The experimental and quantum chemical investigation for two isomeric compounds as aminopyrazine and 2-amino-pyrimidine against mild steel corrosion

2016 ◽  
Vol 63 (5) ◽  
pp. 369-376 ◽  
Author(s):  
Basak Dogru Mert ◽  
Mehmet Erman Mert ◽  
Gülfeza Kardas ◽  
Birgül Yazici
Keyword(s):  
Mild Steel ◽  
Molecular Orbital ◽  
Density Functional ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Molecular Geometry ◽  
Orbital Energy ◽  
Content Type ◽  
Inhibition Effect ◽  
Amino Pyrimidine

Purpose The purpose of this paper is to investigate the adsorption and corrosion inhibition of two isomeric compounds (C4H5N3) as aminopyrazine (AP) and 2-amino-pyrimidine (2AP) on mild steel (MS) in 0.5 M HCl. The study was a trial to combine experimental and modelling studies and research effect of molecular geometry on inhibition effect of inhibitor molecules. Design/methodology/approach The thermodynamic, kinetic and quantum parameters were determined. The electrochemical impedance spectroscopy and anodic polarisation measurements were obtained. The scanning electron microscope was used for monitoring electrode surface. The highest occupied molecular orbital, energy of the lowest unoccupied molecular orbital, Mulliken and natural bonding orbital charges on the backbone atoms, absolute electronegativity, absolute hardness were calculated by density functional theory (DFT)/B3LYP/6-311G (++ d,p). Findings Results showed that AP and 2AP suppressed the corrosion rate of MS. The corrosion current values were 0.530, 0.050 and 0.016 mA cm-2 in HCl, AP and 2AP containing HCl solutions, respectively. It was illustrated with the blocked fraction of the MS surface by adsorption of inhibitors which obeyed the Langmuir isotherm. The inhibition efficiency follows the order: 2AP > AP which is in agreement with experimental and quantum results. Originality/value This paper provides lay a bridge on the molecular geometry and inhibition efficiency by electrochemical tests and modelling study. The inhibition effect of AP and 2AP has not been compared with each other, neither experimentally nor theoretically. This study put forward possible application of 2AP as corrosion inhibitor especially for closed-circuit systems.

scholarly journals Theoretical Study of the Structure and Property of Ionic Liquids as Corrosion Inhibitor

2021 ◽  
Author(s):  
Guocai Tian ◽  
Weizhong Zhou
Keyword(s):  
Ionic Liquids ◽  
Corrosion Inhibitor ◽  
Molecular Orbital ◽  
Electronic Structures ◽  
Density Functional ◽  
Inhibition Efficiency ◽  
Alkyl Chain ◽  
Orbital Energy ◽  
Inhibition Effect ◽  
Molecular Orbital Energy

Three sets of ionic liquids such as 1-alkyl-3-methylimidazole chloride [Cnmim]Cl, 1-alkyl-3-methylimidazolium acetate [Cnmim]Ac and 1-octyl-3-methylimidazole salt [Omim]Y (n = 2, 4, 6, 8, and Y = Cl, BF4, HSO4, Ac and TFO) were used as corrosion inhibitor medium for corrosion protection of carbon steel. Electronic structures and reactivity of these ionic liquids, surface energy and electronic structures of the iron surface were systematically analyzed by density functional theory. By increasing the alkyl chain length of the [Cnmim]Cl and [Cnmim]Ac systems, the lowest unoccupied molecular orbital energy (ELUMO), the highest occupied molecular orbital energy (EHOMO), the softness (S) and polarizability (α) increased gradually, whereas electronegativity (χ), energy gap (ΔE), hardness (η), dipole moment (μ)and electrophilic index (ω) gradually decreased. For the [Omim]Y system, the structure parameters of ionic liquids are quite different, and only the polarizability (α) decreases gradually by increasing the length of the alkyl chain. The results show that inhibition is mainly [Cnmim]+ cations of the [Cnmim]Cl system, and the order of inhibition efficiency follows as [C2mim]Cl < [C4mim]Cl < [C6mim]Cl < [C8mim]Cl. Both [Cnmim]+ cations and the Ac− anion have inhibition effect for the [Xmim]Ac system, and the order of inhibition efficiency is [C8mim]Ac > [C6mim]Ac > [C4mim]Ac > [C2mim]Ac. For the [Omim]Y system, [Xmim]+ cations and anions (BF4−, HSO4−, Ac−, TfO−) have inhibition effect, and the order of inhibition efficiency is [Omim]TfO > [Omim]Ac > [Omim]HSO4 > [Omim]BF4 > [Omim]Cl.

