Pivotal Role of Heteroatoms in Improving the Corrosion Inhibition Ability of Thiourea Derivatives
Dinh Quy Huong, Nguyễn Thị Lan Hương, Tran Thi Nguyet, Trần Dương, Dinh Tuan, Nguyen Minh Thong, Pham Cam Nam
Abstract
M at 30 °C. The Nyquist diagrams show that increasing the concentrations of both DPTU and PPTU will enhance the charge-transfer resistance and reduce the double-layer capacitance. The obtained data based on PPM and electrochemical impedance spectroscopy methods are in accordance to the analysis based on the scanning electrochemical microscopy images. Besides, results from quantum chemical calculations prove that the heteroatoms in the inhibitor molecules are the adsorption centers, and the benzene rings increase the electrostatic interaction between the inhibitor molecules and the steel surface. Results from Monte Carlo and molecular dynamics simulation have clarified the adsorption mechanism of DPTU and PPTU on the steel surface. Adsorption energies confirm that PPTU displays the higher inhibition ability as compared with DPTU.