Anodic Tafel behaviour of mild steel in presence of inhibitors

Khalil, Munawar

doi:10.1002/mawe.19920230311

Cited by 6 publications

(3 citation statements)

References 14 publications

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“…The values of cathodic slopes (c) varied from -121 to -160 mV for TPPH2, from -135 to -193 mV for TPPH2(p-Me), and from -149 to -194 mV for TAcPPH2. These limits represent typical anodic and cathodic Tafel slopes that were reported in the literature for mild steel in acidic solutions [23,24]. As it can be observed from Table 1 and 2, the variations of anodic and cathodic Tafel slopes caused by the addition of the inhibitors, affected both the corrosion potential and the anodic and cathodic current densities.…”

Section: Anodic and Cathodic Tafel Slopessupporting

confidence: 63%

Experimental and theoretical study on corrosion inhibition of mild steel by meso-tetraphenyl-porphyrin derivatives in acid solution

Meraghni

Lanez

et al. 2022

J. Electrochem. Sci. Eng.

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The inhibition effect of meso-tetraphenyl-porphyrin (TPPH2), meso-tetra4-methophenyl-porphyrin TPPH2(p-Me), and meso-tetra4-actophenyl-porphyrin (TAcPPH2) on the corrosion of XC52 mild steel in aerated 0.5 M aqueous sulfuric acid solution was studied by potentiodynamic polarization experiments and quantum chemical calculations. Results from potentiodynamic polarization showed that inhibition efficiency of three compounds increased upon increasing of the inhibitor concentration and they are acting as mixed type inhibitors, having dominant anodic reactions. Adsorption of all compounds follows the Langmuir adsorption isotherm with moderate values of free energy of adsorption. Quantum chemical calculation using DFT/B3LYP method confirmed a strong bond between meso-tetraphenyl-porphyrins and mild steel surface. The inhibition mechanism was also determined by the potential of zero charge (PZC) measurement at the metal/solution interface.

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Section: Anodic and Cathodic Tafel Slopessupporting

confidence: 63%

Experimental and theoretical study on corrosion inhibition of mild steel by meso-tetraphenyl-porphyrin derivatives in acid solution

Meraghni

Lanez

et al. 2022

J. Electrochem. Sci. Eng.

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“…The shift to anodic region is due to control of dissolution of iron. Comparing with the anodic Tafel slope value reported in literature for iron in acid media (38 -40 mV/decade) [49] it can be said that diphosphonic acids work as an anodic and cathodic inhibitor. Similar properties were reported for other phosphonic acids [50,51].…”

Section: Ocp and Potentiodynamic Polarization Testssupporting

confidence: 60%

Homologous alkyl side-chain diphosphonate inhibitors for the corrosion protection of carbon steels

Moschona

Pleşu

Colodrero

et al. 2021

Chemical Engineering Journal

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C8-D), dodecylamine-N,N-bis(methylenephosphonate) (DBMP, C12-D), with carbon steel surfaces are studied by XPS at pH = 3.0. Structurally, they all possess two methylenephosphonate moieties connected to a single N atom. The third substituent on N is a non-polar, variable-length alkyl chain, -(CH 2 ) x CH 3 , where x = 0 (C1-D), 1 (C2-D), 3 (C4-D), 5 (C6-D), 7 (C8-D), and 11 (C12-D). XPS studies (on pristine solid diphosphonate samples and also on carbon steel specimens, immersed in aqueous solutions), indicate significant deprotonation of the diphosphonic acid molecules upon interaction with the 2 metallic surface. They also prove that this surface interaction results in adsorption on the surface via the deprotonated phosphonic acid moieties. The adsorption of inhibitors on the metal surface was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy. The changes detected in the charge transfer resistance (R ct ) and constant phase element (CPE) independently confirm inhibitors adsorption on metal surface. Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FTIR) spectroscopy and Scanning Electron Microscopy was used to investigate the nature of deposited film. Small alkyl chain diphosphonates (C1-D, C2-D and C4-D) exhibited lower corrosion resistance due to the thin, porous and/or incomplete layer formed on carbon steel surface. Longer alkyl chain molecules (C6-D, C8-D and C12-D) were found to adsorb more efficiently and form a more organized and thicker layer. The best results were obtained in the case of C8-D (lower corrosion current, higher R ct and surface coverage). In the presence of C8-D the corrosion rate was reduced by a factor of 6.

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“…A perusal of literature reveals that condensation products derived from aldehydes and amines (Turbina et al, 1971;Desai et al, 1986;Muralidharan et al, 1993a;Quraishi et al, 1995;1997a;1996a;1996b) have been investigated extensively by researches. Aldehydes (Growcock and Lopp, 1988;Frenier, 1996) and thiosemicarbazide (Khalil, 1992;Singh and Chaudhary, 1996) are well known inhibitors, however, the investigation on condensation products of the aldehydes and thiosemicarbazides appears to be scanty.…”

Section: Introductionmentioning

confidence: 99%

The influence of some condensation products on corrosion inhibition of mild steel in acidic solutions

Quraishi

Jamal

2000

Anti-Corrosion Methods and Materials

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Selected condensation products of aromatic aldehydes and thiosemicarbazide have been synthesized and evaluated as corrosion inhibitors of mild steel in 1N hydrochloric acid and 1N sulphuric acid by weight loss and potentiodynamic polarization methods. The values of activation energy and free energy of adsorption have also been determined to understand the mechanism of inhibition. The potentiodynamic polarization studies carried out at room temperature revealed that all the compounds are of mixed type inhibitors in both the acids. The adsorption of all the condensation products on the mild steel surface from both the acids has been found to obey Temkin’s adsorption isotherm. The inhibition efficiency of these compounds has been found to vary with the nature and concentration of the compounds, temperature, immersion time and nature of the acids.

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Anodic Tafel behaviour of mild steel in presence of inhibitors

Cited by 6 publications

References 14 publications

Experimental and theoretical study on corrosion inhibition of mild steel by meso-tetraphenyl-porphyrin derivatives in acid solution

Experimental and theoretical study on corrosion inhibition of mild steel by meso-tetraphenyl-porphyrin derivatives in acid solution

Homologous alkyl side-chain diphosphonate inhibitors for the corrosion protection of carbon steels

The influence of some condensation products on corrosion inhibition of mild steel in acidic solutions

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