scholarly journals Aluminum corrosion inhibition by cefixime drug: experimental and DFT studies

2018 ◽  
Vol 8 (4) ◽  
pp. 303-320 ◽  
Author(s):  
N’guessan Yao Silvere Diki ◽  
Gildas K. Gbassi ◽  
Augustin Ouedraogo ◽  
Mohamed Berte ◽  
Albert Trokourey
Keyword(s):  
Mass Loss ◽  
Corrosion Inhibition ◽  
Density Functional ◽  
Solution Temperature ◽  
Aluminum Surface ◽  
Protective Film ◽  
Tafel Polarization ◽  
Quantum Chemical Methods ◽  
Aluminum Corrosion ◽  
Global And Local

Corrosion inhibition of aluminum in 1 M HCl by cefixime drug has been studied at 298-318 K using mass loss, Tafel polarization (at 298 K) and quantum chemical methods based on density functional theory (DFT) calculations. The results showed that inhibition efficiency increases up to 90.41 % with increase of the inhibitor concentration from 0.02 to 2 mM, but decreases with a rise of the solution temperature. Adsorption of cefixime molecules on the corroding aluminum surface obeys Langmuir adsorption isotherm and occurs spontaneously mostly through a physisorption process. The activation energy (Ea) as well as other thermodynamic parameters of the inhibition process are calculated and discussed. Potentiodynamic polarization data revealed that cefixime acts as mixed-type inhibitor and pointed out an agreement with mass loss results. Surface analysis is performed using scanning electron microscopy (SEM) which confirmed existence of a protective film of inhibitor molecules on the aluminum surface. In addition, global and local reactivity parameters of the studied molecule are analyzed and discussed. The computed results are found in agreement with experimental data.

scholarly journals Aluminum corrosion inhibition by cefixime drug: experimental and DFT studies

2018 ◽  
Author(s):  
N’guessan Yao Silvere Diki ◽  
Gildas K. Gbassi ◽  
Augustin Ouedraogo ◽  
Mohamed Berte ◽  
Albert Trokourey
Keyword(s):  
Mass Loss ◽  
Corrosion Inhibition ◽  
Density Functional ◽  
Solution Temperature ◽  
Aluminum Surface ◽  
Protective Film ◽  
Tafel Polarization ◽  
Quantum Chemical Methods ◽  
Aluminum Corrosion ◽  
Global And Local

<div><p><em>Corrosion inhibition of aluminum (Al) in 1 M HCl by cefixime drug has been studied at 298-318 K using mass loss , Tafel polarization (at 298 K) and quantum chemical methods based on density functional theory (DFT) calculations. The results showed that inhibition efficiency increases up to 90.41 % with increase of the inhibitor concentration from 0.02 to 2 mM, but decreases with a rise of the solution temperature. Adsorption of cefixime molecules on the corroding aluminium surface obeys Langmuir adsorption isotherm and occurs spontaneously mostly through a physisorption process. The activation energy (</em><em>) as well as other thermodynamic parameters of the inhibition process are calculated and discussed. Potentiodynamic polarization data revealed that cefixime acts as mixed-type inhibitor and pointed out an agreement with mass loss results. Surface analysis is performed using Scanning Electron Microscopy (SEM) which confirmed existence of a protective film of inhibitor molecules on the aluminum surface. In addition, global and local reactivity parameters of the studied molecule are analyzed and discussed. The computed results are found in agreement with experimental data.</em></p></div>

scholarly journals Aluminum Corrosion Inhibition by 7-(Ethylthiobenzimidazolyl) Theophylline in 1M Hydrochloric Acid: Experimental and DFT Studies

2018 ◽  
Vol 3 (04) ◽  
pp. 41-53 ◽  
Author(s):  
N’guessan Yao Silvère Diki ◽  
Gbe Gondo Didier Diomandé ◽  
Sagne Jacques Akpa ◽  
Augustin Ouédraogo ◽  
Lemeyonouin Aliou Guillaume Pohan ◽  
...  
Keyword(s):  
Hydrochloric Acid ◽  
Density Functional ◽  
Physical Adsorption ◽  
Basis Set ◽  
Aluminum Surface ◽  
Protective Film ◽  
Tafel Polarization ◽  
Hydrochloric Acid Medium ◽  
Aluminum Corrosion ◽  
Langmuir Isotherm Model

