Adsorption and mitigation impact of the monosodium glutamate (C₅H₈NO₄Na) bio-molecules on the steel rebar corrosion in the chloride-contaminated simulated concrete pore solution

Corrosion has caused significant annual costs for building construction and civil architectural designs. In this study, Monosodium glutamate (GLU) was proposed as a potential candidate for long-lasting corrosion inhibition to slow down the rate of corrosion in the concrete pore environment. In this regard, the electrochemical and morphological properties of the various GLU concentrated systems between 1 to 5 wt.% in the simulated concrete pore solution media were investigated. According to the EIS results, adding 4 wt.% of GLU could reduce the mild steel corrosion process by 86% through a mixed inhibition mechanism. Also, the polarization records represented that the samples' corrosion current density was diminished to 0.169 µA.cm -2 after the addition of 4 wt.% GLU into the harsh environment. Using the FE-SEM method, the growth of the GLU layer over the metal substrate was demonstrated. The results of spectroscopic methods, i.e., Raman and GIXRD, demonstrated that GLU molecules were successfully adsorbed over the surface of the metal. Contact angle test outcomes showed that by increasing the GLU concentration to its optimum level (4 wt.%), the surface hydrophobicity was dramatically raised to 62 degrees.