scholarly journals Structured Thin Films Based on Synergistic Effects of MnTa2O6 Oxide and bis-Carboxy-phenyl-substituted Porphyrins, Capable to Inhibit Steel Corrosion

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1890
Author(s):  
Mihaela Birdeanu ◽  
Camelia Epuran ◽  
Ion Fratilescu ◽  
Eugenia Fagadar-Cosma

Covering steel surfaces with suitable materials with the capacity to protect against corrosion represents a challenge for both research and industry, as steel, due to its paramount utility, is the most recycled material. This study presents the realization of new sandwich type materials based on 5,10-(4-carboxy-phenyl)-15,20-(4-phenoxy-phenyl)-porphyrin or 5,15-(4-carboxy-phenyl)-10,20-diphenylporphyrin and MnTa2O6 designed to improve corrosion inhibition of steel in aggressive media. The thin films, designed as single- or sandwich-type structures were obtained on carbon steel through the drop-casting technique. Morphological investigations of thin films were carried out by field emission-scanning electron microscopy (SEM) and atomic force microscopy (AFM). The inhibition of a steel corrosion process was evaluated in an aggressive environment of 0.1 M HCl by performing electrochemical investigations such as open circuit potential (OCP) and the potentiodynamic polarization technique. The influence of variations in the cathodic Tafel slopes βc and anodic Tafel slopes βa over the corrosion rates was discussed. The best corrosion inhibition efficiency of 91.76% was realized by the steel electrode covered with sandwich-type layers of 5,15-(4-carboxy-phenyl)-10,20-diphenylporphyrin on the bottom layer and MnTa2O6 on the top. The effect of location of the COOH groups in the cis or trans position on the tetrapyrrolic ring was also discussed to understand the corrosion inhibition mechanism.


2019 ◽  
Vol 233 (11) ◽  
pp. 1553-1569 ◽  
Author(s):  
Rola N. Tabesh ◽  
Ashraf Moustafa Abdel-Gaber ◽  
Hassan H. Hammud ◽  
Rami Al-Oweini

Abstract The ligands 1,10-phenanthroline, (P) and para-aminobenzoate, (B); as well as their corresponding MnPB complex [bis-(dimanganese di-μ-paraaminobenzoate dichloro diphenanthroline)] have been investigated as inhibitors of mild steel corrosion in H2SO4 (0.5 M) solutions via potentiodynamic and electrochemical impedance spectroscopy techniques. Stability of the prepared complex was examined by UV-visible spectroscopy. The corrosion inhibition, thermodynamics, and adsorptive properties obtained have shown that MnPB complex has remarkable effects in the acidic solutions. Theoretical fitting of different adsorption isotherms such as Langmuir, Flory–Huggins, and the kinetic-thermodynamic models were tested and the thermodynamic activation parameters were calculated. The data revealed that the corrosion inhibition mechanism of mild steel in acidic solutions by the MnPB complex goes via physicochemical adsorption.



Author(s):  
Prakash Katuwal ◽  
Ramesh Regmi ◽  
Susan Joshi ◽  
Jagadeesh Bhattarai

Effects of Nepal origin plant species of Vitex negundo, Catharanthus roseu, Aegle marmelos and Elaeocarpus ganitrus extracts on mild steel corrosion were explored in bioethanol (E100) and its blend (E15) in airtight condition at 25±2 °C using static immersion, inhibition efficiency and mechanism tests which were complemented with adsorption isotherms and potentiodynamic polarization studies. Corrosion resistance of the mild steel was increased with increasing 500-2000 ppm concentrations of each plant extract in E100 and E15 biofuels. Additions of V. negundo and C. roseus extract separately in both the biofuels seems to be more effective inhibition actions to prevent the mild steel corrosion than A. marmelos or E. ganitrus addition so as the corrosion rates of the mild steel in E100 and E15 are successfully lowered even than in commercial gasoline (E0). The results obtained from the corrosion rate revealed the order of the corrosion inhibition efficiency (IE) as V. negundo > C. roseus > A. marmelos > E. ganitrus. The maximum IE (IEmax) in V. negundo and C. roseus leaves was showed about 89-86% and 71-75%, respectively, at 2000 ppm concentration, in spite of the other two more plants leaf extract also used as the corrosion inhibitors for the mild steel in both E100 and E15 biofuels. The IE increased on increasing inhibitor concentration following the Langmuir and Temkin adsorption isotherms but decreased with immersion time which suggested that the corrosion inhibition mechanism is of physical type of adsorption of the leaves constituents on the mild steel surface. A. marmelos extract acted as an anodic type of inhibitor in E100 and E15, while E. ganitrus acted as mixed



RSC Advances ◽  
2021 ◽  
Vol 11 (22) ◽  
pp. 13497-13512
Author(s):  
Abd El-Aziz S. Fouda ◽  
Samir A. Abd El-Maksoud ◽  
Elsherbiny H. El-Sayed ◽  
Hazem A. Elbaz ◽  
Ashraf S. Abousalem

The inhibitory effect of three newly synthesized hydrazide derivatives on carbon steel corrosion in hydrochloric acid showed better inhibition efficiency (97.5%) and their inhibition mechanism is presented.



