A pumping station located in the Moulouya River in Morocco, Northern Africa suffered from extensi... more A pumping station located in the Moulouya River in Morocco, Northern Africa suffered from extensive corrosion damage. Therefore, in this paper, the inhibition efficiency of Cetamine (CE) for mild steel exposed in water of Moulouya River was examined. This study was performed using electrochemical measurements and surface analysis. The results of potentiodynamic polarization measurements indicated that the CE compound classifies as a cathodic inhibitor type for 500 and 700 ppm, while it acts as a mixed inhibitor type at 1000 ppm CE. It is obtained also that the inhibition efficiency increases with CE concentrations to reach an optimum value of 98% at 1000 ppm CE. In addition, the impedance spectroscopy measurements indicated that this behavior can be explained by the formation of a protective film on the electrode surface. However, this study showed that the CE product takes its performance against aggressive water under various conditions (high Cl − concentration ions, electrode rotation rate, temperature, and immersion time).
Normal 0 21 false false false FR X-NONE AR-SA Manganese dihydrogen orthophosphate dihydrate Mn (H... more Normal 0 21 false false false FR X-NONE AR-SA Manganese dihydrogen orthophosphate dihydrate Mn (H 2 PO 4 ) 2 .2H 2 O was synthesized by solution co-precipitation method and characterized through single crystal X-ray diffraction, FT-IR and Raman spectroscopy. It crystallizes within monoclinic P 2 1 /n space group, with unit cell parameters a = 5.3733(3) A…, b = 10.1700(7) A…, c = 7.3106(5) A… and I² = 94.786(7) °: the least–square refinement converged to final agreement factors R 1 =0.0200 and wR 2 =0.0548 (I>2 Iƒ (I obs )). The three-dimensional network of the structure is made up by the repetition down (101) plane of layers of Mn octahedra and P tetrahedra joint together via vertex sharing. Strong O-H…O hydrogen bonds interconnect the layers, concurring to fix the network; such interactions were also investigated, as well as the whole structure, by means of infrared and Raman spectroscopy. Last, the corrosion inhibition for ordinary mild steel in simulated cooling water was investigated by this compound using electrochemical measurements . The results showed that it acts as a corrosion inhibitor and their inhibition efficiencies depend to its concentration.
A two non-toxic biodegradable epoxy glucose derivatives, namely 5,6-anhydro-3-O-octa-1,2-O-isopro... more A two non-toxic biodegradable epoxy glucose derivatives, namely 5,6-anhydro-3-O-octa-1,2-O-isopropyli-dene-α-D-glucofuranose (EGC8) and 5,6-anhydro-3-O-butadecyl-1,2-O-isopropylidene-α-D-glucofuranose (EGC14), were prepared and characterized by using spectroscopic measurements. These products were tested for mild steel corrosion inhibition in 1.0 M HCl using electrochemical measurements. It is shown that these epoxy glucose derivatives affect the cathodic branches with a shift in the cathodic direction (cathodic - type). So, it found that their inhibition efficiency arise with concentrations to achieve a maximum of 93.2 % and 93.48 % at 10-3 M of EGC8 and EGC14, respectively, and they depends to the carbon number chain following the order : EGC14 > EGC8. Indeed, it is found that these compounds adsorb according the Langmuir’s adsorption isotherm. On the other hand, the temperature effect on the inhibition efficiency of the epoxy glucose derivatives indicated that they take them ...
The inhibition ability of ethyl 6-amino-5-cyano-2-methyl-4-phenyl-4H-pyran-3-carboxylate (Pr3) on... more The inhibition ability of ethyl 6-amino-5-cyano-2-methyl-4-phenyl-4H-pyran-3-carboxylate (Pr3) on low low carbon steel (LCS) in 1.0 M HCl solution was studied by electrochemical techniques. Pr3 inhibited low low carbon steel corrosion in 1.0 M HCl solution significantly and the inhibition efficiency increased with Pr3 concentration. Polarization measurements indicated that, the studied inhibitor acts as mixed-type inhibitor. Phenomenon of physical and chemical adsorption is proposed for the inhibition and the process followed the Langmuir adsorption isotherm and kinetic / thermodynamic model of El-Awady et al. Correlations between the quantum chemical parameters (EHOMO, ELUMO, the energy gap, global hardness, global softness, Mulliken charges were calculated and Fukui index) and experimentally determined inhibition efficiency have been carried out and discussed.