Inhibitive properties of 7-(ethylthiobenzimidazolyl) theophylline (7-ETBT) molecule for the corrosion of aluminum (Al) in one molar hydrochloric acid medium have been investigated using mass loss and Tafel polarization methods. The results suggest spontaneous and predominant physical adsorption of 7-ETBT on the metal surface which obeys Langmuir isotherm model. The studied inhibitor showed excellent inhibition efficiency up to 94.07 % at 298 K for its optimum concentration (2 mM). Moreover, Tafel polarization method revealed that 7-ETBT is a cathodic-type inhibitor. Further investigation on the morphology using scanning electron microscopy (SEM) has confirmed the existence of a protective film of inhibitor molecules on aluminum surface. Theoretical approach for the performance of 7-ETBT as Al corrosion inhibitor is also done using Density Functional Theory (DFT) level with B3LYP exchange correlation functional for 6-31G (d, p) basis set. The results provided by this theoretical study are consistent with the experimental data. All the results have shown an evidence of the effectiveness of the inhibitive effect of 7-ETBT on Al.

scholarly journals Spilanthes acmella Leaves Extract for Corrosion Inhibition in Acid Medium

Coatings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 106
Author(s):  
Akbar Ali Samsath Begum ◽  
Raja Mohamed Abdul Vahith ◽  
Vijay Kotra ◽  
Mohammed Rafi Shaik ◽  
Abdelatty Abdelgawad ◽  
...  
Keyword(s):  
Mild Steel ◽  
Corrosion Inhibition ◽  
Active Sites ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Film Formation ◽  
Protective Film ◽  
Surface Protection ◽  
Tafel Polarization ◽  
Spilanthes Acmella

In the present study, the corrosion inhibition effect of Spilanthes acmella aqueous leaves extract (SA-LE) on mild steel was investigated in 1.0 M HCl solution at different temperature using weight loss, Tafel polarization, linear polarization resistance (LPR), and electrochemical impedance (EIS) measurements. Adsorption of inhibitor on the surface of the mild steel obeyed both Langmuir and Temkin adsorption isotherms. The thermodynamic and kinetic parameters were also calculated to determine the mechanism of corrosion inhibition. The inhibition efficiency was found to increase with an increase in the inhibitor concentration i.e., Spilanthes acmella aqueous leaves extract, however, the inhibition efficiency decreased with an increase in the temperature. The phytochemical constituents with functional groups including electronegative hetero atoms such as N, O, and S in the extract adsorbed on the metal surface are found responsible for the effective performance of the inhibitor, which was confirmed by Fourier-transform infrared spectroscopy (FT-IR) and ultraviolet–visible spectroscopic (UV-Vis) studies. Protective film formation against corrosion was confirmed by scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle studies. The result shows that the leaves extract acts as corrosion inhibitor and is able to promote surface protection by blocking active sites on the metal.

Corrosion inhibition of aluminum by oxalate self-assembling monolayer

2019 ◽  
Vol 66 (6) ◽  
pp. 768-773 ◽  
Author(s):  
P. Satyabama ◽  
Susai Rajendran ◽  
Tuan Anh Nguyen
Keyword(s):  
Corrosion Inhibition ◽  
Potentiodynamic Polarization ◽  
Fluorescence Spectra ◽  
Electrochemical Impedance ◽  
Aluminum Surface ◽  
Protective Film ◽  
Content Type ◽  
Self Assembling ◽  
Uv Visible ◽  
Oxalate Ions

Purpose This paper aims to evaluate the inhibition efficiency (IE) of oxalate ions in controlling corrosion of aluminum at pH 10. Design/methodology/approach The IE has been determined by the classical weight loss method. The corrosion behavior of aluminum was investigated by using potentiodynamic polarization and electrochemical impedance measurements. Ultra violet (UV)-visible and Fluorescence spectra have been used to analyze the film formed on the aluminum surface after immersion. Findings The maximum IE was 88 per cent, which was offered by a mixture of 250 ppm oxalate ions and 50 ppm [Zn2+]. Potentiodynamic polarization data revealed that the protective film was formed on the metal surface. UV-visible and Fluorescence spectra indicated the presence of Al3+−oxalate complex in the protective film formed on aluminum substrate after immersion in [OX]/[Zn2+] solution. Originality/value The findings of this work shed more light on the corrosion inhibition of aluminum by oxalate self-assembling monolayers.

