Addressing the ongoing issue of carbon steel corrosion, this study evaluates the corrosion inhibition performance of two eco-friendly pyridinium-based ionic liquids, 4-(dimethylamino)-1-nonylpyridin-1-ium Bromide (4DMN) and 4-(dimethylamino)-1-(prop-2-yn-1-yl)pyridin-1-ium Iodide (4DMP), in a 3.5 wt% NaCl solution. Weight loss tests, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), quantum chemical calculations (QCCs), and molecular dynamics (MD) simulations were employed to carried out experimental and theoretical studies. Both 4DMN and 4DMP showed concentration-dependent inhibitory effects with 94 % and 92 % effectiveness, respectively. Potentiodynamic data showed that these compounds control both anodic and cathodic reactions without changing the corrosion mechanism. EIS results indicated a decrease in double-layer capacitance, suggesting adsorption of IL molecules on steel surface. Over a 60-h period, 4DMN maintained its effectiveness, although it decreased at higher temperatures. Surface analyses using Field Emission Scanning Electron Microscopy (FE-SEM) and Atomic Force Microscopy (AFM) showed improvements in surface morphology and roughness. Computational studies supported these findings, showing the reactivity and adsorption patterns of the ILs on the Fe (110) surface. Overall, this study contributes to understanding how pyridinium-based ILs can be used for effective and sustainable corrosion control.

中文翻译：

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探索环保型吡啶鎓离子液体在盐介质中抑制碳钢腐蚀的机制：通过实验和计算方法加深理解

针对持续存在的碳钢腐蚀问题，本研究评估了两种环保型吡啶基离子液体 4-(二甲氨基)-1-壬基吡啶-1-溴化鎓 (4DMN) 和 4-(二甲氨基) 的缓蚀性能-1-(prop-2-yn-1-yl)pyridin-1-ium Iodide (4DMP)，溶于 3.5 wt% NaCl 溶液。采用失重测试、电化学阻抗谱（EIS）、动电位极化（PDP）、量子化学计算（QCC）和分子动力学（MD）模拟来进行实验和理论研究。 4DMN 和 4DMP 均表现出浓度依赖性抑制作用，有效性分别为 94% 和 92%。动电位数据表明这些化合物控制阳极和阴极反应而不改变腐蚀机制。 EIS 结果表明双层电容降低，表明钢表面吸附了 IL 分子。在 60 小时内，4DMN 保持了其有效性，尽管它在较高温度下有所下降。使用场发射扫描电子显微镜 (FE-SEM) 和原子力显微镜 (AFM) 进行的表面分析显示出表面形态和粗糙度的改善。计算研究支持了这些发现，显示了离子液体在 Fe (110) 表面上的反应性和吸附模式。总的来说，这项研究有助于了解如何使用基于吡啶的离子液体进行有效和可持续的腐蚀控制。