Evaluation of the corrosion resistance of the vinyltrimethoxsilane film modified with Ce(III) or Ce(IV) ion as carbon steel pretreatment

ABSTRACT Silanes are organo functional compounds used as coupling agents between organic-inorganic interfaces, with good adhesion properties. For this reason, the use of silanes as pre-treatment for carbon steel is becoming more and more applicable , since they are also generators of less toxicity residues to the environmental and human health. In order to improve the barrier protection of the silane film and confer self-healing properties, these films can be modified by addition of cerium ions. Thus, these work aims to evaluate the corrosion resistance of vinythrimethoxysilane (VTMOS) film modified with Ce(III) ions or Ce(IV) ions for carbon steel, using the electrochemical impedance spectroscopy (EIS), scanning vibrating electrode technique (SVET), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results show that Ce(IV) ions addition improved better corrosion resistance than the films with Ce(III) ions. The higher barrier effect is since the film formed in the presence of Ce(IV) ions is better reticulated.

摘要 硅烷是一类用作有机-无机界面偶联剂的有机官能化合物，具备优良的粘附性能。正因如此，硅烷用作碳钢预处理剂的应用愈发广泛，同时其产生的残留物对环境与人体健康的毒性更低。为改善硅烷膜的阻隔防护性能并赋予其自修复特性，可通过添加铈离子对这类膜层进行改性。因此，本研究旨在评估经三价铈（Ce(III)）或四价铈（Ce(IV)）离子改性的乙烯基三甲氧基硅烷（vinythrimethoxysilane, VTMOS）膜对碳钢的耐腐蚀性能，测试方法包括电化学阻抗谱（electrochemical impedance spectroscopy, EIS）、扫描振动电极技术（scanning vibrating electrode technique, SVET）、扫描电子显微镜（scanning electron microscopy, SEM）以及傅里叶变换红外光谱（Fourier transform infrared spectroscopy, FTIR）。研究结果表明，添加四价铈离子的膜层相较于添加三价铈离子的膜层具备更优异的耐腐蚀性能，其更高的阻隔效应源于在四价铈离子存在条件下形成的膜层具有更完善的交联结构。