Decisive properties of graphite-filled cement composites for device application

Graphite-filled cement composites have been explored in order to design a new conductor–insulator composite system that can show higher shielding effectiveness to electromagnetic (EM) radiation besides higher mechanical strength. The fascinating feature of this work is the processing of cement/graphite composites through which both reflection and absorption of EM radiation are anticipated to increase with increase of graphite filler. The dc conductivity was initially found to increase rapidly with the increase in filler concentration; it then approached saturation after incorporation of 10 wt. % graphite. The permittivity increased progressively with increase in filler loading. Decrease in permittivity with increasing frequency has been registered for all compositions of the composites. The dielectric behavior can be endorsed to Maxwell–Wagner–Sillars theory, both in terms of filler concentration and frequency dependence. At a low frequency of 10 Hz, a very high dielectric constant of the order of 10⁸ has been noticed in 5 wt. % graphite composite, which is expected to increase further with increase in graphite content. The D-Shore hardness results have revealed very little alteration in hardness with increasing graphite content. PACS  72.80.Tm; 77.22.Ch; 77.22.Gm; 81.20.Ev; 81.40.Tv