جستجوی مقالات مرتبط با کلیدواژه « mild steel » در نشریات گروه « شیمی »

The aim of this study was to test the performance of Bitter Leaf (Vernonia Amygdalina) ethanol extract as a corrosion inhibitor for mild steel in 1.5 M H2SO4 solution. The study measured the weight loss and corrosion rate of mild steel under different inhibitor concentrations (0.25-1.50 g/ml) and exposure times (1-5 days). The findings indicated that the inhibitor concentration had a positive effect on reducing the weight loss and corrosion rate of mild steel, showing a high inhibition efficiency. On the other hand, the medium without inhibitor had more weight loss and corrosion rate. The study also observed that the weight loss and corrosion rate increased slightly as the exposure time increased, implying that the inhibitor became less effective over time and needed to be regularly replaced. The study used the Langmuir adsorption isotherm model to describe the interaction between the inhibitor molecules and the metal surface. The study demonstrated the corrosion inhibition process of bitter leaf extract on mild steel and emphasized the need to optimize the inhibitor concentration and check its effectiveness over time for corrosion prevention applications.

Corrosion of mild steel is a disturbing phenomenon that deserves effective measures to avert accidents, equipment breakdown, and economic downturns. The corrosion inhibitory potentials of zinc oxide nanoparticles/tenofovir disoproxil fumarate nanocomposite (Z+D) was investigated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS).  PDP analysis revealed that the alteration in corrosion potential values in the presence of Z+D (compared to corrosion potential obtained in the absence of Z+D) was less than 85 mV which suggest that Z+D operated as a mixed-type inhibitor. Corrosion current density (Icorr) decreased tremendously from 1241 μAcm-2 (in the absence of Z+D) to 321 μAcm-2 in the presence of 1000 ppm of the inhibitor. The inhibition efficiency increased with an increase in concentration of inhibitor to reach 74% when 1000 ppm of the inhibitor was introduced. EIS studies revealed a tremendous increase in charge transfer resistance (Rct) from 3533 Ω cm2 (in the absence of the inhibitor) to 21464×cm2 when 1000 ppm of Z+D was introduced. The highest inhibition efficiency (i.e 84%) computed from EIS analysis was obtained when 1000 ppm of the inhibitor was introduced. Electrochemical findings suggest that Z+D exhibited good attributes as a corrosion inhibitor for mild steel in 1 M hydrochloric acid.

The present work describes the corrosion inhibition of one of the widely used alloys in the industrial process, i.e., Mild Steel in Fresh water and demineralized water using acrylic polymer coating, Acrylic/8% Zn3(PO4)2 coatings, and Acrylic/8% Zn3(PO4)2/ 5mM AgNPs coating. The efficiency of coating on mild steel in fresh water and demineralized water was studied using suitable gravimetric and electrochemical techniques and the surface texture of mild steel after coating was studied by Scanning Electron Microscope. The electrochemical study reveals that the coating efficiency was found to decrease with an increase in temperature and Acrylic/8% Zn3(PO4)2/5mM AgNPs exhibited the highest inhibition efficiency of 94% and 95% in fresh water and demineralized water respectively at 303K. The excellent corrosion coating performance is attributed to the physisorption process of adsorption of the coatings on the metal surface which in turn followed the Langmuir adsorption isotherm. The results obtained by both Tafel polarization and electrochemical impedance spectroscopy methods were in good agreement with each other. The density functional theory in the study of acrylic coating also supported the obtained experimental results. To sum up, the acrylic coating with and without 8% Zn3(PO4)2/ 5mM AgNPs is an efficient corrosion coating material.

