scholarly journals EFFISIENSI INHIBISI KOROSI BAJA LUNAK DALAM MEDIA ASAM DENGAN INHIBITOR EKSTRAK KULIT BUAH KAKAO (Theobroma cacao)

Author(s):  
Yuli Yetri ◽  
E Emriadi ◽  
Novesar Jamarun ◽  
G Gunawarman

Efek inhibisi korosi dan sifat-sifat adsorpsi oleh ekstrak kulit buah kakao (Theobroma cacao)  pada baja lunak (mild steel) dalam larutan asam 1,5M HCl telah dipelajari menggunakan teknik konvensional metode berat hilang pada variasi waktu, konsentrasi dan suhu. Parameter-parameter termodinamika seperti energi aktivasi, entalpi, entropi dan perubahan energi bebas dihitung. Polarisasi elektrokimia telah dievaluasi untuk memastikan jenis inhibitor. Spektra infrared dan GCMS dilakukan untuk mengetahui senyawa ekstrak yang berperan  dalam proses inhibisi. Morfologi permukaan sampel diamati dengan menggunakan scanning electro microscopy dengan  energy dispersive X-ray spectroscopy (SEM-EDX) . Keseluruhan hasil penelitian menunjukkan bahwa ekstrak polar kulit buah coklat  dapat digunakan sebagai inhibitor korosi yang efektif pada baja karbon di lingkungan 1,5M HCl dengan pencapaian efisiensi  inhibisi   terkorosi sebesar 96.26% (weight loss) dan 92.08% (Tafel) pada konsentrasi ekstrak 2,5% selama768 jam. Mekanisme inhibisi adalah  adsorpsi chemiadsorpsi berdasar tingginya nilai entalpi dan energi bebas.Effisiensi Inhibisi diketahui meningkat dengan peningkatan konsentrasi dari ekstrak serta menurun dengan peningkatan suhu. Kurva polarisasi menunjukkan inhibitor ini berperilaku sebagai inhibitor campuran dengan dominan pada inhibisi katodik. Ekstrak diadsorpsi oleh permukaan mild steel  mengikuti model adsorpsi isotherm Langmuir. Kondisi permukaan mild steel menunjukan terjadinya adsorpsi di permukaan membentuk lapisan tipis di permukaan logam. Penambahan ekstrak kulit buah kakao ke dalam larutan HCl sangat efektif untuk mengurangi serangan korosi di permukaan mild steel.  Kata kunci: Korosi, Inhibitor, Theobroma cacao, Mild steel, Potensiodinamik Corrosion Inhibition Efficiency Mild Steel in Acid Media with Inhibitor Peels Extract of Cacao (Theobroma cacao)ABSTRACT Inhibition and adsorption properties of Theobroma cacao peel polar extract addition on corrosion inhibition efficiency of 0.3%C mild steel in hydrochloric acid solution for various exposuring time, extract concentration and working temperature were investigated using weight loss test method. Electrochemical polarization test was also conducted to confirm the effectiveness of inhibition. Infrared spectrum of the samples was also evaluated to reveal compounds of the extract which controll the inhibition process. Morphology and local composition of sample surfaces were respectively examined by scanning electron microscope  (SEM) and energy dispersive X-ray spectroscopy (EDX). Thermodynamic parameters such as energy activation, enthalpy, entropy and change in the free energy were then determined using related data. The results show that the inhibition efficiency increases significantly up to 96.3% (by weight loss method) and 92.08% (Tafel) with the increase of TCPE content. The optimum efficiency is obtained at extract concentration of 2,5% for exposuring time of 768h. However, the efficiency decreases slightly with increasing working temperature in the range of 303K-323K. The polarization curve shows the inhibitor behaves as a mixed inhibitor with the dominant cathodic inhibition. The adsorption model is found to obey Langmuir adsorption isotherm. Surface condition is  improved due to the adsorption and then formation of thin layer film protection in the surface of the steel. The addition of extract of cacao peels into HCl is effective to minimize corrosion attack on the mild steel. Key words: Corrosion, inhibitor, Theobroma cacao peel, Mild steel, Potensiodinamic

