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°.

Designing Hybrid Mesoporous Pr/Tannate-Inbuilt ZIF8-Decorated MoS2 as Novel Nanoreservoirs toward Smart pH-Triggered Anti-corrosion/Robust Thermomechanical Epoxy Nanocoatings.

For the first time, organic tannic acid (TA) molecules and then inorganic praseodymium (Pr) cations as corrosion inhibitors were successfully loaded into a zeolitic imidazolate framework (ZIF8)-type porous coordination polymer (PCP) decorated on molybdenum disulfide, MoS2, (MS)-based transition metal dichalcogenides (TMDs) to create novel hybrid mesoporous Pr/TA-ZIF8@MS nanoreservoirs. Thereafter, the hybrid nanoreservoirs were embedded into the epoxy matrix for the preparation of smart pH-triggered nanocoatings. Characterizations of the Pr/TA-ZIF8@MS nanoreservoirs via Fourier transform infrared (FT-IR), X-ray diffraction (XRD), thermogravimetric (TG), Brunauer-Emmett-Teller (BET), and field emission-scanning electron microscopy (FE-SEM)/energy-dispersive X-ray spectroscopy (EDS) experiments confirmed the fabrication of mesoporous structures comprising Pr/TA interfacial interactions with ZIF8-decorated MS nanoplatelets possessing high thermal stability and compact/dense configuration features with a framework reorientation. A remarkable smart release of the inhibited cations (Pr3+ and Zn2+) in the presence of inbuilt TA at both acidic and alkaline media was achieved under inductively coupled plasma (ICP) examination. The superior pH-triggered self-healing inhibition through the smart controlled-release of Pr, tannate, Zn, and imidazole inhibited species/complexes from EP/Pr-TA-ZIF8@MS via ligand exchange was obtained from electrochemical impedance spectroscopy (EIS) assessments of the scratched coatings during 72 h of saline immersion. In addition, the long-term barrier-induced corrosion prevention (log |Z|10 mHz = 10.49 Ω·cm2 after 63 days) of the EP/Pr-TA-ZIF8@MS was actualized. Moreover, efficient increments of the coating cross-link density (56.45%), tensile strength (63.6%), and toughness value (56.5%) compared to the Neat epoxy coating revealed noticeable thermomechanical properties of the EP/Pr-TA-ZIF8@MS.