Spectroscopic investigations and DFT studies of synthesized 4-acetamidophenyl 3,4,5-trimethoxybenzoate and 4-acetyl phenyl 3,4,5-trimethoxybenzoate a novel conjugate of gallic acid

2020 ◽  
Vol 17 ◽  
Author(s):  
Sangeeta Srivastava ◽  
Nadeem Ahmad Ansari ◽  
Sadaf Aleem
Keyword(s):  
Gallic Acid ◽  
Density Functional ◽  
Energy Gap ◽  
Basis Set ◽  
Major Constituent ◽  
Orbital Energy ◽  
Reactivity Descriptors ◽  
Homo And Lumo ◽  
Electrophilic Reactivity ◽  
Global And Local

: Gallic acid is abundantly found in amla (Phyllanthus emblica), a deciduous of the family phyllanthaceae. Gallic acid, the major constituent of the plant was methylated to 3,4,5 trimethoxy gallic acid, which then underwent steglich esterification first with paracetamol and then with 4-hydroxy acetophenone to yield 4-acetamidophenyl 3,4,5-trimethoxybenzoate and 4-acetyl phenyl 3,4,5-trimethoxybenzoate “respectively”. 1H NMR, 13C NMR, UV, FT-IR and mass spectroscopy were used to characterize the synthesized compounds. Density functional theory (B3YLP) using 6-31G (d,p) basis set have been used for quantum chemical calculations. AIM (Atom in molecule) approach depicted weak molecular interactions within the molecules whereas the reactive site and reactivity within the molecule were examined by global and local reactivity descriptors. The HOMO and LUMO energies and frontier orbital energy gap were calculated by time dependant DFT approach using IEFPCM model. Small value for HOMO–LUMO energy gap indicated that easier charge transfer occurs within compound 4. The nucleophilic and electrophilic reactivity were determined by MEP (molecular electrostatic potential) experiment. Polarizability, dipole moment, and first hyperpolarizability values were calculated to depict the NLO (nonlinear optical) property of both the synthesized compounds. The antimicrobial activity was also carried out and broad spectrum antibacterial activity against several strains of bacteria and certain unicellular fungi were exhibited by synthesized compound 3.

scholarly journals Combined Experimental and Theoretical Insights into the Corrosion Inhibition Activity on Carbon Steel Iron of Phosphonic Acids

Molecules ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 135
Author(s):  
Aurelia Visa ◽  
Nicoleta Plesu ◽  
Bianca Maranescu ◽  
Gheorghe Ilia ◽  
Ana Borota ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Corrosion Inhibition ◽  
Density Functional ◽  
Energy Gap ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Phosphonic Acids ◽  
Transfer Resistance ◽  
Potential Map ◽  
Chlorine Ions

The inhibition effect of N,N′-phosphonomethylglycine (PMG) and vinyl phosphonic acid (VPA) on the 3% NaCl acidic solution corrosion of carbon steel iron was studied at different immersion times by potentiodynamic polarization, electrochemical impedance spectroscopy, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, and computational methods. It is found from the polarization studies that PMG and VPA behave as mixed-type inhibitors in NaCl. Values of charge transfer resistance (Rct) and double layer capacitance (Cdl) in the absence and presence of inhibitors are determined. The PMG and VPA inhibitors were capable of inhibiting the corrosion process up to ≈91% and ≈85%, respectively. In the presence of PMG, the synergic effect of chlorine ions was observed. Density functional theory (DFT) was engaged to establish the adsorption site of PMG, VPA, and their deprotonated states. For studied compounds, the resulted values of ELUMO, EHOMO, energy gap (∆E), dipole moment (μ), electronic hardness (η), global softness (σ), electrophilic index (ω), and the electronic potential map are in concordance with the experimental data results regarding their corrosion inhibition behavior and adsorption on the metal surface.

scholarly journals Mannich Base as Corrosion Inhibitors for N80 Steel in a CO2 Saturated Solution Containing 3 wt % NaCl

