Green solution to corrosion problems - At a glance

Abstract

Extracts of natural products are used as corrosion inhibitors since they are non toxic and environmentally friendly. Especially the extracts of leaves have attracted the attention of many researchers. Usually weight loss methods are adopted to measure the corrosion inhibition efficiencies. The mechanistic aspects have been investigated by electrochemical studies such as polarization study and AC impedance spectra. Sometimes noise measurement has also been used. The protective films formed on the metal surface have been analysed by surface analysis techniques such as SEM, EDAX, FTIR and AFM. Experiments have been carried out at various temperatures also. Various adsorption isotherms have been proposed. Of all the metals and alloys used, mild steel has been extensively used. The experiments have been carried out in acid medium and neutral medium (sodium chloride). The extracts of the leaves contain many ingredients which have polar groups such as N, O, S and P atoms. The lone pair of electrons present on these atoms are pumped on to the metal surface. This controls the corrosion process.