scholarly journals EFISIENSI INHIBITOR PADA KOROSI Cu-37Zn

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
Eka Junaidi
Keyword(s):  
Free Energy ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Inhibitor ◽  
Room Temperature ◽  
Electrochemical Impedance ◽  
Inhibitor Efficiency ◽  
Sulfide Ion ◽  
Adsorption Free Energy ◽  
Eis Technique

Abstrak : Salah satu upaya pencegahan korosi pada logam dapat dilakukan dengan penambahan inhibitor ke dalam larutan uji. Inhibitor korosi yang dicoba adalah benzotriazol (BTAH) dan sistein (Cys). Penentuan laju korosi Cu-37Zn tanpa dan dengan adanya inhibitor korosi dilakukan secara elektrokimia dengan menggunakan teknik Electrochemical Impedance Spectroscopy (EIS). Hasil penelitian ini menunjukkan bahwa pada larutan uji dengan komposisi : 5,3 ppm Ca(NO3)2, 78 ppm NaCl dan ion sulfida sebesar 15 ppm diperoleh bahwa efisiensi benzotriazol (80 ppm) dan sistein (25 ppm) pada suhu kamar berturut-turut sebesar 40,74% dan 68,16%. Inhibitor yang di uji dalam penelitian ini teradsorpsi secara fisik pada permukaan logam Cu-37Zn dengan energi bebas adsorpsi (ΔGads) benzotriazol dan sistein berturut-turut adalah –18,53 dan –23,03 kJ/mol. Kata kunci : Inhibitor, EIS, Benzotriazol, Sistein Abstract : An effort to prevent of the corrosion can be performed by mean of inhibitor corrosion addition into the sample of water. We also investigated benzotriazole (BTAH) and cysteine (CYS) as inhibitor. The rates of corrosion Cu-37Zn in absence and presence of the corrosion inhibitor were determined by using Electrochemical Impedance Spectroscopy (EIS) technique. The obtained results were indicated that at sample of water with composition of 5.3 ppm Ca(NO3)2, 78 ppm NaCl and 15 ppm sulfide ion,  the inhibitor efficiency of benzotriazole (80 ppm) and cysteine (25 ppm) at room temperature were 40.74% and 68.16% respectively. Since both inhibitors were physicaly adsorbed on Cu-37Zn with adsorption free energy (ΔGads)of benzotriazole and cysteine is –18.53 kJ/mol and –23.03 kJ/mol respectively. Keywords : Inhibitor, EIS, Benzotriazole, cysteine.

scholarly journals Adsorption Free Energy of Glycine on TiO2 in Water from First Principles Simulations and Electrochemical Impedance Spectroscopy

2021 ◽  
Author(s):  
Lorenzo Agosta ◽  
Luca Fiore ◽  
Noemi Colozza ◽  
Alexander Lyubartsev ◽  
Fabiana Arduini ◽  
...  
Keyword(s):  
Free Energy ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Density Functional ◽  
Electrochemical Impedance ◽  
Computational Study ◽  
Tight Binding ◽  
Quantitative Agreement ◽  
Perfect Agreement ◽  
Adsorption Free Energy

Abstract The adhesion of amino acids and small organic molecules on TiO2 nanoparticles is fundamental for bio-nano functionalization of peptides and proteins. The adsorption free energy is the main physical quantity that regulates the adsorption process. Its evaluation is particularly challenging both experimentally, due to the weak interfacial signal in aqueous environments, and by atomistic simulations, due to the complexity of the physical phenomena occurring at the solid-water interface (polarization and charge transfer effects). We report here an accurate experimental-computational study of hydrated TiO2 nanoparticles interacting with Glycine where we obtain quantitative agreement of the measured adsorption free energy. Ab-initio simulations are performed within the Tight Binding Density Functional Theory in combination with enhanced free energy sampling techniques. The experiments adopt a new and efficient set-up for electrochemical impedance spectroscopy measurements based on screen-printed gold electrodes. The measured adsorption free energy is about -30 kJ/mol (both from experiment and calculation), with preferential interaction of the charged NH3 group which strongly adsorbs on the TiO2 bridging oxygens. The perfect agreement between computation and experiment opens the doors to an extended exploration of the bio-nano interaction for different materials and molecules.

