOT.
The acid corrosive consumption hindrance process by Cherry Sticks extraction as a green corrosion inhibitor had been explored by utilizing the weight loss method. Impact of temperatures on the consumption conduct in the existence of the inhibitor at a concentration of 50*10-2 g/L was examined at the temperatures of 30, 40, 50 and 60 °C. The results demonstrate that the green, inhibitor, CSCI (Cherry Sticks Corrosion Inhibitor), guarantees the inhibitive impacts on the corrosion of metal (mild steel) in one molar hydrochloric acid for all inspected conditions. The efficiency increment with concentration augmentation of the green inhibitor achieves its maximum of 89.5% at 50*10-2 g/L, and its adsorption on a metal surface obeys Langmuir isotherm. To examine the surface morphology of an inhibitor, SEM (scanning electron microscopy) was utilized before and after submersion in HCl. Green inhibitor was extracted and its structures were clarified and affirmed utilizing the following spectroscopical methods: infra_red (IR), and liquid-Chromatography Electrospray-Ionization Mass-Spectrometry (LC-EIS/MS).
The present paper deals with the adsorption and inhibitory effects of the pyridine derivatives, namely 2-amino-6-(2,4-dihydroxyphenyl)-4-(4-methoxyphenyl)nicotinonitrile (ADP) and 2-amino-4-(4-methoxyphenyl)-6-phenylnicotinonitrile (AMP) on N80 steel corrosion in 15% HCl. Among the studied compounds, ADP showed the inhibition efficiency of 90.24% at 200 mg/L. The corrosion study was performed by gravimetric, electrochemical impedance spectroscopy (EIS), Tafel polarization, scanning electron microscopy (SEM), scanning electrochemical microscopy (SECM) and energy-dispersive X-ray spectroscopy (EDX) techniques. The Langmuir isotherm model showed the best fit. The quantum chemical study was used to support the experimental results. 2015 Elsevier Ltd. All rights reserved.
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 mixed-type 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.
The inhibition performance of poly (methacrylic acid) (PMAA) and the effect of addition of iodide ions on the inhibition efficiency for mild steel corrosion in 0.5 M H2SO4 solution were investigated in the temperature range of 303-333 K using electrochemical, weight loss, scanning electron microscopy (SEM), and water contact angles measurements. The results show that PMAA is a moderate inhibitor for mild steel in 0.5 M H2SO4 solution. Addition of small amount of KI to PMAA significantly upgraded the inhibition efficiency up to 96.7%. The adsorption properties of PMAA and PMAA + KI are estimated by considering thermodynamic and kinetic parameters. The results reveal that PMAA alone was physically adsorbed onto the mild steel surface, while comprehensive adsorption mode characterized the adsorption of PMAA + KI. Adsorption of PMAA and PMAA + KI followed Temkin adsorption isotherm. The SEM and water contact angle images confirmed the enhanced PMAA film formation on mild steel surface by iodide ions.
Inhibitory effect of three Schiff bases 2-{[(2-sulfanylphenyl)imino]methyl}]phenol (A), 2-{[(2)-1-(4-methylphenyl)methylidene]amino}-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 200mg/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 (Kads, ΔGads) of studied Schiff bases were calculated using the Langmuir adsorption isotherm. Activation parameters of the corrosion process such as activation energies, Ea, activation enthalpies, ΔH∗, and activation entropies, ΔS∗, 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.
By considering adsorption processes of organic compounds as being determined by the electronic distribution in the “anchoring”
group of an adsorbate, a correlation has been derived between adsorption measurements and Hammett‐like substituent constants
through the use of Linear Free Energy Relations (LFER). The analysis is extended to corrosion inhibitors by assuming that
the mechanism of inhibition by organic molecules is chemisorption and that the energetics of the corrosion process per se are unaffected by the addition of substituents on the parent compound.
The corrosion inhibition of nickel in acid solutions by 2-(triphenyl phosphoranylidene) succinic anhydride (2TPSA) has been investigated using DC and AC techniques. The percentage inhibition was up to 85 percent at a concentration of 400 μM of 2TPSA. The inhibitor used was found (1) to shift the corrosion potential to less negative values and (2) to decrease the anodic dissolution of nickel and hydrogen evolution reaction. The effect, however, was more pronounced on the anodic rather than on the cathodic process. The passivation current density (ip) and the capacitance of the double layer (Cd) were also affected by 2TPSA. Experimental findings reported in this paper show that at the critical concentration of 25 μM of 2TPSA, these parameters attain their lowest values and that subsequent increases of inhibitor concentration do not lead to any significative change of either ip or Cd. Inhibition efficiency results obtained from DC (corrosion current and polarization resistance) and AC (charge transfer resistance) were in good agreement. Moreover, the experimental data fit the Flory-Huggins and the Dhar-Flory-Huggins adsorption isotherms with x=3. This result indicates that each organic molecule replaces three adsorbed water molecules on the nickel surface. In addition, the size of the adsorbed 2TPSA molecule was approximately 37.5 A2.
The present research brings new insights on the role of admixed corrosion inhibitors in the processes of cement hydration
and rebar corrosion. The admixing of NaCl and the corrosion inhibitors in fresh mortar was found to alter the morphology and
microstructure of the hardened mortar at the steel-mortar interfacial region. The admixing of the inhibitors increased the
risk of carbonation of cement hydrates at the steel-mortar interfacial region, but partially displaced chloride ions. Chloride
and the admixed inhibitors facilitated the formation of different cement hydrates and affected chloride binding at the steel-mortar
interfacial region. The admixing of all three inhibitors was found to increase the polarization resistance of steel, indicating
reduced corrosion rate of the steel over 48-day exposures to salt ponding
Laboratory investigations were performed in order to assess the effectiveness and the inhibition mechanism of an amino alcohol-based inhibitor currently used as admixture to prevent corrosion of steel in concrete. The investigation was performed in the presence of chloride ions, using solutions simulating the concrete interstitial solution. Electrochemical measurements allowed to conclude that, an inhibitor film is formed on the surface hindering the anodic activity. Furthermore, the analytical investigation through the use of X-ray photoelectron spectroscopy (XPS) shows that the inhibitor film is able to complex with the chloride ion.
Electrochemical and mass loss investigations of new schiff base as corrosion inhibitor for mild steel
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