The unsatisfactory insulating properties of solid–gas interfaces seriously restrict the development of high-voltage electrical equipment and threaten their power supply stability. Electron-beam irradiation (EBI) can effectively improve the surface flashover voltage of dielectrics. However, the underlying mechanism of EBI in tailoring the surface trap and improving the flashover voltage remains unclear. In this study, the surface morphologies and chemical compositions of epoxy composites treated with EBI were investigated. In addition, the surface wetting properties, surface charge migration parameters, and surface flashover voltages were experimentally characterised. It was found that EBI aggravated the surface morphology, changed the surface chemical components, and repressed surface charge transportation. As a result, the contact angle was reduced from 103.7° to 78.43°, and the flashover voltage in SF₆ was increased from 35.26 to 38.90 kV. DFT calculations showed that the newly generated C–O–H and C=O bonds on the surface molecules after EBI formed charge centres at the molecular electrostatic potential, which enhanced the trapping effect of the surface deep trap. As a result, surface charge migration was repressed, and the surface flashover voltage was improved. This study could promote the further development of EBI on materials modification.

中文翻译：

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电子束辐照对环氧复合材料表面分子及闪络电压的影响

固气界面绝缘性能不佳严重制约了高压电气设备的发展并威胁其供电稳定性。电子束辐照（EBI）可以有效提高电介质的表面闪络电压。然而，EBI 在调整表面陷阱和提高闪络电压方面的基本机制仍不清楚。在本研究中，研究了经 EBI 处理的环氧复合材料的表面形貌和化学成分。此外，还通过实验表征了表面润湿特性、表面电荷迁移参数和表面闪络电压。结果发现，EBI加剧了表面形貌，改变了表面化学成分，抑制了表面电荷传输。结果，接触角从103.7°减小到78.43°，SF ₆中的闪络电压从35.26kV增加到38.90kV。DFT计算表明，EBI后表面分子上新生成的C-O-H和C=O键在分子静电势处形成电荷中心，增强了表面深陷阱的捕获效果。结果，表面电荷迁移受到抑制，表面闪络电压得到改善。该研究可促进EBI在材料改性方面的进一步发展。