Inhibition effect and mechanism of polyacrylamide for steel corrosion in simulated concrete pore solution

The research examined the effect of polyacrylamide (PAM) on corrosion inhibition performance for steel in the simulated concrete pore solution. Linear polarization resistance, electrochemical impedance spectroscopy, potentiodynamic polarization, X-ray Photoelectron Spectroscopy and molecular dynamics simulations are performed to investigate the inhibitive effect and mechanism of PAM for steel corrosion. Results reveal that PAM improves the inhibition performance of steel corrosion and the inhibition efficiency increases with PAM content increasing. The maximum inhibition efficiency (about 99%) is achieved when the concentration of PAM is 0.15%. The improvement of corrosion inhibitive performance by PAM is due to the generation of adsorption film on steel, and the adsorption of PAM is following the Langmuir adsorption isotherm. In addition, the inhibition mechanism by PAM on steel corrosion is determined using molecular dynamics simulations. (C) 2020 Elsevier Ltd. All rights reserved.