The present study investigates the impacts of the extract of Trachyspermum leaves on mild steel corrosion in 0.1M hydrochloric acid (HCl) while highlighting its inhibitory mechanisms. The effects of mild steel corrosion in solutions of HCl were examined using gravimetric and galvanostatic polarization techniques, along with EIS analyses. The EIS data shows the highest coating undamaged index (83 %) after 100 hours of immersion. According to the results, the maximum inhibitory effectiveness corresponding to the minimum corrosion rate could be observed at the highest desirable level of inhibitor concentration equal to 100 ppm, while the corrosion rate decreases with an increase in the extract concentration. The adsorption study promotes that Langmuir isotherm with -31.85kJ/mol in room temperature with R2=0.95 best describes the metal surface interaction with the Trachyspermum leaves extract with the best exposure time for the Trachyspermum to adsorb to the metal surface at all concentrations. SEM, AFM, IR, and XRD showed good coverage of Trachyspermum on the surface of mild steel. Based on the polarization results, the inhibitors can play the role of a mixed inhibitor, which is confirmed by the computational data. The chemical potentials of thymol, cymene, and terpinene are -6.55, -6.91, and -6.49 eV respectively.

In this study, the inhibition effect of Alyssum floribundum Boiss. & Balansa on the corrosion of mild steel was examined using electrochemical measurements in a 1M H2SO4 solution. The experimental results demonstrated that the extract of Alyssum floribundum exhibited significant inhibitory performance. According to the potentiodynamic polarization measurements, the highest inhibition efficiency was 98% when using a 1M H2SO4 solution containing 20 g/l of the plant extract. To determine the activation energy and temperature dependence of the corrosion inhibition process, polarization measurements were conducted at different temperatures ranging from 27°C to 60°C. The inhibition efficiency increased with an increasing concentration of the inhibitor, and the activation energies were found to be 33.56 kJ·mol-1 in a 1M H2SO4 solution and 96.98 kJ·mol-1 in the presence of the inhibitor (1M H2SO4 + 20g/ml). It was observed that the Langmuir adsorption isotherm was suitable for the adsorption of A. floribundum leaf extract on the surface of mild steel in an acidic solution.

Before being used in a variety of sectors, steel is often cleaned using acidic solutions. The steel corrosion rises as a result of this treatment, necessitating the inclusion of inhibitors in the cleaning bath. Due to this, it is constantly crucial to provide new, effective corrosion inhibitors. Rivaroxaban was investigated in the current study as a mild steel corrosion inhibitor in a 1.0 M HCl solution. At 25, 30, 40, and 50 ˚C temperatures and 1, 10, 20, 30, and 40 µM concentrations of inhibitor, corrosion experiments were conducted using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS). Steel sheets' surfaces were analyzed using SEM images in both the absence and presence of the inhibitor. At an ideal concentration of 40 µM, Rivaroxaban demonstrated inhibition efficiency greater than 92%, which was reduced with an increase in temperature and time of immersion in the acidic solution. Charge transfer resistance in the presence of Rivaroxaban after 144h decreased from 1470 to 231 Ω cm2.

The Alchornea laxiflora leaves were introduced as a sustainable corrosion inhibitor with excellent inhibition action on mild steel in 1.0M acidic medium solution. Alchornea laxiflora leaves are found throughout Africa, including three active compounds: quercetin, Quercetin-3-rhamnoside, and Quercetin-7-rhamnoside. The LC-MS and NMR are utilized using the gravimetric method to track the active components in the Alchornea laxiflora leaves extract. Potentiodynamic polarization, electrochemical current noise measurements, and scanning electron microscope (SEM) were conducted to investigate the corrosion inhibition role of various concentrations of Alchornea laxiflora extract toward mild steel corrosion in 1.0M acidic medium solution. Surface analysis, molecular dynamics, and quantum mechanics simulation methods were combined to get insights into inhibitor molecules’ adsorption on the mild steel surface. The results showed that the inhibitory capacity of the leaf extract increased with an increase in the concentration of the extract, whereas the corrosion rate of the steel material after immersion in the acidic solution decreased with increasing extract concentration. The structures were determined using nuclear magnetic resonance in 1D and 2D, and the molecular weight was determined using mass spectrometry. The electrochemical investigations revealed that the maximum inhibition efficiency of 98.8% was obtained in the present extract. The formation of protecting layer on the mild steel surface was proved by scanning electron microscope and atomic force microscope results. The results derived from Monte Carlo simulation MC and QM calculations revealed the adsorption of Alchornea laxiflora components on the steel substrate via donor-acceptor interactions.

