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To investigate the inhibiting effect of the cationic surfactant cetyl trimethylammonium chloride (CTAC) on aluminum (Al).

Pure aluminum rods were immersed in hydrochloric acid (HCl) and sodium hydroxide (NaOH) solutions for weight‐loss tests and potentiostatic polarization measurements.

The inhibition action depends on the concentration of the inhibitor, the concentration of the corrosive media, and the temperature. The inhibition efficiency in NaOH was higher than that in HCl solutions. In both acidic and basic media, the increase in temperature resulted in a decrease of the inhibition efficiency and a decrease in the degree of surface coverage. The results were indicative of increased aluminum dissolution with increasing temperature. It was found that adsorption of CTAC on the aluminum surface follows Temkin's isotherm in HCl and Langmuir's isotherm in NaOH.

Clarifies the effects of concentration and temperature on the inhibition efficiency of a cationic surfactant on aluminum.

The purpose of this paper is to study the inhibition effect of Tween‐40 on the corrosion of cold rolled steel (CRS) in 1.0‐8.0 M HCl over the temperature range of 20‐50°C. It also aims to make an attempt to correlate both thermodynamic parameters and kinetic parameters with the inhibition effect.

The inhibition efficiencies of Tween‐40 are investigated by weight loss and potentiodynamic polarization methods.

Tween‐40 acts as a good inhibitor in 1.0 M HCl, and inhibition efficiency increases with the inhibitor concentration, while it decreases with HCl concentration and temperature. The adsorption of inhibitor on the CRS surface obeys the Langmuir adsorption isotherm equation. The inhibition effect is satisfactorily explained by both thermodynamic and kinetic parameters. Polarization curves show that Tween‐40 is a mixed‐type inhibitor in hydrochloric acid.

The experimental data have been treated with adsorption theory and kinetic equations successfully. Both the thermodynamic and kinetic parameters can be obtained, and used in explaining the inhibition effect satisfactorily.

The purpose of this paper is to investigate the effect that different concentrations of the inhibitor sulphathiazole have on the corrosion of aluminum in 0.01, 0.05 and 0.10 M trichloroacetic acid (TCA), and to elucidate the mechanisms of inhibition for this system.

Gravimetric measurements and galvanostatic polarization were used to investigate the effect of sulphathiazole on the corrosion of aluminum in TCA solution. The findings were used to determine the corrosion rates and efficiencies of the inhibitor at different concentrations.

The corrosion rate of aluminum decreased with increasing inhibitor concentrations and the efficiency of inhibition increased with increasing concentration of inhibitor up to almost 89 percent in 0.01 M TCA and up to 65.87 percent in 0.10 M TCA. The concentrations of inhibitor were in the range of 5‐20 mM. Absorption of the inhibitor was onto the aluminum surface and consistent with the Langmuir adsorption isotherm. A plot of log (θ/1−θ) versus log C gave a straight line, which suggests that the inhibitor covers both the anodic and cathodic regions. From the plot of the isotherm, it was observed that one inhibitor molecule occupies more than one active site. The mean ΔG_ads⁰ values were negative almost in all cases, indicating that the adsorption was spontaneous and that the mechanism of adsorption was physical – i.e. electrostatic attraction. Polarization data revealed that the inhibitor functions as a mixed inhibitor.

The paper deals with the inhibition of corrosion of 2S commercially pure aluminum in 0.01, 0.05 and 0.10 M solutions of TCA. To date, not much detailed information has been generated about this problem.

This study aims to develop eco-friendly corrosion inhibitors for aluminum in acidic media by evaluating the corrosion inhibition properties of corn leaf extract (CLE) using response surface methodology (RSM) and experiments.

The RSM was combined with experiments to evaluate the corrosion inhibition properties of CLE on aluminum in acid media.

The effectiveness of the inhibition increased with increasing inhibitor concentration and time but decreased with increasing temperature. The corrosion inhibition mechanism revealed the corrosion process is spontaneous exothermic physical adsorption. Thermodynamic parameters revealed an activation energy between 32.1 and 24.7 kJ/mol, energy of adsorption between −14.53 and −65.07 and Gibbs free energy of −10.12 kJ/mol which indicated the CLE exothermically spontaneously physisorbed. A model was generated to estimate the effect of the process parameters (inhibitor concentration, reaction time and temperature) using the RSM. Optimization of the process factors was also carried out using the RSM. The percentage inhibition efficiency obtained experimentally (85.61%) was closely comparable to 84.89% obtained by the theoretical technique (RSM). The SEM observations of the inhibited and uninhibited Al samples demonstrated that CLE is an effective corrosion inhibitor for aluminum in acid media.

