scholarly journals Anti-Corrosion Mechanism of Parsley Extract and Synergistic Iodide as Novel Corrosion Inhibitors for Carbon Steel-Q235 in Acidic Medium by Electrochemical, XPS and DFT Methods

Author(s):  
Shan Wan ◽  
Huikai Chen ◽  
Tian Zhang ◽  
Bokai Liao ◽  
Xingpeng Guo

The parsley extract (PLE) was prepared using absolute ethyl alcohol. The PLE and synergistic iodide were firstly utilized as efficacious corrosion inhibitors to slow down the corrosion rate of carbon steel-Q235 in 0.5 mol/L H2SO4 solution. The anti-corrosion performance was researched by weight loss method, electrochemical tests, surface analysis and quantum chemistry calculation. Results of electrochemical and weight loss tests show that the synergetic PLE and I− exhibit the optimal corrosion inhibition efficiency 99%. The combined inhibitor displays the favorable long-term corrosion inhibition effect, and the inhibition efficiency can maintain more than 90% after 144 h immersion. The introduction of I− makes carbon steel surface with higher negative charge amount, which could be beneficial to the interaction between corrosion inhibitor and Fe atoms. The adsorption behavior obeys the Langmuir isotherm adsorption, and involves chemical and physical adsorption. On the basis of electrochemical consequences and theoretical calculation, the adsorption process and anti-corrosion mechanisms are further explored.

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
K. S. Shaju ◽  
K. Joby Thomas ◽  
Vinod P. Raphael ◽  
Aby Paul

The corrosion inhibition efficiency of a potential polynuclear Schiff base, (s)-2-(anthracene-9 (10H)-ylidene amino)-5-guanidinopentanoic acid (A9Y5GPA), on carbon steel (CS) in 1 M hydrochloric acid solution has been investigated using weight loss measurements, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization studies. The corrosion inhibition efficiencies of parent amine [(s)-2-amino-5-guanidinopentanoic acid] and parent ketone (anthracene-9 (10H)-one) on carbon steel in 1.0 M hydrochloric acid solution have also been investigated using weight loss studies. The electrochemical and weight loss data established that the inhibition efficiency on CS increases with the increase in the concentration of inhibitor, A9Y5GPA. The adsorption of A9Y5GPA obeys the Langmuir adsorption isotherm. Thermodynamic parameters (Kads, ΔGads0) were calculated using the adsorption isotherm. Activation parameters of the corrosion process (Ea, ΔH* and ΔS*) were also calculated from the corrosion rates obtained from temperature studies. Tafel plot analysis revealed that A9Y5GPA acts as a mixed-type inhibitor. A probable inhibition mechanism was also proposed. Surface morphology of the carbon steel specimens in the presence and absence of the inhibitor was evaluated by SEM analysis.


2018 ◽  
Vol 34 (5) ◽  
pp. 2471-2476 ◽  
Author(s):  
Hamida Edan Salman ◽  
Asim A. Balakit ◽  
Ali Ahmed Abdulridha

A new aromatic Schiff base with azo linkage (AS) has been synthesized and characterized by FT-IR, 1H NMR and 13C NMR spectroscopic techniques. The new compound (AS) has been evaluated as carbon steel corrosion inhibitor at different concentrations (0.005, 0.01, 0.02, 0.04 and 0.08 mM) and different temperatures (303 – 333 K). The corrosion inhibition efficiency was studied by potentiodynamic polarization and weight loss measurements. The effects of concentration and temperature on the inhibition efficiency were studied by potentiodynamic polarization studies, the results showed that increasing concentration of AS increases the inhibition efficiency while increasing the temperature decreases it, the highest corrosion inhibition efficiency, 93.9% was recorded with 0.08 mM of AS at 313 K in 1 M H2SO4. Weight loss measurements showed that the inhibition efficiency reached 97.1% in the presence of AS (0.08 mM) at 313 K. The adsorption process was found to obey Langmuir isotherm, and the adsorption thermodynamic parameters were studied. Scanning electron microscope (SEM) was used to confirm the results.


Author(s):  
A. H. EL-ASKALANY ◽  
S. I. MOSTAFA ◽  
A. M. EID

The inhibitive action of Saponinic extract of both Zygophylium album and Zygophylium Egyptian leaves which could serve as eco-friendly materials was investigated on the corrosion of N80 carbon steel in 1 M HCl solution. The techniques employed for the study were weight loss measurements. potentiodynamic polarization, electrochemical frequency modulation (EFM), and electrochemical impedance spectroscopy (EIS). The results obtained show that these extracts could serve as an effective inhibitor for N80 carbon steel. The percentage inhibition increases with increasing concentration of the inhibitor at 25 °C The percentage inhibitor efficiency above 90% was obtained at a concentration of 700 ppm for both extracts. The corrosion rates of steel and inhibitive efficiencies obtained from impedance and polarization measurements were in good agreement with those obtained from weight loss measurements. Potentiodynamic polarization studies clearly reveal that both extracts act as mixed-type inhibitors The study shows that the inhibition efficiency decreased with the temperature rise of the medium. Heat of adsorption and thermodynamic parameters and indicated that the adsorption process is mainly controlled by the physical adsorption process.


