A well known approach for reducing the electrical percolationthreshold of an electrically conductive material is to mix therelatively small sized conducting fillers with the relatively largesized inert particles. The percolation limit in terms of the volumefraction of conducting particles is known to decrease with increasingratio of the mean size between the small and large particles. However,both the small conducting and large inert particles rarely exist asmonodispersed, rather, there is a respective size distribution for eachof them. Such a size distribution is expected to affect the developmentof conductivity as well as the percolation threshold. The firsttheoretical model for considering such a size dispersity effect on theconduction development and the percolation limit is reported. It isshown that the present model not only includes all the previous ones forconsidering only the particle size ratio effect, it considers therespective role played by the ratio of mean particle size, the sizedispersity and the volume fraction on the electrical conductiondevelopment and the percolation limit. The model suggests an innovativeroute for processing new conductive adhesives with ultralow percolationlimits. Other implications for manufacturing electrically conductiveadhesives are also discussed
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