Wei Wenchang, Liu Zheng, Liang Chuxin, Han Guo-Cheng, Han Jiaxing, Zhang Shufen
College of Chemical and Biological Engineering, Guilin University of Technology, Guangxi Key Laboratory of Electrochemical and Magneto-chemical Functional Materials Guilin 541004 P. R. China
School of Life and Environmental Sciences, Guilin University of Electronic Technology Guilin 541004 P. R. China
RSC Adv. 2020 May 7;10(30):17816-17828. doi: 10.1039/d0ra01903h. eCollection 2020 May 5.
In this work, two new bis-Schiff bases, namely 2-bromoisophthalaldehyde-2-aminofluorene (M1) and glutaraldehyde 2-aminofluorene (M2), were synthesized, and their structures were characterized and confirmed by infrared spectroscopy, Fourier transform mass spectrometry and UV-visible spectroscopy. Their corrosion inhibition performance on carbon steel in simulated circulating cooling water was investigated by weight loss measurements and electrochemical measurements. The potentiodynamic polarization curves confirmed that two bis-Schiff bases are anode-type inhibitors; electrochemical impedance spectroscopy tests showed that M1 and M2 possess the best inhibition efficiencies of 96.25% and 99.15% at the optimal concentration of 2.50 mmol L, respectively. The weight loss results showed that M1 and M2 exhibit maximum values of 92.62% and 96.31%, respectively. Scanning electron microscopy showed that the inhibitors inhibited carbon steel corrosion. The adsorption isotherm measurements indicated that the two inhibitors exhibited physicochemisorption mechanisms and followed Langmuir adsorption isotherms. The relationships between the molecular structure and inhibition behavior of the inhibitors were explored by density functional theory, frontier molecular orbital studies, and Fukui index analysis, which affirmed that M2 possesses higher corrosion inhibition efficiency than M1.
在本工作中，合成了两种新型双席夫碱，即2-溴间苯二甲醛-2-氨基芴（M1）和戊二醛-2-氨基芴（M2），并通过红外光谱、傅里叶变换质谱和紫外-可见光谱对其结构进行了表征和确认。通过失重测量和电化学测量研究了它们在模拟循环冷却水中对碳钢的缓蚀性能。动电位极化曲线证实两种双席夫碱均为阳极型缓蚀剂；电化学阻抗谱测试表明，在最佳浓度2.50 mmol/L时，M1和M2的最佳缓蚀效率分别为96.25%和99.15%。失重结果表明，M1和M2的最大值分别为92.62%和96.31%。扫描电子显微镜表明缓蚀剂抑制了碳钢的腐蚀。吸附等温线测量表明，两种缓蚀剂表现出物理化学吸附机制，并遵循朗缪尔吸附等温线。通过密度泛函理论、前沿分子轨道研究和福井指数分析探讨了缓蚀剂分子结构与缓蚀行为之间的关系，证实M2具有比M1更高的缓蚀效率。
