Corrosion Inhibition Of Aquilaria Methanolic Leaf Extracts For Mild Steel In Hydrochloric Acid Solution
Loading...
Date
2018-04
Authors
Lee, Helen Yun Sin
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Corrosion is a problem that negatively affects many industries and causes these
industries monetary losses. Many synthetic inhibitors were developed to overcome the
corrosion problem. However, these synthetic inhibitors are harmful to human and the
environment. In this study, the methanolic leaf extracts of Aquilaria malaccensis (noninoculated)
and Aquilaria subintegra (non-inoculated, chemical inoculated, physical
inoculated) leaf were investigated as green and sustainable corrosion inhibitors for
mild steel in 1 M HCl solution. From the quadrupole-time of flight liquid
chromatography/mass spectrometry (Q-TOF LC/MS) analysis, choline, isoleucine,
adenosine, phenylalanine and mangiferin were confirmed to be present. The leaf
extracts and the standard compounds were applied as corrosion inhibitors for mild steel
in 1 M HCl solution. Overall, the leaf extracts were shown to have good corrosion
inhibition efficiency of up to 96 % at the concentration of 1500 ppm from the anticorrosion
measurements namely the electrochemical impedance spectroscopy (EIS)
measurement, the potentiodynamic polarisation measurement and the weight loss
study. Among the studied leaf extracts, the leaf extract of Aquilaria malaccensis seems
to be overall the best as corrosion inhibitor. It was found that there were no relation
between the inhibition efficiencies and the treatment of the tree (inoculated or noninoculated).
The standard compounds had various corrosion inhibition abilities and
adenosine was found to be the best corrosion inhibitor among the tested standard
compounds. The leaf extracts best fitted into the modified Langmuir adsorption
isotherm model and adsorbed by mixed-type but predominantly physisorption process.
Description
Keywords
Corrosion inhibition of aquilaria methanolic leaf extracts , mild steel in hydrochloric acid solution