Results herein provide novel information on the possible application of CLEs as effective eco-friendly corrosion inhibitors.

The purpose of this study is to inspect the corrosion inhibition of API N80 steel pipelines in uninhibited solution and inhibited with a synthesized surfactant compound [N-(3-(dimethyl octyl ammonio) propyl) palmitamide bromide] (DMDPP), which is prepared through a simple and applicable method.

Weight loss was inspected at five different temperatures of 25°C, 30°C, 40°C, 50°C and 60°C Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation were used at room temperature. Density functional theory was used to study the relation between the molecular structure and inhibition theoretically.

Adsorption of the prepared DMDPP fits the Langmuir isotherm model. The inhibition efficiency of the prepared DMDPP amphipathic inhibitor is directly proportional to temperature increase. Polarization results reveal that the investigated DMDPP amphipathic compound behaves as a mixed-type inhibitor. EIS spectra produced one individual capacitive loop.

The originality is the preparation of cationic surfactants through a simple method, which can be used as corrosion inhibitors in oil production. The synthesized inhibitors were prepared from low-price materials. The work studied the behavior of the synthesized surfactants in inhibiting the corrosion of the steel in an acidic medium. Electrochemical and theoretical studies were presented, besides gravimetric and surface examination.

The purpose of this paper was to protect carbon steel from corrosion with self–aggregated, eco-friendly, water-soluble hyperbranched polyamide-ester (Hb-PAE).

Hb-PAE was synthesized through bulk polycondensation reaction between maleic anhydride and di-isopropanol amine. Complete structural analysis for the obtained polymer was performed using Fourier Transfer Infra-Red Spectroscopy, 1H NMR, Thermal gravimetric analysis (TGA) and differential scanning calorimetry, and the molar mass was measured using gel permeation chromatography/refractive index. For this study, the surface activity of Hb-PAE with hydroxyl end groups was investigated. Surface tension of 1.0 × 10−6 to 0.1M of both Hb-PAE/H₂O and Hb-PAE/1N HCl systems was measured, and the critical aggregation concentration (CAC) in both systems was determined. Hb-PAE was examined as a corrosion inhibitor for plain carbon steel in both neutral (distilled water) and acidic (1N HCl) media. The corrosion of the steel was studied quantitatively by measuring its weight loss in both media in the absence and presence of Hb-PAE. The surface morphology of the exposed steel test samples was examined using scanning electron microscopy.

It was found that Hb-PAE inhibited corrosion of steel around the CAC, and its corrosion inhibition efficiency was increased by increasing its concentration.

The research can provide a reference for the relationship between the aggregation concentration of the prepared Hb-PAE with its corrosion inhibition efficiency on plain carbon steel. Hb-PAE as a corrosion inhibitor is environmentally acceptable, economical and readily available.

The purpose of this paper is to provide acid‐dyes, known for the dyeing of porous aluminum oxide films, as inhibitors of the corrosion of aluminum in neutral chloride solutions.

Potentiodynamic polarization plots are recorded on mechanically pretreated aluminum using a three‐electrode cell containing 0.01 M NaCl solution with or without 0.025 mM of the acid‐dyes monosulfonic methyl orange (MO), disulfonic chromotrop RR (CH), disulfonic alphazurine A (AZ) and trisulfonic light green SF yellowish (LG). The X‐ray fluorescence technique is used in certain cases for the estimation of sulfur net content of the surface of the probes and thus of the concentration of the adsorbed dye.

The inhibition efficiency of acid dyes on corrosion of mechanically pretreated aluminum seems to be related more to the presence of a following quinonoid structure which probably contributes more to the formation of mono‐ or bi‐dentate compounds with the aluminum cations in the substrate than to the number of sulfonic groups in their molecule. Thus, the triphenylmethane dyes LG and, to a greater extent AZ, having this quinonoid structure means they are more efficient as corrosion inhibitors in near‐neutral chloride solution than the azo dyes MO and CH, that do not have it.

Selected acid‐dyes such as triphenylmethane sulfonic‐dyes, which have found wide application in the dyeing industry, seem to protect aluminum against the corrosive action of chlorides.

