In the present study, the corrosion inhibition effect of Spilanthes acmella aqueous leaves extract (SA-LE) on mild steel was investigated in 1.0 M HCl solution at different temperature using weight loss, Tafel polarization, linear polarization resistance (LPR), and electrochemical impedance (EIS) measurements. Adsorption of inhibitor on the surface of the mild steel obeyed both Langmuir and Temkin adsorption isotherms. The thermodynamic and kinetic parameters were also calculated to determine the mechanism of corrosion inhibition. The inhibition efficiency was found to increase with an increase in the inhibitor concentration i.e., Spilanthes acmella aqueous leaves extract, however, the inhibition efficiency decreased with an increase in the temperature. The phytochemical constituents with functional groups including electronegative hetero atoms such as N, O, and S in the extract adsorbed on the metal surface are found responsible for the effective performance of the inhibitor, which was confirmed by Fourier-transform infrared spectroscopy (FT-IR) and ultraviolet–visible spectroscopic (UV-Vis) studies. Protective film formation against corrosion was confirmed by scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle studies. The result shows that the leaves extract acts as corrosion inhibitor and is able to promote surface protection by blocking active sites on the metal.

中文翻译：

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螺旋藻的刺叶提取物在酸性介质中的缓蚀作用

在本研究中，使用重量损失，Tafel极化，线性极化电阻（LPR）和电化学阻抗，在不同温度下于1.0 M HCl溶液中研究了尖兰的水提物（SA-LE）对低碳钢的腐蚀抑制作用。 （EIS）测量。缓蚀剂在低碳钢表面的吸附均符合Langmuir和Temkin的吸附等温线。还计算了热力学和动力学参数，以确定腐蚀抑制的机理。发现抑制效率随抑制剂浓度即尖螺旋藻水生叶提取物浓度的增加而增加，但是，抑制效率随温度的升高而降低。通过傅立叶变换红外光谱（FT-IR）证实了在金属表面吸附的提取物中具有包括负电性杂原子（例如N，O和S）的官能团的植物化学成分是抑制剂的有效性能的原因。 ）和紫外可见光谱（UV-Vis）研究。通过扫描电子显微镜（SEM），原子力显微镜（AFM）和接触角研究证实了保护膜的形成不腐蚀。结果表明，叶片提取物起腐蚀抑制剂的作用，并能通过阻断金属上的活性位而促进表面保护。傅立叶变换红外光谱（FT-IR）和紫外可见光谱（UV-Vis）研究证实了这一点。通过扫描电子显微镜（SEM），原子力显微镜（AFM）和接触角研究证实了保护膜的形成不腐蚀。结果表明，叶片提取物起腐蚀抑制剂的作用，并能通过阻断金属上的活性位而促进表面保护。傅立叶变换红外光谱（FT-IR）和紫外可见光谱（UV-Vis）研究证实了这一点。通过扫描电子显微镜（SEM），原子力显微镜（AFM）和接触角研究确认了形成保护膜的防腐蚀性能。结果表明，叶片提取物起腐蚀抑制剂的作用，并能通过阻断金属上的活性位而促进表面保护。