TiO₂ Modified Self-Healing Microcapsules Based on Microfluidic Techniques Achieving UV-Induced Healing in Dielectric Polymers

Dielectric polymers, widely used in various applications, are often subjected to prolonged mechanical, electrical, and thermal stresses, which can result in minor localized damage and increase the risk of insulation failure. To address this, we have developed self-healing microcapsules using micro fluidic techniques. These microcapsules are designed to rupture upon slight damage to the polymers, releasing the core repair agent that fills and cures the damaged area under external UV light. To enhance the UV protection of the repair agent, TiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> nanoparticles were incorporated into the microcapsule shell, acting as a UV shielding medium. The self-healing capacity and intrinsic properties of the microcapsules and their composites were evaluated using scanning electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, broadband dielectric spectroscopy, and a power frequency breakdown test platform. The results demonstrate that the inclusion of TiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> nanoparticles provides effective UV shielding, preserving the reactivity of the core repair agent. Consequently, the composite materials not only achieve self-healing of mechanical damage but also maintain the excellent intrinsic properties of dielectric polymers.