Unique 2-methylimidazole based Inorganic Building Brick nano-particles (NPs) functionalized with 3-aminopropyltriethoxysilane with excellent controlled corrosion inhibitors delivery performance; Experimental coupled with molecular/DFT-D simulations

Abstract

Listen

Translate article

Metal organic frameworks (MOFs) are unique organic-inorganic-based nanomaterials with highly porous structures that can be obtained through the metal ions (as a center) linking to the organic ligands via covalent bond coordination. Despite different applications, i.e., sensing, molecular sieves, and drug delivery, the anti-corrosion properties of the MOFs is an issue that remains rarely reported. ZIF-67, which can be constructed via cobalt ions (Co2+) coordination with 2-methylimidazole ligands, is a new type of MOFs for unique performance i.e., in catalysis/gas adsorption applications. In this study, for the first time, the ZIF-67 NPs were synthesized and modified by 3-aminopropyltriethoxysilane (APS) to control its solubility in water. The field emission scanning electron microscopes (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), ultraviolet-visible spectroscopy (UV–vis), and low-angle X-ray diffraction analysis (XRD) tests were used to investigate the structures of the NPs. Also, the dispersion stability of ZIF-67 and ZIF-67@APS NPs were studied in different solvents at different times. The ZIF-67 and ZIF-67@APS NPs corrosion retardation activities were evaluated in the aquatic simulated seawater solution (NaCl-3.5 wt.%) on the bare steel samples by FE-SEM, grazing incidence X-ray diffraction (GIXRD), and electrochemical techniques. Besides, the theoretical (QM, MC/MD) computations supported the adsorption of ZIF-67 compounds on the metal-based adsorbent. The results showed that the ZIF-67 NPs synthesis and modification were done successfully. Also, the modification of ZIF-67 led to the improvement of its thermal stability and reduction of hydrophilicity. Tafel (potentiodynamic) polarization test demonstrated that in the ZIF-67@APS NPs containing NaCl-based extract, the metal corrosion was diminished by a high inhibition degree of 81% through mixed anodic (Fe oxidation to Fe2+) and cathodic (O2 reduction to OH−) reactions retardation mechanisms. EIS test showed that there is an ascending trend for the values of log |Z|10 mHz in the Bode module plots of ZIF-67 and ZIF-67@APS samples until 24 h and the log |Z|10 mHz values of the sample immersed in ZIF-67@APS solution over immersion time were more than the impedance values of the samples immersed in ZIF-67 and blank solutions.