【作者】 陈玉红；

【导师】 童汝亭；

【作者基本信息】 河北师范大学 ， 物理化学， 2003， 硕士

【摘要】 铜的腐蚀与防护问题是腐蚀科学领域一个重要的研究课题。缓蚀剂由于具有使用简单、用量少、效果好、经济安全等特点，近二三十年来发展较快。席夫碱类化合物由于含有活性基团（-C=N-）对铜有很好的缓蚀作用。自组装膜（Self-Assembled Monolayer，SAM）是20世纪80年代初期发展起来的较为活跃的界面化学和材料化学的前沿领域。在电化学中，自组装膜以其高度的有序性、致密性和稳定性为深入研究电子转移和表面电化学等问题提供了良好的模型。 为了寻找合理、高效的铜缓蚀剂并从理论上对其机理进行探讨，我们合成了一系列的席夫碱类化合物，使其在铜表面自组装成膜，用电化学方法探讨了该系列席夫碱对铜的缓蚀作用。主要实验结论如下： ☆利用交流阻抗技术对成膜工艺条件（电极表面状态、成膜时间、成膜液浓度）进行了探讨。实验结果表明：该类席夫碱是快速、高效的铜缓蚀剂；席夫碱的最佳成膜条件为HNO₃法处理电极、1mM的席夫碱中成膜2h。 ☆通过量子化学计算与实验探讨席夫碱结构与缓蚀性能的关系。结果表明：所研究的系列席夫碱无论在5％的HCl溶液中，还是在3％的NaCl溶液中对铜的缓蚀效率都表现出一定的规律：席夫碱的苯环上引入给电子基团越多，对铜的缓蚀效率越高，并且给电子基团越靠近-C=N-键，缓蚀效率越高。这是因为此类化合物通过П键和反馈П键与金属结合，形成稳定的配位化合物，亚胺或亚胺基特性基团（-RC=N）应是主要的活性区。这些研究可以为设计新型、高效的有机缓蚀剂提供信息。 ☆用交流阻抗技术测试了温度对铜缓蚀作用的影响：随成膜液温度升高，对铜的缓蚀效率先升高，后降低，30℃时缓蚀效率最高；随海水 温度升高，铜的腐蚀速度加快;两者共同作用下，随温度升高，缓蚀 效率降低。☆电解质酸度对铜的缓蚀作用也有影响。虽然电解质的酸度不同，铜的 腐蚀机理不同，但该系列席夫碱对铜的保护作用都有效。更多还原

【Abstract】 The corrosion and protection of copper have been always the important studied, fields in corrosion science for many years. Corrosion inhibitors are effective to protect copper. Self-Assembled Monolayer （SAM） is one of the most popular studied fields of interlace chemistry and material science. In electrochemical field, the SAM is an ideal model for further study such as electron transfer, surface electrochemistry, molecular recognition because of its high-order, compact and stability.In order to search good and effective organic corrosion inhibitors, a series of schiff bases were just synthesized. Self-assemble momolayers of Schiff bases were formed on a copper surface pretreated using different methods and the corrosion protection abilities of the monolayer were evaluated in an 0.5M sodium chloride（NaCl） solution or 0.5M HC1 solution using electrochemical techniques. The primary results are as follows:☆ The effects of the monolayer formation such as surface state of copper, self-assembly time, Schiff bases’ concentration were measured using electrochemical impedance spectroscopy （EIS） .It shows that the schiff bases can quickly form on the copper surface and have high protection capacity. HNO₃ etching of copper electrode before self-assembly can improve the quality of schiff bases SAM. An increase in immersion time and schiff bases’ concentration, undoubtedly improve the coverage .A fairly dense monolayer was formed on copper surface after 2h immersion in 1mM schiff bases.☆ The relationship between schiff base structure and corrosion inhibition efficiency was studied by EIS and quantum chemical calculation. The results show that the nitrogen atom in the -C=N- groups and the oxygen, atom in -OH groups are the mainly reaction groups. The schiff base and copper come into being chelate through II bond and feedback II bond. That schiff bases have high efficiency not only in HC1 solution, but also in NaCl solution. If the molecule of schiff base has bigger conjugate n bonds among the aromatic rings than other schiff base, it will show higher inhibition efficiency.☆ The variation of temperature not only affects the corrosion of copper, but also changes the absorption of schiff base on copper surface, A relative coverage was highest when the schiff base solution was 30 ℃. The Corrosion rate increased with the improving temperature of NaCl solution. The apparent activation energy of corrosion and corrosion inhibition is 38.08 kJ/mol.☆ The corrosion of copper was also affected by the kind of corrosion solution, but the schiff bases have good corrosion inhibition efficiency in wide acidity range of NaCl solution.更多还原