This work proposes initially to identify the initial conceptions of Moroccan students in the firs... more This work proposes initially to identify the initial conceptions of Moroccan students in the first year of secondary college about the notion of earthquakes. The used methodology is based on a questionnaire addressed to students of life science and Earth in Meknes city, before any official teaching about the said phenomenon. The obtained results showed that despite the non-responses, the majority of respondents have less accurate initial conceptions for earthquakes notion, and does not correctly write their answers, they are enough to write snippets of sentences and do not use scientific words. The student’s conceptions seem marked by the earthquakes effects. However, we have identified correlations between the initial conceptions of Moroccan students and those of other French, Turks and Tunisians students. Keywords: Initial designs, Concepts earthquakes, college Secondary cycle, Correlation.
Abstract Nichel-Phosphorus (Ni-P) coatings are deposited on mild steel by using an electroless pl... more Abstract Nichel-Phosphorus (Ni-P) coatings are deposited on mild steel by using an electroless plating process. The effect of three calix[4]arene derivatives, namely tetra methyl ester-P-tertbutyl calix[4]arene (Calix1), tetra acid-P-tertbutyl calix[4]arene (Calix2) and tetra methyl P-tert-butyl-thicalix[4]arene ester (Calix3) on the deposition rate, the deposit composition, and the morphological surface was investigated and the study of growth mechanisms has delivered useful information about the surface properties of deposit. It is found that these additives modify the deposition rate and the nickel crystallization process. In fact, the Calix1 and Calix3 act as an accelerator, while Calix2 acts as an inhibitor for the nickel electroless. Furthermore, it is shown that the chemical bath is more stable with calix[4]arene derivatives addition and the obtained deposits are compact and adherent. It is observed also that the nickel content increases with additives. On the other hand, the X-ray diffraction showed that the orientation peaks are intensified at {111} in the presence of Calix2, confirming obtained results of EDAX spectrum. The cyclic voltammetry revealed that the tested additives strongly influence the cathodic process and slightly affect the hypophosphite oxidation. Finally, it is found that these compounds improve the anticorrosion efficiency of Ni-P coating on the mild steel substrate in 3%(mass) NaCl, where its polarization resistance increases with Calix2 and Calix3 addition.
New Challenges and Industrial Applications for Corrosion Prevention and Control, 2020
In this study, scale inhibition performance Trisodium citrate (TSC) was studied using static scal... more In this study, scale inhibition performance Trisodium citrate (TSC) was studied using static scale inhibition method, and its corrosion inhibition performance was also investigated by weight loss method and electrochemical measurement. Result showed that TSC could form a layer of corrosion and scale produTSC on mild steel surface in synthetic cooling water. Its inhibition increases with concentration and reaches a maximum of 89% and 95% at 10-3 M for corrosion and scale, respectively. It is noted that TSC takes its inhibition at high temperature and act by physic-sorption process. It is found that the TSC obey to the Langmuir isotherm. Scanning electron microscopy (SEM) showed that TSC inhibits the scale and corrosion by the formation of a protective layer on the mild steel surface.
The work presented the corrosion inhibition potency of the sodium gluconate and trisodium citrate... more The work presented the corrosion inhibition potency of the sodium gluconate and trisodium citrate against the corrosion of low carbon steel and revealed that the TSC can be more preferment than the SG molecule. In addition to experimental investigation of the corrosion inhibition capacity of the SG and TSC molecules, the quantum chemical calculations were performed by B3LYP, B3LYP-GD3BJ and M06HF functionals at three basis sets that are 6-31g(d,p), 6-311g(d,p) and 6-311++g(3df, 2pd) basis sets. The global hardness values revealed that the TSC molecule could be preferable to the SG molecule in using the design of the corrosion inhibitor materials because the SG (2.81 eV) was calculated a harder molecule than the TSC (2.70 eV). Molecular dynamic simulations were performed to investigate metal-inhibitor interactions.
New Challenges and Industrial Applications for Corrosion Prevention and Control, 2020
This chapter studies the operational parameters effects, such as immersion time, corrosion produc... more This chapter studies the operational parameters effects, such as immersion time, corrosion products, and pH, on the inhibition efficiency against corrosion for low carbon steel in simulated cooling water system of the mixture 1 (10-3 M 3-MPOX + 20 ppm CTAB), which corresponds to the best inhibition efficiency. The results show that the corrosion inhibition performance of the studied mixture reinforces with immersion time and has a maximum in the pH range 6.5–7.5. In addition, the analysis of the results shows that there is a dependence of the pH value of the solution and the corrosion current density (icorr). Indeed, a correlation can be established between log (icorr) and the pH using the polynomial equation. Finally, the mixture 1 provides good protection for the attack materials. These studies were evaluated from the polarization curves (PP), electrochemical impedance spectroscopy (EIS).
