Browsing by Author "AlFalah M.G.K."

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Corrosion behaviour of new oxo-pyrimidine derivatives on mild steel in acidic media: Experimental, surface characterization, theoretical, and Monte Carlo studies
(2022-02-01) Ferigita K.S.M.; AlFalah M.G.K.; Saracoglu M.; Kokbudak Z.; Kaya S.; Alaghani M.O.A.; Kandemirli F.
In this work, the effects of new compounds, namely, 1-amino-5-(4-methylbenzoyl)-4-(4-methylphenyl) pyrimidin-2 (1H)-thione (AMMP), and 1-(5-(4-Methoxybenzoyl)-4-(4-methoxyphenyl) 2-oxopyrimidin-1 (2H)-yl)-3-phenylthiourea (MMOPH) has been successfully investigated as a corrosion inhibitor for mild steel in a 1 M HCl solution. This investigation has been done by electrochemical techniques (potentiodynamic polarization, and electrochemical impedance spectroscopy), surface characterization (scanning electron microscopy with energy dispersive x-ray spectroscopy, and atomic force microscopy), and theoretical calculations (density function theory and Monte Carlo simulation). The electrochemical results showed that both compounds act as mixed-type inhibitors. However, MMOPH is more efficient than AMMP (95.9% compared with 84.1% at 5 × 10−4 M and an immersion time of 1 h). Additionally, the effect of immersion time on inhibitor efficiency was studied. The current density was reduced with the presence of inhibitors from 517.93 to 56.18 and 9.96 μA.cm−2 at 5 × 10−4 M and an immersion time of 1 h for AMMP and MMOPH, respectively. In both substances, the Langmuir isotherm system showed the best fit, with physisorption and chemisorption being the types of adsorption. The results of surface characterization indicated that both compounds can be adsorbed on mild steel surfaces to minimize corrosion. The obtained Monte Carlo simulation results suggest that the inhibitors are adsorbed vertically and the formation of a protective layer on the metal surface. The density function theory calculations for inhibitors found the protonated state is more reactive than the neutral state and agree with experimental results and follow the order MMOPH ˃ AMMP. The results showed that both compounds can be used as new corrosion inhibitors for mild steel in aggressive environments.
Corrosion inhibition of mild steel in acidic media using new oxo-pyrimidine derivatives: Experimental and theoretical insights
(2023-07-15) Ferigita K.S.M.; Saracoglu M.; AlFalah M.G.K.; Yilmazer M.I.; Kokbudak Z.; Kaya S.; Kandemirli F.
Interesting results have been found for new compounds derived from oxo-pyrimidine to protect of mild steel (MS) in 1 M hydrochloric acid. These the compounds are 1-(5-(4-Methoxy-benzoyl)-4-(4‑methoxy-phenyl)-2-oxo-2H-pyrimidin-1-yl]-(4‑methoxy-phenyl)-urea (MMOM) and 1-(5-(4‑methoxy-benzoyl)-4-(4‑methoxy-phenyl)-2-oxo-2H-pyrimidin-1-yl)-3-(4-methlyphenyl)-thiourea (MMOPM). In this study, the impact of immersion time on inhibitor effectiveness was also investigated. Both substances function as mixed-type inhibitors, according to the electrochemical data. At 5 × 10−4 M and a 72-hour immersion duration, MMOM is more effective than MMOPM (98.42% vs. 94.49%). The Langmuir isotherm system provided the best match for both compounds, with chemisorption as the kind of adsorption. According to the findings of surface characterisation, both chemicals may be adsorbed on mild steel surfaces to reduce corrosion. Inhibitor simulations using density functional theory revealed that the protonated state is more reactive than the neutral state and coincides with experimental findings. The outcomes demonstrated that both compounds may be utilised as new mild steel corrosion inhibitors in harsh conditions and long-term immersion. The theoretical study, based on quantum chemical calculations of the compounds, performed by the DFT/BP86 method with a 6–311G(d,p) basis set by using Gaussian 09, Revision A.02 program, were also included to support experimental results. The various quantum chemical parameters such as EHOMO, ELUMO, chemical hardness and chemical softness, electronegativity of the investigated molecules were calculated, and their inhibition efficiency were discussed. The outcomes demonstrated that both compounds may be utilised as new mild steel corrosion inhibitors in harsh conditions and long-term immersion.
