1M HCl Research Articles

Combination effect of hydro-alcoholic extract of spent coffee grounds (HECG) and potassium Iodide (KI) on the C38 steel corrosion inhibition in 1M HCl medium: Experimental design by response surface methodology

Abstract This paper introduces Response Surface Methodology (RSM) as a method in order to explore the combination effect of hydro-alcoholic used coffee grounds extract (HECG) and potassium iodide (KI) on the corrosion protection of C38 steel in 1M HCl medium. Open circuit potential (OCP) measurements as a function of time until the steady-state potentials were established. The inhibition efficiency (IE) was defined using electrochemical impedance spectroscopy and potentiodynamic polarization. The obtained results have shown that the influence of the combination of HECG and KI on the inhibition efficiency is statically significant. The addition of 0.007 M KI to 1.0 M HCl solution containing 0.30 g/L of HECG decreases the corrosion of iron steel and improves the performance of HECG by a synergistic effect. The optimum inhibition efficiency was about 97 %, showing a high inhibition efficiency in presence of a combination of the inhibitors (KI + HECG).

Towards a theoretical understanding of alkaloid-extract Cytisine derivatives ofRetama monosperma (L.) Boiss. Seeds, as eco-friendly inhibitor for carbon steel corrosion in acidic 1M HCl solution

Because of their availability, lower cost, biodegradability, respect for health, environmental standards and their extremely high efficiency [Benmessaoud Left D, Zertoubi M, Irhzo A, Azzi M, Revue: Huiles et extraits de plantes comme inhibiteurs de corrosion pour différents métaux et alliages dans le milieu acide chlorhydrique, J Mater Environ Sci 4:855–866, 2013], the green corrosion inhibitors are currently the most sought after candidates. The ultimate aim of this work is to study the selectivity and reactivity of a series of three molecules, namely Cytisine, Dehydro-Cytisine and N-methyl Cytisine which are the major constituents of Retama monosperma seeds alkaloid extract (AERS) as eco-friendly inhibitors of corrosion of carbon steel in acidic medium HCl (1M), using the density functional theory (DFT) at B3LYP/aug-cc-pvdz levels. Indeed, this alkaloid extract AERS has proven experimentally its corrosion inhibitory power for carbon steel in 1 M HCl even at lower concentration (94.42% at 400[Formula: see text]mg/L). Besides, its adsorption on the steel surface in 1 M HCl solution followed Langmuir’s isotherm [El Hamdani N, Fdil R, Tourabi M, Jama C, Bentiss F, Alkaloids extract of Retama monosperma (L.) Boiss. seeds used as novel eco-friendly inhibitor for carbon steel corrosion in 1 M HCl solution: Electrochemical and surface studies, Appl Surf Sci 357:1294–1305, 2015, doi: 10.1016/j.apsusc.2015.09.159; El Hamdani N, Contribution a la valorisation des parties aériennes de Retama Monosperma, phytochimie, activités antimicrobiennes et propriétés anticorrosives, Universite Chouaib Doukkali Faculte des sciences El jadida, 2015]. Herein, the major aim of this work is to investigate the likelihood of the carbon steel corrosion being inhibited by the protonated species in the aqueous acidic solution. For this purpose, after proving that the most favorable protonation site for protonation was N9, we have evaluated the structural, global and local reactivity descriptors, partial atomic charge in terms of Natural bond orbital (NBO) of the three protonated inhibitors at the level of N9, which are the most stable in the aqueous acidic solution. NBO analysis and the thermodynamic properties such as entropy, enthalpy, heat capacity and Gibbs free energy were also done. In conclusion, it was observed that three protonated molecules showed a high propensity to adsorb to the mild steel surface with a priority of the molecule d-CytN9H+.

Is acidification of samples for isotopic analysis of carbon and nitrogen necessary for shoreline marine species?