scholarly journals Insight into Anticorrosion Mechanism of Ampicillin on Mild Steel in Acidic Environment: A Combined Experimental and Theoretical Approach

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Tuan Dinh ◽  
Nguyen Minh Thong ◽  
Dinh Quy Huong ◽  
Trinh Le Huyen ◽  
Tran Duc Manh ◽  
...  
Keyword(s):  
Mild Steel ◽  
Molecular Orbital ◽  
Corrosion Inhibition ◽  
Inhibition Efficiency ◽  
Energy Gap ◽  
Electrochemical Impedance ◽  
Carbon Steels ◽  
Orbital Energy ◽  
Acidic Environment ◽  
Molecular Orbital Energy

The corrosion inhibition of mild carbon steels in an acidic environment by using ampicillin (AMP) has been evaluated based on experimental and quantum chemistry techniques. The experimental results indicate that the inhibition efficiency goes up at higher AMP concentration. The highest inhibition efficiency reaches 84.9% for polarization measurement and 90.1% for electrochemical impedance spectroscopy with the inhibitor of concentration 100 ppm at 298 K. The surface characteristics (SEM) also reconfirm the steel corrosion inhibition ability of AMP. Some important chemical factors such as EHOMO (highest occupied molecular orbital energy), ELUMO (lowest unoccupied molecular orbital energy), ΔEL−H (energy gap), and Fukui functions were calculated based on the optimized configuration of AMP at the theoretical level of B3LYP/6-31+G(d,p). Moreover, Monte Carlo and molecular dynamics simulations were used to analyze the absorption behavior of inhibitor on the surface of Fe(110), which supplies the mechanism of inhibition corrosion processes. The obtained results showed that AMP is considered to be a potential corrosion inhibitor for mild steel in 1M HCl medium. Moreover, the protonated state of AMP plays an important role in the protection of Fe surface against the corrosive process.

Electrochemical behaviour of acetyl G as corrosion inhibitor for mild steel in acid medium

2015 ◽  
Vol 44 (6) ◽  
pp. 371-378 ◽  
Author(s):  
Y. Sangeetha ◽  
S. Meenakshi ◽  
C. Sairam Sundaram
Keyword(s):  
Mild Steel ◽  
Corrosion Inhibitor ◽  
Acid Medium ◽  
Steel Surface ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Electrochemical Behaviour ◽  
Green Inhibitor ◽  
Content Type ◽  
Mild Steel Surface

Purpose – The purpose of this paper is to develop an eco-friendly corrosion inhibitor for mild steel in 1 M HCl. Design/methodology/approach – A pharmaceutical drug acetyl G was investigated for its corrosion inhibition efficiency using weight loss method, potentiodynamic polarisation and electrochemical impedance spectroscopy. Findings – The inhibition efficiency increased with increase in inhibitor concentration. Results from polarisation studies revealed mixed type of inhibition. Impedance studies, scanning electron microscopy and Fourier transform spectroscopy confirm the adsorption of inhibitor on the mild steel surface. Research limitations/implications – The drug acetyl G has sulphur and nitrogen atoms which effectively block the corrosion of mild steel and is non-toxic and has good inhibition efficiency. Practical implications – This method provides an excellent, non-toxic and cost-effective material as a corrosion inhibitor for mild steel in acid medium. Originality/value – Application of this drug as a corrosion inhibitor has not been reported yet in the literature. Replacing the organic inhibitors, this green inhibitor shows excellent inhibition efficiency. This is adsorbed excellently on the mild steel surface due to the presence of long chain and hetero atoms. Thus, the drug retards the corrosion reaction.

