The electric conductivity of composites based on various carbonaceous fillers and estimation of their percolation model parameters

We have studied the electric conductivity of composites with various carbonaceous fillers (multiwalled carbon nanotubes, colloidal graphite, and amorphous carbon) as a function of the filler content. The widths of critical regions of the percolation transition to the conducting state are determined and the percolation critical exponents are estimated. It is established that there is a tendency to increase in the width of transition region and values of critical exponents when the filler is varied in the following order: carbon nanotubes–colloidal graphite–amorphous carbon.