Corrosion inhibition behavior of cefuzonam at mild steel/HCl acid interface

The adsorption and corrosion inhibition behavior of cefuzonam (CZM) at mild steel surface were studied gravimetrically and electrochemically by using electrochemical impedance spectroscopy and Tafel polarization techniques. The increase in concentration and immersion time showed a positive effect. Inhibitor molecules directly adsorb on the surface on the basis of donor acceptor interactions between the p-electrons of benzene, sulfur and nitrogen atoms and the vacant d-orbital of iron atoms. The adsorption of CZM followed the Langmuir adsorption isotherm. A potentiodynamic polarization study revealed that CZM acted as mixed type of inhibitor. The results obtained from different methods are in good agreement. The adsorption behavior of CZM was experimentally investigated by contact angle measurement on metal surface. The contact angle of metal surface to the acid solution increased with inhibitor concentration, thereby confirming the increased hydrophobic nature of metal surface to the acid solution having the inhibitor.     

Electrochemical studies of mild steel corrosion inhibition in sulfuric acid chloride by aniline

The corrosion behavior of mild steel in dilute hydrochloric acid under the inhibiting action of various concentrations of aniline was studied using the weight loss and linear polarization resistance technique. The efficiency of the inhibitor increased with the increase in the inhibitor concentration. The results obtained reveal that aniline performed effectively as a corrosion inhibitor. The adsorption mechanism indicates mixed molecular interaction from values of Gibbs free energy. The values of the inhibition efficiency calculated from the two techniques are in reasonably good agreement. The adsorption of the inhibiting compound was found to obey Langmuir, Frumkin and Freudlich adsorption isotherms. The mechanism of inhibition was discussed in the light of the chemical structure of the inhibiting compound and their adsorption on steel surfaces in relation to the potentiodynamic parameters.     

蛋氨酸衍生物的合成及其缓蚀性能研究

本文合成了一种新型蛋氨酸衍生物酸洗缓蚀剂,运用红外光谱及核磁共振氢谱对其结构进行了鉴定。采用失重法和电化学法研究了在0. 5mol·L~(-1)硫酸介质中其对碳钢试片的缓蚀性能,并通过吸附等温模型对缓蚀机理进行初步的探讨。结果表明,蛋氨酸衍生物的缓蚀效率约为90%,整体用量适中,是一种有望得到良好应用的绿色缓蚀剂。电化学分析表明,蛋氨酸衍生物为混合型缓蚀剂,其通过增大金属表面的电荷转移电阻而降低电化学腐蚀速率。     

Corrosion inhibition performance of tannins for mild steel in hydrochloric acid solution

Research on Chemical Intermediates - The corrosion inhibition behavior of commercial hydrolysable tannin (tara tannin), condensed tannin (black wattle tannin) and complex tannin (bayberry tannin)...     

Corrosion behavior of Ti-Nb alloys in sulfuric acid

Specific features of the corrosion behavior of Ti-Nb alloys in a 40% H₂SO₄ solution were studied.     

Corrosion inhibition and mechanism of mild steel in hydrochloric acid by ceftriaxone and amoxicillin

Corrosion inhibition of mild steel in 1 mol/L HCl by amoxicillin and ceftriaxone in the concentration range of 1.00×10-5-1.00×10-2 mol/L has been studied using weight loss,electrochemical potentiodynamic polarization,electrochemical impedance spectroscopy(EIS),scanning electron microscopy(SEM) and quantum chemistry tests at 298 K.The weight loss experiment showed that the inhibition efficiency increased with amoxicillin and ceftriaxone concentrations to attain the maximums of 80.3% and 94.1%,respectively at...     

Adsorption and inhibition effect of curcumin on mild steel corrosion in hydrochloric acid

The inhibition effect of curcumin on the corrosion of mild steel in 1.0 M HCl solution was studied by weight loss, potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) methods. The experimental results suggest that this compound is an efficient corrosion inhibitor and the inhibition efficiency increases with the increase in inhibitor concentration. Adsorption of this compound on mild steel surface obeys Langmuir isotherm. Also the objective of this work is to attempt to find relationships between electronic structure and inhibition efficiency. The structural parameters, such as the frontier molecular orbital energies (E _HOMO and E _LUMO), gap of energy ΔE, from the molecule to iron as well as electronic parameters such as Mulliken atomic populations were calculated and discussed using the Density Functional Theory method (DFT).     