A new insight into corrosion inhibition process of mild steel in sulfuric acid medium: a combined experimental and theoretical study

2019 ◽  
Vol 66 (6) ◽  
pp. 835-852 ◽  
Author(s):  
Aziz Boutouil ◽  
My Rachid Laamari ◽  
Ilham Elazhary ◽  
Hafid Anane ◽  
Abdeslem Ben Tama ◽  
...  
Keyword(s):  
Mild Steel ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Acid Corrosion ◽  
Content Type ◽  
Sulfuric Acid Medium ◽  
Ir Studies ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Structural Parts

Purpose This study aims to investigate the inhibition effect of a newly synthesized1,2,3-triazole containing a carbohydrate and imidazole substituents, namely, 1-((1-((2,2,7,7-tetramethyltetrahydro-5H-bis([1,3]dioxolo)[4,5-b:4′,5′-d]pyran-5-yl)methyl)-1H-1,2,3-triazol-4-yl)methyl)-1H-benzo[d]imidazole (TTB) on the corrosion of mild steel in aerated 1 M H2SO4. Design/methodology/approach The authors have used weight loss measurement, potentiodynamic polarization, electrochemical impedance spectroscopy, FT-IR studies, scanning electron microscopy analysis and energy dispersive X-ray (EDX) spectroscopy techniques. Findings It is found that, in the working range of 298-328 K, the inhibition efficiency of TTB increases with increasing concentration to attain the highest value (92 per cent) at 2.5 × 10−3 M. Both chemisorption and physisorption of TTB take place on the mild steel, resulting in the formation of an inhibiting film. Computational methods point to the imidazole and phenyl ring as the main structural parts responsible of adsorption by electron-donating to the steel surface, while the triazol ring is responsible for the electron accepting. Such strong donating–accepting interactions lead to higher inhibition efficiency of TTB in the aqueous working system. Originality/value This work is original with the aim of finding new acid corrosion inhibitors.

scholarly journals Corrosion Inhibition of Mild Steel in Acidic Media by N-[(3,4-Dimethoxyphenyl)Methyleneamino]-4-Hydroxy-Benzamide

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Kashmitha Muthamma ◽  
Preethi Kumari ◽  
M. Lavanya ◽  
Suma A. Rao
Keyword(s):  
Dft Calculations ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Density Functional ◽  
Surface Characterization ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Low Carbon ◽  
Acid Media

Abstract Mild steel (a low carbon steel) is an affordable engineering material used for many purposes in various environments including mild acidic environment with some precautions. The corrosion behaviour of mild steel (MS) in 0.5 M H2SO4 and 0.5 M HCl, in the temperature range (303–323 K) without and with the inhibitor N-[(3,4-dimethoxyphenyl) methyleneamino]-4-hydroxy-benzamide (DMHB), was investigated using Potentiodynamic polarization and Electrochemical impedance spectroscopy (EIS) techniques supplementing with surface characterization study using scanning electron microscope (SEM) and atomic force spectroscopy (AFM). Experimental observations were found to be in agreement with Density functional theory (DFT) calculations. The inhibition efficiency increases with increase in DMHB concentration and showed maximum inhibition efficiency of 86% in 0.5 M H2SO4 and 81% in 0.5 M HCl, respectively, at concentration of 3 × 10─3 M at 303 K. The inhibition efficiency of DMHB obtained relatively at its lower concentration (3 × 10─3 M) compared to other reported related compounds confirms its potential towards corrosion inhibition. The variation in the kinetic and thermodynamic parameters indicated physisorption of DMHB on MS and its mixed type inhibitive action followed Langmuir’s isotherm model. DFT calculations go along with the experimental results, signifying the potential corrosion inhibition behaviour of DMHB for MS in both the acid media.

