scholarly journals Inhibition Effect of Glycerol on the Corrosion of Copper in NaCl Solutions at Different pH Values

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Santos Lorenzo Chi-Ucán ◽  
Andrea Castillo-Atoche ◽  
Pedro Castro Borges ◽  
José Antonio Manzanilla-Cano ◽  
Gerardo González-García ◽  
...  

The inhibitory effect of glycerol on copper corrosion in aerated NaCl (0.5 M) solutions at three pH values (4, 7, and 10) was evaluated. Inhibition efficiency was assessed with conventional electrochemical techniques: open circuit potential, potentiodynamic polarization, and electrochemical impedance analysis. Glycerol reduced the corrosion rate of copper in NaCl solutions. The best inhibition effect (η≈83%) was produced in alkaline (pH 10) chloride media. This effect can be ascribed to increased viscosity and the presence of copper-glycerol complexes.

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
D. M. Martinez de la Escalera ◽  
J. J. Ramos-Hernandez ◽  
E. Porcayo-Palafox ◽  
J. Porcayo-Calderon ◽  
J. G. Gonzalez-Rodriguez ◽  
...  

In this study, the effect of the addition of Nd3+ ions as a corrosion inhibitor of the API X70 steel in a medium rich in chlorides was evaluated. The performance of the Nd3+ ions was evaluated by means of electrochemical techniques such as potentiodynamic polarization curves, open circuit potential measurements, linear polarization resistance, and electrochemical impedance spectroscopy, as well as by means of scanning electron microscopy and EDS measurements. The results showed that Nd3+ ions reduce the corrosion rate of steel at concentrations as low as 0.001 M Nd3+. At higher concentrations, the inhibition efficiency was only slightly affected although the concentration of chloride ions was increased by the addition of the inhibitor. The adsorption of the Nd3+ ions promotes the formation of a protective layer of oxides/hydroxides on the metal surface, thereby reducing the exchange rate of electrons. Nd3+ ions act as a mixed inhibitor with a strong predominant cathodic effect.


2016 ◽  
Vol 11 (2) ◽  
pp. 3441-3451 ◽  
Author(s):  
A. M. El-Shamy ◽  
M. F. Shehata ◽  
Samir T. Gaballah ◽  
Eman A. Elhefny

Laboratory synthesized ethyl (4-(N-(thiazol-2-yl)sulfamoyl)phenyl)carbamate (TSPC), characterized by 1H NMR spectroscopy, was evaluated as corrosion inhibitor of mild steel in 0.1M HCl using electrochemical techniques. Open circuit potential, potentiodynamic polarization and impedance spectroscopy were used to evaluate the inhibition efficiency of (TSPC) at various concentrations. The obtained electrochemical data indicated that (TSPC) acts as moderate corrosion inhibitor for mild steel in acidic media. It is found that the inhibition efficiency increases with the concentration of the inhibitor till 400ppm. The adsorption isotherm involving physisorption of (TSPC) at room temperature and the experimental data complied to the Langmuir adsorption isotherms and the negative values of the Gibb’s free energy of adsorption obtained suggested that inhibitor molecules have been spontaneously adsorbed onto the mild steel surface.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Yun Liu ◽  
Zhi Dang ◽  
Yin Xu ◽  
Tianyuan Xu

The potential of triethylenetetramine (TETA) to inhibit the oxidation of pyrite in H2SO4solution had been investigated by using the open-circuit potential (OCP), cyclic voltammetry (CV), potentiodynamic polarization, and electrochemical impedance (EIS), respectively. Experimental results indicate that TETA is an efficient coating agent in preventing the oxidation of pyrite and that the inhibition efficiency is more pronounced with the increase of TETA. The data from potentiodynamic polarization show that the inhibition efficiency (η%) increases from 42.08% to 80.98% with the concentration of TETA increasing from 1% to 5%. These results are consistent with the measurement of EIS (43.09% to 82.55%). The information obtained from potentiodynamic polarization also displays that the TETA is a kind of mixed type inhibitor.


Author(s):  
Mohandoss S ◽  
◽  
Srinivasan S.P. ◽  

Development of biocompatible dental implants has become significant impact in dental industry. In the present work, we report for the development of biocompatible nano Yttria stabilised Zirconia (YSZ) coatings on 316L stainless steel (316L SS) obtained by EPD process. The optimized sample (nano YSZ coating on 316 obtained at applied potential of 70 V for 5 minutes) were sintered in air at 600, 800 and 900°C. The surface morphology and composition of the coatings were characterized by XRD and FE-SEM with EDAX. The electrochemical performance of the uncoated metal and nano YSZ coated 316L SS samples were evaluated in artificial saliva (AS) medium using electrochemical techniques such as Open Circuit Potential – time measurement (OCP), Electrochemical Impedance Spectroscopy (EIS) and Cyclic Potentiodynamic Polarization (CPP).


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Van T. H. Vu ◽  
Thanh T. M. Dinh ◽  
Nam T. Pham ◽  
Thom. T. Nguyen ◽  
Phuong T. Nguyen ◽  
...  