AC impedance measurement of cystine adsorption at mild steel/sulfuric acid interface as corrosion inhibitor

Alternating current (AC) impedance measurements of mild steel/sulfuric acid interface in the absence and in the presence of various concentrations of cystine (Cys–Cys) have been carried out in the 100 kHz–10 mHz frequency range. The results revealed that Cys–Cys is a good and effective inhibitor for mild steel corrosion in 0.5 M H₂SO₄ and its percent inhibition efficiency changes with its concentration. Changes in impedance parameters indicated the adsorption of Cys–Cys on the mild steel surface, which was verified by scanning electron microscope (SEM) and atomic force microscope (AFM) photographs. Adsorption of Cys–Cys on mild steel surface was found to obey the Langmuir adsorption isotherm with a standard free energy of adsorption of −33.2 kJ/mol. Energy gaps for the interactions between mild steel surface and Cys–Cys molecule were found to be close to each other showing that Cys–Cys owns capacity to behave as both electron donor and electron acceptor.     

Corrosion inhibition of mild steel in hydrochloric acid using extract of glycine max leaves

Research on Chemical Intermediates - The activity of glycine max leaves extract against corrosion of mild steel in 0.5 M HCl solution has been investigated at different temperatures...     

Corrosion inhibition of mild steel in hydrochloric acid by betanin as a green inhibitor

The effect of betanin (2,6-pyridinedicarboxylic acid, 4-(2-(2-carboxy-5-(beta-D-glucopyr-anosyloxy)-2,3-dihydro-6-hydroxy-1H-indol-1-yl)ethenyl)-2,3-dihydro-(S-(R*,R*))) on the corrosion inhibition of mild steel has been investigated in 1 M HCl solution. Weight loss method, potentiodynamic polarization, and electrochemical impedance spectroscopy techniques were applied to study the mild steel corrosion behavior in the absence and presence of different concentrations of betanin under the influence of various experimental conditions. The results obtained showed that betanin is a good “green” inhibitor for mild steel in 1 M HCl solution. Scanning electron microscopy observations of the steel surface confirmed the protective role of the inhibitor. The polarization curves showed that betanin behaves mainly as a mixed-type inhibitor. Maximum inhibition efficiency (98%) is obtained at betanin concentrations of 0.01 M. The results obtained from weight loss, polarization, and impedance measurements are in good agreement.     

Effect of temperature on adsorption and corrosion inhibition characteristics of gelatin on mild steel in hydrochloric acid medium

Research on Chemical Intermediates - Adsorption characteristics of a water-soluble bio-polymer, gelatin, on mild steel in 1-M hydrochloric acid (HCl) together with its potential corrosion resistive...     

Corrosion inhibition of mild steel in acidic medium by butyl alcohol

The corrosive behavior of mild steel in 1 M H₂SO₄ solutions contaminated with 3.5 % recrystallized sodium chloride at specific concentrations of butyl alcohol was investigated using potentiodynamic polarization and weight loss technique. The results obtained showed butyl alcohol to be an efficient inhibitor in the acid environment with general decrease in corrosion rate as the concentration of the alcohol increases. The adsorption of the inhibitor on the mild steel obeys the Langmuir adsorption isotherm. The thermodynamic parameters of adsorption deduced reveal a mixed interaction with the steel surface and spontaneous adsorption of butyl alcohol.     

Experimental and theoretical investigation on adsorption and corrosion inhibition properties of imidazopyridine derivatives on mild steel in hydrochloric acid solution