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Saeed Mohammadi ◽  
Fatemeh Baghaei Ravari ◽  
Athareh Dadgarinezhad

An investigation was conducted to improve the corrosion inhibition efficiency of molybdate-based inhibitors for mild steel which is the main construction material of cooling water systems, using nitroethane as an organic compound beside zinc. In this study a new molybdate-based inhibitor was introduced with the composition of 60 ppm molybdate, 20 ppm nitrite, 20 ppm nitroethane, and 10 ppm zinc. Inhibition efficiency of molybdate alone and with nitrite, nitroethane, and zinc on the uniform corrosion of mild steel in stimulated cooling water (SCW) was assessed by electrochemical techniques such as potentiodynamic polarization and electrochemical impedance (AC impedance) measurements. Weight loss measurements were made with coupon testing specimens in the room temperature for 48 h. Studies of electron microscopy, including scanning electron microscopy (SEM) photograph and X-ray energy dispersive spectrometry (EDS) microanalysis, were used. The results obtained from the polarization and AC impedance curves were in agreement with those from the corrosion weight loss results. The results indicate that the new inhibitor is as effective as molybdate alone, though at one-ninth of the concentration range of molybdate, which is economically favorable.


RSC Advances ◽  
2015 ◽  
Vol 5 (56) ◽  
pp. 45217-45230 ◽  
Author(s):  
Pooja Singh ◽  
Divya Pratap Singh ◽  
Karishma Tiwari ◽  
Monika Mishra ◽  
Ashish K. Singh ◽  
...  

Metal complexes of 2-amino-benzoic acid (phenyl-pyridin-2-yl-methylene)-hydrazide are synthesized and the structures are determined by X-ray crystallography. These compounds show appreciable corrosion inhibition efficiency for mild steel in 1 M HCl.


2008 ◽  
Vol 5 (2) ◽  
pp. 275-280 ◽  
Author(s):  
Atul Kumar

Effect of Sodium Lauryl Sulfate (SLS), a surfactant on corrosion of mild steel in 1 M hydrochloric acid was studied using three techniques namely: weight loss, electrochemical polarization and metallurgical research microscopy. Results obtained reveal that SLS is good inhibitor and shows very good corrosion inhibition efficiency (IE). The IE was found to vary with concentration of inhibitor and temperature. The electrochemical polarization result revealed that SLS is anodic in nature.


2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Maria Erna ◽  
Herdini Herdini ◽  
Abdullah Abdullah ◽  
Suharmin Suharmin

Abstrak Telah dipelajari efisiensi dan mekanisme inhibisi korosi karboksimetil kitosan (KMK) pada permukaan baja lunak dalam larutanH2SO4.Efisiensi inhibisi korosi ditentukan dengan menggunakan metode pengukuran berat hilang (Weight Loss Method), sedangkan mekanisme inhibisi korosi dipelajari berdasarkan hasil analisis karakterisasi Scanning Electron Microscope- Energy Dispersive X-ray(SEM-EDX). Hasil penelitian menunjukkan bahwa efisiensi inhibisi korosi KMK dalam H2SO4 mencapai 65.12%. Hasil analisis karakterisasi memperlihatkan mekanisme inhibisi KMK pada permukaan baja lunak melalui peristiwa adsorpsi kimia membentuk lapisan pasif berupa senyawa Fe-khelatmelalui unsur O dari gugus –OH dan N dari gugus –NH2 dari molekul KMK Kata kunci : Efisiensi inhibisi korosi, karboksimetil kitosan, mekanisme inhibisi   Abstract The corrosion inhibition efficiencyandmechanism ofcarboxymethylchitosan(CMC) on the surface ofmild steel in H2SO4 solution has studied. Determination of the corrosion inhibition efficiency measurement used Weight Loss Method (WLM), whereas the mechanism of corrosion inhibition studied based on the analysis characterizing Scanning Electron Microscope-Energy Dispersive X-ray (SEM-EDX). The results showed that the corrosion inhibition efficiency of CMC reaches 65.12%. Characterization analysis results showed inhibition mechanism CMC on mild steel surface through chemical adsorption events form a passive layer of Fe-chelate compounds through O elementof -OH group and N element of -NH2 group of molecules KMK. Keywords : corrosion inhibittion efficiency, carboxymethyl chitosan, inhibition mechanism


