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Öğe Corrosion behavior of dual phase 600 and 800 steels in 3.5wt.% NaCl environment(Taylor & Francis Ltd, 2020) Gerengi, Husnu; Sen, Nuri; Uygur, Ilyas; Kaya, ErtugrulDual phase (DP) steels have a great deal of importance in the automotive industry. These steels are used to fabricate structural parts of vehicles with the goal of passenger safety. In this study, the corrosion properties of DP 600 and 800 steel in 3.5wt.% NaCl environment were evaluated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and weight loss methods. Although the samples were quite similar to each other in their composition, it was observed that the very small differences changed the corrosion resistance property. For this reason, the calculated charge transfer resistance (R-ct) of the DP-800 in the 3.5wt.% NaCl environment was 51% greater than that of the DP-600 sample. This finding was confirmed by using weight loss, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), and optical profilometer (OP) analysis.Öğe Corrosion inhibition of reinforcement steel in mixture water by caffeine and L-arginine(Taylor & Francis Ltd, 2021) Kurtay, Mine; Gerengi, Husnu; Chidiebere, Arinzechukwu; Yildiz, MesutMany additives are preferred to extend the usage of concrete constructions in order to increase durability. These compounds have to be non-poisonous and have no undesirable consequences on the environs. Out of all these concerns, amino acids are mainly used in food and drug industries as well as safe corrosion inhibitors in a number of acid solutions. Here, the corrosion inhibition efficacy of optimum concentration (50 ppm) of caffeine and L-arginine has been investigated for reinforcement steel in mixture water (MW) environment. This was performed for a duration of 2 h, 7, 28, 56 and 90 d using electrochemical impedance spectroscopy (EIS), dynamic EIS (DEIS), and potentiodynamic polarization (PDP) techniques. The surface of specimens was also investigated by atomic force microscopy (AFM), optical profilometer (OP) and scanning electron microscopy (SEM). DEIS results indicate that selected inhibitors protected reinforcement steel approximately up to 62% against corrosion till 7 d, then the effectiveness of the protection decreased to 30% on 90th day. It was also observed that L-arginine showed better inhibition efficiency than caffeine.Öğe Corrosion inhibition performance of dwarf palm andCynara cardunculusleaves extract for St37 steel in 15% H2SO4: a comparative study(Taylor & Francis Ltd, 2021) Lahbib, Hana; Ben Hassen, Samia; Gerengi, Husnu; Rizvi, Marziya; Ben Amor, YasserThe inhibition effect of extracts obtained from the commercially insignificant, perennial and overgrowing plants in Tunisia such as Dwarf palm (DP) andCynara cardunculus(CC) plants leaves against St37 steel corrosion in 15% H(2)SO(4)has been investigated with weight loss experiments (WL) and classical electrochemical methods. The investigations were conducted at the various concentrations of studied extracts, experiment temperature and time. The obtained results were compared with electrochemical impedance spectroscopy (EIS), dynamic electrochemical impedance spectroscopy (DEIS) and surface imaging method outcomes. The results showed that DP and CC extracts exhibit good corrosion inhibitor for St37 steel in 15% H(2)SO(4)solution. From all applied methods, DP extracts approximately showed better inhibition efficiency than CC. The adsorption of the inhibitors was found to obey the Langmuir adsorption isotherm. Results of infrared spectroscopy (FTIR) and physical electronics spectrometry (XPS) analysis strengthen the authenticity of other experimental results by proving that the extract molecules have bonded with the surface of the St37 steel.