Imidazopyridine derivatives, namely 4‐methoxy‐N‐((2‐(4‐methoxyphenyl)H‐imidazo[1,2‐a]pyridin‐3‐yl)methylene)benzenamine (MMPIPB) and 4‐chloro‐N‐((2‐(4‐methoxyphenyl)H‐imidazo[1,2‐a]pyridin‐3yl)methylene)benzenamine (CMPIPB), were investigated as inhibitors for mild steel corrosion in 15% HCl solution using the weight loss and electrochemical techniques. According to electrochemical impedance spectroscopy studies, MMPIPB and CMPIPB show corrosion inhibition efficiency of 84.8 and 77.2% at 10‐ppm concentration and 98.1 and 94.8% at 80‐ppm concentration, respectively at 303 K. The corrosion inhibition efficiency of both inhibitors increased with increasing inhibitor concentration and decreased with increasing temperature. The adsorption of both inhibitor molecules on the surface of mild steel obeys Langmuir adsorption isotherm. Polarization studies showed that both studied inhibitors were of mixed type in nature. Electrochemical impedance spectroscopy studies showed that for both inhibitors, the value of charge transfer resistance increased and double‐layer capacitance decreased on increasing the concentration of inhibitors. Scanning electron microscopy, energy‐dispersive X‐ray spectroscopy (EDX), and atomic force microscopy were performed for surface study. The density functional theory was employed for theoretical calculations. Copyright © 2014 John Wiley & Sons, Ltd.     

Corrosion inhibition and adsorption properties of Azadirachta indica mature leaves extract as green inhibitor for mild steel in HNO3

Abstract

The corrosion inhibition and adsorption properties of Neem (Azadirachta indica – AZI) mature leaves extract as a green inhibitor of mild steel (MS) corrosion in nitric acid (HNO₃) solutions have been studied using a gravimetric technique for experiments conducted at 30 and 60°C. The results disclose that the different concentrations of the AZI extract inhibit MS corrosion and that inhibition efficiency of the extract varies with concentration and temperature. For extract concentrations studied and ranging from 9.09 to 28.57 mg/L, the maximum inhibition efficiency was 80.5 and 80.07% both at 28.57 mg/L AZI at 30 and 60°C, respectively, in 2.0 N HNO₃. The adsorption of the inhibitor on the MS surface was exothermic and consistent with the physical adsorption mechanism, best described by the Frumkin adsorption isotherm.     

The effect of 2-aminoquinoline-6-carboxylic acid on the corrosion behavior of mild steel in hydrochloric acid

The inhibitive effect of 2-aminoquinoline-6-carboxylic acid (AQC) against mild steel corrosion in 1?M HCl solutions was investigated using conventional weight loss, potentiodynamic polarization, linear polarization and electrochemical impedance spectroscopy methods. The weight loss results showed that AQC is an excellent corrosion inhibitor since its efficiency increased with the concentration to attain 91.8?% at 500?mg?l^?1. Electrochemical polarization measurements revealed that AQC acted as a mixed-type inhibitor and the results of electrochemical impedance spectroscopy have shown that the change in the impedance parameters, charge transfer resistance and double layer capacitance, with the change in concentration of the inhibitor is due to the adsorption of the molecule leading to the formation of a protective layer on the surface of mild steel. The adsorption was assumed to occur on the steel surface through the active centers of the molecule. The inhibition action of AQC was discussed in view of Langmuir adsorption isotherm. Density functional theory calculations of quantum parameters were used to explain efficiency in relation with molecular structure.     

柠檬酸中锌防蚀剂（1,3-Dioxolan-2-ylmethyl）三苯基溴化磷和碘离子的协同效应研究

采用称重法、动电位极化法和电化学交流阻抗技术研究了30 ^oC时(1,3-Dioxolan-2-ylmethyl)三苯基溴化磷（DTPB）对0.5 mol·L^-1柠檬酸中锌腐蚀行为的影响. 通过在环保型电解槽中对锌进行酸洗,这在文献中是不常用的. 结果表明,DTPB作为一种有效的防蚀剂,添加浓度仅为3×10^-3 mol·L^-1时,锌在柠檬酸溶液中的防蚀效率可达98.9%. 由于DTPB和碘化钾存在协同效应,两者联用时的防蚀效果要比单独使用DTPB强,防蚀参数为1.2,并随温度升高而减小. 本文提出了碘化钾作为吸附媒介,可使金属表面与DTPB结合的防蚀机制.     