Corrosion inhibition performance of 2-ethyl phenyl-2, 5-dithiohydrazodicarbonamide on Fe (110)/Cu (111) in acidic/alkaline solutions: Synthesis, experimental, theoretical, and molecular dynamic studies
(2022-09-01) AlFalah M.G.K.; Guo L.; Saracoglu M.; Kandemirli F.
Herein, 2-ethyl phenyl-2,5-dithiohydrazodicarbonamide (2EPDCA) was synthesised and tested as a corrosion inhibitor for mild steel (MS) and copper (Cu) in 1 M HCl and 3.5% NaCl, respectively. Fourier transform infrared spectroscopy (FT-IR) and (NMR) nuclear magnetic resonance (1H, 13C) were used to identify the chemical structure. Both experimental and computational approaches have been conducted to evaluate inhibitor efficiency on both metal systems. The electrochemical results showed that the 2EPDCA inhibition efficiency for MS systems was 95% at 1 × 10−2 M, while in copper systems it was 97.5% at 1 × 10−2 M. The Langmuir adsorption isotherm was fitted using adsorption surface coverage data, and for inhibitor in both systems, the kind of adsorption was mixed (physisorption and chemisorption). Through scanning electron microscopy (SEM), EDX, and atomic force microscopy (AFM) tests, we have confirmed the presence of the inhibitor molecules on the metal surface in both systems. Quantum chemistry simulations indicate that the superior corrosion inhibition efficacy of 2EPDCA on copper compared to mild steel surfaces is attributable to the former's greater electron donating propensity on copper. The adsorption of 2EPDCA molecules on Fe (110) and Cu (111) surfaces was further verified by molecular dynamic simulations, with the former having a greater adsorption energy. The results indicate that the corrosion inhibitor was effective even in harsh conditions, and it can be thought of as a novel corrosion inhibitor for mild steel and copper that provides good protection.
Corrosion Inhibition Potential of Dithiohydrazodicarbonamide Derivatives for Mild Steel in Acid Media: Synthesis, Experimental, DFT, and Monte Carlo Studies
(2022-05-01) AlFalah M.G.K.; Kandemirli F.
In the present work, new compounds, namely 2-fluoro phenyl-2,5-dithiohydrazodicarbonamide (2FPDC) and 4-fluoro phenyl-2,5-dithiohydrazodicarbonamide (4FPDC), were successfully synthesized and examined as corrosion inhibitors for mild steel in 1 M HCl. The molecular structures were characterized by Fourier transform infrared spectroscopy (FT-IR) and 1H, 13C nuclear magnetic resonance (NMR). A scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), and atomic force microscope (AFM) were conducted to identify the surface morphology of mild steel in the absence and existence of a corrosion inhibitor. Several electrochemical techniques have been conducted to evaluate inhibitor efficiency. The influence of immersion time on the efficiency of inhibitors was also investigated. The electrochemical results showed that both compounds appeared to be mixed type. However, 4FPDC is slightly more efficient than 2FPDC (97.3% compared with 96.5% at 1 × 10−2 M and an immersion time of 5 h). The resistance polarization for inhibitors was found to obey an order of 4FPDC ˃ 2FPDC. The Langmuir isotherm system revealed the best match, and the type of adsorption was physisorption and chemisorption in both compounds. SEM and EDX results have confirmed the presence of particles of inhibitor on the metal surface. A smooth surface was observed in the presence of inhibitors approved by AFM. Quantum chemical results showed that the adsorption of molecules of inhibitor takes place predominantly through protonated structures, and strongly agreed with experimental results. The results reveal that excellent inhibition efficiency was attained even in aggressive conditions, and they can be viewed as novel corrosion inhibitors for mild steel with excellent protection.