Alkaloid and Flavonoid extracts of Salvia Officinalis Leaves ( AESOL and FESOL) as eco-friendly corrosion inhibitors of 817M40T Mild Steel in 0.5 M Hydrochloric acid concentrated environment was carried out. Weight loss, Thermometric, electrochemical impedance spectroscopy and potentiodynamic polarization techniques were employed. The corrosion rate values of the alkaloid and flavonoid were seen to be in the decrease from 1.6 – 0.01 and 1.6 – 0.1 while the inhibition efficiency values were in the increase from 79.7 % - 99.3 % and 75.1 % - 93.8 % for alkaloid and flavonoid fractions respectively at concentrations of 150 – 1000 ppm which defined the inhibitors a good inhibitors. A slight effect of temperature on the inhibition process was observed from the thermometric result as temperature was increased owing to strong agitation of heat. Electrochemical data showed that charge transfer resistance and inhibition efficiency were increasing while double layer capacitance and corrosion current density values were decreasing with concentration. A mixed type inhibition was recorded while adsorption process proved that the inhibitors were a monolayer type and physically adsorbed. Thermodynamic data revealed an inhibitor that is stabled, spontaneous, associative and endothermic in reaction.

Quinolinyl triazole derivatives 4-(4-chlorophenyl)-5-{[(5-chloroquinolin-8-yl)oxy]methyl}-2,4-dihydro-3H-1,2,4-triazole-3-thione (4-4CPCQMT), 4-(3-chlorophenyl)-5-{[(5-chloroquinolin-8-yl)oxy]methyl}-2,4-dihydro-3H-1,2,4-triazole-3-thione (4-3CPCQMT) and 4-(4-fluorophenyl)-5-{[(5-chloroquinolin-8-yl)oxy]methyl}-2,4-dihydro-3H-1,2,4-triazole-3-thione (4-4FPCQMT) are of great importance in pharmaceutical chemistry such as antifungal, antituberculosis, anticonvulsant, anticancer activities, etc. The present work highlights the synthesis of the quinolinyl triazole derivatives ((4-4CPCQMT, 4-3CPCQMTand 4-4FPCQMT). The substituents present and the compounds 4-4CPCQMT, 4-3CPCQMTand 4-4FPCQMT were confirmed by FTIR and NMR spectroscopy. These compounds having many reactive sites were used as inhibitors for mild steel in 1.0 M hydrochloric acid medium at 303 to 323K. An inhibition study was done by electrochemical measurement. The prevention efficiency is in the order 4-4FPCQMT>4-4CPCQMT>4-3CPCQMT. The surface morphology of the mild steel surface was done using SEM, AFM, and, EDX.

Using the decoction extraction method, we obtained twice crude aqueous extracts of Artemisia absinthium or (wormwood) that was made to start a comparative study, between the first extract which corresponds to the leaves of our plant (AQL) and the second which belongs to the stems (AQS). The inhibitory activity of the twice extracts of Artemisia absinthium was studied by weight loss, potentiodynamic polarization and electrochemistry impedance spectroscopy. The morphology of the mild steel surface was examined by SEM.The inhibitory efficiency increased with the increase of the concentration, we reach an efficiency of 85% for AQL and 82% for AQS at 303 K for a concentration of 0.2 g/ L. Two Artemisia absinthium extracts used to prevent corrosion in mild steel adhere to the Langmuir adsorption isotherm during adsorption. The majority compound is 3,4-dihydroxybenzoic acid in the case of extracts with percentages of 42.4% for AQL and 42.2% for AQS. The DFT results of the majority compounds allowed us to have an idea on the power of adsorption of these last ones on the surface of the metal, indeed there can be a combined effect of the various molecules constituting the extracts on the corrosion inhibition.

