scholarly journals Theoretical study of a new oxazolidine -5- one derivative as a corrosion inhibitor for carbon steel surface

2021 ◽  
pp. 1396-1403
Author(s):  
Rehab Majed Kubba ◽  
Nada Mohammed Al-Joborry

A newly derivative of oxazolidin-5- one namely [2-(2-biphenyl-4-yl-imidazo [1,2-a] pyridine-3-yl)-3-(4-nitro-phenyl)-oxazolidin-5-one (BIPNO5)] was examined as an corrosion inhibitor for carbon steel surface. Quantum mechanical method of Density Functional Theory (DFT) with (B3LYP (6-311++G (2d, 2p)) level of theory was used to calculate the minimize structure, physical properties and inhibition chemical parameters, in vacuum and two solvents (DMSO and H2O), all at equilibrium geometry. The results indicated that the new derivative could adsorb on the surface of carbon steel through the heteroatom, showing that the new inhibitor has good corrosion inhibition performance.

2021 ◽  
Vol 18 (1) ◽  
pp. 0113
Author(s):  
Rehab Majid Kubba ◽  
Mustafa Alaa Mohammed ◽  
Luma S. Ahamed

A theoretical and protection study was conducted of the corrosion behavior of carbon steel surface with different concentrations of the derivative (Quinolin-2-one), namly (1-Amino-4,7-dimethyl-6-nitro-1H-quinolin-2-one (ADNQ2O)). Theoretically, Density Functional Theory (DFT) of B3LYP/ 6-311++G (2d, 2p) level was used to calculate the optimized geometry, physical properties and chemical inhibition parameters, with the local reactivity to predict both the reactive centers and to locate the possible sites of nucleophilic and electrophilic attacks, in vacuum, and in two solvents (DMSO and H2O), all at the equilibrium geometry. Experimentally, the inhibition efficiencies (%IE) in the saline solution (of 3.5%) NaCl were studied using potentiometric polarization measurements. The results revealed that the (%IE) for carbon steel corrosion by ADNQ2O is (89.88%). The obtained thermodynamic parameters support the physical adsorption mechanism. The adsorption followed the Langmuir isotherm. The surface change on carbon steel was studied using SEM (Scanning Electron Microscopy).


2019 ◽  
Vol 13 (1) ◽  
pp. 4434-4448
Author(s):  
R. Nanthini ◽  
M. I. Mutalib

This corrosion study assessed the inhibition performance of carbon steel in 1 M of hydrochloric acid (HCl) using Good’s buffer ionic liquids (GBIL) namely 1-Butyl-3-methylimidazolium 2-(N-Morpholino) propane, [BMIM][MOPS] using electrochemical impedance, potentiodynamic polarization, and weight loss (gravimetric) measurements. GBIL are synthesized by the combination of Good's buffer as anion and various organic bases as the cation. The gravimetric measurements exhibit higher reduction in weight for carbon steel exposed to the acidic environment in the absence of corrosion inhibitor (CI) as compared to carbon steel immersed in the presence of inhibitor molecule. Potentiodynamic polarization study indicates that the synthesized inhibitor acted as a mixed type inhibitor. The inhibition efficiency increases with increase in the concentration of [BMIM][MOPS]. Corrosion protection efficiency ranging from 88% to 90% was featured at 800 ppm of CI in the HCl medium. The adsorption of [BMIM][MOPS] on the carbon steel surface was described by the Langmuir's adsorption isotherm. The scanning electron micrographs inspected the morphology of the carbon steel surface exposed to the solution without and with the presence of inhibitor. The result showed that compound effectively suppressed corrosion by the appearance of an improved surface structure of carbon steel with increasing concentration of [BMIM][MOPS].


2020 ◽  
pp. 1842-1860
Author(s):  
Nada Mohammed Al-Joborry ◽  
Rehab Majed Kubba

A new imidazolidine 4-one derivative, of namly 2-[2-(4-Bromo-phenyl)-imidazo [1,2-a] pyridine-3-yl]-3-(4-nitro-phenyl)-imidazolidine-4-one (BPIPNP) was investigated as corrosion inhibitor for carbon steel in salty (3.5% NaCl) and acidic (0.5M HCl) solutions using potentiometric polarization measurements. The results revealed that the percentage inhibition efficiencies (%IE) in the salty solution (90.67%) are greater than that in the acidic solution (83.52%). Experimentally, the thermodynamic parameters obtained have supported a physical adsorption mechanism and which followed Langmuir adsorption isotherm. Density Functional Theory (DFT) of quantum mechanical method with B3LYP 6-311++G (2d, 2p) level was used to calculate geometrical structure, physical properties and inhibition efficiency parameters, in vacuum and two solvents (DMSO and H2O), all at the equilibrium geometry. The surface changes of carbon steel were studied using  Scanning Electron Microscopy SEM and Atomic Force Microscopy (AFM) techniques.


