中空二氧化硅微球包覆2-巯基苯并噻唑自修复涂层防腐性能

涂层技术广泛应用于金属设备腐蚀防护，而针对传统涂层服役过程中的微损伤难以及时探测并修复，导致损伤后涂层防腐性能失效、金属腐蚀进程加速等问题。开发一种中空介孔SiO₂微球包覆2-巯基苯并噻唑的自修复涂层，并对涂层的自修复性能进行全面表征测试。将包覆2-巯基苯并噻唑的SiO₂微球作为填料，添加到无溶剂环氧树脂涂层中制备自修复涂层，在质量分数为3.5%的NaCl溶液中探查受损涂层在铜基体表面的自修复过程。采用多种测试表征方法测试SiO₂微球包覆2-巯基苯并噻唑的可行性，对涂层的自修复机理进行深入分析，综合评价自修复涂层的防腐性能。采用溶胶-凝胶法对SiO₂微球进行制备，制备的SiO₂微球具有中空结构，微球直径约为623nm。通过XDR、FTIR与TG等测试表征技术验证SiO₂微球实现对2-巯基苯并噻唑的包覆，且负载量良好；通过EIS阻抗测试对自修复涂层的修复性能进行测试，经对照实验测试自修复涂层具有较为良好的防腐性能，并在6d时防腐性能达到最大；通过SEM、ED...

Corrosion Protection Performance of a Self-repairing Coating with Hollow Mesoporous Silica Microspheres Loaded with 2-mercaptobenzothiazole

In view of the corrosion of metal equipment in the marine environment, coating technology has been widely adopted to prevent metal corrosion. Microdamage to traditional coatings is difficult to detect and repair in time. Once microdamage has occurred, the failure of anti-corrosion performance follows, accelerating the corrosion process. To address this issue, a self-repairing coating has been developed that could adapt to the complex marine environment and repair microdamage intelligently. The self-repairing performance of the coating was comprehensively evaluated. Hollow mesoporous silica microspheres(HMSN) were selected as carriers for storing 2-mercaptobenzothiazole(MBT). The self-repairing coating was prepared with the addition of MBT-loaded HMSN. In this study, HMSNs were prepared and characterized using scanning electron microscopy and transmission electron microscopy. The prepared HMSN, by definition, had a hollow mesoporous structure, and the diameter of the microspheres was about 623 nm. The self-repairing coating was prepared by adding the MBT-loaded HMSN, accounted for 18 wt.% of the coating mass, as fillers to solvent-free epoxy resin coatings. The self-repairing process of the prepared coating was simulated on a damaged copper substrate in 3.5 wt.% NaCl solution. When the scratched coating was immersed in a corrosive environment, the MBT in each exposed HMSN was slowly released. The MBT was subsequently combined with the copper substrate through strong chemical adsorption, and an adsorption film was formed on the surface of the bare metal substrate. The film prevented the corrosion of copper from the corrosive medium in the external environment, and hence active repair of the coating damage was realized. As the immersion time increased, the scale of the adsorption film became larger, and the corrosion resistance increased. On the sixth day of the immersion, the corrosion resistance of the coating reached its maximum resistance value, and the coating repair was complete. Compared with the beginning of the immersion, the copper content decreased from 80.233 wt.% to 2.548 wt.% after the coating repair. The performance of the MBT-loaded HMSN coating was tested using various test and characterization methods. Firstly, X-ray diffraction spectrum characterization proved that the prepared HMSNs were amorphous, and the loading of MBT did not change the crystal structure of the HMSN. Secondly, infrared characterization confirmed that MBT was able to be loaded into the HMSN. Thirdly, thermogravimetric analysis showed that HMSN, as excellent nanocarriers, were used to encapsulate MBT with a 14 wt.% loading rate. Next, the anti-corrosion performance of the self-repairing coating was evaluated by electrochemical impedance spectroscopy, and was further confirmed by the scanning Kelvin probe microscopy. At the end of the study, the self-repairing mechanism was summarized and clarified, and process was described. The self-repair performance of the prepared coating was excellent according to a variety of test characterizations. In the complex corrosion environment, the self-repairing coating had the ability to repair coating damage, and thus has a high practical value. The service life of metal equipment coated with the proposed coating can be effectively prolonged because of the remarkable anti-corrosion effect of the coating, enabling working equipment to realize long-term operation.