Investigation of corrosion inhibition by Cassava leaf DNA on AISI 1015 low carbon steel in sodium chloride solution

In the past few years many corrosion inhibitors research has been oriented towards eco-friendly extracts from plants.In this research cassava (Manihot esculenta) leaf Deoxyribonucleic acid (DNA) was extracted as green inhibitor compound for low carbon steel protection from corrosion.The mechanism of inhibition was investigated in 3.5% w/v NaCl (simulating naturally aerated seawater) by weight loss, potentiodynamic polarization measurements and SEM/EDX and FTIR assessments.These measurements investigated the corrosion resistance and morphology of low carbon steel using electrochemical parameters (corrosion potential, corrosion current and corrosion rate) and gravimetric analysis (weight loss and surface coverage).The electrochemical (potentiodynamic polarization) test results showed that a concentration of 20 mg/L of DNA, inhibited the corrosion of low carbon steel in 3.5% w/v NaCl with an inhibition efficiency of 96.4%.Inhibition efficiency of 88.37% from weight-loss measurements after immersion in the test solution for 240 hours were obtained as well.Potentiodynamic polarization tests plots demonstrated that DNA is a mixed inhibitor; it reduces both cathodic and anodic reactions by forming films on the surface of mild steel.The adsorption model of DNA corresponds to the Langmuir isotherm.This demonstrated the suitability of cassava leaf DNA as an inhibitor of mild steel corrosion for saline environment.