Furan and Phenyl Substituted Triazolothiadiazine Derivatives as Copper Corrosion Inhibitors: Electrochemical and DFT Studies

Protection of Metals and Physical Chemistry of Surfaces - This paper presents experimental aspects of two triazolodiathiazine derivatives 1...     

Benzodiazepine Derivatives as Corrosion Inhibitors of Carbon Steel in HCl Media: Electrochemical and Theoretical Studies

Protection of Metals and Physical Chemistry of Surfaces - New benzodiazepine derivatives, namely 8-Chloro-1,2,3,4,10,11-hyxahydrospiro[cyclohexane-1,11-dibenzo[1,4]diazipine] and...     

曼尼希碱缓蚀剂在盐酸中对N80钢缓蚀性能

目的制备一种新型曼尼希碱缓蚀剂并研究其性能。方法利用失重法研究缓蚀剂缓蚀效率与缓蚀剂的质量浓度、盐酸质量分数、腐蚀温度、腐蚀时间的关系,确定缓蚀剂的吸附曲线。通过动电位极化曲线法和交流阻抗法研究缓蚀剂的综合性质。利用扫描电镜观察腐蚀前后N80钢片的表面形态。结果缓蚀剂缓蚀效率随缓蚀剂添加量的增大而增大,随测试温度的升高而下降,随盐酸质量分数的升高先增大后减小,随腐蚀时间的延长先增大后减小。60℃时,在质量分数为15%盐酸中浸入4 h、缓蚀剂添加量在1.0 g/L的条件下,缓蚀剂缓蚀效率为99.18%,腐蚀反应的活化能由56.34 k J/mol提高到了86.54 k J/mol。缓蚀剂在N80钢表面符合Langmiur吸附模型,吸附吉布斯自由能为-29.94 k J/mol。极化实验结果显示该缓蚀剂为以阴极抑制为主的混合型缓蚀剂。阻抗谱图显示添加缓蚀剂后,阻抗明显增大。扫描电镜结果显示缓蚀剂有效抑制了盐酸对N80钢片的腐蚀。结论所制备的缓蚀剂在质量分数为15%的盐酸中对N80钢片有良好的缓蚀效果。     

Aminophenols as Corrosion Inhibitors for Aluminium–Copper Alloy in Sodium Hydroxide

Abstract

The inhibition by aminophenols of the corrosion of Al–4% Cu alloy (B26S) in solutions of sodium hydroxide has been studied in relation to the concentration of alkali and of inhibitor, the period of immersion and temperature. In general, at constant alkaliconcentration, inhibitor efficiency increases with concentration of inhibitor but, at constant inhibitor concentration, decreases with increase in alkali concentration, the effect being less pronounced with o-aminophenol. The inhibitive efficiency remains almost constant with temperature in the range 20–50°c, but decreases as the period of immersion is increased. At an inhibitor concentration of O·01–2·0% in 0·1 M NaOH the efficiency increases in the order: p-aminophenol < m-aminophenol < phenol < o-aminophenol.

The inhibitors appear to function through adsorption following the Freundlich adsorption isotherm. The comparatively better inhibitive efficiency of o-aminophenol appears to be due to chelate formation. From galvanostatic polarisation data all thefour compounds appear to be mixed type inhibitors.     

Chemical,Electrochemical and Morphology Studies on Methyl Hydroxyethyl Cellulose as Green Inhibitor for Corrosion of Copper in Hydrochloric acid Solutions

Protection of Metals and Physical Chemistry of Surfaces - Methyl hydroxyethyl cellulose was tested as a green inhibitor for corrosion of copper in 1M HCl solution, because it is nonpoisonous,...     

Studies on a Few Substituted Piperidin-4-one Oximes as Corrosion Inhibitor for Mild Steel in HCl

The corrosion inhibition of mild steel in 1 M hydrochloric acid by a few piperidin-4-one oxime derivatives, namely, 1,3-dimethyl-2,6-diphenyl piperidin-4-one oxime (I), 3,3-dimethyl-2,6-diphenyl piperidin-4-one oxime (II), and 3-isopropyl-2,6-diphenyl piperidin-4-one oxime (III) was studied using chemical weight loss method, electrochemical polarization and impedance spectroscopy, SEM with EDS, XRD, FT-IR measurements, and semi-empirical AM1 method for electronic properties. The weight loss measurements at four different temperatures such as 30, 40, 50, and 60 °C showed that the percentage inhibition efficiency (IE) of these compounds increased with increase of concentration and decreased with increase of temperature. The IE followed the order III < II < I. It was found that these inhibitors function through physical adsorption mechanism obeying Temkin’s isotherm. Polarization studies showed that these compounds act as mixed-type inhibitors. Impedance measurements revealed the increase of charge transfer resistance with inhibitor concentration. Surface analysis using SEM, XRD, and FT-IR revealed the formation of protective film over the mild steel surface. The electronic properties calculated using AM1 semi-empirical method explained the inhibition characteristics. The quantum chemical studies showed that ring nitrogen and phenyl rings are the probable active centers to inhibit corrosion process.     

Electrochemical and Molecular Dynamic Investigation of Some New Pyrimidine Derivatives as Corrosion Inhibitors for Aluminium in Acid Medium

Protection of Metals and Physical Chemistry of Surfaces - A new class of corrosion inhibitors, namely, pyridine-2,6-diamine (PD) , pyrimidin-2-amine (PA), 6-amino-3,4-dihydropyrimidine-2(1H)-thione...     

