Synthesis and application of ionic liquid/ZIF-8 as a pH-sensitive nanocarrier for slow release of 1-(2-hydroxy ethyl)-3-methylimidazolium dicyanamide corrosion inhibitor in neutral chloride solution

This study investigated the design and synthesis of a pH-responsive corrosion inhibitor hybrid based on zeolite ‎imidazolate framework-8 (ZIF-8) structure as nanocarrier and the ionic liquid. The hybrid structure contained the room temperature ionic liquid, (‎1-(2-‎hydroxyethyl)− 3-methylimidazolium ‎dicyanamide as a green anti-corrosion agent. The XRD, BET, FT-IR, TGA, and FE-‎SEM techniques were utilized to study the morphological and fundamental features of the hybrid. The loading and releasing properties of the hybrid were studied using ‎UV–Visible spectroscopy. Also, the efficiency criteria were evaluated for released inhibitors using electrochemical impedance spectroscopy (EIS). Based on the results, the long-term inhibition capability of synthesized hybrid for carbon steel was shown in 3.0 wt% NaCl solution. The maximum release rate of anti-corrosion agent occurs in strongly acidic and basic conditions from the mesoporous structure ‎of ZIF-8. It was found that the hybrid structure encompasses a substantial amount of anti-corrosion IL ‎within the next 30 h of releasing process. At the same time, the inhibition efficiency of the mixture rises with the immediate upturn of the inhibitor ‎concentration. ‎These results are potentially utilized in many applications anywhere the required active corrosion protection of materials is in demand.