Prediction of particle size distribution effects on thermal conductivity of particulate composites

A material property that is of crucial importance for many industrial applications is the effective thermal conductivity. This property is a function of the thermal conductivities of components, their geometry, the spatial distribution of the components (including volume fraction and shape), the thermal resistances between phases, the possible contact between the filler particles and their size distribution law. The way the particles size distribution law influences the effective properties is not yet established, due to the fact that this law is not characterized in a unitary way. The numerous equivalent diameters (depending on the measurement technique) and the lack of a methodology of correspondence between them, complicates the solving of the problem regarding the size distribution dependence of the composite materials effective properties. The main goal of this paper was to introduce the predictions regarding the influence of the descriptors of the particle size distributions on the thermal conductivity of a composite material. It was found that the mean diameter is an inconsistent parameter for comparing the effective thermal conductivities of composite materials, and that the coefficient of variation offers an alternative criterion, as well as the Pearson's mode skewness.