Ma Ji, Zhang Kaili, Du Lili, Wang Xujie, Chen Zhijie, Chen Hao, Chen Changfeng, Qiu Ping
College of New Energy and Materials, China University of Petroleum, Beijing 102200, China.
College of Safety and Ocean Engineering, China University of Petroleum, Beijing 102200, China.
ACS Appl Mater Interfaces. 2024 Jul 3;16(26):34100-34112. doi: 10.1021/acsami.4c05347. Epub 2024 Jun 20.
Corrosion-resistant coatings with self-healing capabilities are still a great challenge for metal protection. In this study, a corrosion-resistant coating with intrinsic self-healing capabilities was developed by compounding hydroxy-terminated silicone oil (HTSO) with 2-ureido-4[1]-pyrimidone (UPy) derivatives. The smooth surface of the coating was shown by scanning electron microscopy (SEM), and good smoothness was also exhibited in the cross-section, which indicated that the coating is very homogeneous from the top to the bottom. Thermogravimetric analysis (TG) was employed to illustrate the temperature-resistant characteristics of the coating, revealing its significant chemical stability up to 360 °C. The corrosion resistance of the coating is assessed through electrochemical impedance spectroscopy (EIS), the typical impedance at 0.01 Hz is 1.70 × 10 and 2.44 × 10 Ω·cm before and after exposure to a 3.5 wt % NaCl solution for 70 days. There was no significant change in the water contact angle of the coatings before and after immersion; however, the adhesion strength was reduced. Notably, the coating demonstrates immediate and multiple self-healing properties. The tensile stress of the associated healing sample experiences an augmentation within the temperature range of 30-120 °C, with the critical fracture strain of the healed sample reaching 235% at 120 °C. The self-healing mechanism of the coating is systematically investigated using in situ Raman spectroscopy.