This paper presents the results of an experimental investigation carried out to study the effect of surface applied organic and inorganic corrosion inhibitors on reinforced steel in concrete. The reinforcement bars were coated with Neem powder (organic inhibitor) and Zinc powder (inorganic inhibitor) as corrosion inhibitors. The samples of beams of size 100X100X640mm having 4 steel bars as reinforcement were prepared and cured in normal water for 15 days and in saline environment for 42 days. The inhibitors were applied in the form of 2 coats, 4 coats and blend of both. The grade of concrete used was M30. Half-cell Potential and Weight loss measurements were carried out to determine the efficiency of corrosion inhibitors [11]. The corrosion inhibition efficiency of controlled specimen and coated specimens were compared. From the results it was seen that samples with 4 coats of Neem showed 44% inhibition efficiency as compared to control specimens. Similarly specimens with two coats of Neem, four coats of Neem and Zinc also showed better corrosion inhibition efficiency. Highest weight loss was observed in case of control specimen. The study concludes that use of surface applied corrosion inhibitors prove efficient in enhancing the corrosion inhibition efficiency of concrete. Surface applied corrosion inhibitors provide protective layer to the reinforcement thereby protecting it from corrosion and increasing the durability of the structure. This type of technique of using corrosion inhibitors in concrete can be used in various structures such as buildings, bridges, sewage pipes, marine structures, abutments & piers, RCC roads which are subjected to harsh environmental conditions.


Author(s):  
N’guessan Yao Silvère Diki ◽  
Nagnonta Hippolyte Coulibaly ◽  
Kadjo François Kassi ◽  
Albert Trokourey

The corrosion inhibition of mild steel by 7-(ethylthiobenzimidazolyl) theophylline (7-ETBT) in 1 M HCl medium was investigated through weight loss and Tafel polarization techniques within a temperature range of 298 to 318 K. The inhibition efficiency depends on the concen­tration of 7-ETBT and reaction system temperature. The maximum inhibition efficiency values of 90.73 and 87.06 %, respectively, were estimated using both weight loss and Tafel polarization techniques at 298 K. The results suggest spontaneous and predominant physical adsorption of 7-ETBT on the metal surface which obeys Langmuir isotherm model. Furthermore, Tafel polarization method revealed that 7-ETBT is a mixed-type inhibitor. Po­tentiodynamic polarization results are in accordance with weight loss data to a good extent.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Liang Liu ◽  
Ting-Ting Cao ◽  
Qi-Wei Zhang ◽  
Chong-Wei Cui

Circulating cooling water plays an important role in industrial water use. In this study, the corrosion inhibition effects of PBTCA, HEDP, and ATMP organic phosphorus inhibitors were investigated using the weight loss method by varying the dosage of inhibitors, ClO2 concentrations, and pH values on carbon steel in recirculating cooling water with a low concentration of ClO2 solution. The results showed that the three corrosion inhibitors had a satisfactory corrosion inhibition effect and that corrosion inhibition efficiency is positively correlated with the concentration of organic phosphorus inhibitors and pH. The average corrosion inhibition efficiency of the three inhibitors was about 80% at the concentration of inhibitors = 35 mg/L, pH = 9.0, and the concentration of ClO2 = 7.0 mg/L, of which the single-phosphorus molecular corrosion inhibitor proved to be the best inhibitor. When the ClO2 concentration was 7 mg/L, the corrosion inhibition efficiencies of the three corrosion inhibitors were relatively stable. Using the density functional theory (DFT) algorithm in the Gaussian 09 program, the optimization calculation was completed by the B3LYP/6-31G (d, p) method at the microlevel. The molecular structures of the three organic phosphorus inhibitors and the number of phosphorus-containing atoms were compared to the sustained-release properties. Organic phosphorus inhibitors, as an electronic buffer, not only provided electrons but also received electrons. They formed a complex with iron and zinc ions in water in order to attach to the surface of the carbon steel and to alleviate corrosion. In addition, the adsorption with a metal surface followed the Langmuir adsorption isotherm.