International Journal of Industrial Chemistry, 2020
The micro-structural effects on the corrosion resistance of three classes of mild steels (A, B an... more The micro-structural effects on the corrosion resistance of three classes of mild steels (A, B and C) suitable for galvanizing industry, according to their silicon, phosphorus content, grain number and size of carbides (Fe 3 C) in concentrated hydrochloride acid solution was investigated by a series of known techniques, such as potentiodynamic polarization curves, electrochemical impedance spectroscopy measurements, optical microscope and scanning electron microscopy. Results showed that the corrosion rate of the three classes of mild steel depends on their silicon and silicon/phosphorus combinations contents. It is found also that the corrosion rate depends on grain number and size of carbide content in mild steels. These findings were confirmed by micro-structural characterization and scanning electron microscopy techniques. They indicated that the severe corrosion cavities formed on the carbon steel surfaces and their sizes depended to silicon and silicon/phosphorus combinations contents. These results explained by micro-galvanic corrosion process between cementites and ferrites which became more serious with silicon and silicon/phosphorus combinations contents.
In this investigation, attempts have been made to study the corrosion inhibition properties of th... more In this investigation, attempts have been made to study the corrosion inhibition properties of three new 2-phenyl-4(3H)quinazolinone-substituted compounds for mild steel in 1.0 M hydrochloric acid medium. The evaluation was carried out using mass loss, electrochemical impedance spectroscopy, and polarization curves measurement. It is shown that 2-phenyl-4(3H)quinazolinone-substituted compounds are very good inhibitor's for mild steel corrosion in 1.0 M hydrochloric acid medium, which acts as mixed-type inhibitors. So, the inhibition efficiency was increased with inhibitor concentration in the order Q-p-Cl > Q-m-Cl > Q-H, which depends on their molecular structures and the chloride para/metapositions. Electrochemical impedance spectroscopy has shown that all compounds act by the formation of a protective film at the metal surface. The correspondence between inhibition property and molecular structure of the 2-phenyl-4(3H)-quinazolinone-substituted compounds is investigated, using density functional theory (DFT). The effect of molecular structure on the inhibition efficiency has been explored by quantum chemical computations and obvious correlations were observed. The binding energies of tested compounds on Fe(110) surfaces were calculated using molecular dynamics simulation. Experimental and DFT study was further supported by molecular dynamic (MD) simulations study.
Three new organic compounds primarily based on 8-hydroxyquinoline have been successfully synthesi... more Three new organic compounds primarily based on 8-hydroxyquinoline have been successfully synthesized and characterized via different spectroscopic methods (FTIR, 1H, and 13C NMR).
Journal of the Taiwan Institute of Chemical Engineers, 2016
Abstract The adsorption and corrosion inhibition properties of three piperidine derivatives namel... more Abstract The adsorption and corrosion inhibition properties of three piperidine derivatives namely, (1-(5-fluoro-2-(methylthio) pyrimidine-4-yl) piperidine-4-yl)-2,5-dimethoxybenzenesulfonamide (FMPPDBS), (1-(5-fluoro-2-(methylthio) pyrimidine-4-yl) piperidine-4-yl)-4-nitrobenzenesulfonamide (FMPPNBS), (1-(5-fluoro-2-(methylthio) pyrimidine-4-yl) piperidine-4-yl)-3-methoxybenzenesulfonamide (FMPPMBS) on the corrosion of iron were investigated by performing quantum chemical calculations and molecular dynamics simulations. Global reactivity parameters such as E HOMO , E LUMO , HOMO–LUMO energy gap (∆ E ), chemical hardness, softness, electronegativity, proton affinity, electrophilicity and nucleophilicity have been calculated and discussed. The adsorption behaviors of these piperidine derivatives on Fe(110), Fe(100) and Fe(111) surfaces were investigated using molecular dynamics simulation. The binding energies on metal surface of studied compounds followed the order: FMPPDBS > FMPPMBS> FMPPNBS and this ranking obtained is consistent with the experimental data.
