摘要
直链型巯基醇分子具有双头基两亲分子的特殊结构,研究其烷烃链长对缓蚀性能的影响具有十分重要的理论和现实意义。利用腐蚀试验研究了巯基乙醇(C_2)、3-巯基丙醇(C_3)、6-巯基-1-己醇(C_6)和9-巯基-1-壬醇(C_9)4种分子对Q235钢的缓蚀率,结合量子化学从头算和分子动力学模拟方法讨论了链长对其缓蚀性能的影响机理。通过前线轨道分布、Fukui函数和构效关系对分子的反应活性进行了分析,同时在气相条件下模拟缓蚀剂在金属界面的吸附行为。结果表明:4种分子有相同的活性位点,且长链巯基醇分子因带有较多的负电荷、供电子能力强以及在金属表面具有高的吸附能等特点而具有较大的缓蚀率,表现出较高的缓蚀能力。
The corrosion inhibition efficieneies of four kinds of mercaptoalcohols molecules such as mercaptoethanol （C2） , 3-mercaptopropan- 1 -ol （C_3） , 6-mercaptohexan-1-ol （C_6） and 9-mereaptononan-1-ol （C_9） on the Q235 steel were measured by corrosion experiment, and the influence mechanism of length of the carbon chain on the inhibition performance was discussed by density functional theory （ quantum chem- istry） and molecular dynamic simulation. In addition, the parameters of the frontier molecular orbital distributions, Fukui function, hardness, chemical potential and so on were employed to analyze the global activity of molecules, and the nature of the inhibitors adsorbed on the surface of Q235 was simulated and analyzed. Results showed that these four kinds of molecules possessed similar active sites, and the mercaptoalcohols molecule with long carbon chain had the larger corrosion inhibition efficiency, due to its most negative charges, the strongest capability of donating electrons and the highest energy of absorbing on Q235 surface, which indicated C_9 had the optimal corrosion-inhibition capability.
出处
《材料保护》
CSCD
北大核心
2017年第11期18-22,48,共6页
Materials Protection
基金
中国自然科学基金面上项目(51641108)资助
关键词
巯基醇
缓蚀机理
密度泛函理论
构效关系
分子动力学
Q235钢
mercaptoalchols
inhibition mechanism
density functional theory
structure- activity relationship
molecular dynamic simulation
Q235 steel