The acidification of samples for the simultaneous measurement of stable carbon (δ13C) and nitrogen (δ15N) isotopes represents an important methodological question still not clarified because the removal of calcium carbonate (CaCO3) from samples may affect the outcome of the stable-isotope analysis. We investigated the effect of acidification on samples of 25 different taxa of benthic marine organisms from a rocky shore, to determine whether acidification affects the isotopic values of δ13C and δ15N. After washing with distilled water and drying, each sample was divided into two parts; one part was acidified by adding 1M HCl with a pipette, until no more CO2 was released, whereas the other part was retained as a non-acidified sample. Organisms with little CaCO3 showed no difference in carbon isotopic signatures after acidification, from those in the non-acidified part. Some organisms with a high CaCO3 content did show differences in carbon isotopic signatures after acidification. The nitrogen isotopic signature presented a significant difference; however, to what extent this difference is biologically important is discussed. Avoiding sampling parts containing a high concentration of carbonate is an efficient way to circumvent this problem. Acidification of samples as a pre-treatment for isotopic analysis is not useful for marine organisms without calcareous structures and is necessary only when the sampled parts contain significant amounts of carbonate.

CORROSION PROTECTION OF MILD STEEL AND ALUMINIUM IN 0.1M AND 1M HCL ACID SOLUTIONS USING PTEROCARPUS OSUN.

The inhibition effect of Pterocarpus osun on the corrosion of mild steel and aluminium in acidic medium was studied using gravimetric techniques. Weight loss measurements were determined on metal coupons in 0.1M and 1M HCl acid within the immersion time of 24-h for 5 consecutive days. Inhibition efficiency was determined by comparing the corrosion rates of mild steel and aluminium in 0.1M and 1M HCl in the presence and absence of additives. The trend of inhibition efficiency was used to propose the mechanism of inhibition. It was found that the plant extract act as inhibitor for acid-induced corrosion of mild steel and aluminium in 0.1M and 1M HCl. Inhibition efficiency of 94.5% and 94.9% were obtained for P. osun for aluminium in 0.1M and 1M HCl and 98.9%and 96.9% for mild steel in 0.1M and 1M HCl respectively. The inhibition efficiency was found to increase with increase in inhibitor concentrations. The adsorption of the inhibitor obeyed Langmuir Adsorption Isotherm. Based on the findings, P. osun stem extract is highly recommended as an alternative to synthetic, toxic chemical inhibitors.

Fluconazole and fragments as corrosion inhibitors of API 5L X52 steel immersed in 1M HCl

The corrosion inhibition of API 5 L X52 in 1 M HCl due to fluconazole as active substance 1 or drug (Afungil), and its fragments: 1,2,4-triazole 2 and 1-bromo-2,4-difluorobenzene 3 was evaluated through electrochemical techniques and DFT calculations. At 20 °C, 1 exhibited c.a. 90 % corrosion inhibition efficiency, IE, from 5–200 ppm. The fragment 2 displayed an IE of 83 % at 30 ppm, while the fragment 3 reached 80 % at all concentrations. However, the inhibition kinetics study of 1 demonstrated that it retained its IE properties up to 168 h of immersion with 84 % IE. 1 followed a Langmuir-type physisorption-chemisorption process while 2 and 3 a physisorption process. From SEM and AFM images it was directly verified the steel-protective capacity of 1 and from XPS analysis its presence onto the steel surfaces. Theoretical calculations, carried out at the dispersion corrected density functional theory BPW91-D2/6-311++G(2d,2p) level, are in full agreement with experimental observations, explaining that the physisorption-chemisorption process was provoked by the electrostatic interaction and electron pairs donation of fluconazole on the iron atoms. Similarly, the adsorption process of protonated fluconazole is due to electrostatic interactions and electrons shared from the metal cluster to the protonates species. Reactivity indices indicate that the steel surface is effectively covered and passivated.

Effectivity of Water-Soluble Chitosan from Rajungan Shell Waste as Corrosion Inhibitor on Iron in 1 M HCl