The inhibition effect of new three heterocyclic compounds, namely (2-(1,3-dioxoisoindolin-2-yl) a... more The inhibition effect of new three heterocyclic compounds, namely (2-(1,3-dioxoisoindolin-2-yl) acetonitrile (IND), 2-((1H-tetrazol-5-yl) methyl) isoindoline-1,3-dione (IND-TET) and 5-(chloromethyl)-1H-tetrazole (TET)) on mild steel corrosion in molar hydrochloric acid (1 M HCl) has been investigated. It was studied through polarization and electrochemical impedance spectroscopy techniques. The inhibiting efficiency was found to depend on both concentration and immersion time and circa temperature-independent. IND and IND-TET were of cathodic type wile TET was mixed type influencing predominately cathodic process. From the temperature dependences, the activation energy in the presence of inhibitors found to be inferior to that in uninhibited medium. The adsorption of the inhibitors was well described by the Langmuir adsorption isotherm model. The influence of molecular structure was discussed and no synergism was observed in the case of IND-TET inhibitor.
The inhibitor effect of N-1-naphthylethylenediamine dihydrochloride monomethanolate (N-NEDHME) on... more The inhibitor effect of N-1-naphthylethylenediamine dihydrochloride monomethanolate (N-NEDHME) on the corrosion of carbon steel in 2.0 M H 3 PO 4 at 303-328Kwas investigated by weight loss, potentiodynamic polarization and electrochemical impedance. The results show that inhibition efficiency increases with the inhibitor concentration, while decreases with temperature. The value of activation energy (E a), Arrhenius factor, enthalpy and entropy for N-NEDHME values were discussed. Langmuir isotherm was found to provide an accurate description of the adsorption behaviour of the investigated compound. The thermodynamic parameters (adsorption equilibrium constant (K ads), free energy of adsorption (ads G°∆
This work based on the mechanism action study of sodium gluconate (SG) for ordinary mild steel us... more This work based on the mechanism action study of sodium gluconate (SG) for ordinary mild steel used for cooling water system treatment. In the first time, we evaluated the temperature effect on the scale inhibition of SG using statistic scale inhibition method. Result showed that the inhibition efficiency became more important with increasing temperature, at great concentration (10 À2 and 10 À3 M). This can be explained by forming of stable complex SG-Ca 2+. In the second time, the present work focuses on the study of operational parameters and corrosion products effect on SG performance using potentiodynamic polarization and electrochemical impedance spectroscopic method. The obtained results show that SG is a very good inhibitor for corrosion and scale and remains effective in the presence of corrosion products. For this study we were proposed a mechanism action for SG on metallic surface. In addition, the SG keeps its effectiveness in a more aggressive medium such as 3% NaCl. Finally, to complete the formulation, we added a not oxidizing biocide (CTAB) to SG. The results obtained show that SG remains its effective.
Electrodeposition of tin from acidic baths was investigated using S-dodecylmercaptobenzimidazole ... more Electrodeposition of tin from acidic baths was investigated using S-dodecylmercaptobenzimidazole (DMBI). Cyclic voltammetry measurements indicated that this compound isn't electroactive and changed the electrodeposition mechanism. It is found also that the reduction of Sn 2+ ions run under diffusion control and the hydrogen evolution was affected by the nature of the working electrode. In addition, the averages of the effective diffusion coefficients of metal species were determined. Indeed, it is shown that the transfer coefficient, tin diffusion coefficient and electron transfer number depend with the potential. The morphology of electrodeposition of tin was also presented. So, the deposit became more uniform and smooth with the DMBI addition. It is found that the electrodeposition rate of tin and the cathodic current efficiency (P) increased with DMBI.
Electroless Ni-Cu-P alloy coatings were deposited on the ordinary steel substrate in an acidic hy... more Electroless Ni-Cu-P alloy coatings were deposited on the ordinary steel substrate in an acidic hypophosphite-type plating bath. These coatings were characterized by a scanning electron microscope (SEM) and an X-ray diffraction. The micrograph shows that coating presents a nodular aspect and is relatively homogeneous and very smooth. The EDX analysis shows that the coating contains 12 wt.% of phosphorus element with a predominance of nickel element. In addition, the anticorrosion properties of the Ni-Cu-P coatings in 1 M HCl, 1 M H2SO4, and 3% NaCl solutions were investigated using Tafel polarization curves, electrochemical impedance spectroscopy, and SEM/EDX analysis. The result showed a marginal improvement in corrosion resistance in 3% NaCl solution compared to acidic medium. It also showed that the corrosion mechanism depends on the nature of the solution.