Corrosion inhibition and adsorption behavior of imidazoline salt on N80 carbon steel in CO2-saturated solutions and its synergism with thiourea

The inhibition and adsorption behavior of 2-undecyl-1-sodium ethanoate-imidazoline salt (2M2) and thiourea (TU) on N80 mild steel in CO₂-saturated 3 wt.% NaCl solutions was studied at 25?°C, pH 4, and 1 bar CO₂ partial pressure using electrochemical methods. It was found that inhibition efficiency (η%) increased with increase in 2M2 concentration but decreased with increase in TU concentration with optimum η% value at 20 mg l^?1 TU. The data suggest that the compounds functioned via a mixed-inhibitor mechanism. The inhibition process is attributed to the formation of an adsorbed film of 2M2 and TU via the inhibitors polycentric adsorption sites on the metal surface which protects the metal against corrosion. A synergistic effect was observed between TU and 2M2. Potential of unpolarizability, E _u, was observed in the presence of 100 mg l^?1 TU which was shifted positively in the presence of 2M2–100 mg l^–1 TU blends, which suggests that the presence of 2M2 stabilized the adsorption of TU molecules on the surface of the metal. The adsorption characteristics of 2M2 were approximated by Langmuir adsorption isotherm.     

Corrosion inhibition of mild steel by Laurus nobilis leaves extract as green inhibitor

The efficiency of Laurus nobilis leaves?? extract as a corrosion inhibitor for mild steel in acidic medium (1?M H₂SO₄) was investigated by use of the electrochemical techniques potentiodynamic polarization, electrochemical impedance spectroscopy, and polarization resistance measurements. According to the experimental results, L. nobilis extract acts as a good corrosion inhibitor. In the presence of the inhibitor, corrosion potential shifted toward a more negative value than for the blank solution. Inhibitor efficiency increased with increasing inhibitor concentration, as expected. According to the potentiodynamic polarization results the corrosion of mild steel increased with increasing temperature both in the presence and absence of the inhibitor. The activation energy (E _a) of the corrosion process was calculated from the variation of corrosion current density with temperature.     

Surface interaction and corrosion inhibition of carbon steel in sulfuric acid using Petroselinum crispum extract

With the aid of the mass loss (ML) method, and a few electrochemical techniques [potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS)], the inhibitory impact of Petroselinum crispum (PC) extract on C-steel corrosion in solutions of 1 M sulfuric acid was assessed. By employing Fourier-transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) techniques, the C-steel surface morphology was investigated. The data showed that the solution of plant extract can be effectively utilized to inhibit C-steel corrosion in solutions of 1 M sulfuric acid. The effectiveness of the extract was enhanced by the higher extract dose and rising temperature. The apparent activation energy and the enthalpy of the dissolution process were determined and discussed. The presence of PC decreases the double-layer capacity from 493.1 to 107.3 μF cm⁻² and raises the charge transfer resistance in a solution of 1 M sulfuric acid from 43.39 to 287.7 Ω cm². PC is a mixed-type inhibitor, as demonstrated by PDP tests. The PC extract demonstrated the highest productivity for the C-steel protection up to 90.2% at 300 ppm from the extract, according with the PDP technique. The attained data indicated that PC extract was adsorbed chemically (ΔG^o_ads > 40 kJ mol⁻¹) onto the surface of the C-steel following the Temkin isotherm. The results of numerous tests appear to agree.     

A study of synthesized Mannich base inhibition on mild steel corrosion in acid medium

1((Cyclohexylamino)methyl)urea Mannich base was synthesized and characterized using FT-IR, H¹NMR and C¹³NMR spectra and it was tested as a corrosion inhibitor for mild steel in 1?N HCl and 1?N H₂SO₄ solutions using potentiodynamic polarization and AC impedance techniques over the temperature range of 303?C333?K. The inhibition efficiency was increased with respect to concentration of inhibitor and temperature in 1?N HCl, whereas the inhibition efficiency was increased with respect to concentration of inhibitor and decreased with respect to temperature in 1?N H₂SO₄. Potentiodynamic polarization results revealed that the inhibitor acts as mixed type inhibitor. AC impedance study indicates that the corrosion of steel was mainly controlled by a charge transfer process. Surface analysis was carried out using SEM technique. The adsorption of inhibitor follows Langmuir adsorption isotherm. Activation and adsorption parameters were calculated to gain information about the inhibitive action mechanism.