This paper is intended to be the nucleus for the electrochemical studies of the effectiveness of acid dyes as corrosion inhibitors for aluminum.

The purpose of this paper was to test the extract of barley as an environmentally friendly inhibitor for the acid corrosion of steel due to its wide availability as a popular major crop and its richness with different chemical constituents reported in literature (40) like alanine, glycine, serine, aspartic acid, leucine, valine, tyrosine and isoleucine with various number of functional groups that are able to chelate metal cations and to discuss the effect of temperature on its inhibition efficiency.

Electrochemical impedance spectroscopy (EIS) and polarization measurements were carried out using frequency response analyzer Gill AC instrument. The frequency range for EIS measurements was 0.1 ≤ f ≤ 1 × 103 with an applied potential signal amplitude of 10 mV around the rest potential. Polarization measurements were carried out at a scan rate of 30 mV/min, utilizing a three-electrode cell. A platinum sheet and saturated calomel electrode were used as counter and reference electrodes, respectively. The working electrode was constructed with steel specimens that have the following composition (weight per cent): C, 0.21; S, 0.04; Mn, 2.5; P, 0.04; Si, 0.35; and balance Fe.

Barley extract could act as an effective corrosion inhibitor for the acid corrosion of steel. The inhibiting action of the barley extract was attributed to its adsorption over the metal surface that blocks the available cathodic and anodic sites. Adsorption isotherms indicated that the adsorbed extract molecules cover one active center over the metal surface.

The research included the first use of an important world crop as an effective corrosion inhibitor that can reduce the corrosion of steel to an extent of 94 per cent.

The purpose of this paper is to investigate the effect of polyethylene glycol (PEG), polyvinylpyrrolidone (PVP) and blended formulations on the corrosion inhibition of aluminium in HCl solutions at 30-60°C and to study the mechanism of action.

The inhibitive effect of the homopolymers and polymer blend was assessed using weight loss and hydrogen evolution methods at 30 and 60°C. The morphology of the corroding aluminium surface without and with the additives was visualized using atomic force microscopy. The trend of inhibition efficiency with temperature was used to propose the mechanism of inhibition and type of adsorption.

Results obtained show that inhibition efficiency (η%) increases with increase in concentration of the polymers but decreases with increase in temperature. The inhibition efficiency of the homopolymers and their blends decreased with rise in temperature. Inhibition efficiency was found to be synergistically enhanced on blending the two homopolymers with highest inhibition efficiency obtained for (PEG:PVP) blending ratio of 1:3. The phenomenon of physical adsorption is proposed from the trend of inhibition efficiency with temperature.

The mechanistic aspect of the corrosion inhibition can be better understood using electrochemical studies such as potentiodynamic polarization and electrochemical impedance spectroscopy.

Studies involving the use of polymer blends/mixtures as corrosion inhibitor for metals in corrosive environments are scarce. The results suggest that the mixture could find practical application in corrosion control in aqueous acidic environment. The data obtained would form part of database on the use of polymer–polymer mixtures to control acid-induced corrosion of metal.

The purpose of this paper was to find a simple and easy-operated method for filtering eco-friendly corrosion inhibitors.

The molecular structures and atomic electronegativities of the four kinds of natural reagents, iota-Carrageenan, sodium alginate, sodium dodecanesulphonate (SDS) and sodium dodecylbenzene sulfonate were calculated by Gaussian and Natural Bond Orbital, and the corrosion inhibition rates were forecasted by the calculated results. Then, the realistic corrosion inhibition efficiency were confirmed by electrochemical impedance spectroscopy and potentiodynamic polarization tests in 3.5 Wt.% sodium chloride corrosive solutions. At the same time, the function of pefloxacin mesylate (PM) was explored in this paper polarization tests in 3.5 Wt.% sodium chloride corrosive solutions.

Results showed that the order calculated by the chemical software was correct, and the corrosion inhibition of SDS was the best. Optimum addition of PM not only can reduce microbial corrosion but also can improve the corrosion inhibition by spatial cooperation.

This method can be used to filter eco-friendly corrosion inhibitors quickly. PM can be also used to improve the corrosion inhibition rate of corrosion inhibitors.

The present method to filter corrosion inhibitors was time-consuming, which needed lots of experiments to verify the corrosion inhibitive efficiency. The calculated method was simpler than others, which need complicated calculation process.