Corrosion is the process of metal oxidation in the presence of oxygen which causes losses in the industrial field. This study was conducted with the aim to determine the effectivity of water-soluble chitosan from crab shells as a corrosion inhibitor on iron in 1M HCl media. Crab shell waste was demineralized and deproteinated to obtain chitin. Chitin obtained was then deacetylated to obtain Water Soluble Chitosan (WSC). The inhibition efficiency of WSC on iron corrosion in HCL 1 M media was determined by the weight loss method. The results showed that the corrosion rate decreased with the increase of inhibitor concentrations of 0, 100, 300 and 500 ppm. However, the increase in temperatures (303, 313 and 323 K) also increased the corrosion rate. The inhibition efficiency increased as the inhibitor concentration increased. The optimum efficiency occurred at a temperature of 303 K and a concentration of 500 ppm which was equal to 98.94%. The corrosion rate decreased with the increase of pH values (3, 4 and 5). WSC adsorption from crab shell waste on the surface of iron in 1M HCl media follows the isothermal model of Freundlich adsorption. In the thermodynamic study, the values of Ea, ΔH ΔS, and ΔG0 Ads were used to determine the adsorption of iron inhibitors. The results of the study showed that the reaction is a physical reaction (physisorption), endothermic, and spontaneous.

Highly selective extraction of palladium from spent automotive catalyst acid leachate using novel alkylated dioxa-dithiacrown ether derivatives

Novel macrocyclic extractants were synthesized and employed in liquid–liquid extraction (LLE) for palladium/platinum (Pd/Pt) separation in aqueous feed source. Dioxadithia-benzo-crown ether diols (BCES2O2) 2g–2i were prepared through bis-epoxide cyclization with aqueous 1,2-benzenedithiol under mild basic conditions. For improved miscibility and stability in the organic diluent (i.e. toluene), 2g–2i were alkylated to afford dimethoxy-BCES2O23g–3i. LLE experiments reveal their high stability, extraction efficiency, and separation performance (βPd2+/Pt2+=104−105) in highly acidic feed solutions (∼6M HCl). The most suitable extractant 3i followed a 1:1 3i-Pd2+ complex with stability constant Kex∼105. Density functional theory calculations reveal that the rigid cavity size (1.58–1.65Å) of 3i is ideal for Pd2+ (1.56Å) in forming S4 coordination geometry. The Pd2+ can be repeatedly extracted by 3i [in toluene] and stripped by 1M HCl+0.15M thiourea solution without performance deterioration. Each cycle can be accomplished <1h based on the derived extraction (kex=0.038min−1) and stripping (kstrip=0.063min−1) rate constants. The high extraction efficiency (99.5%) and purity (98.5%) of recovered Pd2+ from simulated acidic spent automobile catalyst liquor demonstrate the potential of 3i [in toluene] LLE system for selective Pd2+ recovery from automotive wastes.

Evaluation of the corrosion inhibition efficacy of Cola acuminata extract for low carbon steel in simulated acid pickling environment.

In this study, Kola nut extract (KE) was evaluated for inhibiting ability towards low carbon steel corrosion in 1M HCl solution using weight loss and electrochemical techniques. The surface of the corroded carbon steel was examined by Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM). Elemental composition of the corrosion products and/or adsorbed inhibitor film on the carbon steel surface was determined with the aid of an energy-dispersive X-ray spectroscopy (EDX). The ultraviolet-visible (UV-vis) experiments were also performed to get information about the interaction of KE with the carbon steel surface. It was found that KE exhibited good corrosion protection property. From weight loss technique, corrosion rate was reduced from 0.387 to 0.054mm/year by 700ppm of KE at room temperature after 24h immersion and this corresponded to inhibition efficiency (IE) of 86%. The IE however depreciated with rise in temperature. FTIR results reveal that KE interacted with the carbon steel surface through the O and N heteroatoms of its phytoconstituents. FTIR spectroscopy, UV-vis, SEM, AFM, and EDX data provided proof of KE adsorption on the steel surface as reason for the corrosion inhibition.

Corrosion inhibition of Fe-19Cr stainless steel by glutamic acid in 1M HCl

Abstract Electrochemical methods, weight loss and surface analysis technique were used to study the effect of glutamic acid on the corrosion of Fe-19Cr stainless steel in 1 M hydrochloric acid solution. Results revealed that the corrosion inhibition of glutamic acid of Fe-19Cr in 1 M HCl was enhanced in the presence of the iodide ions due to synergistic effect. In the absence of KI, the inhibition of Fe-19Cr corrosion by glutamic acid was glutamic acid concentration dependent. Potentiodynamic polarization curves demonstrated that glutamic acid acts as a mixed type inhibitor. Self-Assembled Monolayers of glutamic acid were able to protect stainless steel from corrosion effectively. The adsorption of the inhibitor onto the stainless steel surface follows Langmuir adsorption isotherm. The value of free energy of the adsorption indicated that there is a physical interaction between the glutamic acid and the stainless steel surface.