Öğe The effect of caffeine molecule on the physico-chemical properties of blended cement(Elsevier Sci Ltd, 2020) Kurtay, Mine; Gerengi, Husnu; Kocak, YilmazCaffeine is a nontoxic and eco-friendly natural molecule used in the food industry as well as a corrosion inhibitor in various corrosive media. However, its behavior and performance as an additive in the construction industry has not been explored. This paper investigates the effect of caffeine as an additive on strength, water demands, setting time and hydration mechanism of cement. In the first instance, the water demand, volume expansion and setting time of cement pastes, incorporating 0, 25, 50 and 75 ppm of caffeine were determined. In the second section, the rate of hydration and cement pastes' products were conducted by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermal analysis and scanning electron microscope (SEM) at 28 days. Finally, the cement mortars' compressive strengths were determined at 2, 7 and 28 days intervals. Consequently, mortars containing 75 ppm caffeine registered higher strength than the pure cement mortars due to high quantities of primary C-S-H gel, chemically bound water, compact structure at 28 days. Furthermore, by result of analysis and experiments, it was determined that caffeine had no negative effect on cement. (C) 2020 Elsevier Ltd. All rights reserved.Öğe Effect of Chemical Treatment on the Corrosion Behavior of Mg-2Zn-1Mn (ZM21) Magnesium Alloy(Springer, 2024) Kaya, Ertugrul; Gerengi, Husnu; Cabrini, MarinaMagnesium alloys have gained interest as biomedical implant materials in dental and orthopedic applications due to their biodegradability and similarities to human bones. However, their high rate of degradation in physiological systems poses a significant challenge for their use. To address this issue, chemical modification is being explored to improve the corrosion resistance of magnesium and its alloys. In this study, they investigated the effects of chemical modification using NaOH and H2O2 on the bioactivity and corrosion resistance of a Mg-2Zn-1Mn (ZM21) magnesium alloy in simulated body fluid (SBF) using advanced techniques such as dynamic electrochemical impedance spectroscopy (dynamic EIS), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), atomic force microscopy, and x-ray diffraction (XRD). Results obtained using DEIS measurements after 30 hours showed that the charge transfer resistance of the untreated ZM21 alloy was 229.4, 1226.8 omega cm(2) for the NaOH-treated surface, and 1066.3 omega cm(2) for the H2O2-treated surface. The study found that NaOH is more effective than H2O2 in improving the corrosion resistance of the ZM21 magnesium alloy in simulated body fluid. Additionally, the mechanism of corrosion for both untreated and treated samples in the corrosive environment was investigated and discussed in the study.Öğe Öğe Inhibition effect ofCynara cardunculusleaf extract on corrosion of St37 steel immersed in seawater with and without bleach solution(Taylor & Francis Inc, 2021) Lahbib, Hana; Ben Hassen, Samia; Gerengi, Husnu; Ben Amor, YasserThe inhibition performance of an aqueous extract ofCynara cardunculusleaves on the corrosion of St37 steel immersed in seawater and seawater with bleach was investigated using weight loss measurements, electrochemical methods, and surface characterization techniques. It was found that the extract components acted primarily as a mixed-type inhibitor, and inhibition efficiency increased with increasing inhibitor concentration. Electrochemical impedance spectroscopy (EIS) and dynamic electrochemical impedance spectroscopy (DEIS) confirmed the formation of a protective layer on the metallic surface in both solutions. The adsorption of inhibiting molecules conformed to the Langmuir isotherm model. The thermodynamic parameter values indicated that chemisorption constituted the major contribution to the adsorption process. This result was corroborated by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analyses. The significant inhibition effect can be related to the large amount of phenolic compounds in the CC aqueous extract as revealed by the Fourier-transform infrared (FTIR) spectrum.