Natural Corrosion Inhibitor Research Articles

Evaluation of Idesia polycarpa Maxim fruits extract as a natural green corrosion inhibitor for copper in 0.5 M sulfuric acid solution

Idesia polycarpa Maxim fruits extract (IFE) was investigated as a natural green corrosion inhibitor. The inhibition efficiency obtained from electrochemical impedance spectroscopy (EIS) reached up 90.8% at 298 K, 93.3% at 303 K, and 93.8% at 308 K for 300 mg/L IFE. The results of the polarization test agree with those gained by EIS. The X-ray photoelectron spectroscopy (XPS) analysis was adopted to illustrate the bonding information between Cu and IFE, and the peak of N:Cu bond was detected. The scanning electron microscopy (SEM) observation showed that an effective and protective film was formed on Cu surface, which confirmed the outstanding inhibition capacity of IFE obtained by electrochemical methods. The adsorption of IFE on Cu surface conformed to the Langmuir adsorption model by fitting the EIS data and included both physisorption and chemisorption. Quantum chemical calculation and molecular dynamic simulation were employed to further account for the inhibition mechanism.

Studies onRhoeo discolorplant extract as a natural corrosion inhibitor

The use of plant extracts as natural corrosion inhibitors is gaining prominence as they contain different organic compounds adsorbed on the surface of metals. Studies were carried out on the ethanolic extract of the abundantly available Rhoeo discolor leaves, commonly known as boat lily, as it is a natural inhibitor in hydrochloric acid (HCl) (0.1–0.5 M) on mild steel. R. discolor plant extract is biodegradable, cheap and readily available in nature. Inhibition efficiencies were obtained from weight loss, potentiodynamic polarisation and electrochemical impedance spectroscopic study at 30°C. A scanning electron microscopy report confirms the adsorption of the inhibitor on mild steel. Fourier transform infrared spectroscopy and gas chromatography and mass spectroscopy reports support the presence of functional groups in the inhibitor. The effect of inhibitor dosage from 0.1 to 0.5 g/l is investigated at 30°C. Corrosion inhibition efficiency for mild steel in 0.1 M of hydrochloric acid and 0.5 g/l of inhibitor is found to be maximum at 94.6% estimated by the weight loss method. The potentiodynamic polarisation method indicates 85.28%, and it stands at 88.60% by the impedance method. Results suggest that R. discolor acts as a good inhibitor of the corrosion process on mild steel.

Experimental and Theoretical Evaluation of Acacia catechu Extract as a Natural, Economical and Effective Corrosion Inhibitor for Mild Steel in an Acidic Environment

The corrosion inhibition of the Acacia catechu bark was tested on mild steel in a 0.5 M sulphuric acid solution using weight loss, Tafel and EIS. A. catechu showed its best corrosion resistance of 93.85% at a concentration of 600 mg/L. SEM and AFM were used to verify the formation of a protective layer on the surface of the mild steel. The adsorption phenomenon was verified using UV–Vis. spectroscopic technique while FT-IR confirmed the presence of different functional groups containing heteroatoms. The adsorption of the inhibitory molecules on the surface of the mild steel followed the Langmuir adsorption isotherm. Theoretical studies were carried out as a supplementary study. All the results obtained to assure that the bark extracts of A. catechu can create an effective blocking layer and control the corrosion process.

Electrochemical Impedance Spectroscopy (EIS) Study of Coconut Water as Natural Inhibitor in Malay Traditional Preservation of Iron Artefact

Treating and cleaning corroded artefact has resulted in long-term loss of artefact integrity and intangible historical value in museum preservation method. Inhibitors and coatings are preferable methods applied in heritage conservation as it is the easiest way for corrosion protection. However, issue of health and environment has led conservators to find a better inhibitor, natural or green corrosion inhibitors. Surprisingly, Malay traditional practice has since long ago used Coconut water (CW) as corrosion inhibitor to preserve keris blades, showing that the knowledge in corrosion protection has been practiced in old Malay civilization for metal preservation. This paper intends to clarify the compositional effect of CW in the inhibition efficiency to iron-based keris blade. Through Tafel and Electrochemical Impedance Spectroscopy (EIS) and Energy dispersive analysis of X-rays (EDAX) analysis, the study showed that CW formed passivation with the highest IE of 92% as compared to other natural inhibitors existing and used in industries such as Ascorbic Acid (AA) and Tartaric acid (TA). EIS and Scanning Electron Microscope (SEM) study has shown and conclude that CW has displayed protective abilities that exceeds both AA and TA.