Inhibition effect of E and Z conformations of 2-pyridinealdazine on mild steel corrosion in phosphoric acid

2017 ◽  
Vol 64 (1) ◽  
pp. 23-35 ◽  
Author(s):  
Mohammed Elalaoui Belghiti ◽  
Ayssar Nahlé ◽  
Abdeslam Ansari ◽  
Yasser Karzazi ◽  
S. Tighadouini ◽  
...  
Keyword(s):  
Weight Loss ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Mild Steel ◽  
Electrochemical Impedance ◽  
Steel Corrosion ◽  
Content Type ◽  
Inhibition Effect ◽  
Tafel Polarization ◽  
Mild Steel Corrosion

Purpose This paper aims to study the inhibition effect of 2-pyridinealdazine on the corrosion of mild steel in an acidic medium. The inhibition effect was studied using weight loss, electrochemical impedance spectroscopy, and Tafel polarization measurements. Design/methodology/approach Weight loss measurements, potentiodynamic tests, electrochemical impedance spectroscopy, X-ray diffraction and spectral and conformational isomers analysis of A (E-PAA) and B (Z-PAA) were performed were investigated. Findings 2-pyridinealdazine (PAA) acts as a good inhibitor for the corrosion of steel in 2.0 M H3PO4. The inhibition efficiency increases with an increase in inhibitor concentration but decreases with an increase in temperature. Originality/value This paper is intended to be added to the family of azines which are highly efficient inhibitors and can be used in the area of corrosion prevention and control.

Mild steel protection with tannic and polyaspartic acid in cooling systems

2019 ◽  
Vol 66 (5) ◽  
pp. 583-594
Author(s):  
Esma Sezer ◽  
İpek Öztürk
Keyword(s):  
Mild Steel ◽  
Corrosion Inhibition ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
Inhibition Mechanism ◽  
Polyaspartic Acid ◽  
Cooling Systems ◽  
Environmental Aspect ◽  
Content Type

Purpose Tannic acid (TA) is one of the green corrosion inhibitors for mild steel; its anti-corrosive performance in alkaline water on mild steel when it is used together with polyaspartic acid (PASA) still has not been investigated. The purpose of this study is to develop an effective, biodegradable and environment-friendly novel corrosion inhibitor based on TA and PASA as an alternative to the conventional inorganic inhibitors for mild steel in decarbonised water, which is common in cooling systems. Design/methodology/approach Corrosion inhibition mechanism is investigated by electrochemical techniques such as polarisation measurements and electrochemical impedance spectroscopy, and results were evaluated to determine the optimum inhibitor concentration for industrial applications. Additionally, practice-like conditions are carried out in pilot plant studies to simulate the conditions in cooling systems. Thus, the efficiencies of the inhibitors are evaluated through both weight loss and linear polarisation resistance measurements. Moreover, the corrosion product is characterised by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR) analysis. Findings TA shows high inhibition efficiency especially towards pitting corrosion for mild steel in decarbonised water. PASA addition in the cooling systems improves the inhibition efficiency of TA, and at lower concentrations of TA + PASA, it is possible to obtained better inhibition efficiency than TA alone at higher inhibitor amounts, which is essential in economic and environmental aspect. Originality/value A blended inhibitor program including TA and PASA with suggested concentrations in this work can be used as an environmental friendly treatment concept for the mild steel corrosion inhibition at cooling systems.

Studying effect of plantain extract behavior as an eco-friendly corrosion inhibitor on the mild steel in 1 M HCl solution

2018 ◽  
Vol 65 (3) ◽  
pp. 310-316 ◽  
Author(s):  
Moosa Es’haghi ◽  
Amirhossein Amjad ◽  
Sorayya Asghari ◽  
Ali Lotfi
Keyword(s):  
Mild Steel ◽  
Electrochemical Impedance ◽  
Physical Adsorption ◽  
Steel Corrosion ◽  
Sample Surface ◽  
Green Inhibitor ◽  
Content Type ◽  
Inhibition Effect ◽  
Mild Steel Corrosion ◽  
Hcl Solution