Öğe Investigation of Propolis as a Green Inhibitor of SAE 1010 Carbon Steel Corrosion in 3.5% NaCl Environment(Amer Chemical Soc, 2020) Rizvi, Marziya; Gerengi, Husnu; Yildiz, Mesut; Kekecoglu, Meral; Pehlivan, Mustafa MertThe anticorrosion performance of ethanolic extract of propolis (EEP) on SAE 1010 carbon steel specimens dipped in 3.5% NaCl was evaluated by advanced electrochemical and surface morphological assessments. The adsorption of EEP on the surface of the specimens investigated was delineated by an optical profilometer (OP), atomic force microscopy (AFM), and scanning electron microscopy (SEM) before and after immersion in aqueous solution of 3.5% NaCl. The electrochemical feedback assisted by PDP, EIS, and DEIS of the inhibited electrodes was compared with that of the uninhibited electrodes, and EEP's role in the formation of a protective barrier was identified. All the qualitative and quantitative data thus obtained establish EEP as a potential inhibitor for the SAE 1010 carbon steel corrosion in NaCl solution.Öğe A newly synthesized ionic liquid as an effective corrosion inhibitor for carbon steel in HCl medium: A combined experimental and computational studies(Elsevier, 2021) Ozturk, Serkan; Gerengi, Husnu; Solomon, Moses M.; Gece, Gokhan; Yildirim, Ayhan; Yildiz, MesutSurfactants present exciting adsorption chemistry due to their dual nature, i.e the present of the hydrophobic and hydrophilic parts in their structures. However, the inhibition performance of surfactants is influenced by their chemical structure as well as the nature of the electrolyte. In acidic media, high concentration of tri-cationic surfactants is required for effective surface protection. Herein, we report the synthesis of a novel tri-cationic surfactant containing three quaternized nitrogen atoms and its corrosion inhibitive effect for carbon steel in 1 M aqueous HCl medium. The molecular structure of the surfactant was elucidated by 1H NMR and C-13 NMR spectroscopic techniques and its anti-corrosion activity was investigated by electrochemical impedance spectroscopy, potentiodynamic polarization and dynamic electrochemical impedance spectroscopy methods. The results obtained from the corrosion studies show that the synthesized surfactant is quite effective against the low carbon steel corrosion and at low inhibitor concentration. The inhibition efficiency obtained at 5 mg/L concentration is above 90%, showing that the anti-corrosion effect of the synthesized surfactant on the metal surface is strong even at low inhibitor concentration. Moreover, some physicochemical parameters namely, the critical micelle concentration, surface tension, micelle formation free energy, and emulsion stability have been calculated and used to explain the correlation with the corrosion inhibition mechanism. Additionally, to support the results from the electrochemical measurements, surface morphological examination using energy dispersive Xray spectroscopy (EDAX) and scanning electron microscope (SEM) methods have been performed. The EDAX and SEM results prove the adsorption of the tri-cationic surfactant molecule on the metal surface. The adsorption followed the Langmuir adsorption isotherm and calculated Kads (equilibrium constant of the adsorption process) value reflects strong interaction. More so, density functional theory (DFT) results corroborate the experimental results. The synthesized tri-cationic surfactant is a potential candidate for the formulation of acid corrosion inhibitor for acid cleaning applications.Öğe Newly Synthesized Pyridinium Salt Based Tricationic Surfactants as Corrosion Inhibitor for Carbon Steel in 1.0 M HCl Medium(Maik Nauka/Interperiodica/Springer, 2023) Ozturk, Serkan; Gece, Gokhan; Yildirim, Ayhan; Gerengi, HusnuTwo pyridinium salt based tricationic surfactants were synthesized using quarternization reaction. The characterization of the surfactants were done by spectroscopic methods (FT-IR and NMR). Some pysicochemical properties like critical micelle concentration, surface tension at critical micelle concentration, Gibbs free energy of micelization, foam height, foam stability and emulsion stability were measured. The anticorrosion properties of the synthesized compounds were investigated by gravimetric measurements. In corrosion tests, where both compounds showed inhibitory activity against the corrosion of carbon steel in 1.0 M HCl environment, while the inhibition efficiency of the compound containing 6 carbon atoms in the long chain was determined in the range of 62-76%, those of the compound containing 8 carbon atoms in the long chain was found in the range of 85-93%. On the other hand, density functional theory (DFT) calculations were applied to arrive at basic molecular/electronic level scale details about the synthesized compounds, in addition to the surface images of the metal obtained by scanning electron microscopy to support the corrosion prevention results.