不同维度的ZnO对MMT-SiC/EP微纳米复合材料电学性能的影响

Effect of different dimensions of ZnO on the electrical properties of MMT-SiC/EP micro-nano composites

具有非线性电导特性的电介质被广泛应用于解决许多领域的高能放电问题(如航天器充电和电机绝缘)。本文通过在含有SiC和蒙脱土(MMT)微纳米复合体系中继续添加零维或一维纳米材料来进一步优化复合材料的非线性电导特性及其他电学性能。通过X射线衍射仪对MMT有机化改性前后的层间距进行了表征;通过扫描电子显微镜对复合材料内部各填料的分散情况以及界面状态进行了表征;通过对复合材料进行电导、击穿和介电频谱测试来研究纳米填料的维度对电学性能的影响规律。实验结果表明,在MMT-SiC/EP复合体系中添加一维四针状氧化锌(T-ZnOw)比零维颗粒状ZnO,可以更加有效增加体系中界面重合率,更加容易在复合材料内部构成良好的载流通路,能够在有效降低复合材料的阈值场强,提高复合材料的电导率和非线性系数,使得复合材料具备优越非线性电导特性的同时,不仅可以保证击穿场强不会太低,还可以降低复合材料的相对介电常数和介质损耗角正切值。

Nonlinear conductivity dielectric is widely used today to solve high energy discharge problems in many fields(such as spacecraft charging and motor insulation).In this paper,we optimize the nonlinear conductivity properties and other electrical properties of the composites by continuing the addition of zero-or one-dimensional ZnO to the micro-nano composite systems containing micron SiC and montmorillonite(MMT).The layer spacing before and after the organic modification of MMT was characterized by X-ray diffractometry.The dispersion of each filler inside the composite and the interfacial state were characterized by scanning electron microscopy.Conductivity,breakdown,and dielectric spectroscopy tests were performed on the composites to investigate the pattern of influence of the dimensionality of the nanofillers on the electrical properties.The experimental results showed that the addition of one-dimensional four-needle zinc oxide(T-ZnOw)was more effective than zero-dimensional granular ZnO in the MMT-SiC/EP composite system.Thus,the same content of T-ZnOw can increase the interfacial recombination rate in the composite system and constitute the conductive pathway more effectively.Improved nonlinear conductivity properties of the composite.Moreover,T-ZnOw also ensures stable breakdown field strength of the composite material and reduces the relative permittivity and dielectric loss angle tangent values.