论文部分内容阅读
纳米复合介质的介电性能与纳米粒子分散性密切相关。选取两种具有不同分散能力的纳米Si O2粉末分别与低密度聚乙烯(low density polyethylene,LDPE)复合,研究了纳米粒子分散性对纳米复合介质的直流电导电流、空间电荷及直流击穿强度特性影响。应用原子力显微镜的静电力模式观察了Si O2/LDPE纳米复合介质的表面电势分布。结果表明:改善纳米粒子分散性对于抑制SiO 2/LDPE复合介质的直流电导电流,提高空间电荷抑制能力及直流击穿强度有积极影响。通过静电力分析证实了SiO 2/LDPE纳米复合介质中,Si O2粒子与基体聚合物界面存在荷电分布,该荷电分布可对载流子迁移起散射作用,从而降低直流电到电流和提升击穿强度。通过引入观测的界面核电区厚度参数,理论计算证实了改善纳米粒子分散性可增加单位体积荷电域所占的体积分数,且被认为是高分散型Si O2/LDPE纳米复合介质介电性能显著提升的主要原因。
The dielectric properties of nanocomposite are closely related to the dispersion of nanoparticles. Two kinds of nano-Si O2 powders with different dispersing ability were selected to compound with low density polyethylene (LDPE) respectively. The effects of nano-particle dispersion on DC current, space charge and DC breakdown strength of nanocomposite influences. The surface potential distribution of Si O2 / LDPE nanocomposite was observed by electrostatic force mode of atomic force microscope. The results show that improving the dispersibility of nanoparticles has a positive effect on the inhibition of DC conduction current, space charge suppression and DC breakdown strength of SiO 2 / LDPE composites. Electrostatic force analysis confirmed that there exists charge distribution in the interface of Si O2 particles and matrix polymer in SiO 2 / LDPE nanocomposite media. The charge distribution can scatter the carrier migration and reduce the direct current to current and lift Wear strength. By introducing the thickness parameters of the observed nuclear interface region, theoretical calculations show that improving the dispersibility of nanoparticles can increase the volume fraction of the charge domain per unit volume and is considered as a highly dispersive Si O2 / LDPE nanocomposite with significant dielectric properties The main reason for promotion.