Purpose Corrosion inhibitors most commonly are used in the acid pickling, cleaning and etching solutions. Plant extracts as rich and cheap resources are among the eco-friendly inhibitors. This study aims to investigate the inhibition effect of plantain extract on mild steel corrosion. Design/methodology/approach The inhibition influence of plantain extract on mild steel corrosion was investigated through Tafel polarization, electrochemical impedance spectroscopy and weight loss techniques in 1 M HCl solution. Furthermore, the sample surface morphology was verified by scanning electron microscopy. Findings The inhibition effect of the plantain extract was increased with the increase in the inhibitor concentration due to its adsorption on the surface of samples. The adsorption mechanism of the plantain extract on mild steel is physical adsorption and follows Langmuir isotherm. Originality/value The results obtained from different methods showed that the plantain extract has good inhibition performance on corrosion mild steel in 1 M HCl solution as a green inhibitor.

scholarly journals Acid Corrosion Inhibition and Adsorption Behaviour of Ethyl Hydroxyethyl Cellulose on Mild Steel Corrosion

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
I. O. Arukalam ◽  
I. O. Madu ◽  
N. T. Ijomah ◽  
C. M. Ewulonu ◽  
G. N. Onyeagoro
Keyword(s):  
Mild Steel ◽  
Molecular Orbital ◽  
Corrosion Inhibition ◽  
Density Functional ◽  
Inhibition Efficiency ◽  
Acid Corrosion ◽  
Hydroxyethyl Cellulose ◽  
Chemical Calculation ◽  
Free Energy Of Adsorption ◽  
Ethyl Hydroxyethyl Cellulose

The corrosion inhibition of mild steel in 1.0 M H2SO4 solution by ethyl hydroxyethyl cellulose has been studied in relation to the concentration of the additive using weight loss measurement, EIS, polarization, and quantum chemical calculation techniques. The results indicate that EHEC inhibited corrosion reaction in the acid medium and inhibition efficiency increased with EHEC concentration. Further increase in inhibition efficiency is observed in the presence of iodide ions, due to synergistic effect. Impedance results reveal that EHEC is adsorbed on the corroding metal surface. Adsorption followed a modified Langmuir isotherm, with very high negative values of the free energy of adsorption (ΔGads). The polarization data indicate that the inhibitor was of mixed type, with predominant effect on the cathodic partial reaction. The frontier molecular orbitals, HOMO (the highest occupied molecular orbital) and LUMO (the lowest unoccupied molecular orbital) as well as local reactivity of the EHEC molecule, were analyzed theoretically using the density functional theory to explain the adsorption characteristics at a molecular level. The theoretical predictions showed good agreement with experimental results.

Inhibition of acid corrosion of mild steel by aqueous nettle extracts

2014 ◽  
Vol 43 (3) ◽  
pp. 127-138 ◽  
Author(s):  
Aida Zaabar ◽  
Razika Aitout ◽  
Laid Makhloufi ◽  
Kamel Belhamel ◽  
Boualem Saidani
Keyword(s):  
Mild Steel ◽  
Corrosion Inhibitor ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Physical Adsorption ◽  
Acid Corrosion ◽  
Critical Concentration ◽  
Healthy Plant ◽  
Content Type ◽  
First Time

Purpose – The aim of this research was to investigate the use of aqueous extracts of nettle plant (NE) as a green corrosion inhibitor of mild steel in hydrochloric acid solution. Design/methodology/approach – The inhibition efficiency was investigated by weight loss measurements, potentiodynamic polarizations, electrochemical impedance spectroscopy, SEM observations and EDX analysis. Findings – The inhibition efficiency increased with an increase in concentration of NE up to a critical concentration of 1.5×10−3 g · cm−3 where the highest inhibition efficiency of 97 percent was obtained. The adsorption of the inhibitor was spontaneous (reflected by the negative value of ΔGads0), supported the mechanism of physical adsorption and obeyed to the Langmuir adsorption isotherm. The inhibition action of the extracts was independent on the storage time; it could be conserved without any specific conditions of time and temperature. Research limitations/implications – The anticorrosion effect can be better understood when the active compound in the extracts is identified and what is the inhibition efficiency of one component in the presence of another in the mixture (synergetic or antagonist effects). Practical implications – Nettle is a healthy plant, without particular toxicity that can find possible applications as environmentally friendly inhibitor of mild steel used as materials in food industry. Originality/value – Aqueous nettle extracts were studied for the first time as corrosion inhibitor and its anticorrosion effect was proven by standard methods.

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