Evaluation of the Corrosion Inhibitive Properties of Three Different Leave Extracts on Mild Steel Iron in Sulphuric Acid Solution
Gabriel N. Chukwueze
Department of Chemical Engineering, Enugu State University of Science and Technology, P.M.B 01660, Enugu, Nigeria.
Christian O. Asadu *
Department of Chemical Engineering, Gregory University, Uturu, P.M.B 1012, Abia State, Nigeria.
Chijioke E. Onu
Department of Chemical Engineering, Nnamdi Azikiwe University, P.M.B 5052, Awka, Nigeria.
Innocent S. Ike
Department of Chemical Engineering, Federal University of Technology, Owerri, Imo State, Nigeria and African Centre of Excellence in Future Energies and Electrochemical System (ACE-FUELS), Federal University of Technology, Owerri, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
The inhibitive ability of pawpaw, neem and curry leaf extracts on corrosion of mild steel in sulfuric acid solution were investigated in this work. The extracts obtained from their respective leaves, were characterized to determine their phytochemical constituents as well as functional groups present using Fourier Transform Infrared Spectroscopy (FTIR) technique. Weight loss techniques was employed to evaluate the corrosion inhibition efficiency of the leaf extracts. The Scanning Electron Microscopy (SEM) was used to study the morphology of the mild steel before and after corrosion experiments. The process factors studied was exposure time, concentration of leaf extracts (inhibitor) and temperature. The results revealed that the phytochemical constituents of the leaves are capable of inhibiting corrosion due to high concentration of tannins which is responsible for the corrosion inhibition of mild steel. The rate of corrosion decreased with increase in the concentration of the extracts while the inhibition efficiency increased with increase in the concentration of the extracts. Scanning Electron Microscopy (SEM) revealed that the corroded mild steel in the presence of the extracts had smoother surfaces than corroded mild steel in the absence of the extracts. Also, neem leaf extract demonstrated higher potential as corrosion inhibitor than pawpaw and curry leaf extracts.
Keywords: Inhibitor, leaf extracts, curry leaf, pawpaw leaf, neem leaf, mild steel iron