Corrosion performance of electrospinning nanofiber ZnO-NiO-CuO/polycaprolactone coated on mild steel in acid solution
(2020-12-01) AlFalah M.G.K.; Kamberli E.; Abbar A.H.; Kandemirli F.; Saracoglu M.
In the present work, PCL/ZnO (polycaprolactone/ zinc oxide), PCL/NiO (polycarprolactone/nickel oxide), PCL/CuO (polycarprolactone/copper oxide), and PCL/ZnO-NiO-CuO (polycarprolactone/ zinc oxide- nickel oxide- copper oxide) have been successfully fabricated and deposited on a mild steel through electrospinning technique. SEM, EDX, and FT-IR had been used to characterize all nanofiber coatings on the mild steel. A nanofiber layer of ZnO/NiO/CuO/PCL was utilized to coating the mild steel as a corrosion protector film in 1M HCl. A series of electrochemical techniques like Open circuit potential (OCP), Electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR), and potentiodynamic polarization (PDP) were used to analyse the anti-corrosion performance of the nanofiber layer ZnO/NiO/CuO/PCL. The results showed that both anodic and cathodic reactions sharp decline with shift in corrosion potential toward a positive direction in the Tafel plots. LPR results showed that the highest protection efficiency was 94.8% with ZnO-NiO-CuO/PCL nanofiber coating. EIS spectra showed that mild steel coated with ZnO/PCL, NiO/PCL, CuO/PCL, and ZnO-NiO-CuO/PCL, realization of capacitive conduct at high frequency and coating strength at law frequency part with resistor component 474.76 ohm.cm2, 527.35 ohm.cm2, 714.73 ohm.cm2, 744.80 ohm.cm2 respectively, indicating the good barrier properties and high ohmic resistance of coatings. SEM displayed a straight, interconnected structure, relatively less porosity with uniform fibers diameter. The fibers had average diameter 429 nm, 525 nm, 639 nm, and 443 nm for ZnO/PCL, NiO/PCL, CuO/PCL, and ZnO-NiO-CuO/PCL respectively. EDX and FT-IR results confirmed the existence of ZnO, NiO, and CuO and approved the distribution into PCL matrix. Results of the present study confirmed that ZnO-NiO-CuO/PCL electrospinning nanfiber coating could be considered as a new metallic oxide nanocomposite coating for a mild steel with excellent corrosion resistance.
Room Temperature Columnar Liquid Crystalline Perylene Bisimide as a Novel Corrosion Resistant Surface Film for Mild Steel Surface
(2023-03-01) Behera P.K.; Rao S.; Popoola L.T.; Swamirayachar S.A.; AlFalah M.G.K.; Kandemirli F.; Kodange S.; Prashanth G.K.; Achalkumar A.S.
The corrosion process can be seen as a widespread phenomenon, which is both pervasive and unstoppable. This is an undesirable phenomenon that reduces the life of materials and takes away their beauty. Potentiodynamic and electrochemical impedance tests are used to explore the corrosion inhibition abilities of a room temperature columnar liquid crystalline perylene bisimide (PBIO10) on mild steel (MS) samples in 1 M HCl. The inhibitor PBIO10 was demonstrated to be an outstanding corrosion inhibitor, with a maximum inhibition efficiency of 76%. In light of potentiometric polarization results, corrosion inhibition was achieved as the inhibitor getting adsorbed on the metal, and they fit into the category of anodic inhibitors. The protective layer was examined from SEM to confirm the protective coating generated on the MS surface. The increase in contact angle confirms the formation of a uniform layer on the MS surface. Analysis of the optical textures observed in POM, the nature of the mesophase under examination to columnar rectangular (Colr) phase. From the TGA, it was found that PBIO10 exhibits higher thermal stability u to 370 ℃. The density functional theory (DFT) and Monte Carlo simulation approach were used to investigate the relationship between molecular structure and inhibitory efficacy. The thermal behavior of PBIO10 was investigated by polarizing optical microscopy (POM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and X-ray diffraction (XRD) studies. The phase transition from crystal to LC phase was at first examined with the help of POM observation. Graphical Abstract: [Figure not available: see fulltext.]