Evaluation of Purple Onion (Allium cepa L.) Extract as a Natural Corrosion Inhibitor for Carbon Steel in Acidic Media

The capacity of the Allium cepa L. extract from peel (ACP) and bulb (ACB) as a natural corrosion inhibitor for carbon steel was evaluated. The corrosion characterization was performed by a gravimetric test, showing an inhibitor efficiency of 60% (ACP) and 67% (ACB). Electrochemical tests indicated higher corrosion resistance for carbon steel in the presence of the extracts, and the SEM images of steel samples confirm the results. These extracts were analyzed by the DPPH (2,2-diphenyl-1-picrylhydrazyl) method, confirming the antioxidant activity. The chemical characterization of the extracts by FTIR measurements revealed the presence of phenolic compounds with antioxidant capacity.

Evaluation of pectin isolated from tomato peel waste as natural tin corrosion inhibitor in sodium chloride/acetic acid solution

The pectin from tomato peel waste (TPP) was employed as tin corrosion inhibitor with the aim to enhance the knowledge regarding the application of natural inhibitors, instead synthetic, and reducing the waste disposal for value-added biopolymers production. To evaluate the TPP anticorrosion activity the commercial apple pectin (CAP) was also utilised. The gravimetric tests show that the highest inhibitive impact (η) of 75.9 % (CAP) and 73.9 % (TPP) are gained at concentration of 20 g L−1. By electrochemical, potentiodynamic polarization and impedance spectroscopy measurements, the maximum η (60.05–65.5 %) are reached at lower concentration (4 g L−1), due to tendency of pectins to form viscous solution. The prominent decreases in current density with the shifts of potential in the cathodic direction revealed that pectins provided cathodic protection of tin surface. Similar inhibition impact of pectins, and fine agreement between applied methods confirmed their suitability against tin corrosion.

Adsorption ability, stability and corrosion inhibition mechanism of phoenix dactylifera extrat on mild steel

Adsorption ability, stability and corrosion inhibition of phoenix dactylifera (date palm) seed extract (PDSE) as a natural corrosion inhibitor were studied on mild steel (MS) in 1 M HCl solution after different exposure times. Linear polarization resistance (LPR), potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS) techniques were utilized to define the inhibiting performance of the extract on the rate of corrosion. The stability of the organic film formed over the metal surface was investigated with the help of chronoamperometry (CA) technique. The MS surface was characterized using scanning electron microscopy (SEM), x-ray diffraction (XRD) and contact angle measurements. Surface charge of the metal after exposing to the solution was determined by measuring the potential of zero charge (PZC) using the EIS technique and an adsorption mechanism was proposed. The results of the electrochemical measurements showed that PDSE reduces sufficiently the rate of MS corrosion. The SEM studies showed that the inhibitor strictly attached to the metal surface and form a protective film over the metal surface. The average inhibition efficiency determined from LPR, EIS and PP techniques was found to be 97.3%, which is quite efficient for the practical applications.

Study the efficiency of tobacco extracts as corrosion inhibitor for steel pipes buried in organic and clay soil

This research includes an experimental study of tobacco extract to be used as natural corrosion inhibitors by applying it on steel pipe (Steel 355) buried in soil, by selecting a suitable extract. Two types of soil were studied (organic soil and clay soil). The steel pipes treated with tobacco extract were buried for a period of (five months), and the effectiveness of tobacco extract on pipes’ corrosion is studied. The results showed the effectiveness of the tobacco extract as an inhibitor of corrosion، as well as it is better than its standard counterparts in both studied soils (organic and clay). The inhibitory activity of both (tobacco extract and potassium chromate) was recorded in organic soil for the first month as (71.42and 58.9%) respectively. The inhibitory effectiveness was found in clay soil of both (tobacco extract، potassium chromate) for the first month as (67.65 and 54.05%)، respectively. The results of this study also showed a better inhibitory effect of the extract of tobacco in organic soil than in the clay soil during the study period (five months)، where the inhibitory effect of the tobacco extract was for the fifth month in both organic soil and clay soil (38.55 and 34.99%) respectively.