Silica/Polypyrrole nanocomposites (SiO2/PPy) incorporating oxalate as counter anion (SiO2/PPyOx) were chemically polymerized in the solution with the presence of pyrrole, silica, and sodium oxalate. Nanocomposites SiO2/PPyOx at different concentrations of oxalate anion were characterized with FTIR, XRD, EDX, TGA, and TEM. The corrosion protective properties for carbon steel of nanocomposites in epoxy coating were studied by electrochemical techniques including electrochemical impedance spectroscopy (EIS) and open circuit potential (OCP). FTIR results of nanocomposites show a slightly red-shift in terms of wavelength compared with the case of PPy and SiO2 spectra. It may be due to a better conjugation and interactions between PPy and SiO2 in nanocomposite structure. TEM image indicated that nanocomposites have spherical morphologies with diameters between 100 and 150 nm. The EIS results showed that |Z| modulus values of epoxy coatings containing SiO2/PPyOx composites reached about 109.7 Ω.cm2, always higher than that of epoxy coating. These results are also confirmed by OCP results. It proves that the presence of oxalate anion can enhance the resistance against corrosion and it has been shown that the content of counter anion strongly affects the anticorrosion ability.


2020 ◽  
Vol 71 (7) ◽  
pp. 187-196
Author(s):  
Maria Magdalena Pricopi ◽  
Romeu Chelariu ◽  
Nicolae Apostolescu ◽  
Doina-Margareta Gordin ◽  
Daniel Sutiman ◽  
...  

The aim of this study was to investigate the influence of different process parameters as chemical composition, the pH value and immersion time on the corrosion of the some TiMoNb alloys, using different electrochemical techniques such as: cyclic voltammetry, open circuit potential (OCP) measurement, polarization curves and electrochemical impedance spectroscopy (EIS). The alloys were analyzed in the natural pH of the Ringer solution, but also with an acidic modification of the solution (ph = 4) and a basic modification (ph = 8). The more acidic values of pH, the more evident are differences between corrosion behavior of titanium-based alloys depending on their chemical compositions and immersion times.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
G. Thenmozhi ◽  
P. Arockiasamy ◽  
R. Jaya Santhi

The oxidative chemical polymerizations of three isomers of aminophenol,ortho,meta, andpara(PoAP, PmAP, and PpAP), were performed in aqueous HCl using ammonium persulfate as an oxidant at 0–3°C. The synthesized polymers were characterized by employing elemental analysis, GPC, UV-VIS-NIR, FT-IR, XRD, and TGA. The corrosion inhibition effect of these three polymers on mild steel in 1 M HCl solution was studied by using electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy. These measurements reveal that the inhibition efficiency obtained by these polymers increased by increasing their concentration. The inhibition efficiency follows the order PpAP > PoAP > PmAP. The results further revealed that PpAP at a concentration of 250 mg/L furnishes maximum inhibition efficiency (96.5%). Polarization studies indicated that these three polymers act as the mixed type corrosion inhibitors.


2016 ◽  
Vol 1139 ◽  
pp. 46-51
Author(s):  
Lidia Benea ◽  
Eliza Dănăilă ◽  
Valentin Marian Dumitraşcu

Vegetable extracts have become important as an environmentally acceptable, readily available and renewable source for wide range of inhibitors. They are the rich sources of ingredients which have very high inhibition efficiency. The aim of the present work is to study the corrosion inhibition characteristics of aqueous extract of USINHIB (the abbreviation attributed to garlic extract, derived from romanian language, which was used as vegetable inhibitor), which have been studied as an eco-friendly green inhibitor for corrosion control of carbon steel in 0.5 M hydrochloric acid. The inhibitive effect of naturally available vegetable extract USINHIB toward the corrosion of carbon steel in 0.5 M HCl solution has been investigated by electrochemical techniques. Open circuit potential, potentiodynamic polarization, electrochemical impedance spectroscopy and cyclic voltammetry in presence and absence of vegetable inhibitor were used to provide detailed information about the corrosion of steel surface which occurs in acidic environment. The three electrode electrolytic cell was used. The obtained results showed the increase in the inhibition efficiency.


2012 ◽  
Vol 66 (7) ◽  
Author(s):  
Marija Petrović ◽  
Ana Simonović ◽  
Milan Radovanović ◽  
Snežana Milić ◽  
Milan Antonijević

AbstractThe effect of purine (concentration range of 1.00 × 10−6–1.00 × 10−2 M) on the behavior of copper in a 0.5 M Na2SO4 solution (pH 7 and pH 9) was studied using the open circuit potential measurement, potentiodynamic polarization, and chronoamperometry. Potentiodynamic polarization shows that purine acts as a copper corrosion inhibitor in both alkaline and neutral sulfate solutions. The efficiency of inhibition increases as the purine concentration increases. Chronoamperometric results follow the same trend as the results of potentiodynamic polarization. The inhibition effect can also be observed visually by microscopic examination of the electrode surface. Purine is adsorbed on copper surface according to the Langmuir adsorption isotherm.


2011 ◽  
Vol 399-401 ◽  
pp. 1577-1581
Author(s):  
Yu Xuan Li ◽  
Zhen Duo Cui ◽  
Xian Jin Yang ◽  
Sheng Li Zhu

Porous Ti alloys are novel biomedical candidates for surgical implant application. The corrosion resistance of porous Ti-24Nb-4Zr alloy with 41.54% porosity prepared from conventional sintering was investigated by means of open circuit potential, potentiodynamic polarization and electrochemical impedance spectroscopy techniques in 0.9% NaCl physiological and Hank’s solutions with different pH values (2.4, 5.4, 7.4) at 310 K, respectively. Meaning solid Ti-24Nb-4Zr alloy was chosen as a reference. Porous Ti-24Nb-4Zr alloy shows wide passive regions based on anodic polarization curves. These observations suggest that porous Ti-24Nb-4Zr alloy owns excellent corrosion resistance. Therefore, they are potential for biomedical applications.


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