Mobin Mohammad, Aslam Ruby, Salim Rajae, Kaya Savaş
Corrosion Research Laboratory, Department of Applied Chemistry, Faculty of Engineering and Technology, Aligarh Muslim University, Aligarh 202002, India.
Corrosion Research Laboratory, Department of Applied Chemistry, Faculty of Engineering and Technology, Aligarh Muslim University, Aligarh 202002, India.
J Colloid Interface Sci. 2022 Aug 15;620:293-312. doi: 10.1016/j.jcis.2022.04.036. Epub 2022 Apr 10.
The development of green corrosion inhibitors is a challenging task as it has to comply with strict environmental regulations. Ionic liquids (ILs) have recently been proposed as promising corrosion inhibitors. The present paper reports on two ILs designed to act as green and efficient high-temperature corrosion inhibitors. The prepared ILs, namely, choline formate (ChF) and choline acetate (ChA), are composed of biologically active ions. To elucidate their structure and corrosion inhibition effect on mild steel in 5% HCl the ILs were subjected to characterization tests like proton nuclear magnetic resonance (H NMR), carbon nuclear magnetic resonance (C NMR) and Fourier Transform infra-red (FT-IR) spectroscopy and corrosion tests like weight loss measurements, potentiodynamic polarization measurements (PDP), and electrochemical impedance spectroscopy (EIS). The effectiveness of the inhibition (%IE) increased with increasing concentrations and temperature up to 50 °C. ChF and ChA exhibited the highest inhibition efficacies of 96.9% and 99.5%, respectively at a temperature of 50 °C and concentration of 2 × 10 M. Above 50 °C their inhibition performance diminished, displaying an efficacy of 77.6% for ChF and 79.3% for ChA at 80 °C. The results of polarization measurements suggested mixed type behavior of inhibitors, and adsorption followed Langmuir adsorption isotherm. Furthermore, surface studies like scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) revealed protecting capability of the investigated inhibitors. FT-IR, and Raman spectroscopic studies revealed the adsorption of ILs on the Fe surface, and an ultra-violet visible (UV-vis.) spectroscopy study confirms the formation of Fe- ILs complex. X-ray Photoelectron Spectroscopy (XPS) was conducted to study the formation of corrosion products and protective film over the mild steel surface. Density functional theory (DFT) calculations and molecular dynamics (MD) simulations were also done to understand the inhibition mechanism of ILs.
开发绿色缓蚀剂是一项具有挑战性的任务，因为它必须符合严格的环境法规。离子液体（ILs）最近被提议作为有前景的缓蚀剂。本文报道了两种被设计用作绿色高效高温缓蚀剂的离子液体。所制备的离子液体，即甲酸胆碱（ChF）和乙酸胆碱（ChA），由生物活性离子组成。为了阐明它们的结构以及在5%盐酸中对低碳钢的缓蚀效果，对这些离子液体进行了表征测试，如质子核磁共振（H NMR）、碳核磁共振（C NMR）和傅里叶变换红外（FT-IR）光谱，以及腐蚀测试，如失重测量、动电位极化测量（PDP）和电化学阻抗谱（EIS）。缓蚀效率（%IE）随着浓度和温度的升高而增加，直至50°C。在50°C温度和2×10⁻³M浓度下，ChF和ChA分别表现出96.9%和99.5%的最高缓蚀效率。高于50°C时，它们的缓蚀性能下降，在80°C时，ChF的缓蚀效率为77.6%，ChA为79.3%。极化测量结果表明缓蚀剂为混合型行为，且吸附遵循朗缪尔吸附等温线。此外，扫描电子显微镜 - 能谱（SEM-EDS）等表面研究揭示了所研究缓蚀剂的保护能力。FT-IR和拉曼光谱研究揭示了离子液体在铁表面的吸附，紫外可见（UV-vis.）光谱研究证实了铁 - 离子液体络合物的形成。进行了X射线光电子能谱（XPS）研究低碳钢表面腐蚀产物和保护膜的形成。还进行了密度泛函理论（DFT）计算和分子动力学（MD）模拟以了解离子液体的缓蚀机理。