Use of Endostemon tereticaulis (Pear.) M.Ashby and Hyptis spicigera Lam. Plant Extracts as Corrosion Green Inhibitors for Mild Steel in 1M HCl: Electrochemical and Surface Morphological Studies

Protection of Metals and Physical Chemistry of Surfaces - In the present study, we evaluated the effect of corrosion inhibition of ethanol extracts from Endostemon tereticaulis and Hyptis spicigera...     

Synthesis and Characterization of a Bis-Pyrazoline Derivative as Corrosion Inhibitor for A283 Carbon Steel in 1M HCl: Electrochemical,Surface, DFT and MD Simulation Studies

Protection of Metals and Physical Chemistry of Surfaces - The effect of a new synthesized bis-pyrazoline derivative namely: 5,5'-(1,4-phenylene) bis [1?formyl-4,5-dihydro-3-phenyl-1H...     

Experimental and Theoretical Investigation by DFT on the Some Azole Antifungal Drugs as Green Corrosion Inhibitors for Aluminum in 1.0M HCl

Protection of Metals and Physical Chemistry of Surfaces - The inhibiting power of three compounds of azole antifungal drugs to ward the dissolution of aluminum in 1.0 MHCl solutions was elaborated...     

Diphenolic Schiff bases as corrosion inhibitors for aluminium in 0.1 M HCl: Potentiodynamic polarisation and EQCM investigations

The effects of novel synthesised two Schiff bases on the corrosion of aluminium in 0.1 M HCl were investigated using potentiodynamic polarisation and electrochemical quartz crystal microbalance measurements. Results show that inhibition efficiencies increase with increase in inhibitor concentration. This reveals that the inhibition occurs through adsorption of the inhibitor molecules on the metal surface. Adsorption of these inhibitors follows Temkin adsorption isotherm. The correlation between the inhibitor performances and their molecular structures has been investigated using quantum chemical parameters obtained by MNDO (modified neglect of diatomic overlap) semi-empirical method. Calculated quantum chemical parameters indicate that Schiff bases adsorbed on aluminium surface by chemical mechanism.     

Corrosion Control of Mild Steel Material in HCl Electrolyte by a Non-Steroidal Anti-Inflammatory Drug: Electrochemical and Kinetic Study

Protection of Metals and Physical Chemistry of Surfaces - The corrosion inhibition of mild steel by a drug substance, namely piroxicam, in HCl (1 M) solution was investigated. The Electrochemical...     

Thermodynamic and Electrochemical Studies of Aniline and Phenylhydrazine and Their Derivatives Substituted POCl3-Based Compounds as Corrosion Inhibitor for Mild Steel in Hydrochloric Acid Solution

Protection of Metals and Physical Chemistry of Surfaces - The achievement of high corrosion inhibition performances by manipulating the molecular structure of organic substances has gained much...     

Essential Oil of Salvia officinalis as Novel Eco-Friendly Inhibitor for Carbon Steel in HCl Solution: Weight Loss,Electrochemical and XPS Studies

Protection of Metals and Physical Chemistry of Surfaces - Essential oil of a medicinal plant (Salvia officinalis), used as an eco-friendly inhibitor for the corrosion of carbon steel in 1 M HCl, is...     

Augmentation of Polyethylene Terephthalate Reusability as Efficient Corrosion Inhibitors in Oilfield Protection: Synthesis,Evaluation, and Antibacterial Study

Protection of Metals and Physical Chemistry of Surfaces - In the presented study, polyethylene terephthalate was recycled using chemical modification process to obtain efficient corrosion...     

Synthesis and Inhibition Behavior of the Quaternary Ammonium Salt-type Tetrameric Surfactant for Corrosion of N80 Steel in HCl Medium

Protection of Metals and Physical Chemistry of Surfaces - The quaternary ammonium salt-type tetrameric surfactant with hydrocarbon chain length of 12 was synthesized, and characterized using FT-IR...     

Theoretical Prediction and Experimental Study of Benzimidazole Derivate as a Novel Corrosion Inhibitor for Carbon Steel in 1.0 M HCl

Protection of Metals and Physical Chemistry of Surfaces - The inhibiting effect of benzimidazole derivate (DBI) on corrosion of carbon steel (CS) at temperature range of 303–333 K was...     

Inhibition effects of methionine and tyrosine on corrosion of iron in HCl solution: Electrochemical,FTIR, and quantum-chemical study

The inhibiting effect of methionine and tyrosine on the corrosion of iron is researched electrochemically in 0.1M HCl, Quantum chemical calculations were performed. The level of HF with the 6–311G(d,p) basis set for methionine and tyrosine. Corrosion current density has been determined by polarization measures and the inhibition effect was calculated. With an increase in the concentration of inhibitor, the effectiveness of inhibition increases. The highest inhibition is determined as 97.8% at 100 ppm methionine. The effect of temperature is determined by chronoammetric measures. Surface analysis is performed with FTIR spectroscopy. Methionine and tyrosine adsorb on the iron surface according to Langmiur isotherm. The highest occupied and the lowest unoccupied molecular orbital energy, as well as Mulliken and atomic charges with hydrogens summed into heavy atoms of C, N, O, S atoms and of methionine, tyrosine, and protonated forms have been examined. The text was submitted by the authors in English.