Caffeine as A Natural Corrosion Inhibitor for Mild Steel in Nacl Solution

Corrosion inhibitors are substances that added to the environment in small concentration and can effectively reduce the corrosion rate that of a metal surface. Natural inhibitors are one types of inhibitor being researched as it brings less environmental impact on the environment. This research was focused on the application of caffeine as inhibitor for corrosion of mild steel in seawater condition. The objective of this project was to develop the relationship between caffeine concentration on the corrosion of mild carbon steel in both static and moving solution contained 3.5-wt% NaCl. Three types of solution were prepared, which are NaCl without addition of caffeine, NaCl with 1-wt% of caffeine and NaCl with 2-wt% of caffeine. Corrosion testing was carried out by weight loss measurement. The microstructures of corroded mild steel specimens were observed under optical microscope. The experimental results indicated that by adding caffeine into the environment medium, weight loss of mild steel specimen was reduced. The corrosion rate of specimens was decreased when more caffeine was added to the environment. From optical microscopic observation, caffeine performed its inhibition effect likely by forming a protective layer which acts as barrier to prevent further corrosion of mild steel in NaCl solution.

Thermodynamic and kinetic insights into the role of amino acids in improving the adhesion of iota-carrageenan as a natural corrosion inhibitor to the aluminum surface

The effect of amino acids on improving the corrosion inhibition performance of i-carrageenan through increasing the polymer adhesion to the aluminum surface in 2 M HCl solution was evaluated by using weight loss measurements at temperatures ranging from 25°C to 45°C. The studied amino acids, including Glycine, Alanine, Isoleucine, Serine, and Cysteine, are believed to play an adsorption mediating role to reach a coherent protection layer on the metal surface. The obtained weight loss data are used to calculate the activation parameters of the transition state formation (Ea, and ) to explain the mechanism of inhibition. A thermodynamic insight into the adsorption phenomenon of the inhibitor on the aluminum surface in the presence and absence of amino acids is provided by calculating the standard Gibbs free energy (), enthalpy (), and entropy () of the adsorption process. The results show a significant enhancement in the inhibition efficiency of i-carrageenan in the presence of amino acids. The obtained values are negative and become more negative with the addition of amino acid to the medium. This indicates that the inhibitor adsorption on the metal surface has a spontaneous nature, and this spontaneity increases in the presence of amino acids. It is also found that the adsorption process of i-carrageenan in the presence of amino acids is driven by a change in entropy, whereas it is controlled by changes in both enthalpy and entropy in the absence of amino acids.

Valorisation of Tomato Peel Waste as a Sustainable Source for Pectin, Polyphenols and Fatty Acids Recovery Using Sequential Extraction

The opportunity of tomato peel waste exploitation for simultaneous recoveries of high value compounds, such as pectin, polyphenols and fatty acids (FAs) is presented in this work. Prior to polyphenols and FAs extraction, the pectin removed from tomato cuticle was evaluated as possible tin corrosion inhibitor using electrochemical impedance spectroscopy. Subsequently, de-pectinized tomato peels are evaluated as appropriate bio-substrate for polyphenols and FAs recovery, using chromatographic analyses. Corrosion tests (24 h) showed that pectin (4 g/L) isolated from tomato peel act as more efficient tin corrosion inhibitor (η = 65.8%) than commercial apple pectin (η = 52.3%), which points out that it could be used as natural corrosion inhibitor. The polyphenols data showed that de-pectinized samples contained higher amounts of total phenols (2485.68–4064.46 mg/100 g, in 96% ethanol) and chlorogenic acid derivative (86.13–454.34 109 mg/100 g, in 70% ethanol) than samples with pectin incorporated in tomato cuticle. In addition, de-pectinized samples contained more polyunsaturated FAs (~ 45%) than samples with pectin (~ 26). Furthermore, both types of peels contained linoleic, palmitic and oleic acids as three dominants, and thus represented valuable source of nutritive oils. Their presence was also confirmed by FTIR and NMR spectroscopy. Therefore, obtained findings revealed that already exploited tomato peel for pectin production could be effectively re-used for polyphenols and FAs recoveries, providing valuable benefits, either for producers and consumers, such as decreasing the waste disposal costs and take opportunity that isolated compounds could be reintroduced into food.

Estudio de inhibición de la corrosión del cobre en agua de mar sintética por Equisetum arvense como inhibidor verde de la corrosión

Extract of the stems of Equisetum arvense was studied as a natural corrosion inhibitor (NCI) in synthetic seawater exposing samples of copper. To determine the protection of the metal by the NCI, electrochemical tests using potentiodynamic polarization curves, electrochemical impedance spectroscopy and linear polarization resistance were performed at room temperature. The morphological characterization of the material with and without NCI was carried out by scanning electron microscopy. The chemical composition of the NCI was determined by Fourier transform-infrared spectroscopy (FTIR) and gas chromatography coupled to mass spectrometry (GC-MS). The results showed that Equisetum arvense acts as a mixed-type NCI, achieving an inhibition efficiency of 53.78% when using 1000 ppm of NCI. From EIS the charge transfer resistance increased in the first 21 h, obtaining an inhibition efficiency of 87.5%. LPR results showed similar behavior than EIS at the same concentration. FTIR revealed that the chemical structure of the compounds of methanol extract of Equisetum arvense have functional groups such as: -OH, C-H, C=O and C-O, whereas GC-MS showed that eight compounds are present in the NCI.