This research aimed at studying the optimization of cocoa pod-Ficus exasperate (CP-FE) extract preparation as mild steel anticorrosive agent in hydrochloric acid solution using a central composite design as an optimization tool. The maximum inhibition efficiency of 95.42% was obtained at ethanol volume, extraction time, CP-FE mixing ratio, and CP-FE mass of 500 mL, 48 hr, 5, and 100 g respectively. The coefficient of determination value of 0.9674 between experimental and predicted values suggested that the model developed was exact. The optimum predicted point for CP-FE extract preparation by CCD was 62.02 mL, 9.51 hr, 3.42, and 75.68 g for the ethanol volume, extraction time, CP-FE mixing ratio, and CP-FE mass respectively. SEM images revealed an acid attack on the mild steel surface. Adsorption of CP-FE extracts on the mild steel surface prevents acid attack. FT-IR revealed the presence of carboxyl (-COOH) and hydroxyl (-OH) functional groups. EDS revealed high iron composition on mild steel surface in the presence of CP-FE extracts. Loss of Fe2+ into free HCl solution was observed from the AAS result. Conclusively, mixed cocoa pod-Ficus exasperate extracts exhibited effective corrosion inhibitory attributes for mild steel in HCl solution.

Three expired antibiotic drugs namely, ampiclox, ciprofloxacin, and ampicillin were studied at low concentrations on the corrosion inhibition of mild steel (MS) in 0.1 M HCl medium using weight loss and scanning electron microscopy (SEM) techniques. Subsequently, the molecular structures of the antibiotic inhibitors were subjected to molecular dynamic (MD) simulation using Material Studio 8.0 software to have insight into their dynamic binding energy onto the Fe (110) surface in an acidic medium. The results showed that the weight loss and corrosion rate decrease with an increase in the inhibitor concentration, while the inhibition efficiency (%) and surface coverage increase with the increase in the inhibitor concentration respectively. The maximum inhibition efficiency of 97.72 % was attained at 0.009M concentration for ciprofloxacin followed by ampiclox and ampicillin. The SEM analysis of the MS with the expired ciprofloxacin (0.009 M) revealed a soother surface through the formation of a protective film that prevented the corrosion attack which confirms the highest inhibition efficiency. The MD simulation showed that the ciprofloxacin has the highest binding energy of -474.582 kcal/mol, followed by -248.448 kcal/mol for ampicillin and -234.955 kcal/mol for ampiclox respectively. Hence, the ciprofloxacin with the more negative magnitude of the binding energy was predicted to exhibit stronger chemisorption interaction onto the Fe (110) metal surface when compared with ampicillin and ampiclox. The findings in this research reveal good agreement between the experimental and theoretical results in studying the corrosion inhibition of the studied antibiotic drugs.

In this study, curcuma zedoaria extract was investigated as a mild steel (MS) corrosion inhibitor in 0.5 M H2SO4 solution by conventional methods of weight loss (WL), electrochemical impedance spectroscopy (EIS) and polarization at 25 °C. The highest percentage of inhibition was obtained for the concentration of 0.5 g/l of curcuma zedoaria extract. The results of polarization method showed that curcuma zedoaria extract acts as a mixed inhibitor. Examination of MS immersion time by weight loss method showed that with increasing immersion time, the inhibitory effect decreases in low concentrations of curcuma zedoaria extract but in higher concentrations of curcuma zedoaria extract (concentration 1.0 g/L), the inhibitory effect remains almost constant over time. The effect of temperature on the performance of curcuma zedoaria extract by electrochemical polarization method in the temperature range of 35-65 °C shows a decrease in inhibition percentage with increasing temperature. Adsorption of curcuma zedoaria extract molecules on the surface of MS at all studied temperatures follows the Langmuir adsorption isotherm. Using the results of kinetic and thermodynamic calculations, the adsorption of molecules of curcuma zedoaria extract on the surface of MS physical adsorption type was observed.

Mild steel is an affordable engineering material used for various applications, including the mild acidic environment with some precautions. The (NPK1, Urea, DAP, and NPK2), inhibition efficiency in the control of the carbon steel corrosion in solution that contains 1M HCl in the absence and presence of the potassium chromate (K₂CrO₄) as one of the oxidizing agents were assessed through the weight loss. and spectrophotometer. Results have exhibited that the formulation consisting of 100 ppm from every one of (Urea, NPK1, DAP, and NPK2) and 100 ppm K2CrO4 presents 81.08%, 92%, 90% and 97%, respectively efficiency of inhibition. Whereas 100 ppm from every one of the Urea, NPK1, DAP, and NPK2, offers 63.27%, 69.93%, 76.56% and 71.69%, respectively efficiency of inhibition and 100 ppm of K2CrO4 had given 76% efficiency of inhibition. Fe+2/Fe+3 concentration in the solution is decreased with the increase in the concentration of the inhibitor. The inhibitor’s properties of the adsorption were found to be obeying the isotherm of Langmuir adsorption.

