Electrical Conductivity of Composites
To make efficient use of composite materials, the variations of physical properties such as electrical conductivity with the kind and concentration of filler particles should be known. For example, electrically nonconducting particles are often added to a metal matrix to enhance the mechanical properties. However, the addition of nonconducting particles can decrease the electrical conductivity of the metal by a significant amount. From a practical point of view, it is important to be able to predict this decrease in electrical conductivity with the increase in volume fraction of insulating filler. Likewise, it is important to be able to predict the increase in electrical conductivity of an insulating matrix with the increase in electrically conducting filler content; many practical applications in electronics and electrical industries require electrically conductive polymer composites (composites of nonconducting polymer matrix and electrically conducting filler particles).