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Hansol Lee

Bio: Hansol Lee is an academic researcher. The author has contributed to research in topics: Adsorption & Chemistry. The author has an hindex of 2, co-authored 7 publications receiving 7 citations.

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TL;DR: In this paper , four 4-oxo-1,4-dihydroquinoline-3-carboxylate derivatives were synthesized through the Gould-Jacobs method and evaluated as corrosion inhibitors for 1020 mild steel in 1 mol/L hydrochloric acid.

3 citations

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TL;DR: In this article , two compounds of isonicotinohydrazide organic class, namely (E)-N′-(1-(4-(dimethylamino)phenyl)ethylidene) isonic-drugs (MAPEI) and (Z)- N′-(2-oxo-2, 3-dihydro-1H-inden-1-ylidene), were synthesized and evaluated for corrosion protection of N80 steel in a concentrated acidic medium (15 wt% HCl) at a temperature of 303 K.
Abstract: In this work, two compounds of isonicotinohydrazide organic class, namely (E)-N′-(1-(4-(dimethylamino)phenyl)ethylidene) isonicotinohydrazide (MAPEI) and (Z)-N′-(2-oxo-2, 3-dihydro-1H-inden-1-ylidene) isonicotinohydrazide (OHEI) were synthesized and evaluated for corrosion protection of N80 steel in a concentrated acidic medium (15 wt.% HCl) at a temperature of 303 K. The weight loss method (gravimetric method) and electrochemical techniques, i.e., electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization curves (PPC), were used to evaluate the inhibition and adsorption characteristics of tested compounds. Further, surface characterization using a scanning electron microscope (SEM) was used to assess the surface morphology of steel before and after inhibition. Weight loss experiments at 303 K and 363 K showed that tested compounds’ performance decreased with the increase in temperature, particularly at low concentrations of inhibitors whereas they exhibited good stability at higher concentrations. Electrochemical tests showed that MAPEI and OHEI inhibitors were effective at 5 × 10−3 mol/L, reaching an inhibition efficiency above 90%. It was also determined that the adsorption of both inhibitors followed the Langmuir adsorption isotherm model. Furthermore, SEM analysis showed that the investigated compounds can form a protective layer against steel corrosion in an acidic environment. On the other hand, the corrosion inhibition mechanism was established from density functional theory (DFT), and the self-consistent-charge density-functional tight-binding (SCC-DFTB) method which revealed that both inhibitors exerted physicochemical interactions by charge transfer between the s- and p-orbitals of tested molecules and the d-orbital of iron. The results of this work are intended to deepen the research on the products of this family to control the problem of corrosion.

1 citations

Journal ArticleDOI
TL;DR: In this paper , the performance of two pyridine oximes with the iron surface was investigated using molecular dynamics (MD), and self-consistent charge density-functional tight-binding (SCC-DFTB) simulations.
Abstract: The development of corrosion inhibitors with outstanding performance is a never-ending and complex process engaged in by researchers, engineers and practitioners. The computational assessment of organic corrosion inhibitors’ performance is a crucial step towards the design of new task-specific materials. Herein, the electronic features, adsorption characteristics and bonding mechanisms of two pyridine oximes, namely 2-pyridylaldoxime (2POH) and 3-pyridylaldoxime (3POH), with the iron surface were investigated using molecular dynamics (MD), and self-consistent-charge density-functional tight-binding (SCC-DFTB) simulations. SCC-DFTB simulations revealed that the 3POH molecule can form covalent bonds with iron atoms in its neutral and protonated states, while the 2POH molecule can only bond with iron through its protonated form, resulting in interaction energies of −2.534, −2.007, −1.897, and −0.007 eV for 3POH, 3POH+, 2POH+, and 2POH, respectively. Projected density of states (PDOSs) analysis of pyridines–Fe(110) interactions indicated that pyridine molecules were chemically adsorbed on the iron surface. Quantum chemical calculations (QCCs) revealed that the energy gap and Hard and Soft Acids and Bases (HSAB) principles were efficient in predicting the bonding trend of the molecules investigated with an iron surface. 3POH had the lowest energy gap of 1.706 eV, followed by 3POH+ (2.806 eV), 2POH+ (3.121 eV), and 2POH (3.431 eV). In the presence of a simulated solution, MD simulation showed that the neutral and protonated forms of molecules exhibited a parallel adsorption mode on an iron surface. The excellent adsorption properties and corrosion inhibition performance of 3POH may be attributed to its low stability compared to 2POH molecules.
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TL;DR: A new imine derivative, namely 4-amino-2-((2,4 dihydroxybenzylidene)amino)-4 oxobutanoic acid (ADAO), was synthesized, characterized, and evaluated as a corrosion inhibitor for carbon steel (CS) in 1.0 mol/L HCl as discussed by the authors .