Electrochemical performance of 2-meracaptobenzothiazole on the corrosion inhibition of selected metallic alloys in dilute acid media

The inhibition performance of 2-meracaptobenzothiazole on the corrosion of 316 austenitic stainless steel in 3M HCl, mild steel in 1M HCl and 1060 aluminium alloy in 2M H2SO4 solution alloy was studied by coupon measurement. Results showed the compound performed more effectively on the 316 steel with average corrosion inhibition performance result of 90% followed by the aluminium alloy with average inhibition performance value of 70%. 2-meracaptobenzothiazole performed poorly on mild steel with average inhibition performance results of 55% at low concentration and results below 0% and high inhibitor concentrations. Statistical data through showed that inhibitor concentration only influenced the inhibition performance of 2-meracaptobenzothiazole. Inhibitor concentration and exposure time were statistically relevant to the inhibition performance of 2-mercaptobenzothiazole on mild steel at varying degrees while both inhibitor concentration were statistically irrelevant to the inhibition performance of 2-meracaptobenzothiazole on 1060 aluminium alloy. Adsorption isotherm studies showed SD adsorption on the metallic alloys aligned with Langmuir, Frumkin and Freudlich adsorption with general correlation coefficient above 0.9991.

Data on the corrosion resistance as-received, annealed and quenched 1060 aluminum alloy in dilute H2SO4 and HCl acid concentrations

The effect of annealing and quenching heat treatment processes on the corrosion resistance of 1060 aluminum alloy was studied by weight loss method in 0.5, 1, 1.5 and 2M H2SO4 and HCl acid media. Alteration of the microstructural constituents of the alloy significantly influenced its corrosion resistance. Data obtained confirmed that quenched aluminum depicted the highest corrosion resistance with highest corrosion rate value of 0.00149 mm/y and 0.02151 mm/y from 2 M H2SO4 and HCl solution. Annealed aluminum exhibited the lowest corrosion resistance with optimal corrosion rates of 0.00768 mm/y and 0.02792 mm/y. Corrosion resistance of as-received aluminum was observed to be intermediate between the values obtained for quenched and annealed aluminum alloy. Annealed AL1060 exhibited the highest standard deviation value in H2SO4 while quenched AL1060 exhibited the highest values in HCl solution. Mean values generally increased with increase in acid solution for the as-received, annealed and quenched AL1060. Statistical data from analysis of variance (ANOVA) shows acid concentration is the statistically relevance sources of variation influence the the corrosion behaviour of as-received, annealed and quenched AL1060 in H2SO4 and HCl solution. The statistical relevance values for acid concentration obtained in H2SO4 solution 83.40%, 97.04% and 89.29% while the corresponding values in HCl solution are 97.94%, 99.29% and 96.07%. The values for exposure time were calculated to be statistically irrelevant in both acids.

Nitro substituent effect on the electronic behavior and inhibitory performance of two quinoxaline derivatives in relation to the corrosion of mild steel in 1M HCl

Two quinoxaline derivatives, 2-(2,3-dimethoxyphenyl)-1,4-dihydroquinoxaline (HHQ) and 2-(2,3-dimethoxyphenyl)-6-nitro-1,4-dihydroquinoxaline (NHQ) were selected as inhibitors for mild steel corrosion in 1 M HCl using experimental techniques and theoretical approaches (DFT and the simulations of Monte Carlo (MC) and molecular dynamics (MD)). The results obtained by electrochemical polarization measurements show that these two molecules inhibit the corrosion rate of mild steel in the corrosive media. The HHQ and NHQ inhibitors showed a mixed, predominantly anodic character, decreasing the rate of cathodic and anodic corrosion reactions. As reported in electrochemical impedance spectroscopy (EIS) tests, the adsorbed inhibitor molecules built up a pseudo-capacitive response of the interface. The inhibition efficiency is reduced by the effect of the electron attractor group NO2 in the NHQ inhibitor. Adsorption is in accordance with the Langmuir isothermal model. Scanning electron microscopy (SEM) identified that the formation of a protective layer of inhibitor on the surface of mild steel. Analyses inhibited Electrolyte by UV–visible spectroscopy provide concrete evidence on the complexation of iron cation with both quinoxaline molecules in 1 M HCl. The results obtained by the theoretical approaches through the different methods via DFT, MC and MD simulations show a satisfactory concordance with the results of the experimental part.

