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

Abstract

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.

Nanocomposites of Multiphase Polymer Blend Reinforced with Carbon Nanotubes: Processing and Characterization

“…The distribution of the nanofiller usually varies in the final part depending on the distance from the injection molding gate and the sample walls. [202] The latter skin effect can be observed as a gradient of filler load and alignment near the surface of the specimen and arises due to the temperature gradient inside the mold. [60,97] The skin effect has a comparable impact on the properties of the material to the position (and shape) of the injection gate.…”