Abstract

This research encapsulated hollow silica microspheres with Mg-Al layered double hydroxides (LDHs) via in-situ solution deposition, integrating them into an epoxy matrix to enhance its properties. Electrochemical impedance spectroscopy revealed that SiO2@Mg-Al-NO2-LDHs-EP maintained a high impedance of 1.42×109 Ω·cm2 after a 50-day immersion period, significantly outperforming the base epoxy. The impedance change in the scratch area in the local electrochemical impedance spectroscopy demonstrates the self-healing property of the coating. According to the thermal conductivity meter test results, adding SiO2-LDHs to the coating can reduce the thermal conductivity of the coating by about 20%. Furthermore, microcalorimeter and cone calorimeter tests show that SiO2@Mg-Al-NO2-LDHs can significantly improve the flame retardancy properties of the coating. This study demonstrates the potential advantages of LDHs-coated silica microspheres in functional coatings.