A pumping station located in the Moulouya River in Morocco, Northern Africa suffered from extensi... more A pumping station located in the Moulouya River in Morocco, Northern Africa suffered from extensive corrosion damage. Therefore, in this paper, the inhibition efficiency of Cetamine (CE) for mild steel exposed in water of Moulouya River was examined. This study was performed using electrochemical measurements and surface analysis. The results of potentiodynamic polarization measurements indicated that the CE compound classifies as a cathodic inhibitor type for 500 and 700 ppm, while it acts as a mixed inhibitor type at 1000 ppm CE. It is obtained also that the inhibition efficiency increases with CE concentrations to reach an optimum value of 98% at 1000 ppm CE. In addition, the impedance spectroscopy measurements indicated that this behavior can be explained by the formation of a protective film on the electrode surface. However, this study showed that the CE product takes its performance against aggressive water under various conditions (high Cl − concentration ions, electrode rotation rate, temperature, and immersion time).
Normal 0 21 false false false FR X-NONE AR-SA Manganese dihydrogen orthophosphate dihydrate Mn (H... more Normal 0 21 false false false FR X-NONE AR-SA Manganese dihydrogen orthophosphate dihydrate Mn (H 2 PO 4 ) 2 .2H 2 O was synthesized by solution co-precipitation method and characterized through single crystal X-ray diffraction, FT-IR and Raman spectroscopy. It crystallizes within monoclinic P 2 1 /n space group, with unit cell parameters a = 5.3733(3) A…, b = 10.1700(7) A…, c = 7.3106(5) A… and I² = 94.786(7) °: the least–square refinement converged to final agreement factors R 1 =0.0200 and wR 2 =0.0548 (I>2 Iƒ (I obs )). The three-dimensional network of the structure is made up by the repetition down (101) plane of layers of Mn octahedra and P tetrahedra joint together via vertex sharing. Strong O-H…O hydrogen bonds interconnect the layers, concurring to fix the network; such interactions were also investigated, as well as the whole structure, by means of infrared and Raman spectroscopy. Last, the corrosion inhibition for ordinary mild steel in simulated cooling water was investigated by this compound using electrochemical measurements . The results showed that it acts as a corrosion inhibitor and their inhibition efficiencies depend to its concentration.
A two non-toxic biodegradable epoxy glucose derivatives, namely 5,6-anhydro-3-O-octa-1,2-O-isopro... more A two non-toxic biodegradable epoxy glucose derivatives, namely 5,6-anhydro-3-O-octa-1,2-O-isopropyli-dene-α-D-glucofuranose (EGC8) and 5,6-anhydro-3-O-butadecyl-1,2-O-isopropylidene-α-D-glucofuranose (EGC14), were prepared and characterized by using spectroscopic measurements. These products were tested for mild steel corrosion inhibition in 1.0 M HCl using electrochemical measurements. It is shown that these epoxy glucose derivatives affect the cathodic branches with a shift in the cathodic direction (cathodic - type). So, it found that their inhibition efficiency arise with concentrations to achieve a maximum of 93.2 % and 93.48 % at 10-3 M of EGC8 and EGC14, respectively, and they depends to the carbon number chain following the order : EGC14 > EGC8. Indeed, it is found that these compounds adsorb according the Langmuir’s adsorption isotherm. On the other hand, the temperature effect on the inhibition efficiency of the epoxy glucose derivatives indicated that they take them ...
The inhibition ability of ethyl 6-amino-5-cyano-2-methyl-4-phenyl-4H-pyran-3-carboxylate (Pr3) on... more The inhibition ability of ethyl 6-amino-5-cyano-2-methyl-4-phenyl-4H-pyran-3-carboxylate (Pr3) on low low carbon steel (LCS) in 1.0 M HCl solution was studied by electrochemical techniques. Pr3 inhibited low low carbon steel corrosion in 1.0 M HCl solution significantly and the inhibition efficiency increased with Pr3 concentration. Polarization measurements indicated that, the studied inhibitor acts as mixed-type inhibitor. Phenomenon of physical and chemical adsorption is proposed for the inhibition and the process followed the Langmuir adsorption isotherm and kinetic / thermodynamic model of El-Awady et al. Correlations between the quantum chemical parameters (EHOMO, ELUMO, the energy gap, global hardness, global softness, Mulliken charges were calculated and Fukui index) and experimentally determined inhibition efficiency have been carried out and discussed.