2006 ◽  
Vol 84 (12) ◽  
pp. 1658-1666
Author(s):  
B Ramesh Babu ◽  
A K Parande ◽  
P L Ramasamy

Inhibition studies of N-cetyl-N,N,N-trimethylammonium bromide (CTAB) and orthophenylenediamine (OPD) have shown that they were effective inhibitors of corrosion of carbon steel in HCl. The inhibitive behaviour of OPD with CTAB on the corrosion of carbon steel in 1 mol/L HCl was studied by gravimetric weight loss, potentiodynamic polarization, and electrochemical impedance measurements. Inhibition efficiency (IE) was found to increase with the increase in concentration of CTAB and it was also found that CTAB was effective only when used above a concentration of 100 mmol/L. Furthermore, the addition of 20 mmol/L of OPD to CTAB slightly increased the IE. The adsorption of these compounds on carbon steel in 1 mol/L HCl obeyed Langmuir's adsorption isotherm. These inhibitors reduced the permeation current. The IE was observed as high for 200 mmol/L of CTAB with 20 mmol/L of OPD in all the techniques studied. Scanning electron microscopy clearly showed that the inhibition was due to a polymolecular film formed by the physical adsorption of the inhibitor on the metal surface.Key words: carbon steel, corrosion, inhibitors, impedance, potentiodynamic polarization.


2020 ◽  
Vol 10 (1) ◽  
pp. 9-17
Author(s):  
Roland Tolulope Loto ◽  
Asamaige Ogaga

AbstractStudy of the synergistic inhibition properties of the combined admixture of 4-methyl-norvalin and 2-methoxy-4-formylphenol (non-toxic organic compounds) on the corrosion of P4 low carbon mold steel in 1.5 M H2SO4 and HCl solution was performed with weight loss measurement, potentiodynamic polarization and optical microscopy analysis. Results obtained showed the inhibition efficiency of the admixed compound performed above the value for effective corrosion inhibition at very low concentrations in H2SO4 solution. However, from mid concentration to the highest concentration studied, the inhibition efficiency of the compound was above 85% from electrochemical tests. In HCl solution the inhibition efficiency of the compound was well above 80% and 90% for weight loss and polarization tests at all concentration studied. Anodic corrosion inhibition mechanism was determined for the compound in H2SO4 according to Freundlich and Frumkin adsorption isotherms due to weak Van der Waals attraction between the inhibitor molecules and the steel’s surface. The mechanism of corrosion inhibition in HCl was calculated to be cathodic type according to Langmuir isotherm model.Morphological images of inhibited and non-inhibited steel surfaces significantly contrast each other though the extent of deterioration was much severe for the steel from H2SO4 solution.


2012 ◽  
Vol 581-582 ◽  
pp. 755-758
Author(s):  
Ying Li Wei ◽  
Ya Qiang Tian ◽  
Yue Hua Wang ◽  
Xiao Hong Yang

The corrosion inhibition performance of molybdate and molybdate compound corrosion inhibitor of carbon steel in seawater were tested using weight loss method, electrochemical polarization curve, and the quaternary compound molybdate corrosion inhibitor were made sure through the experiments. The experiment results show that the compound corrosion inhibitors have obvious synergistic corrosion inhibition effects in the proportion of 40 mg/L molybdate, 10mg/L HEDP, 4mg/L Zn2+ and 50 mg/L glucose acid salts.


2019 ◽  
Vol 233 (11) ◽  
pp. 1571-1601
Author(s):  
Elsayed A. El-Sharaky ◽  
Eman A. Khamis ◽  
Olfat E. El-Azabawy ◽  
Aziza S. El-Tabei

Abstract A new star shape tetra-cationic surfactant was synthesized to evaluate as corrosion inhibitors for carbon steel in different acid media. This surfactant prepared by the reaction of tris(2-(dimethylamino)ethyl) O,O′,O′′-(nitrilotris(ethane-2,1-diyl)) trimaleate with 1-bromododecane and abbreviated as STCS. The chemical structure of the prepared surfactant was confirmed by FT-IR, 13C and 1HNMR and elemental analysis. Their aggregation behavior in watery solution was explored by surface tension measurements. The surface tension of water was decreased nearly to 35 mN m−1 when adding the surfactant. This result demonstrates that the surfactant shows remarkable surface activity, due to the effect of the head groups. Corrosion inhibition efficiency of the surfactant on the carbon steel surface in 1 M hydrochloride acid and 1 M H2SO4 was evaluated using the electrochemical measurements. These measurements revealed that the synthesized surfactant act as effective mixed-type corrosion inhibitors. Their adsorption on a carbon steel surface was well described by the Langmuir adsorption isotherm. Corrosion inhibition efficiency was enhanced with increasing the concentration of inhibitor and increasing the temperatures. The results of the quantum chemical calculations and the electrochemical measurements were in good agreement.


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