scholarly journals Electrochemical and quantum chemical parameters of (-)-(S)-9-flu¬oro-2,3-dihydro-3-methyl-10-(4-methyl-1-pipera-zinyl)-7-oxo-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acidas anti-corrosive agent for API 5L X-52 steel

2020 ◽  
Vol 10 (3) ◽  
pp. 234-244
Author(s):  
Fidelis Ebunta Abeng ◽  
Magdalene Edet Ikpi ◽  
Victor E. Okpashi ◽  
Onumashi A. Ushie ◽  
Mbang E. Obeten

The inhibitive action of (-)-(S)-9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-7-oxo-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid (Levaquin) on API 5L X-52 steel in 2 M HCl solution was investigated using potentiodynamic polarization method and quantum chemical study. Levaquin drug showed good inhibition efficiency of 88 and 95 % at 303 and 323 K, respectively. The results of experimental measurements revealed that Levaquin drug works as a mixed type inhibitor. Langmuir thermodynamic model was tested to describe the mode of inhibitor adsorption on the steel surface. The quantum chemical calculations confirmed the efficacy of Levaquin drug as a corrosion inhibitor.

2019 ◽  
Vol 2 (1) ◽  
pp. 88
Author(s):  
Saprizal Hadisaputra ◽  
Zohrul Iskandar ◽  
Dina Asnawati

This study aims to determine the the efficiency of corrosion inhibition of imidazole derivatives in carbon steel based on quantum chemical parameters. Density functional theory method was applied in this study. Corrosion inhibition efficiency values ​​are strongly influenced by substituent groups. Corrosion inhibition efficiency values ​​have a linear correlation with quantum chemical parameters. The amine substituent increased the value of corrosion inhibition efficiency, in contrast nitro group reduced the efficiency of corrosion inhibition. The predicted corrosion inhibition efficiency data of imidazole does agree with the experimental data.  


2009 ◽  
Vol 6 (3) ◽  
pp. 785-795 ◽  
Author(s):  
R. Saratha ◽  
S. V. Priya ◽  
P. Thilagavathy

The inhibition efficiency of acid extract of leaves ofCitrus aurantiifolia[CAL] plant on the corrosion of mild steel in 1 M HCl was investigated by weight loss measurements and electrochemical studies. The corrosion rate of mild steel and the inhibition efficiencies of the extract were calculated. The results obtained show that the extract could serve as an effective inhibitor for the corrosion of mild steel in HCl media. Inhibition was found to increase with increasing concentration of the plant extract. The inhibitive action of plant extract is discussed on the basis of adsorption of stable complex at the mild steel surface. Theoretical fitting of different isotherms, Langmuir, Temkin, Freundlich, Frumkin, Flory-Huggins and the kinetic thermodynamic model, were tested to clarify the nature of adsorption. Polarisation curves revealed that this inhibitor act as a mixed type inhibitor and the inhibition efficiency of up to 97.91% can be obtained. The surface analysis study confirms the corrosion of mild steel and its inhibition by the inhibitor CAL.


Author(s):  
Ismail Fahim ◽  
Malika Tridane ◽  
Said Belaaouad

The corrosion inhibition of mild steel in 1 M HCl solution by some dihydropyridine has been studied using gravimetric, electrochemical impedance spectroscopy, potentiodynamic polarization techniques and quantum chemical study. The results of weight loss and Tafel polarization measurements showed that among the studied compounds, Isradipine has good inhibiting properties for steel corrosion in acidic bath, with 98% inhibition efficiency at optimum concentration 400ppm. The inhibition is of a mixed anodic–cathodic nature. The adsorption behaviour of the investigated compounds is found to obey Langmuir adsorption isotherm. Quantum chemical parameters, were correlated with the experimental results.


2018 ◽  
Vol 59 (1) ◽  
pp. 51-53
Author(s):  
M. V. Makarova ◽  
◽  
S. G. Semenov ◽  
R. R. Kostikov ◽  
◽  
...  

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