This work proposes initially to identify the initial conceptions of Moroccan students in the firs... more This work proposes initially to identify the initial conceptions of Moroccan students in the first year of secondary college about the notion of earthquakes. The used methodology is based on a questionnaire addressed to students of life science and Earth in Meknes city, before any official teaching about the said phenomenon. The obtained results showed that despite the non-responses, the majority of respondents have less accurate initial conceptions for earthquakes notion, and does not correctly write their answers, they are enough to write snippets of sentences and do not use scientific words. The student’s conceptions seem marked by the earthquakes effects. However, we have identified correlations between the initial conceptions of Moroccan students and those of other French, Turks and Tunisians students. Keywords: Initial designs, Concepts earthquakes, college Secondary cycle, Correlation.
Abstract Nichel-Phosphorus (Ni-P) coatings are deposited on mild steel by using an electroless pl... more Abstract Nichel-Phosphorus (Ni-P) coatings are deposited on mild steel by using an electroless plating process. The effect of three calix[4]arene derivatives, namely tetra methyl ester-P-tertbutyl calix[4]arene (Calix1), tetra acid-P-tertbutyl calix[4]arene (Calix2) and tetra methyl P-tert-butyl-thicalix[4]arene ester (Calix3) on the deposition rate, the deposit composition, and the morphological surface was investigated and the study of growth mechanisms has delivered useful information about the surface properties of deposit. It is found that these additives modify the deposition rate and the nickel crystallization process. In fact, the Calix1 and Calix3 act as an accelerator, while Calix2 acts as an inhibitor for the nickel electroless. Furthermore, it is shown that the chemical bath is more stable with calix[4]arene derivatives addition and the obtained deposits are compact and adherent. It is observed also that the nickel content increases with additives. On the other hand, the X-ray diffraction showed that the orientation peaks are intensified at {111} in the presence of Calix2, confirming obtained results of EDAX spectrum. The cyclic voltammetry revealed that the tested additives strongly influence the cathodic process and slightly affect the hypophosphite oxidation. Finally, it is found that these compounds improve the anticorrosion efficiency of Ni-P coating on the mild steel substrate in 3%(mass) NaCl, where its polarization resistance increases with Calix2 and Calix3 addition.
New Challenges and Industrial Applications for Corrosion Prevention and Control, 2020
In this study, scale inhibition performance Trisodium citrate (TSC) was studied using static scal... more In this study, scale inhibition performance Trisodium citrate (TSC) was studied using static scale inhibition method, and its corrosion inhibition performance was also investigated by weight loss method and electrochemical measurement. Result showed that TSC could form a layer of corrosion and scale produTSC on mild steel surface in synthetic cooling water. Its inhibition increases with concentration and reaches a maximum of 89% and 95% at 10-3 M for corrosion and scale, respectively. It is noted that TSC takes its inhibition at high temperature and act by physic-sorption process. It is found that the TSC obey to the Langmuir isotherm. Scanning electron microscopy (SEM) showed that TSC inhibits the scale and corrosion by the formation of a protective layer on the mild steel surface.
The work presented the corrosion inhibition potency of the sodium gluconate and trisodium citrate... more The work presented the corrosion inhibition potency of the sodium gluconate and trisodium citrate against the corrosion of low carbon steel and revealed that the TSC can be more preferment than the SG molecule. In addition to experimental investigation of the corrosion inhibition capacity of the SG and TSC molecules, the quantum chemical calculations were performed by B3LYP, B3LYP-GD3BJ and M06HF functionals at three basis sets that are 6-31g(d,p), 6-311g(d,p) and 6-311++g(3df, 2pd) basis sets. The global hardness values revealed that the TSC molecule could be preferable to the SG molecule in using the design of the corrosion inhibitor materials because the SG (2.81 eV) was calculated a harder molecule than the TSC (2.70 eV). Molecular dynamic simulations were performed to investigate metal-inhibitor interactions.
New Challenges and Industrial Applications for Corrosion Prevention and Control, 2020
This chapter studies the operational parameters effects, such as immersion time, corrosion produc... more This chapter studies the operational parameters effects, such as immersion time, corrosion products, and pH, on the inhibition efficiency against corrosion for low carbon steel in simulated cooling water system of the mixture 1 (10-3 M 3-MPOX + 20 ppm CTAB), which corresponds to the best inhibition efficiency. The results show that the corrosion inhibition performance of the studied mixture reinforces with immersion time and has a maximum in the pH range 6.5–7.5. In addition, the analysis of the results shows that there is a dependence of the pH value of the solution and the corrosion current density (icorr). Indeed, a correlation can be established between log (icorr) and the pH using the polynomial equation. Finally, the mixture 1 provides good protection for the attack materials. These studies were evaluated from the polarization curves (PP), electrochemical impedance spectroscopy (EIS).
