Visualization of the conductive paths in injection moulded MWNT/polycarbonate nanocomposites by conductive AFM

Electrical conductivity of MWNT filled polymer composites can strongly depend on the dispersion of the filler. Injection moulding of the same nanotube filled conductive composite materials can lead to significant differences in conductivities while the corresponding morphological changes seem to be moderate. Here we report on a conductive atomic microscopy (C-AFM) study of a series of polycarbonate/MWNT settings injection moulded with different injection speeds and melt temperatures, completed with optical microscopy, SEM and TEM characterization. C-AFM was found to be able to visualize the significant differences in the morphology of electrical pathways in cross section. These morphological variations seem to correlate to the differing volume resistivity data and are in agreement with the expected structural effects of injection moulding processes with different parameters. © 2013 Elsevier Ltd.