Cited by
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TL;DR: In this paper , a quantitative structure-property relationship (QSPR) method has been used to analyze the corrosion inhibition properties of furan derivative inhibitors against mild steel using DFT at B3LYP/6-31 G(d).
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TL;DR: In this paper , the effects of different titanium currents on the structure, mechanical properties, and friction properties of the films were investigated by SEM, Raman spectroscopy, and nanoindentation.
Abstract: To meet the requirements of friction and corrosion resistance performance of helicopter transmission bearings under harsh environments, Ti/TiN/Ti-DLC multilayer composite films were prepared on a 40Cr15Mo2VN substrate by a non-equilibrium magnetron sputtering technique. The effects of different titanium currents on the structure, mechanical properties, and friction properties of the films were investigated by SEM, Raman spectroscopy, and nanoindentation. Moreover, the tribological and corrosion resistance of developed films under acidic conditions were investigated. The results show that the sp3-C/sp2-C ratio in the films gradually decreases with increasing Ti current from 0 A to 2 A, leading to decreased hardness and elastic modulus. The bonding force of the DLC films also gradually increases with increasing Ti current and reaches the maximum value of 41.69 N at 2 A; the friction coefficient of the films gradually decreases under a load of 20 N. In summary, the best performance of thin film at Ti-2 A was compared with the corrosion and wear performance of thin film and substrate in acetic acid solution and aqueous solution at Ti-2 A. The wear amount of thin film and substrate in aqueous solution is significantly lower than in acetic acid solution, and the corrosion potential of thin film is higher than that of substrate in both solutions, which can play a protective role against the substrate.
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TL;DR: In this paper , three 2-(2-pyridyl)benzothiazole derivatives were synthesized for their potentiality to impart corrosion resistance to mild steel exposed to 1 M aqueous HCl.
Abstract: Three new 2-(2-pyridyl)benzothiazole derivatives, namely 2-(benzothiazol-2-yl)pyridin-3-amine (APYBT), 2-(benzothiazol-2-yl)pyridin-5-ol (HPYBT) and 2-(pyridin-2-yl)benzothiazole (PYBT), have been synthesized. Those are tested for their potentiality to impart corrosion resistance to mild steel exposed to 1 M aqueous HCl. Both electrochemical and gravimetric experiments establish the studied benzothiazole (BT) derivatives as promising corrosion inhibitors, with APYBT standing out as the most effective one exerting more than 97% inhibition efficiency at 1 mM concentration. PYBT exerts the least inhibitory performance. The electron donating property of the amine group present on the pyridine moiety in APYBT could be responsible for the superiority of APYBT as a corrosion inhibitor among the three. A potentiodynamic polarization study revealed that the inhibitors could retard both the cathodic and anodic reactions. The adsorption of the inhibitors on metal surfaces follows the Langmuir adsorption isotherm. SEM images provide visual confirmation of the protection of mild steel surfaces from corrosion in the presence of the studied benzothiazole (BT) derivatives. The interaction pattern between the mild steel and the inhibitors is explored using results derived from density functional theory (DFT) calculations. Variation of the interaction energy as obtained from molecular dynamics (MD) simulation confirms the corrosion inhibitory trend. Fukui index calculation enables the role played by the substituent group towards the relative electron donation/acceptance properties of the atoms present at the different parts of the inhibitor molecule.
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TL;DR: In this paper , a novel approach that combines machine learning (ML) and density functional theory (DFT) methods to construct a quantitative structure-properties relationship (QSPR) model for diazine derivatives as anti-corrosion inhibitors was proposed.
Abstract: This study proposes a novel approach that combines machine learning (ML) and density functional theory (DFT) methods to construct a quantitative structure-properties relationship (QSPR) model for diazine derivatives as anti-corrosion inhibitors. A dataset is constructed by combining three existing diazine isomer datasets to represent diazine compounds. Thirty-two different ML algorithms were implemented on the dataset, and the gradient boosting regressor (GBR) model was identified as the best predictive model for diazine and each isomer dataset based on the coefficient of determination (R2) and root mean square error (RMSE) metric values. This consistency was also observed when the GBR model was implemented on four other diazine derivatives, resulting in high corrosion inhibition efficiency (CIE) values ranging from 85.02% to 94.99%. The DFT calculations for these derivatives also showed strong adsorption energies ranging from -4.41 to -6.09 eV, in line with the CIE trend obtained from the ML prediction. This novel approach can provide insights into the properties of prospective organic corrosion inhibitors prior to experimental investigations, which could accelerate the development of new and effective organic corrosion inhibitors.