物理化学学报 >> 2008, Vol. 24 >> Issue (07): 1239-1244.doi: 10.3866/PKU.WHXB20080720

研究论文 上一篇    下一篇

苯并咪唑类缓蚀剂缓蚀性能的理论评价

张军; 赵卫民; 郭文跃; 王勇; 李中谱   

  1. 中国石油大学物理科学与技术学院, 山东 东营 257061; 中国石油大学机电工程学院, 山东 东营 257061
  • 收稿日期:2008-01-16 修回日期:2008-03-25 发布日期:2008-07-04
  • 通讯作者: 郭文跃; 王勇 E-mail:wyguo@hdpu.edu.cn;wangyong@hdpu.edu.cn

Theoretical Evaluation of Corrosion Inhibition Performance of Benzimidazole Corrosion Inhibitors

ZHANG Jun; ZHAO Wei-Min; GUO Wen-Yue; WANG Yong; LI Zhong-Pu   

  1. College of Physics Science and Technology, China University of Petroleum, Dongying 257061, Shandong Province, P. R. China; College of Mechanical and Electronic Engineering, China University of Petroleum, Dongying 257061, Shandong Province, P. R. China
  • Received:2008-01-16 Revised:2008-03-25 Published:2008-07-04
  • Contact: GUO Wen-Yue; WANG Yong E-mail:wyguo@hdpu.edu.cn;wangyong@hdpu.edu.cn

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摘要： 采用量子化学计算和分子动力学模拟相结合的方法, 对2-巯基苯并咪唑(A)、2-氨基苯并咪唑(B)、2-甲基苯并咪唑(C)和苯并咪唑(D)等四种缓蚀剂抑制HCl对碳钢腐蚀的性能进行理论评价, 并对其缓蚀机理进行分析. 全局活性指数的计算表明, 四种分子中, 2-巯基苯并咪唑分子具有最强的反应活性; 对于其他三种分子, Fukui指数和全电子密度分布指出, 2-氨基苯并咪唑具有两个亲电攻击中心, 可在金属表面形成双中心吸附, 其缓蚀性能应优于2-甲基苯并咪唑和苯并咪唑; 缓蚀剂分子与三层铁原子表面相互作用的分子动力学模拟进一步确认2-甲基苯并咪唑比苯并咪唑在金属表面吸附更稳定. 综合量子化学计算和分子动力学模拟的计算结果, 四种缓蚀剂分子缓蚀效率的顺序应为A>B>C>D, 缓蚀性能的理论评价结论与实验结果相吻合.

关键词: 苯并咪唑, 缓蚀剂, 理论评价, 量子化学计算, 分子动力学模拟

Abstract: The inhibition performance of four corrosion inhibitors in HCl mild steel corrosions, including 2-mercaptobenzimidazole (A), 2-amidobenzimidazole (B), 2-methylbenzimidazole (C), and benzimidazole (D), was theoretically evaluated using quantum chemistry calculations and molecular dynamics simulations, and the corrosion inhibition mechanism was analyzed. Global activity indices indicated that 2-mercaptobenzimidazole bore the highest reaction activity among the four molecules. For the three other molecules, Fukui indices and total electron density distributions suggested that 2-amidobenzimidazole possessed two electrophilic attack centers, which enabled multi-center adsorption of the molecule on metal surfaces and thus had preferable corrosion inhibition performance compared to 2-methylbenzimidazole and benzimidazole. Molecular dynamics simulation results showed that 2-methylbenzimidazole was more stably adsorbed on the metal surfaces than benzimidazole did when the interaction of the inhibitor molecules with three layers of iron atoms was considered. With the help of the theoretical results, the efficiency order of the four inhibitors was found to be A>B>C>D, which accorded well with experimental results.

Key words: Benzimidazole, Corrosion inhibitor, Theoretical evaluation, Quantumchemistry calculation, Molecular dynamics simulation