Gum Arabic as corrosion inhibitor in the oil industry: experimental and theoretical studies

ABSTRACTCorrosion inhibitors are commonly used in the oil industry due to their effectiveness, easy application and relatively low cost. Electrochemical and molecular simulation methods were used to investigate the application of Gum Arabic (GA) as a natural polymer corrosion inhibitor for carbon steel. The Tafel analysis results showed that GA works as a mixed-type corrosion inhibitor on carbon steel with the increased Open Circuit Potential. In synthetic brine, the adsorption isotherm study showed that GA inhibitor films were mainly formed via chemisorption. The corrosion efficiency of GA measured by polarisation curve, polarisation resistance and impedance measurements, were 94.0, 83.5 and 90%, respectively. Molecular simulations studies indicated that high molecular weight of carbohydrates have strong interaction with Fe (111) surface.

Latest Exploration on Natural Corrosion Inhibitors for Industrial Important Metals in Hostile Fluid Environments: A Comprehensive Overview

In current years, green extracts have turn out to be the focus of non-toxic corrosion inhibitor due to their economical, easy of availability and low toxicity. Currently plants, signify a group of exciting source of substances that is being explored for employing the metal protection against corrosion in most of the corrosive systems, a possible substitute of toxic corrosion inhibitors. This review explores the application of natural extracts to be used as non-toxic corrosion inhibitors for different metals in various corrosive solutions. The main constituents of plant extract, corrosion inhibition mechanism and adsorption mode of the natural extracts were summarized. The testing methods and important factors influencing the efficiency of the inhibitor were thoroughly discussed. Finally, additional information related to future improvements such as different techniques, corrosion inhibition mechanism, and practical applications of plant extract towards inhibition of metal corrosion in industrial sections was presented in this review article. Knowing the maximum protection rate of the natural inhibitor in a precise corrosive solution is very helpful to decrease the metal corrosion rate in several industrial units. This review article is an effort in this explicit direction.

Assessment of the electrochemical behaviour of Nickel-Titanium-based orthodontic wires: Effect of some natural corrosion inhibitors in comparison with fluoride.

BackgroundThe aim of this study is to assess the corrosion resistance behaviour of Nickel-Titanium-based orthodontic wires (NiTi) in different concentrations of Sodium Fluoride (NaF) and the corrosion’s inhibitory effect of the extracts of some medicinal plants (essential oils, hydrosols and extract).Material and MethodsIn this study we used NiTi (3M) and CuNiTi (ORMCO, 35°C, California) orthodontic wires. The following electrolytes were prepared: Lactate Ringer solution with additions of 0.1%, 0.5% or 1% of Sodium Fluoride and the extracts of different plants: Artemisia, Syzygium aromaticum (Clove) and Celtis australis. Corrosion resistance was studied using anodic potentiodynamic polarisation and electrochemical impedance spectroscopy measurements. At the end of the experiment, microscopic images of wires were performed. ANOVA test with the comparison of Bonferroni and Tukey tests were performed to elucidate comparisons among all groups.ResultsThe higher sodium fluoride concentration is related to negative corrosion potential for both NiTi and CuNiTi orthodontic wire. Hydrosols are associated to positive values of corrosion potential. CuNiTi has a lower corrosion resistance than NiTi.ConclusionsThe prescription of toothpastes containing sodium fluoride should be reduced especially for patients wearing fixed orthodontic appliances. Eugenol may be considered as alternative of sodium fluoride for orthodontic patients for its anti-microbial and anti-corrosive effects. Key words:Corrosion behaviour, Sodium Fluoride, Nickel-Tatanium, orthodontic wires, corrosion inhibitors, aromatical plants.

Corrosion Inhibition of Steel by Addition of Birch Sap in Chloride Solution, 염화물 수용액에서 자작나무 수액을 이용한 철강의 부식 억제

The effects of birch sap, a possible natural corrosion inhibitor, on the corrosion behavior of steel in chloride solution were investigated. The corrosion rate was significantly reduced by the addition of 1~5 mL of birch sap to 500 mL of 3wt% NaCl or 3wt% $CaCl_2$ solution. A remarkable increase i...