Öğe The potency of zeolite and diatomite on the corrosive destruction of reinforcing steel in 1 M HNO3 environment(Elsevier Sci Ltd, 2020) Kurtay, Mine; Gerengi, Husnu; Kocak, Yilmaz; Chidiebere, Maduabuchi A.; Yildiz, MesutConsidering the high neutralizing power of concrete, it is seen as the major material for preserving reinforcing steel. This is observed in reinforced concrete (RC) formation. It is obvious that under corrosive situations, concrete is subject to noticeable quality losses. The aim of this research is to conduct an inquiry on the disintegration of reinforcing steel subjected to 1 M HNO3 solution over 200 days. For this purpose, concrete samples were produced having three different formulations, which included the reference (pure Portland cement), 20% diatomite and 20% zeolite. Reinforcing steel was embedded into these concrete samples. Afterwards, the electrochemical impedance spectroscopy (EIS) approach was used to monitor the system every seven days. The results clearly revealed that long-term experiments are required for accurate electrochemical measurements. The addition of diatomite and zeolite protected the reinforcement better against corrosion. Although it loses its effectiveness over time, zeolite provided better resistance against corrosion than diatomite for the reinforcement bars in 1 M HNO3 solution. (C) 2019 Elsevier Ltd. All rights reserved.Öğe A Probe into the Corrosion Behavior of a WE43B Magnesium Alloy in a Simulated Body Fluid using Dynamic Electrochemical Impedance Spectroscopy(Springer, 2023) Gerengi, Husnu; Lorenzi, Sergio; Solomon, Moses M.; Slepski, Pawel; Gratton, Sara; Cabrini, MarinaWE43B is one of the newest Mg alloys with practical application in biomedical implant technology. This work attempts to scrutinize the corrosion characteristics of WE43B alloy in a simulated body fluid (SBF) at a typical body temperature. The dynamic-electrochemical impedance spectroscopy with the capacity to track changes on surfaces in a dynamic corrosive system is used in combination with other classical techniques namely, linear polarization, EIS, and hydrogen evolution to track the corrosion pattern of the alloy in SBF for 24 h. The electrochemical results reveal a steady increase in the corrosion resistance of the alloy with immersion time reaching 1398 ohm cm2 at 24 h. This corroborates the hydrogen evolution results in which a declining trend in the corrosion rate with immersion time is observed. The corrosion rate of the alloy is in the range of 1.326-1.338 mm y-1 at 24 h. The results from the applied techniques are comparable. The surface analysis (scanning electron microscope, energy-dispersive x-ray spectroscopy, atomic force microscopy AFM) results conform with the results obtained from applied methods.Öğe Protection of steel hooks embedded in glass- fi ber-reinforced concrete against macrocell corrosion(Keai Publishing Ltd, 2024) Gerengi, Husnu; Maras, Muhammed; Rizvi, Marziya; Kohen, Beni; Taskiran, IsmailThis study evaluated the corrosion behavior of steel hooks embedded in GFRC, which were protected by a zinc-rich (96% Zn) galvanizing coating. The coating provided the hooks with active cathodic protection and a passive physical shield. Macrocell corrosion may form when the anode is smaller than the total steel surface. Thus, the steel hooks at the embedment juncture were additionally sealed against water ingress and air exchange using a construction sealant. The study was conducted in three phases in a saltspray chamber. First, the electrogalvanized steel hooks embedded in GFRC were allowed to freely corrode for 7 days. In the second phase, the electrogalvanized steel hooks were painted with the zinc-rich coating and observed over 7 days. In the third phase, the steel hooks were protected by the zinc-rich coating together with a primer and construction sealant, and observed over 7 days. To evaluate the electrogalvanized hooks and the corrosion products formed, the thickness of the material was measured. Corrosion on the metal surface was inferred by studying the surface morphology of the hooks at various points of contact and after different periods of time. (c) 2024 The Authors. Publishing services provided by Elsevier B.V. on behalf of KeAi Communication Co. Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/ by-nc-nd/4.0/).Öğe Shallow cryogenic treatment: effect on the corrosion resistance and hardness properties of AA5083-H111 alloy in chloride-ions enriched medium(Iop Publishing Ltd, 2021) Uz, Dogancan; Solomon, Moses M.; Gerengi, Husnu; Sahin, Mukerrem; Yildiz, MesutThe influence of cryogenic and cryogenic time (10, 24, 36, 48, and 72 h) on the hardness, surface roughness, and corrosion resistance properties of AA5083-H111 alloy in 3.5 wt.% NaCl solution have been investigated. The hardness property was analysed via the Brinell hardness measurement, the corrosion resistance property was measured electrochemically, while the morphological studies were undertaken using the SEM (scanning electron microscopy) and atomic force microscopy (AFM). The results disclose that the shallow cryogenic treatment at -80 degrees C improves the alloy's hardness, surface roughness, and the corrosion resistance. The best cryogenic treatment time is 24 h. Cryogenic treatment for 24 h increases the alloy's hardness from 71.3 HB to 74.90 HB, reduces the average surface roughness from 534.000 nm to 105.634 nm, and increases the total charge transfer resistance from 18139 omega cm(2) to 26230 omega cm(2). The improvement is linked to settling of fine particles on the alloy surface. The SEM results support these claims.Öğe Sodium nitrite as a corrosion inhibitor of copper in simulated cooling water(Nature Research, 2021) Rizvi, Marziya; Gerengi, Husnu; Kaya, Savas; Uygur, Ilyas; Yildiz, Mesut; Sarioglu, Ibrahim; El Ibrahimi, BrahimThe corrosion inhibition behavior of sodium nitrite (NaNO2) towards pure copper (99.95%) in simulated cooling water (SCW) was investigated by means of electrochemical impedance spectroscopy (EIS) and dynamic electrochemical impedance spectroscopy (DEIS). NaNO2 interferes with metal dissolution and reduce the corrosion rate through the formation or maintenance of inhibitive film on the metal surface. Surface morphologies illustrated that the surface homogeneity increased on adding sodium nitrite. Sodium nitrite's adsorption on copper surface followed the modified form of Langmuir, Freundlich and Frumkin isotherms. Physiosorption mode was involved in the corrosion protection. Electrochemical results revealed an corrosion resistance of copper increases on increasing the inhibitor concentration. The DEIS results indicated that copper corrosion mechanism could be hindered by 50% even after interval of 24 h by optimum concentration of sodium nitrite. The maximum inhibition was achieved with 2000 ppm of NaNO2. With this concentration, inhibition efficiency of up to 61.8% was achievable.Öğe Synthesis and anticorrosion studies of 4-[(2-nitroacetophenonylidene)-amino]-antipyrine on SAE 1012 carbon steel in 15 wt.% HCl solution(Taylor & Francis Ltd, 2020) Gerengi, Husnu; Cakmak, Resit; Dag, Besir; Solomon, Moses M.; Tuysuz, Hatice Aslihan Akbal; Kaya, ErtugrulA novel corrosion inhibitor, ((E)-1,5-dimethyl-4-((1-(3-nitrophenyl)ethylidene)amino)-2-phenyl-1,2-dihydro-3H-pyrazol-3-one) (DNPP) was synthesized in high yield by the condensation reaction of 4-aminoantipyrine with 2-nitroacetphenone derived from acetophenone as a starting material and characterized by FT-IR,H-1, and(13)C NMR techniques. DNPP was tested against the corrosion of SAE 1012 carbon steel in 15 wt.% HCl solution using electrochemical and surface characterization techniques. Results obtained show that DNPP is effective in retarding the corrosion of SAE 1012 carbon steel. With 4 mM of DNPP, the charge transfer resistance of SAE 1012 in 15 wt.