Chemical, electrochemical and surface morphology investigation of Cichorium intybus extract (CIE) as beneficial inhibitor for Al in 2 M HCl acid

The inhibiting activity of CIE(CIE) to the dissolution of Al in 2M HCl medium was carried out by chemical strategies (mass loss and gasometry) and electrochemical systems, for example, tafel polarization (TP), electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM). Surface morphology was examined utilizing atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). Fourier transform infrared spectroscopy (FTIR) outcomes indicated that the inhibition mechanism was by adsorption process through the functional groups that exist in the investigated extract. The results demonstrated that the inhibiting efficiency expanded with expanding amounts of the extract. Polarization information demonstrated that CIE goes about as an inhibitor of mixed type. The procedure of adsorption on Al surface ascribed to Langmuir isotherm. All thermodynamic calculations were determined and discussed. The inhibitive efficiencies obtained from all utilized procedures have acceptable values.

Newly synthesized triazolopyrimidine derivative as an inhibitor for mild steel corrosion in HCl medium: an experimental and in silico study

A new triazolopyrimidine derivative, namely, 6-hydroxy-7-phenyl-6,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidin-5(4H)-one (HPTP) was synthesized. Its corrosion inhibition performance on mild steel in 1M HCl solution was researched through weight loss, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and scanning electron microscope (SEM) approaches. The experimental results show that the inhibition efficiency of HPTP increases with the increase of concentrations, whereas decreases as the temperature rises. PDP data reveal that the HPTP acts as a mixed type inhibitor. EIS results imply that the HPTP molecules form an antiseptic layer at the steel/solution interface. The adsorption of the inhibitor molecules on the steel surface follows Langmuir's adsorption isotherm. In addition, density functional theory (DFT) calculations were also employed to gain further insight into the adsorption behavior and inhibition mechanism.

Theoretical and Experimental Studies on the Adsorption of N- [(E)-Pyridin-2-ylmethylidene] Aniline, a Schiff Base, on Mild Steel Surface in Acid Media

The adsorption of N-[(E)-Pyridin-2-ylmethylidene] aniline, a Schiff base, on to mild steel surface in 1M HCl and 0.5M H2SO4 solutions and the consequent corrosion protection were studied employing weight loss method, electrochemical impedance spectroscopy and potentiodynamic polarization measurements. DFT calculations were performed to investigate its interaction with the metal surface at the atomic level to understand its inhibition mechanism. The adsorption process is well described by the Langmuir isotherm. The thermodynamic parameters indicated that the adsorption is spontaneous and the interaction of the inhibitor at the mild steel surface is mainly through physisorption. The Ra values obtained in AFM studies for the uninhibited and inhibited sample in HCl media respectively are 0.756 and 0.559 μm, and that in H2SO4 media are 0.411 and 0.406 μm. The lesser roughness values of the inhibited sample shows the adsorption of the molecules onto the mild surface. The inhibition efficiencies were found to improve with concentration of the inhibitor and the maximum efficiency was observed at 400ppm in all the investigation methods adopted. The inhibitor was found to exhibit a higher efficiency in HCl media (95.7%) than in H2SO4 (92.8%). The theoretical and experimental results are found to be in good agreement. Keywords: Corrosion, Inhibitor, Potential of Zero Charge, Atomic Force Microscopy, Density Functional Theory

Analysis of drugs as corrosion inhibitors in metallic materials

The use of metallic materials is very important for our society, and corrosion is a spontaneous degradation process that turns their application harder and more expensive. Therefore, alternative and cheap methods for the reduction or elimination of this process are necessary, as drugs with anti-corrosive properties. The objective of this study was measuring the efficiency, through gravimetric analysis in acid media (HCl 1M), of Dipyrone Monohydrate and Ticlopidine Hydrochloride as corrosion inhibitors, on four materials: steel, cast iron, brass and aluminum. The Ticlopidine Hydrochloride on steel had the max efficiency of 99,17% and the Dipyrone Monohydrate on brass had the minimum efficiency of 0,22%.