Evaluation of the Inhibition Efficiency of a Green Inhibitor on Corrosion of Cu-Ni Alloys in the Marine Application

The aim of this article describes the application of green tea aqueous extract as an eco-friendly corrosion inhibitor for two Cu-Ni alloys in 3.5% NaCl solution. This ability has been studied by using electrochemical techniques (i.e. PDP, CT and EIS), IR spectroscopy measurements and the surface analysis technique (i.e. SEM/EDX). This ability was compared with it's of a commercial cooling water (green water). The results show that tested extract exhibited a good ability to decrease the corrosion rate of alloys in 3.5% NaCl solution.The inhibition efficiency of the green water and green tea extract inhibitors increased with increasing the concentration and decreased with increasing the temperature. The inhibition efficiency of two Cu-Ni alloys which reaching ̴ 91.5% and ̴ 93.9% with 50 % green tea aqueous extract for Cu-10 Ni and Cu-30 Ni alloy, respectively. Electrochemical impedance showed that the change in charge transfer resistance (Rct) and double layer capacity (Cdl) which adsorbed on the alloy surface. Adsorption of the inhibitors gives a good fit to Langmuir isotherm model. Some thermodynamic parameters of activation and adsorption processes were also determined and discussed. Surface examination studies by SEM and EDX confirm the presence of protective film on the alloy surface. In the present study, we investigated the corrosion of the Cu-Ni (cupronickel) alloys in 3.5 % NaCl environment to simulate the seawater desalination plants conditions. Therefore, the future studies can be focused on the development of polymeric compounds used as self- healing or production of new natural corrosion inhibitors especially recommended the waste product of green tea.

Inibidor de corrosão ambientalmente seguro: avaliando extratos de Plectranthus barbatus Andrews

O trabalho apresenta uma avaliação dos extratos etanólico e aquoso de Plectranthus barbatus Andrews (boldo brasileiro) como potenciais inibidores naturais de corrosão para o aço carbono P110 e inoxidável 22Cr-7Ni-3Mo (duplex 22 %Cr), em meio contendo ácido clorídrico 1,0 mol.L-1 e ácido sulfúrico 0,5 mol.L-1. O estudo foi realizado a partir de ensaios gravimétricos com variação na concentração dos extratos e obtenção das eficiências de inibição, e pela análise do perfil químico para identificar metabólitos presentes nos extratos. Os resultados indicaram a ausência de terpenos e a presença de flavonoides, taninos e compostos fenólicos em ambos os extratos. Os ensaios gravimétricos mostraram que os extratos apresentam excelentes resultados para o aço carbono, em ambos os ácidos, com valores de eficiência de inibição superiores a 90 %, revelando o potencial dos extratos como inibidores de corrosão para o aço carbono. Contudo, não apresentam para o aço inoxidável o mesmo desempenho, revelando valores baixos de eficiência de inibição não justificando o uso dos extratos como inibidores para este aço. Os extratos aquoso e etanólico possuem comportamentos diferentes conforme o ácido empregado, com o etanólico proporcionando melhores resultados em ácido sulfúrico e o aquoso em ácido clorídrico.

Opuntia Ficus indica Slime As a Natural Corrosion Inhibitor of Steel in Cement Based Materials in Marine Environment

This research includes results on the electrochemical performance of carbon steel in cement-based mortar when Opuntia Ficus Indica (OFI) slime was used as an addition in the mortar water mixture. Two were the OFI slimes used: cooked and exudate. The cooked OFI slime was produced from boiling cladodes with water in a 1:1 mass ratio, during 1 hour. The exudate OFI slime was extracted by placing OFI cladodes in water, same 1:1 ratio, during 48 hours. The OFI slime addition was mixed at different concentrations (4%, 8%, 15%, and 30% by water content). Half-cell potentials (E) and linear polarization resistance (LPR) measurements were performed at different time periods to characterize the possible corrosion inhibiting effect of the tested addition concentrations. Results showed better corrosion inhibiting effect of the cooked OFI slime for carbon steel, as compared with exudate OFI slime additions.

Technological applications of volatile corrosion inhibitors

Abstract The objective of this review is to create a body of knowledge on the theoretical and practical aspects of corrosion inhibition to prevent and/or to eliminate corrosion in natural environments such as water, air, and acids and in industrial facilities such as oil, natural gas, concrete, paints and coatings, electronics, and military equipment. Corrosion inhibitors (CIs) and volatile corrosion inhibitors (VCIs) are applied in diverse forms such as powders, pellets, aqueous, or solvent solutions and in impregnated papers; closed in pouches and sachets; and added to coatings. Natural CIs are extracted by water or organic solvents from suitable plants. They represent the advanced trends of corrosion management based on green chemistry.