MANAGEMENT TRAITS OF THE PROJECTS CONCERNING POWER GENERATION AND WASTE RECOVERY

Abstract

Electric resistivity ρ of graphite (including thermoexfoliated one) are mainly governed both by its structure and morphology. The analysis of electric properties in this case is strongly complicated by the presence of the high anisotropy of ρ for graphite crystal and peculiar conductivity mechanism in the disordered areas at the boundaries of the ordered graphite crystals. That is why, the mechanisms determining the transport properties of the graphite-based structures remains still discussible. Here, several speculations concerning the interpretation of ρ(Т) dependencies for nanocomposite materials (NCM) on the base of thermoexfoliated graphite (TEG) containing different metal constituent are thoroughly analyzed. The specimens for investigation were prepared by the compacting of the source materials under the pressure ranging from 60 to 450 MPa. Metal modifier has been involved into NCM structure by chemical deposition. The ρ(Т) dependencies within 77-450 К temperature range were investigated by the routine four-probe method. Electron microscopy investigation shows that the metal modifier particles 100-300 nm in size are located at the surface of the graphite platelets (Fig.1). The size of these platelets along a axis is much greater that along c axis. The X-ray diffraction studies evidence for high extend of texture of the compacted specimens. Since с axis was oriented along the compacting axis, the electric current in our experimental geometry flowed in the basis plain for the majority of the graphite crystallites. The size of the graphite crystallites L along с axis was determined by the width of (002) and (004) TEG reflections) It is ranged within 70-120 nm (see Table). The values of L were reduced down to 40-50 nm in a result of impregnation by mineral-organic composition with the subsequent thermal shock at 800°С