Anti-stress phytohormones impact on proteome profile of green gram (Vigna radiata) under salt toxicity

Anti-stress phytohormones impact on proteome profile of green gram (Vigna radiata) under salt toxicity

X-Ray Photoelectron Spectroscopy Estimation of Cobalt Seed Layer Reactivity Toward Air Exposure: A Challenge?

The impact of the air-exposure of an electroplated cobalt film has been investigated to assess the effect of oxygen interaction on metallic cobalt surface. XPS is used in order to evaluate the Co2p spectra of different time air exposure. We demonstrate that the oxidation start very quickly and then is stabilized toward a limited oxide thickness. Dipping oxidized electrodeposited Co film in two acidic solutions (HCl 1M and Kari© aveni acidic Co chemistry) shows that the oxide dissolution must be considered as a main phenomenon for the seed layer during plating process.

Comprehensive use of products generated during acid leaching of basic oxygen furnace sludge

A novelty process based on acid leaching basic oxygen furnace sludge by means of medium of 2,5M H2SO4 and 1M HCl was proposed. The new medium used in the study leaches franklinite ZnFe2O4 present in the tested sludge, which is hardly soluble in weak sulphuric acid solutions and well soluble in HCl solutions. This allows for 100% zinc extraction from the basic oxygen furnace sludge. The component of the leaching medium in the form of a sulphuric acid solution transforms the calcium compounds contained in the basic oxygen furnace sludge into insoluble calcium sulphate. The study examined the effect of solid to liquid ratio S/L (g/mL), temperature, time and rotational speed of stirrer on zinc and iron extraction from the sludge. Optimal leaching conditions were: t = 120 min, T = 60 °C, n = 500 min−1, S/L: 0.2. The leached solid filtration product obtained after leaching, dried and magnetically processed is separated into pure iron-bearing concentrate, which contains 77% Fe3O4 and 23% Fe2O3 and calcium sulphate waste. Their composition is confirmed by the X-ray diffraction analysis. The use of ethyl alcohol to precipitate sulphate iron compounds is a new alternative to recover and reuse the precipitant. The pure iron sulphate compounds with different hydration are obtained, which is confirmed by the X-ray diffraction analysis. The utilitarian aim of the study was to specify technological guidelines of the presented process and its material balance. Acid leaching of basic oxygen furnace sludge helps solve the problem of lack of selectivity in acid leaching of zinc and iron. This suggests the possibility of comprehensive use of the obtained products.

Phosphorus Fraction in a Yellow Latosol Cropped Under No-tilage System in the Brazilian Amazon

Phosphorus (P) deficiency is one of the main factors that limits productivity in Brazilian soils. However, soil management under no-tillage system (NT) may alter the availability of P in the soil. The objective of this study was to evaluate the dynamics of P fractions in a dystrophic Yellow Latosol, cropped under no-tillage for a long period of time in the Amazon Biome. The study was conducted on a farm located in the municipality of Paragominas, southeastern Pará. This experiment evaluated plots cultivated in plots at nine (NT9), 11 (NT11) and 13 (NT13) years of no-tillage system adoption, in one plot under conventional cultivation system (CS) and a surrounding area under native forest (NF) at depths of 0-10, 10-20, 20-30 and 30-40 cm. The soil samples were subjected to P chemical fractionation to determine the different fractions. The soil management systems showed differential capacity of P accumulation. In the areas under no-tillage, P is accumulated in the toplayer and drastically reduced with depth, while in CS, this reduction is less pronounced. In the 0-20 cm depth layer during the adopted period of the no-tillage system, it was observed an increase in the content of inorganic phosphorus extracted by resin and 0.5 M NaHCO3 (PiAER and PiBIC) and organic phosphorus extracted by 0.5 M NaHCO3 (PoBIC), fractions considered as available for Biomass. Regardless of the year of adoption, the no-tillage system was superior to CS and NF. This was also observed for the inorganic and organic fractions extracted by NaOH 0.1M (PiHid-0.1 and PoHid-0.1)and inorganic fraction extracted by HCl 1M (PiHCl).