Propolis Extract as Corrosion Inhibitor of Iron Alloy Immersed in an Ethylene Glycol / Water, 0.1 M NaCl Solution

2021 ◽  
Vol 406 ◽  
pp. 265-273
Author(s):  
Hakima Hachelef ◽  
Abdallah Khelifa ◽  
Abderrahim Benmoussat
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Ethylene Glycol ◽  
Corrosion Inhibitor ◽  
Electrochemical Impedance ◽  
Iron Alloy ◽  
Activation Parameters ◽  
Propolis Extract ◽  
Solution Interface ◽  
Isotherm Adsorption

The behaviour of a corrosion inhibitor based on proplolis extract via an iron alloy immersed in an electrolyte containing ethylene glycol water in NaCl 0.1 M was evaluated by a stationary technique not destructive which is the technique of electrochemical impedance. The diameter of the Nyquist curves increases with the increase of the concentration of propolis extract and it reaches an optimum concentration at 1.25 g / L, the maximum surface coverage percent at this concentration is 71.98% .The activation parameters reveal that the inhibitor molecules on iron surface are absorbed by physisorption and a chimisorption and obey Langmuir isotherm adsorption. These results were supplemented by Scanning electron microscopy (SEM) and (EDX) spectrum of chemical composition. The metal solution interface is simulated as a physical model by using electrochemical impedance spectroscopy (EIS). Keywords: Iron Alloy, Propolis extract, ethylene glycol;, Lamgmuir isotherm, Electrochemical impedance Spectroscopy (EIS).

scholarly journals Inhibitive Effect by Acid Extract of Ficus Exasperata Leaves on the Sulphuric Acid Corrosion of Mild Steel

2009 ◽  
Vol 6 (s1) ◽  
pp. S189-S194 ◽  
Author(s):  
N. S. Patel ◽  
S. Jauhari ◽  
G. N. Mehta
Keyword(s):  
Weight Loss ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Mild Steel ◽  
Corrosion Inhibitor ◽  
Electrochemical Impedance ◽  
Electron Microscopic ◽  
Scanning Electron Microscopic ◽  
Microscopic Studies ◽  
Scanning Electron

Extract ofFicus exasperataleaves was investigated as corrosion inhibitor of mild steel in 1 N H2SO4using conventional weight loss, electrochemical polarizations, electrochemical impedance spectroscopy and scanning electron microscopic studies. The weight loss results showed that the extract ofFicus exasperatais excellent corrosion inhibitor. Electrochemical polarizations data revealed the mixed mode of inhibition. The results of electrochemical impedance spectroscopy shows that the change in the impedance parameters, charge transfer resistance and double layer capacitance, with the change in concentration of the extract is due to the adsorption of active molecules leading to the formation of a protective layer on the surface of mild steel. Scanning electron microscopic studies provided the confirmatory evidence of improved surface condition, due to the adsorption, for the corrosion protection.

Evaluation of N,N-Dimethylformamide as Corrosion Inhibitor on API 5L X70 using 3% NaCl

MRS Advances ◽  
2019 ◽  
Vol 4 (44-45) ◽  
pp. 2391-2399
Author(s):  
Pablo Martínez Jiménez ◽  
Araceli Espinoza Vázquez ◽  
Francisco Javier Rodríguez Gómez
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Inhibitor ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Electrochemical Technique ◽  
Metallic Surface ◽  
Hydrodynamic Conditions ◽  
Metallic Material ◽  
Corrosive Solution

AbstractDimethylformamide (DMF) has been tested as corrosion inhibitor in a metallic material like API 5LX70 in a corrosive solution of 3% of NaCl and using electrochemical technique as electrochemical impedance spectroscopy. The results showed that 20 ppm is the best concentration to protect the metallic surface of API 5L X70 with η∼ 94%. Hydrodynamic conditions (100 and 1000 rpm) demonstrated that the DMF at different concentration afforded moderate protection against corrosion with inhibition efficiency ∼70%. Finally, the adsorption of this compound follows the Langmuir isotherm with a chemisorption-physisorption process.

