This study investigates the promotion of epoxy resin (ER) surface electrical insulation and its stability by atmospheric fluorocarbon dielectric barrier discharge (DBD) plasma. Surface physicochemical and electrical properties of untreated and plasma treated samples are evaluated by scanning electron microscopy, X-ray photoelectron spectroscopy, surface and volume resistivity, surface charge accumulation, dissipation measurements, and flashover tests. Analysis shows that dusty-like fluorocarbon granules formed in plasma phase are deposited on ER samples and the concentration of fluorine groups is increased after plasma treatment. The surface withstand strength of epoxy resin in vacuum can be promoted up to 50%. Surface resistivity decreases by two orders of magnitude with treatment time while volume resistivity reduces slightly. The surface charge accumulation on treated ER samples is prohibited and the maximum surface charge density decreases from 77.84 to 1.42 pC/mm2. The surface charge dissipation is accelerated with the central energy levels reducing to below 0.9eV and the density of electron traps increases from ∼1021 to ∼1022eV−1m−3. Furthermore, the stability of surface flashover strength is tested. It is found that promotion of surface flashover strength of treated ER sample is stable after being kept in ambient air for a month. The physicochemical changes caused by plasma treatment prevents electrons from transferring to the surface which leads to a better surface insulation performance.

中文翻译：

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大气氟碳介质阻挡放电提高环氧树脂表面电绝缘性能及其稳定性

本研究调查了大气氟碳介质阻挡放电 (DBD) 等离子体对环氧树脂 (ER) 表面电绝缘性的促进及其稳定性。通过扫描电子显微镜、X 射线光电子能谱、表面和体积电阻率、表面电荷积累、耗散测量和闪络测试来评估未处理和等离子处理样品的表面物理化学和电性能。分析表明，等离子相中形成的粉尘状碳氟化合物颗粒沉积在 ER 样品上，等离子处理后氟基团的浓度增加。环氧树脂在真空中的表面耐受强度可提高50%。表面电阻率随处理时间降低两个数量级，而体积电阻率略有降低。禁止在处理过的 ER 样品上积累表面电荷，最大表面电荷密度从 77.84 降至 1.42 pC/mm2。随着中心能级降低到0.9eV以下，表面电荷耗散加速，电子陷阱的密度从~1021增加到~1022eV-1m-3。此外，还测试了表面闪络强度的稳定性。发现处理过的ER样品在环境空气中放置一个月后表面闪络强度的提升是稳定的。等离子体处理引起的物理化学变化阻止电子转移到表面，从而导致更好的表面绝缘性能。随着中心能级降低到0.9eV以下，表面电荷耗散加速，电子陷阱的密度从~1021增加到~1022eV-1m-3。此外，还测试了表面闪络强度的稳定性。发现处理过的ER样品在环境空气中放置一个月后表面闪络强度的提升是稳定的。等离子体处理引起的物理化学变化阻止电子转移到表面，从而导致更好的表面绝缘性能。随着中心能级降低到0.9eV以下，表面电荷耗散加速，电子陷阱的密度从~1021增加到~1022eV-1m-3。此外，还测试了表面闪络强度的稳定性。发现处理过的ER样品在环境空气中放置一个月后表面闪络强度的提升是稳定的。等离子体处理引起的物理化学变化阻止电子转移到表面，从而导致更好的表面绝缘性能。