Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Materials Science Poland

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Study of the electrical properties of polystyrene-foliated graphite composite

Srivastava N. K., Mehra R. M.

Materials Science Poland

2009

Vol. 27, No. 1

109--122

The present paper reports the development of polystyrene-foliated graphite composites via a hot compression moulding technique. Foliated graphite, as obtained by the sonication of expanded graphite, was used as a filler. A distinct percolative behaviour was observed in the variation of conductivity of the composites as a function of graphite concentration. At the percolation concentration of graphite content (0.02 vol. fraction), the conductivity is found to be ca. 10-5 S/cm. The percolation behaviour was analyzed using the generalized effective media equation. An estimation of the interparticle distance between the filler particles/clusters in the composites was made. The analysis of current-voltage characteristics revealed that near the percolation threshold the electrical transport is due to tunnelling of charge carriers, while above the threshold it is ohmic in nature.

Pre-localized graphite/polyvinyl chloride compositesfor electromagnetic interference hielding in the X-band frequency range

Sachdev V.K., Srivastava N.K., Kamlesh K., Mehra R.M.

Materials Science Poland

2005

Vol. 23, No. 1

269--277

The paper reports the development of compression moulded pre-localized graphite/polyvinyl chloride (graphite/PVC) segregated composites with different concentrations of graphite and their application to the shield effectiveness of electromagnetic radiation in the X-band frequency range 8-12 GHz. The incorporation of graphite is related to the formation of conducting channels. It is found that conducting channels are formed above 3 wt. % of graphite. The electrical conductivity is also found to be strongly dependent on the graphite content, and the data are analysed using a percolation model. Variations in SE with graphite loading, due to changes in the conductivity of the composite, have been investigated.