Author(s):  
Hamze Foratirad ◽  
Majid Golabadi ◽  
Masoud Asgari ◽  
Mohammad Ghasem Gholami ◽  
Meysam Karimi

Abstract In this study, the synergistic effects of 2-mercaptobenzotiazole molecules and zinc nitrate on the corrosion behavior of carbon steel were investigated using electrochemical techniques in 3.5% NaCl solution. The experimental results revealed that combination of 2-mercaptobenzoimidazole (MBT) and zinc nitrate with ratio of 100 ppm : 100 ppm, resulted in the least corrosion current (1.03 lA cm-2) and the highest corrosion inhibition efficiency. Polarization results showed that the inhibition mechanism of inhibitor was mixed-type (anodic and cathodic mechanism) corrosion inhibition which was predominantly influenced by a reduction in dissolution rate of the substrate (decrease in anodic current density). Electrochemical impedance spectroscopy analysis yielded more accurate results about the formation mechanism and stability of the inhibitor film over prolonged time. The precipitation of chelate from inhibitor molecules and zinc cations on steel surface was found to be the main mechanism for increasing the corrosion resistance of steel substrate.



2018 ◽  
Vol 56 (3B) ◽  
pp. 63
Author(s):  
Quan Vo An ◽  
Tuan Anh Nguyen ◽  
Ha Tran Thi ◽  
Que Le Xuan

As the growing interest on green corrosion inhibitors, plant extracts have gradually showed the potential in replacing the traditional hazardous chemicals due to the eco-friendly and economy characteristics. Previous study reported that rose myrtle leaf-extract (Rhodomyrtus tomentosa, Myrtaceae) was as an efficient corrosion inhibitor for rust removal process of mild steel in H2SO4 acid medium. This study presents the corrosion inhibition assessments of rose myrtle leaf-extract on mild steel surface in HCl 1M solution. The potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods have been used to study the corrosion behaviors of mild steel. The corrosion rate, corrosion current and corrosion potential results indicate that only small amount of the leaf-extract (2% vol.) was required for high inhibition efficiency (Hin=83.9%). By affecting on both anodic and cathodic branches of the Tafel plot, the corrosion inhibition mechanism is proposed by an adsorption forming different barriers on the steel surface.Green inhibitor, Rhodomyrtus tomentosa, steel corrosion, EIS



2021 ◽  
Vol 14 ◽  
pp. 1-7
Author(s):  
MK Harun ◽  
I Ismail ◽  
MZA Yahya

The corrosion inhibition of sodium deodecylbenzenesulfonate (SDBS) surfactant and ZnSO4 on mild steel in 0.05 M NaCl solution was conducted through the impedance spectroscopy and linear polarisation measurement. The inhibitors performance was measured separately and as a mixed composite of both at a ratio of 200:200 ppm. Results obtained from both these measurements indicate high corrosion inhibition of the mild steel substrates was achieved. Porosity calculation of the formed inhibition layer was done through the obtained linear polarisation data, and its dielectric properties were deduced from the impedance measurements. Two possible structures of the formed inhibitive layers are proposed. The first structure involved the formation of a stable but porous zinc oxide/hydroxide layer with the surfactant filling up the pores, thus forming a continuous inhibitive barrier film layer while the second, involved a formation of a continuous inhibitive barrier layer due to the chelation of the surfactant and ZnSO4 compounds. The results obtained also indicated that corrosion resistance induced by the inhibitive barrier layers is much more dependent on its charge transfer resistance properties rather than its dielectric properties and that the corrosion inhibition provided is not directly related to the double-layer capacitance values of the barrier layer.



Author(s):  
E. P. Othaki ◽  
N. C. Ngobiri

The corrosion inhibition characteristics of Chrysophyllum cainto cotyledon aqueous extract was studied for the corrosion of pipeline steel in 0.5 M HCl using gravimetric technique. The corrosion surface morphology and corrosion surface film were studied using Scanning electron microscope and Fourier transform infrared spectroscopy respectively. The results obtained showed Chrysophyllum cainto aqueous extract as a good corrosion inhibitors of pipeline steel corrosion in acidic environment, recording an average corrosion inhibition efficiency above 90% at 303 K. The Scanning electron micrograph showed a smoother corrosion surface morphology in the presence of the extract while the Fourier transform infrared spectroscopic data showed the corrosion inhibition mechanism to be through adsorption.



2020 ◽  
Vol 22 (6) ◽  
pp. 3329-3344 ◽  
Author(s):  
G. Sruthi ◽  
K. Shakeela ◽  
R. Shanmugam ◽  
G. Ranga Rao

The corrosion inhibition mechanism for SS316 coated with FcPMo hybrid material is shown.



Coatings ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 454 ◽  
Author(s):  
Arman Dastpak ◽  
Kirsi Yliniemi ◽  
Mariana de Oliveira Monteiro ◽  
Sarah Höhn ◽  
Sannakaisa Virtanen ◽  
...  

In this study, a waste of biorefinery—lignin—is investigated as an anticorrosion coating on stainless steel. Corrosion behavior of two lignin types (hardwood beech and softwood spruce) was studied by electrochemical measurements (linear sweep voltammetry, open circuit potential, potentiostatic polarization, cyclic potentiodynamic polarization, and electrochemical impedance measurements) during exposure to simulated body fluid (SBF) or phosphate buffer (PBS). Results from linear sweep voltammetry of lignin-coated samples, in particular, demonstrated a reduction in corrosion current density between 1 and 3 orders of magnitude cf. blank stainless steel. Furthermore, results from cross cut adhesion tests on lignin-coated samples demonstrated that the best possible adhesion (grade 0) of ISO 2409 standard was achieved for the investigated novel coatings. Such findings suggest that lignin materials could transform the field of organic coatings towards more sustainable alternatives by replacing non-renewable polymer coatings.



Author(s):  
Gianni Rondelli ◽  
Luciano Lazzari ◽  
Marco Ormellese ◽  
Ramon Novoa ◽  
Elmer Pérez


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