Abstract

The inhibition efficacy of N-(4,6-dimethylpyrimidin-2-yl)-4-[(quinazoline-4-yl)amino]benzene-1-sulfonamide (DMQS) as a new corrosion inhibitor on mild steel (MS) in 0.1 M HCl medium at varied temperature has been analysed and it has ensued 97.6% high efficiency at 4 × 10^–5 M of DMQS. The electrochemical techniques employed were impedance spectroscopy and potentiodynamic polarization. Surface analysis of MS was carried out through scanning electron microscopy (SEM) and energy dispersion spectroscopy (EDS). Inhibitory effect of DMQS escalated with elevated concentration and declined with elevation in solution temperature. The adsorption of DMQS on MS has consent with the Langmuir adsorption isotherm. The computational study using density functional theory (DFT) with the B3LYP/3-21G basis set level for DMQS was investigated through the association between their molecular and electronic structure. The parameters involved in quantum chemical calculations were energy gap, E_HOMO, E_LUMO, absolute electronegativity, electrophilicity, softness, global hardness, energy gap, ionisation energy, electron affinity and dipole moment. DMQS shows E_HOMO value of –6.256 eV, fortifying MS from corrosive attack and implicating it to be an effectual inhibitor. The results of the implemented studies show the corrosion inhibition efficiency of the DMQS is in good accord.

中文翻译：

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N-(4,6-二甲基嘧啶-2-基)-4-[(喹唑啉-4-基)氨基]-苯-1-磺酰胺作为低碳钢在盐酸中的有效缓蚀剂的实验和计算研究

摘要

的抑制功效ñ - （4,6-二甲基嘧啶-2-基）-4 - [（喹唑啉-4-基）氨基]苯-1-磺酰胺（DMQS）如低碳钢一个新的腐蚀抑制剂（MS）已分析了不同温度下的 0.1 M HCl 介质，并在 4 × 10 ^–5下获得了 97.6% 的高效率DMQS 的 M。所采用的电化学技术是阻抗谱和动电位极化。通过扫描电子显微镜 (SEM) 和能量色散光谱 (EDS) 对 MS 进行表面分析。DMQS 的抑制作用随浓度升高而增强，随溶液温度升高而减弱。DMQS 在 MS 上的吸附符合朗缪尔吸附等温线。使用密度泛函理论 (DFT) 和 DMQS 的 B3LYP/3-21G 基组水平的计算研究通过它们的分子和电子结构之间的关联进行了研究。涉及量子化学计算的参数有能隙、E _HOMO、E _LUMO、绝对电负性、亲电性、柔软度、整体硬度、能隙、电离能、电子亲和力和偶极矩。DMQS 显示的E _HOMO值为 –6.256 eV，可加强 MS 免受腐蚀攻击并暗示其是一种有效的抑制剂。实施研究的结果表明DMQS的缓蚀效率符合良好。