Electrical Properties of Plasma-Fluorinated Nano-ZnO/Epoxy Resin at Ultralow Temperatures

Epoxy resin, known for its excellent insulating properties, is widely used in superconducting and aerospace fields. In order to further improve the electrical properties of epoxy resin in the field of ultra-low temperature, the surface treatment of nano-ZnO was carried out by plasma fluorination technology, and it was used to modify the epoxy resin filler. The electrical properties of fluorine-containing nano-ZnO/epoxy resin composites at ultra-low temperature were studied. The results show that compared with the KH570 silane coupling agent treatment method, under the cryogenic environment of liquid nitrogen, the epoxy nanocomposites filled with plasma-fluorinated nano-zinc oxide exhibit higher volume resistivity, partial discharge inception field strength, and AC breakdown strength, while having lower relative dielectric constant and dielectric loss. The fluctuations in electrical property parameters are also reduced. The study finds that plasma fluorination treatment on the surface can introduce fluorine-containing active groups on the nano ZnO surface, improving interfacial characteristics, effectively suppressing the concentration of internal stress and the development of micro-cracks in the epoxy resin, and hindering the transport of charge carriers, thereby enhancing the electrical performance and stability of the composite material in ultra-low temperature environments.