Eco-friendly gemini ionic liquid as a corrosion inhibitor for carbon steel in petroleum pipelines

We conducted an experiment to test the effectiveness of a new gemini ionic liquid, labeled as <i>N</i>₁,<i>N</i>₁,<i>N</i>₃,<i>N</i>₃-tetramethyl-<i>N</i>₁,<i>N</i>₃-bis(4-nitrobenzyl) propane 1,3-diaminium chloride, in prohibiting carbon steel corrosion in a 1 M hydrochloric acid solution. We successfully synthesized this compound and characterized it using various analytical techniques, comprising elemental examinations, mass spectroscopy, FT-IR spectroscopy and ¹H-NMR spectroscopy. To assess corrosion and corrosion inhibition efficiency, we utilized electrochemical techniques. The trials were performed at a temperature of 298 K, with adjustments made to the inhibitor concentrations. We maintained standardized conditions to maximize the inhibition efficiency. Additionally, AFM, SEM, and EDAX analyses were employed to identify the surface morphology. Our results showed that the inhibition efficiency increased with increasing inhibitor concentrations, reaching up to 90.6% at 200 ppm of the synthesized compound at 298 K. Notably, the formed gemini ionic liquid operated as a mixed inhibitor, adopted a physico-chemisorption mechanism, and fitted well with the Langmuir adsorption model.