2018 ◽  
Vol 34 (6) ◽  
pp. 3016-3029 ◽  
Author(s):  
A. El-Yaktini ◽  
A. Lachiri ◽  
M. El-Faydy ◽  
F. Benhiba ◽  
H. Zarrok ◽  
...  

The inhibition ability of a new Azomethine derivatives containing the 8-hydroxyquinoline (BDHQ and MDHQ) towards carbon steel corrosion in HCl solution was studied at various concentrations and temperatures using weight loss, polarization curves and electrochemical impedance spectroscopy (EIS) methods. The experimental results reveal that BDHQ and MDHQ are efficient mixed type corrosion inhibitors, and their inhibition efficiencies increase with increasing concentration. The adsorption of these inhibitors on mild steel surface obeys Langmuir isotherm. Quantum chemical parameters are calculated using the Density Functional Theory method (DFT) and Monte Carlo simulations. Correlation between theoretical and experimental results is discussed.


2020 ◽  
pp. 2776-2796
Author(s):  
Rehab M Kubba ◽  
Nada M. Al-Joborry ◽  
Naeemah J. Al-lami

Two derivatives of Iimidazolidin 4-one (IMID4) and Oxazolidin 5-one (OXAZ5), were investigated as corrosion inhibitors of corrosion carbon steel in sea water by employing the theoretical and experimental methods. The results revealed that they inhibit the corrosion process and their %IE followed the order: IMID4 (89.093%) > OXAZ5 (80.179%). The %IE obtained via theoretical and experimental methods were in a good agreement with each other. The thermodynamic parameters obtained by potentiometric polarization measurements have supported a physical adsorption mechanism which followed Langmuir adsorption isotherm. Quantum mechanical method of Density Functional Theory (DFT) of B3LYP with a level of 6-311++G (2d, 2p) were used to calculate the geometrical structure, physical properties and inhibition efficiency parameters, in vacuum and two solvents (DMSO and H2O), all calculated at the equilibrium geometry, and correlated with the experimental %IE. The local reactivity has been studied through Mulliken charges population analysis. The morphology of the surface changes of carbon steel were studied using SEM and AFM techniques.


2016 ◽  
Vol 11 (1) ◽  
Author(s):  
Saprini Hamdiani ◽  
Jannatin Arduha ◽  
Agus Abhi Purwoko ◽  
Saprizal Hadisaputra

Abstrak. Sifat inhibitor korosi senyawa turunan thiaamida-pirazolindol (TP) telah dikaji menggunakan teori fungsional kerapatan pada tingkatan teori B3LYP/6-31G(d). Pengaruh gugus substitusi pendonor dan penarik elektron (NH2, SH, CHCH2, CH3, OH, CHO, COOH, F, NO2) terhadap efisiensi anti korosi senyawa thiaamida-pirazolindol juga dihitung. Parameter kuantum untuk senyawa anti korosi seperti energi orbital (EHOMO dan ELUMO), potensial ionisasi (I), afinitas elektron (A) dan elektronegativitas (χ) memiliki hubungan yang linier dengan efisiensi anti korosi (IE%) senyawa turunan thiaamida-pirazolindol. Gugus pendonor elektron meningkatkan nilai IE%. Urutan kenaikan IE% adalah NO2 < CHO < COOH < F < CHCH2 < OH < CH3 < NH2. Penambahan gugus pendonor elektron amina (NH2) meningkatkan IE% hingga 98,76 % dibandingkan IE% thiaamida-pirazolindol murni 90,80 %. Penambahan gugus penarik elektron menurunkan IE% hingga mencapai 82,82 %. Kajian teoritis ini akan berkontribusi besar dalam mendesain dan sintesis senyawa inhibitor organik dengan efisiensi inhibitor tinggi.Kata kunci: inhibitor korosi, teori fungsional kerapatan, thiaamida-pirazolindolAbstract. Corrosion inhibitor properties of thiamide pyrazolindole and its derivatives has been elucidated by means of density functional theory (DFT) at B3LYP/6-31G(d) level of theory. Effect of electron donating and withdrawing groups such as NH2, SH, CHCH2, CH3, OH, CHO, COOH, F and NO2 on the corrosion inhibitor of thiamide pyrazolindole derivatives also have been studied. The quantum chemical parameters such as the frontier orbital energies (EHOMO), ionization potential (I), electron affinity (A) and electronegativity (χ) are closely related to the corrosion inhibition efficiency (IE%) of thiamide pyrazolindole derivatives. The presence of electron donating groups increases IE% values meanwhile electron withdrawing groups reduce IE% values. The enhancement of IE% follows NO2 < CHO < COOH < SH < F < CH3 < CHCH2 < OH < NH2. Electron donating NH2 group gives 98,76 % of IE%, pure thiamide pyrazolindol IE% = 90,80 %. In contrast, electron withdrawing NO2 group gives IE% only 82,82 %. This theoretical study would have a significant contribution in designing high-efficiency organic corrosion inhibitors.Keywords: corrosion inhibitors, density functional theory, thiamide pyrazolindol


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