Electrical Properties of Insulator-Conductor Composites

本项目的主要目的是以介电和阻抗谱为主要实验工具，以有限元模拟为主要计算机模拟工具，研究绝缘子-导体复合材料的电学性质。将制备一系列不同体积分数的炭黑-聚合物复合材料并进行测试。一旦确定了渗流阈值，将制备大量具有临界炭黑体积分数的样品并进行测试。还将对所有测试样品进行介电函数(介电常数、阻抗、电模和导纳)的多平面分析并进行建模。将评估所有被测样品的微观结构，并将电学数据与微观结构参数(例如，尺寸、分布、连通性)之间进行定量关联。微结构结果将被用作有限元建模的输入，以进一步完善解释。预计该项目将有助于确定渗流参数的重要性，因为它们与材料的实际微观结构有关。这个项目将在这个主题上培养3名研究生。这个项目的主题是导体-绝缘体混合物中的%渗流。电话线在网络中的分布有助于解释渗流。基本概念是，如果建立了所有必要的连接，在温哥华拨打的电话将立即到达亚特兰大。如果任何连接中断或不起作用，则电话呼叫不会完成，所需的通信也会中断。这一概念可以应用于各种领域的许多其他问题。在本项目中，将通过评估绝缘颗粒和导电颗粒混合物的导电性来研究渗流。尽管对渗流的研究已经很多年了，但大多数以前的工作只考虑了直流行为。本项目的主要目的是评估频率(交流电)对渗流行为的影响。将使用理想化的绝缘体-导体混合物的实验测量和计算机模拟。该项目将培训多达3名研究生学习这一主题。*

The main objective of this project is to investigate the electrical properties of insulator-conductor composites using dielectric and impedance spectroscopy as the primary experimental tool and finite element modeling as the primary computer simulation tool. A series of carbon black-polymer composites with varying volume fractions will be fabricated and tested. Once the percolation thresholds have been identified, a large number of samples with the critical volume fraction of carbon black will be prepared and tested. Multiplane analysis of the dielectric functions (permittivitty, impedance, electric modulus and admittance) will also be done and modeled for all samples tested. The microstructure of all measured samples will be evaluated and quantitative correlations between the electrical data and the microstructural parameters will be made (e.g. size, distribution, connectivity). The microstructural results will be used as input for the finite element modeling to further refine the interpretation. It is expected that this project will help determine the significance of the percolation parameters as they relate to the actual microstructure of materials. This project will train up to 3 graduate students in this subject matter.%%%Percolation in conductor-insulator mixtures is the subject of this project. Distribution of telephone lines in a network helps explain percolation. The basic concept is that if all the necessary connections are made, a phone call placed in Vancouver will reach Atlanta instantaneously. If any connections are broken or are inoperative, the phone call does not complete and the desired communication is broken. This concept can be applied to many other problems in a variety of fields. In this project, percolation will be studied by evaluating the electrical conductivity of mixtures of insulating and conducting particles. Even though percolation has been studied for many years, most previous work has only considered direct current behavior. The main objective of this project is to evaluate the effect of frequency (alternating current) on the percolation behavior. Both experimental measurements and computer simulations of idealized insulator-conductor mixtures will be used. This project will train up to 3 graduate students in this subject matter.***