A geometric percolation model for non-spherical excluded volumes
A geometric percolation model for non-spherical excluded volumes
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非球形排除体积的几何渗流模型
DOI：
10.1088/0022-3727/36/6/317
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
I. Youngs
中科院分区：
文献类型：
--
作者：
I. Youngs
本文提供了实验证据，证明导体-绝缘子复合材料的渗透阈值可以是组分粒度比和颗粒形状的函数。当导电颗粒被排除在复合体积的区域（例如绝缘体颗粒的核心）之外时，这种渗透阈值的趋势是可以预期的。所研究的复合体系由炭黑粉末分散在聚四氟乙烯粉末中组成。为促进这一效果的实现，专门选择了复合制备的体系和方法。本实验研究的目的是为最近报道的基于遗传算法的方法提供额外的信心，以分析渗透复合材料的介电光谱。实验结果与一系列几何渗透模型进行了比较，其中一个模型适用于椭球体绝缘子颗粒。将此修正与绝缘子颗粒的实际粒度分布相结合，模型与实验结果吻合较好。
This paper presents experimental evidence that the percolation threshold in conductor–insulator composites can be a function of the particle size ratio of the constituents, as well as the particle shape. This trend in percolation threshold is to be expected when the conducting particles are excluded from regions of the composite volume (e.g. the core of the insulator particles). The composite system investigated consisted of carbon black powder dispersed in PTFE powder. The system and the method of composite preparation was chosen specifically to promote the realization of this effect. The purpose of this experimental investigation was to provide additional confidence in a recently reported genetic algorithm-based approach to analysing the dielectric spectra of percolative composites. The experimental results are compared to a range of geometric percolation models and one such model is adapted to account for ellipsoidal insulator particles. Good agreement between model and experiment is achieved when this modification is used in conjunction with the actual particle size distribution of the insulator particles.