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

2016 ◽  
Vol 7 (2) ◽  
pp. 67-80
Author(s):  
Yuli Yetri ◽  
E Emriadi ◽  
Novesar Jamarun ◽  
G Gunawarman
Keyword(s):  
Weight Loss ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Theobroma Cacao ◽  
Inhibition Efficiency ◽  
Energy Dispersive ◽  
X Ray ◽  
Extract Concentration ◽  
Working Temperature ◽  
Corrosion Inhibition Efficiency

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

Adsorption and corrosion inhibition characteristics of two medicinal molecules

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Hydrochloric Acid ◽  
Corrosion Rate ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Half Life ◽  
Thermodynamic Data ◽  
Inhibition Efficiency ◽  
Gravimetric Method ◽  
Corrosive Environment ◽  
Corrosion Inhibition Efficiency

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.

scholarly journals A Comparative Study on the Corrosion Inhibition of Mild Steel and Aluminium by Synthesized Inhibitors in Organic Acidic Medium

2020 ◽  
pp. 41-51
Author(s):  
Lalita Saini ◽  
R. K. Upadhyay
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Acidic Medium ◽  
Trichloroacetic Acid ◽  
Inhibition Efficiency ◽  
Corrosion Inhibition Efficiency ◽  
Scanning Electron Microscope Method ◽  
Scanning Electron

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.

New phosphonate based corrosion inhibitors for mild steel in hydrochloric acid useful for industrial pickling processes: experimental and theoretical approach

2017 ◽  
Vol 41 (21) ◽  
pp. 13114-13129 ◽  
Author(s):  
Neeraj Kumar Gupta ◽  
Chandrabhan Verma ◽  
R. Salghi ◽  
H. Lgaz ◽  
A. K. Mukherjee ◽  
...  
Keyword(s):  
Hydrochloric Acid ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Theoretical Approach ◽  
Corrosion Inhibitors ◽  
Inhibition Efficiency ◽  
Phosphorus Containing ◽  
Corrosion Inhibition Efficiency

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

scholarly journals Improvement in Corrosion Inhibition Efficiency of Molybdate-Based Inhibitors via Addition of Nitroethane and Zinc in Stimulated Cooling Water

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Saeed Mohammadi ◽  
Fatemeh Baghaei Ravari ◽  
Athareh Dadgarinezhad
Keyword(s):  
Electron Microscopy ◽  
Weight Loss ◽  
Mild Steel ◽  
Corrosion Inhibition ◽  
Inhibition Efficiency ◽  
Cooling Water ◽  
Ac Impedance ◽  
Uniform Corrosion ◽  
Corrosion Inhibition Efficiency ◽  
Zinc Inhibition

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.

scholarly journals Synergistic Effect of Thiourea-Zn2+ and L-Phenylalanine on the Inhibition of Corrosion of Mild Steel in Acid Medium

2019 ◽  
Vol 7 (2) ◽  
pp. 72-77
Author(s):  
M.B. Geetha ◽  
◽  
J. Sathish ◽  
S. Rajendran ◽  
◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Mild Steel ◽  
Acid Medium ◽  
Corrosion Inhibition ◽  
Metal Surface ◽  
Inhibition Efficiency ◽  
Protective Film ◽  
Surface Smoothness ◽  
Polarization Study ◽  
Corrosion Inhibition Efficiency

The formulation consisting of 100 ppm Thiourea, 25 ppm Zn2+ and 250 ppm of L-Phenylalanine has 95% corrosion inhibition efficiency with a synergistic effect among Thiourea, L-Phenylalanine and Zn2+ ions. Polarization study shows that this formulation as a mixed inhibitor. FTIR spectra exposed the presence of Fe2+-Thiourea, Fe2+-L-Phenylalanine complex and Zn(OH)2 in protective film. AFM study confirmed the metal surface smoothness following engrossed in the inhibitor and the presence of formed protective film on the metal surface.

scholarly journals Anti-corrosive effect of Cassia alata leaves extract on Mild steel in 1.0N Hydrochloric acid

2006 ◽  
Vol 2 (2) ◽  
pp. 82-90
Author(s):  
Petchiammal A.p ◽  
P.Deepa Rani ◽  
S.Seetha Laks ◽  
S. Selvaraj
Keyword(s):  
Mild Steel ◽  
Corrosion Inhibition ◽  
Inhibition Efficiency ◽  
Spectroscopic Studies ◽  
Protective Film ◽  
Cassia Alata ◽  
Langmuir Adsorption ◽  
Corrosive Effect ◽  
Ft Ir ◽  
Corrosion Inhibition Efficiency

The inhibition effect of Cassia alata leaves extract on corrosion of mild steel in 1N HCl was investigated through mass loss measurements with various time and temperature. The observed result indicated that the corrosion inhibition efficiency and degree of surface coverage were increased with increase of inhibitor concentration and temperature. The thermodynamic parameters (Ea, ∆Hads, ∆Gads, ∆Sads) were evaluated for corrosion inhibition process which suggests that the adsorption is endothermic, spontaneous and chemisorptions and also the inhibitor follows Langmuir adsorption isotherm. The protective film formed on metal surface was analyzed using spectroscopic studies viz, UV, FT-IR and EDX techniques.

Sign in / Sign up

Export Citation Format

Share Document