Study on the Synergistic Mechanism of Sodium Silicate-Based Three-Component Corrosion Inhibitors

Abstract— In this study, a highly efficient and environmentally friendly three-component corrosion inhibitor for carbon steel with low side effects was prepared, consisting of sodium silicate (SS), calcium gluconate (CaGlu) and dimethylaminopropyl methacrylamide (DMAPMA) in low concentration. The corrosion inhibition efficiency of the corrosion inhibitor was ηw = 91.45%, ηi = 95.21% by corrosion tests and electrochemical tests at a concentration of 0.1 wt % and a ratio of 1 : 1 : 1 of the composite corrosion inhibitor. The mechanism of action of this ternary complex corrosion inhibitor was explored by Scanning electron microscopy, atomic force microscopy techniques, Fourier transform attenuated total reflection infrared spectroscopy, X‑ray photoelectron spectroscopy, cyclic voltammetry and adsorption fitting model. The results showed that the corrosion inhibitor formed a composite protective film layer on the surface of carbon steel, consisting of an organic film of DMAPMA and a Si/Fe oxide film formed by SS. CaGlu played a role in increasing the reactive sites and the coverage of the protective film.