Percolation for Coated Conductive Paper: Electrical Conductivity as a Function of Volume Fraction of Graphite and Carbon Black

Conductive papers were prepared via surface coating with graphite or carbon black using either carboxylated styrene butadiene latex or starch as the binder. It is of practical interest to determine the percolation threshold for the coated paper product made using a binary system consisting of conductive filler and binder. In this study, the electroconductivity threshold of various conductive papers was determined based on experimental data according to the percolation law. Results showed that the conductivity of coated, conductive paper is a function of the volume fraction of conductive filler, which can be described well by the percolation theory. The percolation thresholds of graphite/latex, graphite/starch, carbon black/latex, and carbon black/starch coatings were 17.66, 12.36, 11.71, and 8.69 vol.%, respectively. At concentrations higher than the percolation threshold, the conductivity of conductive paper using graphite as the conductive filler was much higher than that achieved using carbon black at a similar volume fraction. The present paper has significant practical implications for conductive paper technology using graphite filler based on surface coating technology.