A new organic compound, namely dihydropyrimido [4,5-b][1,6] naphthyridine-2,4, 6, 8(1H,3H,7H,9H)-tetraones with amino acid moiety (DHPN) was synthesized and characterized by 1H, 13C Nuclear magnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopy experiments.  DHPN was investigated for the first time as a green inhibitor of mild steel (A105) corrosion in acidic (0.1, 0.5 mol L-1 H2SO4 and HCl) solutions using potentiodynamic polarization technique. The results showed that, inhibition efficiency increased with the inhibitor concentration within the range of 0.95-19 mg L-1. The polarization curves demonstrated that, this compound act as a mixed type inhibitor. The adsorption of the DHPN molecule on the surface of mild steel was found to obey the Langmuir adsorption isotherm. Besides, data processing methods like support vector machine modelling was performed to prove the relationship between inhibitory effect and molecular structure.

The corrosion inhibition efficiency of (3-(4-chlorophenyl isoxazole-5-yl) methanol (CPIM) and (3-(2,4 dichlorophenolisoxazole-5-yl) methanol (DCPIM) for mild steel in 1 M HCl has been studied using electrochemical methods at 40 and 50 °C. Polarization studies showed that the inhibitors are efficient mixed-type corrosion inhibitors, and their inhibition performance increased with the rise of inhibitor concentration and decrease of temperature. The result of EIS measurements was analyzed through an appropriate equivalent circuit model to model the corrosion inhibition.

The usage of synthetic-based inhibitors for protection of metals against corrosion is always accompanied by environmental and economic challenges, including a threat to human health. Therefore, the corrosion inhibition efficiency of sweet prayer (Thaumatococcus danielli) leaf extract on mild steel in alkaline medium (NaOH) was investigated. The effects of temperature and concentration of the inhibitor on corrosion inhibitive potential of the leaf extract were evaluated. The equilibrium data were subjected to isotherm analysis (Langmuir, Freundlich and Temkin models). Langmuir model was the best model that provided information on the adsorption of the corrosion systems. The values of Langmuir equilibrium constant (KL) increased from 0.1581 g/L to 0.6523 g/L as the temperature increased from 298 K to 333 K. The findings revealed that sweet prayer leaf extract at different concentrations had inhibitive effects of mild steel on alkaline medium. The values of activation energy of the inhibited corrosion systems were greater than that of obtained for uninhibited system. Thermodynamic study revealed a feasible and spontaneous adsorption of sweet prayer leaf extract on mild steel. The trends of inhibition efficiencies and the results obtained from the thermodynamic parameters suggested a physical adsorption mechanism. The study proved that the sweet prayer leaf extract could serve as a low-cost corrosion inhibitor of mild steel in alkaline medium.

In this article, the inhibition capability of poly(epichlorohydrin) containing phenylhydrazine(PMP), 4-nitrophenylhydrazine(PMN), and 2,4- dinitrophenylhydrazine(PMDN) on mild steel was investigated in 0.5 M hydrochloric acid. The electrochemical studies demonstrate that these polymers act as mixed-type inhibitors but increasing their concentration caused the shift of corrosion potential to cathodic potential. Also, adsorption of these polymers on the mild steel surface obeys a Langmuir adsorption isotherm. The results obtained from the potentiodynamic polarization and Electrochemical Impedance Spectroscopy (EIS) are confirmed by Field Emission Scanning Electron Microscopy (FE-SEM), X-ray Energy Dispersive Spectroscopy (EDS), and Mapping analysis (MAP). The results of this study indicate that samples of PMDN have the lowest corrosion speed.