Enhancement of the transport and dielectric properties of graphite oxide nanoplatelets-polyvinyl alcohol composite showing low percolation threshold

Graphite oxide nanoplatelets (GOnP) were prepared using standard method and used to make GOnP-polyvinyl alcohol (PVA) composites by using solution cast technique. Significant enhancement of electrical conductivity and dielectric permittivity of the GOnP/PVA composites are observed at low GOnP concentration (fGOnP = fc similar to 0.41 vol%) which is the percolation threshold value estimated from the concentration dependent transport and dielectric data. Nearly 300 times increase in dielectric permittivity (compared with that of PVA) is observed in the GOnP/PVA composite around fc. We notice interesting metal-insulator like transition (a sudden increase in resistivity) from the temperature dependent resistivity data in the pure GOnP sample around TMI similar to 275 K which is shifted to 300 K in the GOnP/PVA composite for fc = 0.41 vol%, indicating drastic change of sp3/sp2 ratio around respective TMI. The present graphite-based composite material might be processed for different applications. POLYM. COMPOS., 2012. (c) 2012 Society of Plastics Engineers