为抑制环氧树脂绝缘的表面电荷积累、研究处理时间对表面电荷积累的影响,使用氟/氮混合气在实验室反应釜中对环氧试样进行了不同时间（10 min,30 min和60 min）的表面氟化处理.衰减全反射红外分析与SEM断面和表面观察表明随氟化时间的增加,氟化层的氟化度和厚度增大,表面微观粗糙度降低、表面组织变得致密.与开路热刺激放电电流测量所表明的、未氟化（原）试样有深的表面电荷陷阱和稳定的表面电荷相比,这些氟化试样的表面不能存储电荷.沉积在它们表面上的电晕电荷于室温下分别约在2 min,10 min和15 min内快速衰减为零,展现随氟化时间的延长而减慢的电荷释放速率.表面电导率和接触角测量及表面能计算表明氟化引起表面电导率和表面润湿性与极性的显著增加,但它们随氟化时间的延长而减小.氟化试样表面电导率的显著增大归因于表面电荷陷阱的非常可能的实质变浅和表面吸附的水分.表面充电电流测量进一步地表明,与原试样几乎为零的稳态表面电流相比,这些氟化试样在连续充电期间显现大的稳态表面电流.这意味着这些氟化试样在充电期间比原试样有少得多的表面电荷积累.%In order to suppress surface charge accumulation on the epoxy resin insulation and to investigate the influence of treatment time on the charge accumulation,epoxy samples are surface fluorinated for the different times of 10 min,30 min and 60 min in a laboratory vessel using an F2/N2 mixture.Attenuated total reflection infrared analyses and the observations of the cross section and the surface of the samples by SEM indicate the increases in degree of fluorination,thickness and compactness of the fluorinated layer, and the decrease in surface roughness,with treatment time increasing.Compared with the deep surface charge traps and stable surface charge of the unfluorinated（original） sample,as indicated by the open-circuit thermally stimulated discharge current measurement, the fluorinated surface cannot store the charge.The corona charges deposited on the sample surfaces fluorinated for 10 min,30 min or 60 min rapidly decay to zero in about 2 min,10 min or 15 mi at room temperature respectively,showing a slowed-down release of charge with fluorination time.The measurements of surface conductivity and contact angle and the calculation of surface energy reveal that fluorination gives rise to dramatic increases in surface conductivity,surface wettability and polarity,while they decrease with treatment time.The significant increase in surface conductivity of the fluorinated sample is attributed to a very likely substantial decrease in trap depth and the adsorbed water on the fluorinated surfac.Surface charging current measurements further show that large steady state current flows along the fluorinated surface during corona charging,in comparison with the almost zero steady state current for the original sample.This implies that the fluorinated sample has much lower surface charge accumulation in the period of charging, than the original sample.
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