Effect of manufacturing processes on percolation threshold and electrical conductivity of polymer/multi layers graphene nanocomposites

摘要

Electrical conductivities of the high performance poly(ether ketone)/multi layers graphene or graphite nano-platelet (2-10 net thick) (PEK/GNP) nanocomposites manufactured by three different methods were compared and studied. The percolation threshold of the nanocomposites manufactured by; planetary ball mill followed by hot pressing (method-1) and planetary ball mill followed by cold pressing + sintering (method-2) is lowest, i.e., 0.755 vol% (or 0.0076 volume fraction) GNP, while that of manufactured by a solution method followed by hot pressing (method-3) is about 1.21 vol%.The lower percolation threshold for the method-1 and method-2 was attributed to the better dispersion of GNP in the PEK matrix while the higher percolation threshold for the method-3 was attributed to a non-uniform dispersion of GNP and GNP-aggregates in the matrix. However, above percolation for a given volume fraction (i.e., 1.52 vol%), the electrical conductivities of the nanocomposites manufactured by method-3 showed higher values compared to those of method-1 and method-2. The electrical conductivity of the 3 vol% nanocomposite increased by 12 orders of magnitude as compared to pure matrix. The highest electrical conductivity of the nanocomposites manufactured by method-3 is 1004 S/cm which is interesting.