% HCl solution is raised from 17.42 to 140.50 ohm cm(2)and the substrate surface is protected by 87%. The inhibition is through adsorption mechanism (mixed-adsorption type) and has been confirmed by SEM and EDAX results. Potentiodynamic polarization results reveal that DNPP acted as a mixed-type corrosion inhibitor. DNPP is a promising candidate for the formulation of an inhibitor cocktail for the strong acid environment.Öğe Synthesis of novel PVA-PFPAMA nanocomposites by the hydrothermal method: Evaluation of thermal, antimicrobial, and anticarcinogenic properties(Elsevier Science Sa, 2023) Erol, Ibrahim; Hazman, Omer; Ozkan, Mehmet; Uygur, Ilyas; Khamidov, Gofur; Gerengi, HusnuIn this study, a mixture of poly 2-(4-fluorophenyl)-2-oxoethyl-2-methylprop-2-enoate (PFPAMA) and PVA was first prepared and characterized using the hydrothermal method. Copper (II) oxide nanoparticles (CuO NPs) prepared by solution plasma process (SPP) were hydrothermally incorporated into the PVA-PFPAMA blend at 3 %, 5 %, and 7 %. FTIR spectroscopy was used to identify the functional groups of the obtained materials. Morphological and structural analysis of the materials was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), and atomic force microscopy (AFM). The glass transition temperatures (Tg) of the materials were investigated by differential scanning calorimetry (DSC), and their thermal stability by thermogravimetric analysis (TGA). All materials showed excellent antimicrobial effects against E. coli, S. aureus, and C. albicans strains. It was also found that the anticarcinogenic activity increased with the proportion of CuO NPs in the nanocomposites. The results showed that the thermal and biological properties of the nanocomposites were positively affected after the inclusion of CuO NPs in the PVA-PFPAMA blend. The synergistic effects of PFPAMA and CuO NPs improved the overall performance of the materials.Öğe Synthesis, characterization, and studies of the interfacial and anticorrosion properties of a ternary cationic ionic liquid on carbon steel in a molar concentration of hydrochloric acid: Experimental and computational insights(Elsevier, 2024) Ozturk, Serkan; Gerengi, Husnu; Solomon, Moses M.; Gece, Gokhan; Yildirim, Ayhan; Olasunkanmi, Lukman O.Corrosion in acidic environments is a serious industrial challenge that must be addressed and cationic ionic liquid play a critical role in tackling the wet corrosion menace for the metal industry. For this purpose, a novel ternary cationic ionic liquid namely N1-(3-(11-(octadecyldimethylammonio)undecanamido)propyl)-N1,N1,N2,N2,N2pentamethylethane-1,2-diaminium tribromide (Mono-18-11-di-N) is synthesized and elucidated for anticorrosion activity on St37-2 grade steel in a molar concentration of hydrochloric acid medium. The structural elucidation of Mono-18-11-di-N was achieved by FT-IR, 1H NMR, and 13C NMR methods while the electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), dynamic-EIS, density functional theory (DFT) calculations, and Monte Carlo (MC) simulation techniques were adopted in the anticorrosion evaluation. The Critical Micelle Concentration (CMC) of Mono-18-11-di-N is 0.000491 M and at CMC, the surface tension is 21.86 dyn cm ? 1 inferring good surface activity properties. Mono-18-11-di-N is effective against the wet corrosion of St37-2 steel. It can, at 20 mg/L decrease the corrosion rate of the metal from 0.57 mm/y to 0.11 mm/y and enhance the polarization resistance from 363 omega cm2 to 1908 omega cm2. A corrosion rate of 0.03 mm/ y and an inhibition efficiency of 93% is achievable after 24 h of immersion at 25 degrees C. Additionally, surface morphological examination using scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX), optical profilometer (OP), and atomic force microscope (AFM) methods prove the adsorption of Mono -18-11-di-N molecules on the substrate surface. Moreover, DFT and MC simulations revealed that Mono-18-11-di -N relies on lone pairs of electrons in bromide anion, oxygen, and nitrogen atoms to adsorb parallel to the St37-2 surface and protect it against corrosion.
