Youssif Mahmoud M, El-Nahass Marwa N, Fayed Tarek A, El-Daly Hosny A, El-Gamil Mohammed M, Eldesoky Ahmed M
Department of Chemistry, Faculty of Science, Tanta University, Tanta 31527, Egypt.
Department of Toxic and Narcotic Drug, Forensic Medicine, Mansoura Laboratory, Medico Legal Organization, Ministry of Justice, Mansoura 35516, Egypt.
ACS Omega. 2023 Jul 27;8(31):28314-28332. doi: 10.1021/acsomega.3c02105. eCollection 2023 Aug 8.
Herein, we synthesized three novel benzothiazole azo dyes, including 4-chloro-2-(4-methyl-benzothiazol-2-ylazo)-phenol (CMBTAP), 1-(6-chloro-benzothiazol-2-ylazo)-naphthalen-2-ol (CBAN), and 2-(6-chloro-benzothiazol-2-ylazo)-4-methyl-phenol (CBAMP), and investigated their corrosion inhibition effect on carbon steel. The dyes were characterized by Fourier transform infrared spectroscopy, H nuclear magnetic resonance (NMR), C NMR, and mass spectroscopy. Weight loss, electrochemical impedance spectroscopy, and potentiodynamic polarization measurements were performed to investigate the corrosion inhibition effect of the dyes on carbon steel in a 1.0 M HCl solution. The synergistic effects of the dyes with potassium iodide (KI) were also investigated. The inhibition efficiency (IE%) was enhanced by increasing the dose of the dyes (1 × 10 to 2 × 10 M) and decreased as the temperature increased from 25 to 45 °C. The addition of KI to a 1.0 M HCl solution containing the dyes improved the performance and efficiency as iodide ions promoted the formation of inhibition films on the surface of carbon steel. The dyes are mixed-type inhibitors, according to Tafel polarization. Scanning electron microscopy and energy dispersive X-ray analysis were used to evaluate the surface morphology of carbon steel sheets. Quantum theory calculations were utilized to evaluate the relationship between the dyes' chemical structures and their inhibitory efficiency, which confirmed the experimental results. The calculations revealed that the dyes have low energy gap and Milliken and Fukui indices. Among all of the dyes, CMBTAP showed the highest adsorption energy. The corrosion IE was in the order CMBTAP > CBAMP > CBAN.
在此，我们合成了三种新型苯并噻唑偶氮染料，包括4-氯-2-(4-甲基-苯并噻唑-2-基偶氮)-苯酚(CMBTAP)、1-(6-氯-苯并噻唑-2-基偶氮)-萘-2-醇(CBAN)和2-(6-氯-苯并噻唑-2-基偶氮)-4-甲基-苯酚(CBAMP)，并研究了它们对碳钢的缓蚀作用。通过傅里叶变换红外光谱、氢核磁共振(NMR)、碳核磁共振和质谱对染料进行了表征。进行了失重、电化学阻抗谱和动电位极化测量，以研究染料在1.0 M HCl溶液中对碳钢的缓蚀作用。还研究了染料与碘化钾(KI)的协同作用。通过增加染料剂量(1×10至2×10 M)，缓蚀效率(IE%)提高，而随着温度从25℃升高到45℃，缓蚀效率降低。向含有染料的1.0 M HCl溶液中添加KI可改善性能和效率，因为碘离子促进了碳钢表面缓蚀膜的形成。根据塔菲尔极化，这些染料是混合型缓蚀剂。使用扫描电子显微镜和能量色散X射线分析来评估碳钢片的表面形貌。利用量子理论计算来评估染料的化学结构与其缓蚀效率之间的关系，这证实了实验结果。计算表明，这些染料具有低能隙以及米利肯和福井指数。在所有染料中，CMBTAP表现出最高的吸附能。缓蚀效率顺序为CMBTAP>CBAMP>CBAN。
