Corrosion inhibition of mild steel by Laurus nobilis leaves extract as green inhibitor

2011 ◽  
Vol 38 (7) ◽  
pp. 1311-1321 ◽  
Author(s):  
Avcı Gülşen
2021 ◽  
pp. 139-150
Author(s):  
Vidhya Thomas K ◽  
Joby Thomas Kakkassery ◽  
Vinod P. Raphael ◽  
K. Ragi ◽  
Reeja Johnson

The corrosion inhibition power of an eco-friendly green inhibitor Ixora coccinea extract (ICE) for mild steel in 1 M HCl and 0.5 M H2SO4 was analysed using physicochemical and electrochemical techniques. 1–5 v/v% ICE was prepared and added into the corrosive acidic media for different analyses. Weight loss measurements conducted for a period of 24hrs for mild steel immersion revealed 89.38% and 77.96% inhibition capacity of ICE in 1 M HCl and 0.5 M H2SO4 medium respectively. Electrochemical impedance parameters show that as concentration is increased, efficiency increases and double layer capacitance decreases. Potentiodynamic polarization techniques are also in good agreement with impedance studies and exhibit the mixed type inhibition character of ICE. Electrochemical noise spectrum also strongly supports the anti-corrosive property of ICE and the magnitude of noise signal decreases concerning the increase in ICE concentration. Ixorene, which is one of the major constituents of Ixora coccinea leaves was also studied for its corrosion inhibition nature by quantum mechanical calculations and was found to match with all other results. Adsorption studies of ICE are in accordance with Langmuir isotherm. Surface morphological studies confirm the formation of a protective barrier on mild steel surface in both media, i.e., 1 M HCl and 0.5 M H2SO4.


Author(s):  
Irfan A Abro ◽  
Muhammad I Abro ◽  
Mamdouh EH Assad ◽  
Mohammad Rahimi-Gorji ◽  
Nguyen M Hoang

It is a well-established fact that corrosion of mild steels occurs in pipelines, storage tanks, oil reservoirs, boilers, and petrochemicals industries. Green inhibitors are economical, non-toxic and eco-friendly, and forming barrier type layer of organic compounds over metallic materials. In this paper, weight loss, electrochemical measurements containing potential measurements, potentiodynamic polarization and impedance spectroscopy were applied to inspect the neem leaves extract inhibition efficiency and corrosion phenomenon under three conditions (X1, X2 and X3) in 1.0 M HCl medium. The characterization technique including scanning electron microscopy coupled with energy dispersive spectroscopy was conducted to scrutinize the elemental analysis, corrosive pitting and morphology of corrosion products of mild steel immersed in 1.0 M HCl medium with and without neem leaves extract concentration. The corrosion inhibition efficiency of neem leaves extract increased with increasing concentration and conditioning time. By increasing the conditioning time from 0.08 h to 72 h, the corrosion inhibition efficiency of neem leaves extract was increased from 75% to 97%. The neem leaves extract corrosion inhibitor works quite effectively only for 24 h, thereafter its efficiency drastically decreases. For 24 h, neem leaves extract prevented 80–90% corrosion attack but when steel immersion time was increased to 48 h and 72 h, its efficiency decreased from 83% to 65% and 52% to 42%, respectively.


2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Chiedozie C. Aralu ◽  
Helen O. Chukwuemeka-Okorie ◽  
Kovo G. Akpomie

AbstractGongronema latifolium was used as a low-cost green inhibitor for mild steel by applying the weight loss method at 303–323 K. There was a decrease in percentage inhibition with temperature increase and a rise in inhibition efficiency with an increase in the concentration of inhibitor. The obtained results showed that Gongronema latifolium extract of methanol had percentage inhibition efficiencies in the range of 59.06–81.69%. Corrosion inhibition of mild steel showed a good fit to the Langmuir model compared to the Freundlich and El-Awardy adsorption models. Thermodynamics parameters, such as $$ E_{\text{a}} $$ E a , $$ Q_{\text{ads}} $$ Q ads and $$ \Delta G_{\text{ads}} $$ Δ G ads were evaluated and showed that the mechanism of corrosion inhibition of mild steel by methanol extract of Gongronema latifolium was physisorption. The results of this work indicated efficient potentials of the methanol extract of Gongronema latifolium as a low-cost corrosion inhibitor in acidic media for mild steel, which could be applied to reduce corrosion of metals in industries.


Sign in / Sign up

Export Citation Format

Share Document