2019 ◽  
Author(s):  
Chem Int

The corrosion inhibition characteristics of two medicinal molecules phenylalanine and rutin on mild steel in 1.0M Hydrochloric acid were evaluated using gravimetric method. Corrosion inhibition efficiency of 83.78 and 90.40 % was obtained respectively after seven days. However, phenylalanine showed weak accumulative higher corrosion inhibition efficiency. The presence of both molecules in the corrosive environment reduced the corrosion rate constant and increased the material half-life. Thermodynamic data calculated suggests a spontaneous adsorption of the molecules on the mild steel’s surface.


Author(s):  
Lalita Saini ◽  
R. K. Upadhyay

Mass loss and Scanning Electron Microscope method (SEM) have been used to study the corrosion inhibition efficiency on mild steel and aluminium using synthesized inhibitors i.e. N-Benzylidene aniline (CI1) and N-Benzylidene 4-methylaniline (CI2) in Trichloroacetic acid (TCAA). Study reveals that both mild steel and aluminium are prone to corrosion in organic acid like TCAA. Out of these two metals, aluminium is more vigorously corroded by the TCAA in comparison to mild steel in same conditions and synthesized inhibitors CI1 and CI2 are almost same effective for mild steel and aluminium.


Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4245
Author(s):  
Gaetano Palumbo ◽  
Kamila Kollbek ◽  
Roma Wirecka ◽  
Andrzej Bernasik ◽  
Marcin Górny

The effect of CO2 partial pressure on the corrosion inhibition efficiency of gum arabic (GA) on the N80 carbon steel pipeline in a CO2-water saline environment was studied by using gravimetric and electrochemical measurements at different CO2 partial pressures (e.g., PCO2 = 1, 20 and 40 bar) and temperatures (e.g., 25 and 60 °C). The results showed that the inhibitor efficiency increased with an increase in inhibitor concentration and CO2 partial pressure. The corrosion inhibition efficiency was found to be 84.53% and 75.41% after 24 and 168 h of immersion at PCO2 = 40 bar, respectively. The surface was further evaluated by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), grazing incidence X-ray diffraction (GIXRD), and X-ray photoelectron spectroscopy (XPS) measurements. The SEM-EDS and GIXRD measurements reveal that the surface of the metal was found to be strongly affected by the presence of the inhibitor and CO2 partial pressure. In the presence of GA, the protective layer on the metal surface becomes more compact with increasing the CO2 partial pressure. The XPS measurements provided direct evidence of the adsorption of GA molecules on the carbon steel surface and corroborated the gravimetric results.


2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
M. G. Tsoeunyane ◽  
M. E. Makhatha ◽  
O. A. Arotiba

The ecofriendly poly(butylene succinate) extended with 1,6-diisocynatohexane composted with L-histidine (PBSLH) polymer composite was synthesized by condensation polymerization. The polymer composite was characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM-EDX). The inhibition action of the polymer composite was investigated by conventional weight loss, potentiodynamic polarization, variable amplitude micro (VASP), and electrochemical impedance spectroscopy (EIS). The maximum corrosion inhibition efficiency of 78 % was obtained at concentration level of 600 ppm. The results revealed PBSLH as a mixed type corrosion inhibitor. The thermodynamic and kinetic parameters also revealed adsorption of PBSLH on to mild surface as exothermic and the adsorption was conformed to Langmuir model. The morphology of mild steel coupons was investigated by SEM and atomic force microscope (AFM) and the results showed PBSLH to have inhibited corrosion on mild steel in 1 M HCL.


2017 ◽  
Vol 41 (21) ◽  
pp. 13114-13129 ◽  
Author(s):  
Neeraj Kumar Gupta ◽  
Chandrabhan Verma ◽  
R. Salghi ◽  
H. Lgaz ◽  
A. K. Mukherjee ◽  
...  

Phosphorus containing compounds have been evaluated by experimental and theoretical techniques and more than 96% corrosion inhibition efficiency was observed at 200 ppm concentration.


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