In this work, the effect of gas-phase fluorination concurrent with nano-Al 2 O 3 doping on space charge distribution, as well as trap level and density of epoxy resin, is investigated. Epoxy resins with different concentrations of Al 2 O 3 nano-fillers (0, 1, 3, and 5 wt%) are prepared and fluorinated by a gas mixture of F 2 /N 2 (20/80 v/v) for 30 min at 40 °C and 0.05 MPa. Fourier-transform infrared (FTIR) spectroscopy confirms the breakage of molecular-chain during the gas-phase fluorination process. The space charge behavior is observed by the pulsed electroacoustic (PEA) method before and after fluorination. PEA results indicate that 30-minute fluorination is useful against space charge injection into the bulk of epoxy resin/Al 2 O 3 nanocomposites. The trap density and trap energy level distribution are determined by isothermal surface potential decay (ISPD) measurement. The results indicate that fluorination introduces shallow traps on the surface, which can increase the conductivity of surface, and, thus, the trap depth is considerably reduced after fluorination. Moreover, it is found that incorporating 1 wt% nano-Al 2 O 3 particles into epoxy resin can level up the energy level of deep traps. However, further increasing the nano-Al 2 O 3 concentration, e.g., 3 and 5 wt%, promises the overlap of interaction zones between polymer matrix and nanoparticles, reducing the trap energy level.

中文翻译：

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气相氟化和纳米Al2O3掺杂对环氧树脂空间电荷行为和陷阱能级的比较研究

在这项工作中，气相氟化与纳米铝同时发生的影响 2 哦 3研究了掺杂对空间电荷分布以及环氧树脂的陷阱能级和密度的影响。不同Al浓度的环氧树脂 2 哦 3 纳米填料（0、1、3 和 5 wt%）由 F 的气体混合物制备和氟化 2 /N 2(20/80 v/v) 在 40 °C 和 0.05 MPa 下保持 30 分钟。傅里叶变换红外 (FTIR) 光谱证实了气相氟化过程中分子链的断裂。通过脉冲电声（PEA）方法观察氟化前后的空间电荷行为。PEA 结果表明，30 分钟的氟化作用有助于防止空间电荷注入环氧树脂/Al 本体 2 哦 3纳米复合材料。陷阱密度和陷阱能级分布由等温表面电位衰减 (ISPD) 测量确定。结果表明，氟化在表面引入了浅陷阱，可以增加表面的电导率，因此氟化后陷阱深度大大降低。此外，发现掺入 1 wt% 的纳米铝 2 哦 3粒子进入环氧树脂可以提高深陷阱的能级。然而，进一步增加纳米铝 2 哦 3 浓度，例如 3 和 5 重量％，承诺聚合物基质和纳米粒子之间的相互作用区域重叠，降低陷阱能级。