Corrosion Inhibition Of Self-Assembly Monolayer For Copper And Its Mechanism Study

Self-assembly monolayer (SAM) on metal surface provides a method to prevent the oxidation and corrosion of metal. Amino acid compounds have advantages of non-toxic and biodegradable. The amino acid has become the main trend of green corrosion inhibitors. This dissertation focuses on the photosensitive SAM of aromatic amino acid against copper corrosion. The role of dissolved oxygen and oxidants on the SAM formation is investigated by using cysteine as a model compound. The polarization-treatment technology is used to study the effect of surface state on the formation of SAM. Triazole is assembled on copper surface by click-assembly method. The main results are as following:(1) Owing to its high-sensitivity and easy-operation, fluorescence analysis has been widely used in the characterization of biomolecule. We study the protective effect of phenylalanine (Phe), tyrosine (Tyr) and tryptophan (Trp) mixed self-assembled film by electrochemical experiments and fluorescence spectrometry, and the protection efficiency is93.4%、0.3%、88.4%for Phe、 Tyr and Trp, respectively. The results show that the electron transfer between amino acid molecules affects the protective effect of the mixed assembled film.(2) Cysteine is assembled on copper surface with the presence of dissolved oxygen and a small amount of oxidant in the assembling solution. The effect of the copper surface states on the assembled monolayer formation is investigated by the polarization-treatment technology. The results show that the cuprous ion and cupric ions may participate in the formation of cysteine assembled monolayer, and the presence of a few oxidants can improve the protective effect of cysteine assembled monolayer. In the presence of10-3mol/L potassium permanganate, the protection rate of Cysteine SAM is90.4%.(3) The triazole ring is synthesized by click chemistry reaction.2-Methyl-3-butyn-2-ol (MBY) and Dodecylbenzene sulfonyl azide (DBSA) are used as regents to form a triazole assembled monolayer on the copper surface. Relationship between the membrane structure, formation and function are investigated. MBY on the copper surface has a good protective effect. The presence of Fe2+ions promotes the protective effect of MBY film. The experiment proved that the protection efficiency of the triazole ring on copper surface can reach95.3%.