International Journal of Industrial Chemistry, 2020
The micro-structural effects on the corrosion resistance of three classes of mild steels (A, B an... more The micro-structural effects on the corrosion resistance of three classes of mild steels (A, B and C) suitable for galvanizing industry, according to their silicon, phosphorus content, grain number and size of carbides (Fe 3 C) in concentrated hydrochloride acid solution was investigated by a series of known techniques, such as potentiodynamic polarization curves, electrochemical impedance spectroscopy measurements, optical microscope and scanning electron microscopy. Results showed that the corrosion rate of the three classes of mild steel depends on their silicon and silicon/phosphorus combinations contents. It is found also that the corrosion rate depends on grain number and size of carbide content in mild steels. These findings were confirmed by micro-structural characterization and scanning electron microscopy techniques. They indicated that the severe corrosion cavities formed on the carbon steel surfaces and their sizes depended to silicon and silicon/phosphorus combinations contents. These results explained by micro-galvanic corrosion process between cementites and ferrites which became more serious with silicon and silicon/phosphorus combinations contents.
In this investigation, attempts have been made to study the corrosion inhibition properties of th... more In this investigation, attempts have been made to study the corrosion inhibition properties of three new 2-phenyl-4(3H)quinazolinone-substituted compounds for mild steel in 1.0 M hydrochloric acid medium. The evaluation was carried out using mass loss, electrochemical impedance spectroscopy, and polarization curves measurement. It is shown that 2-phenyl-4(3H)quinazolinone-substituted compounds are very good inhibitor's for mild steel corrosion in 1.0 M hydrochloric acid medium, which acts as mixed-type inhibitors. So, the inhibition efficiency was increased with inhibitor concentration in the order Q-p-Cl > Q-m-Cl > Q-H, which depends on their molecular structures and the chloride para/metapositions. Electrochemical impedance spectroscopy has shown that all compounds act by the formation of a protective film at the metal surface. The correspondence between inhibition property and molecular structure of the 2-phenyl-4(3H)-quinazolinone-substituted compounds is investigated, using density functional theory (DFT). The effect of molecular structure on the inhibition efficiency has been explored by quantum chemical computations and obvious correlations were observed. The binding energies of tested compounds on Fe(110) surfaces were calculated using molecular dynamics simulation. Experimental and DFT study was further supported by molecular dynamic (MD) simulations study.
Three new organic compounds primarily based on 8-hydroxyquinoline have been successfully synthesi... more Three new organic compounds primarily based on 8-hydroxyquinoline have been successfully synthesized and characterized via different spectroscopic methods (FTIR, 1H, and 13C NMR).
Journal of the Taiwan Institute of Chemical Engineers, 2016
Abstract The adsorption and corrosion inhibition properties of three piperidine derivatives namel... more Abstract The adsorption and corrosion inhibition properties of three piperidine derivatives namely, (1-(5-fluoro-2-(methylthio) pyrimidine-4-yl) piperidine-4-yl)-2,5-dimethoxybenzenesulfonamide (FMPPDBS), (1-(5-fluoro-2-(methylthio) pyrimidine-4-yl) piperidine-4-yl)-4-nitrobenzenesulfonamide (FMPPNBS), (1-(5-fluoro-2-(methylthio) pyrimidine-4-yl) piperidine-4-yl)-3-methoxybenzenesulfonamide (FMPPMBS) on the corrosion of iron were investigated by performing quantum chemical calculations and molecular dynamics simulations. Global reactivity parameters such as E HOMO , E LUMO , HOMO–LUMO energy gap (∆ E ), chemical hardness, softness, electronegativity, proton affinity, electrophilicity and nucleophilicity have been calculated and discussed. The adsorption behaviors of these piperidine derivatives on Fe(110), Fe(100) and Fe(111) surfaces were investigated using molecular dynamics simulation. The binding energies on metal surface of studied compounds followed the order: FMPPDBS > FMPPMBS> FMPPNBS and this ranking obtained is consistent with the experimental data.
