Deposition of layers of ethanolic extract of waste pineapple crown on mild steel through drop casting and examination of their corrosion behavior

Corrosion causes serious damage to the metals and decreases their usefulness as well as economic values. Inhibitors are generally used to control corrosion of metals. However, synthetic inhibitors are being used in limited conditions due to environment and cost concerns. The waste natural materials (WNM) have become the preference choice of the scientists for corrosion prevention applications. A WNM provide a cost effective, efficient, and economic solution of corrosion of metals. The present work examines the effectiveness of a WNM, pineapple crown (PC), against the mild steel (MS) corrosion in 0.5 M sodium chloride (NaCl). PC has been extracted into ethanol (EEPC) and characterized by FTIR spectroscopy (FS) and UV-visible spectroscopy (US). The EEPC layers (1-3) are coated on MS through drop casting using simple set-up, and coated MS has been tested for corrosion prevention by open circuit potential (OCP), Tafel polarization curves (TC), and electrochemical impedance spectroscopy (EIS). The results have confirmed that EEPC layers significantly prevent MS in NaCl. However, the best performance is obtained for 2 layers of EEPC (80%, TC). The surface images are clicked by field emission scanning electron microscopy (FESEM), which shows that EEPC has covered most of the places on the MS surface after coating and effectively protected MS in NaCl. The similar observations are recorded with atomic force microscope (AFM). Based on the overall results, a mechanism for corrosion prevention has also been introduced.