Electrochemical Investigation of Cyproconazole as Corrosion Inhibitor for Copper in Synthetic Seawater

2013 ◽  
Vol 763 ◽  
pp. 23-27 ◽  
Author(s):  
Ji Liu ◽  
Li Zheng ◽  
Hai Bo Gan ◽  
Huan Liu ◽  
Zhi Hua Tao ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Inhibitor ◽  
Inhibition Efficiency ◽  
Electrochemical Impedance ◽  
Copper Surface ◽  
Electrochemical Investigation ◽  
Nacl Solution ◽  
Adsorption Film ◽  
Synthetic Seawater

This paper presents the investigation of cyproconazole,namely2-(4-chlorophenyl)-3-cyclopropyl-1-(1H-1,2,4-triazol-1-yl) butan-2-ol,ascorrosion inhibitor for copper in synthetic seawater (3.5% NaCl solution).The inhibition action of cyproconazole on the corrosion of copper was investigated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization.The selective desorption of Cyproconazole from copper surface was also studied by the differential polarization curves.EIS indicates that the inhibition formed an adsorption film on copper surface.The inhibition efficiency increases with increasing concentration.Polarization curves show that Cyproconazole acts as mixed-up inhibitor.

Performance of cactus mucilage and brown seaweed extract as a steel corrosion inhibitor in chloride contaminated alkaline media

2017 ◽  
Vol 64 (5) ◽  
pp. 529-539 ◽  
Author(s):  
Eddisson Francisco Hernández ◽  
Prisciliano Felipe de Jesus Cano-Barrita ◽  
Frank Manuel León-Martínez ◽  
Andres Antonio Torres-Acosta
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Inhibitor ◽  
Electrochemical Impedance ◽  
Brown Seaweed ◽  
Alkaline Media ◽  
Alkaline Solutions ◽  
Content Type ◽  
Cent Concentration ◽  
Cactus Mucilage

Purpose This paper aims to present experimental results related to the performance of cactus mucilage (CM) and brown seaweed extracts (SEs) to inhibit reinforcing steel bar (rebar) corrosion in saturated calcium hydroxide alkaline solutions (pH = 12.5). Design/methodology/approach Electrochemical cells were prepared using CM solutions at 0.5, 1 and 1.38 per cent concentration (w/v), SE solutions at 0.5, 1, 1.38, 2 and 3 per cent concentration (w/v), sodium alginate at 1 per cent concentration (w/v) and calcium nitrite at 11.3 per cent (v/v). Each cell contained six deformed reinforcing steel bars of 9.5 mm nominal diameter. The experiments were performed at 23 ± 2°C in two stages. The first stage was aimed at stabilizing the rebar until passivation was reached. The second stage included adding NaCl in six steps from 0.5 to 16 g/L. Half-cell potential, linear polarization resistance and electrochemical impedance spectroscopy measurements were monitored during both stages. Findings The electrochemical test results indicated that both additions reduce the corrosion rate of rebars and pitting in an alkaline media with chloride ions (16 g/L NaCl). Electrochemical impedance spectroscopy results for rebars in natural-added solutions showed higher charge transfer resistance and double layer capacitance values, indicative of the formation of a second interface between the rebar and the electrolyte. Research limitations/implications The information obtained was for alkaline solutions only. Further investigation is performed using concrete as the alkaline electrolyte. Practical implications CM and SE may be suitable low-cost corrosion inhibitors for steel in concrete. Social implications The use of botanical or algae products for this application will encourage people to consider its production for this particular application. Also, the possible harvest in an environmental friendly way will diminish in the future the use of biohazards and toxic inhibitors. Originality/value This investigation is a continuation of a one presented in 2007, which uses only nopal mucilage. This new investigation corroborates what was concluded in the early investigation and incorporates a new natural by product, algae, as a possible corrosion inhibitor product.

A study of hydroxyethyl imidazoline as H2S corrosion inhibitor using electrochemical noise and electrochemical impedance spectroscopy

2009 ◽  
Vol 40 (2) ◽  
pp. 393-399 ◽  
Author(s):  
M. A. Lucio-Garcia ◽  
J. G. Gonzalez-Rodriguez ◽  
A. Martinez-Villafañe ◽  
G. Dominguez-Patiño ◽  
M. A. Neri-Flores ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Corrosion Inhibitor ◽  
Electrochemical Noise ◽  
Electrochemical Impedance ◽  
H2s Corrosion
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