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Abstract

Specific electric conductivity of composite materials based on graphite dispersions was studied. The aim of the work is to optimize electrical properties of composites. It was found that with increase of graphite mass fraction from 0.06 to 0.2 electrical conductivity of the system cement-quartz-graphite increases from 0.85 to 13.11 ohm-1•cm-1. Temperature dependences of the model systems cement-graphite, quartz-graphite, cement-quartz-graphite on conductive phase mass fraction were analyzed. To obtain effective compositions with stable electrical characteristics threshold concentration of a conductive component for cement-quartz composites equal to 0.06 was determined; any excess of this value leads to a great increase in the electrical conductivity due to formation of continuous chain structures. Temperature dependence of an electric conductivity logarithm in the model system cement-quartz-graphite is described by rising curves. Activation energies of electrical conductivity in the model systems cement-graphite, quartz-graphite, cement-quartz-graphite were calculated at different mass fraction of graphite.