The inhibition effect of new three heterocyclic compounds, namely (2-(1,3-dioxoisoindolin-2-yl) a... more The inhibition effect of new three heterocyclic compounds, namely (2-(1,3-dioxoisoindolin-2-yl) acetonitrile (IND), 2-((1H-tetrazol-5-yl) methyl) isoindoline-1,3-dione (IND-TET) and 5-(chloromethyl)-1H-tetrazole (TET)) on mild steel corrosion in molar hydrochloric acid (1 M HCl) has been investigated. It was studied through polarization and electrochemical impedance spectroscopy techniques. The inhibiting efficiency was found to depend on both concentration and immersion time and circa temperature-independent. IND and IND-TET were of cathodic type wile TET was mixed type influencing predominately cathodic process. From the temperature dependences, the activation energy in the presence of inhibitors found to be inferior to that in uninhibited medium. The adsorption of the inhibitors was well described by the Langmuir adsorption isotherm model. The influence of molecular structure was discussed and no synergism was observed in the case of IND-TET inhibitor.
The inhibitor effect of N-1-naphthylethylenediamine dihydrochloride monomethanolate (N-NEDHME) on... more The inhibitor effect of N-1-naphthylethylenediamine dihydrochloride monomethanolate (N-NEDHME) on the corrosion of carbon steel in 2.0 M H 3 PO 4 at 303-328Kwas investigated by weight loss, potentiodynamic polarization and electrochemical impedance. The results show that inhibition efficiency increases with the inhibitor concentration, while decreases with temperature. The value of activation energy (E a), Arrhenius factor, enthalpy and entropy for N-NEDHME values were discussed. Langmuir isotherm was found to provide an accurate description of the adsorption behaviour of the investigated compound. The thermodynamic parameters (adsorption equilibrium constant (K ads), free energy of adsorption (ads G°∆
This work based on the mechanism action study of sodium gluconate (SG) for ordinary mild steel us... more This work based on the mechanism action study of sodium gluconate (SG) for ordinary mild steel used for cooling water system treatment. In the first time, we evaluated the temperature effect on the scale inhibition of SG using statistic scale inhibition method. Result showed that the inhibition efficiency became more important with increasing temperature, at great concentration (10 À2 and 10 À3 M). This can be explained by forming of stable complex SG-Ca 2+. In the second time, the present work focuses on the study of operational parameters and corrosion products effect on SG performance using potentiodynamic polarization and electrochemical impedance spectroscopic method. The obtained results show that SG is a very good inhibitor for corrosion and scale and remains effective in the presence of corrosion products. For this study we were proposed a mechanism action for SG on metallic surface. In addition, the SG keeps its effectiveness in a more aggressive medium such as 3% NaCl. Finally, to complete the formulation, we added a not oxidizing biocide (CTAB) to SG. The results obtained show that SG remains its effective.
Electrodeposition of tin from acidic baths was investigated using S-dodecylmercaptobenzimidazole ... more Electrodeposition of tin from acidic baths was investigated using S-dodecylmercaptobenzimidazole (DMBI). Cyclic voltammetry measurements indicated that this compound isn't electroactive and changed the electrodeposition mechanism. It is found also that the reduction of Sn 2+ ions run under diffusion control and the hydrogen evolution was affected by the nature of the working electrode. In addition, the averages of the effective diffusion coefficients of metal species were determined. Indeed, it is shown that the transfer coefficient, tin diffusion coefficient and electron transfer number depend with the potential. The morphology of electrodeposition of tin was also presented. So, the deposit became more uniform and smooth with the DMBI addition. It is found that the electrodeposition rate of tin and the cathodic current efficiency (P) increased with DMBI.
Electroless Ni-Cu-P alloy coatings were deposited on the ordinary steel substrate in an acidic hy... more Electroless Ni-Cu-P alloy coatings were deposited on the ordinary steel substrate in an acidic hypophosphite-type plating bath. These coatings were characterized by a scanning electron microscope (SEM) and an X-ray diffraction. The micrograph shows that coating presents a nodular aspect and is relatively homogeneous and very smooth. The EDX analysis shows that the coating contains 12 wt.% of phosphorus element with a predominance of nickel element. In addition, the anticorrosion properties of the Ni-Cu-P coatings in 1 M HCl, 1 M H2SO4, and 3% NaCl solutions were investigated using Tafel polarization curves, electrochemical impedance spectroscopy, and SEM/EDX analysis. The result showed a marginal improvement in corrosion resistance in 3% NaCl solution compared to acidic medium. It also showed that the corrosion mechanism depends on the nature of the solution.
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Papers by Rachid Touir