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 449 ◽  
Author(s):  
Mingjin Tang ◽  
Jianbo Li ◽  
Zhida Li ◽  
Luoping Fu ◽  
Bo Zeng ◽  
...  
Keyword(s):  
Corrosion Inhibitor ◽  
Corrosion Inhibition ◽  
Steel Sheet ◽  
Mannich Base ◽  
Saturated Solution ◽  
Control Group ◽  
Protective Film ◽  
Blank Control Group ◽  
Inhibition Effect ◽  
N80 Steel

In this paper, a corrosion inhibitor containing nitrogen atoms and a conjugated π bond was synthesised, and its final product synthesised by the optimal conditions of the orthogonal test results is named multi-mannich base (MBT). The corrosion inhibition effect on the N80 steel sheet of the corrosion inhibitor was evaluated in a CO2 saturated solution containing 3 wt % NaCl; the corrosion rate was 0.0446 mm/a and the corrosion inhibition rate was 90.4%. Through electrochemical and adsorption theory study, MBT is a mixed corrosion inhibitor that mainly shows cathode suppression capacity. The adsorption of MBT on the surface of the steel sheet follows the Langmuir adsorption isotherm; it can be spontaneously adsorbed on the surface of the N80 steel sheet, which has a good corrosion inhibition effect. The surface of the N80 steel sheet was microscopically characterised by atomic force microscope (AFM). It can be seen from the results that the N80 steel sheet with MBT added is significantly different from the blank control group; the surface of the steel sheet is relatively smooth, indicating that MBT forms an effective protective film on the surface of N80 steel, which inhibits the steel sheet.

Investigation of corrosion inhibition of C38 steel in 5.5 M H3PO4 solution using Ziziphus lotus oil extract: an application model

2019 ◽  
Vol 66 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Walid Belmaghraoui ◽  
Aimad Mazkour ◽  
Hicham Harhar ◽  
Mourad Harir ◽  
Souad El Hajjaji
Keyword(s):  
Carbon Steel ◽  
Corrosion Inhibition ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Electric Circuit ◽  
Oil Composition ◽  
Content Type ◽  
Tafel Polarization ◽  
Chemical Content ◽  
Oil Extract

Purpose This study aims to investigate the corrosion inhibition effect of extracted oil from Ziziphus lotus fruit on corrosion of C38 carbon steel in 5.5 M H3PO4 solution using potentiodynamic polarization and impedance techniques. Design/methodology/approach Oil composition was determined using gas chromatography, and the results showed that oleic and palmitic acids present approximately 84.0 per cent of its total chemical content. Electrochemical impedance spectroscopy (EIS) data were analyzed by adapting it to a well-developed electric circuit model. The inhibition efficiency of Z. lotus oil was calculated and compared using Tafel polarization and EIS. Findings Accordingly, the oil extract was found to act as an anodic type inhibitor. Furthermore, inhibition efficiency of Z. lotus oil extract increase with oil concentrations and achieve approximately 70.5 per cent at 3 g/L solution of Z. lotus oil. Originality/value The results obtained from different tested methods were in line, and the oil was able to reduce significantly the kinetics of the corrosion process of C38 carbon steel.

Effect of Chlorine Atoms for Development of Aluminum Corrosion

2016 ◽  
Vol 879 ◽  
pp. 2170-2174 ◽  
Author(s):  
Junko Yamashita ◽  
Norio Nunomura
Keyword(s):  
Density Functional ◽  
Charge Density Distribution ◽  
High Coverage ◽  
Functional Theory ◽  
Chlorine Atoms ◽  
Structural And Electronic Properties ◽  
Aluminum Corrosion ◽  
Dft Model ◽  
Low Coverage ◽  
Effect Of Chlorine

Computational density functional theory (DFT) model of the adsorption of chlorine atoms onto the perfect Al (111) surface has been performed. The structural and electronic properties of chlorine atoms adsorbed on the surface are investigated within a supercell approach for chlorine coverages of 0.25, 0.33, 0.5 and 1 ML respectively. It is found that the adsorbates prefer on-top sites over bridge, hcp and fcc sites in low coverage while fcc sites in high coverage, and the binding energy decrease with increase of coverage due to the interactions of chlorine atoms. The discussion of geometrical and electronic analysis by plotting differential charge density distribution and projected density of states (PDOS) are presented.

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