Carbon Nanotubes and Graphene - Research and Applications

Nano-composite made by two different dispersion procedures has been considered to investigate the distribution of multi-walled carbon nanotubes within an epoxy resin. The correlation between the electrical conductivity of the epoxy/MWNTs composite and nanotube dispersion has been carried out using an eddy-current technique (ECT) based on an induction coil probe.

- the EC image is capable to distinguish the spatial inhomogeneities between the nanotubes bundles and the presence of interconnected nanotubes, as confirmed by optical transmission microscopy images;
- there is a correlation between the nanotube dispersion, within the polymer matrix, and the increasing of the electrical conductivity. It could be noted that the electrical conductivity of the epoxy polymer matrix is generally of about 10^(-9) S/m while the electrical conductivity measured for the specimens D and E, loading with 0.1% of nanotube, is 0.8 S/m. Therefore, the dispersion procedure adopted for the samples D and E enhances effectively the electrical conductivity of the polymer matrix. This is an important result for the potential application of the nanotube loaded epoxy system to build components capable of dissipating electrostatic charge or shielding devices from electromagnetic radiation.

This work confirms the capability of the eddy current testing based on the use of an induction coil to evaluate in contactless, fast and non destructive way, the anisotropy distribution of CNTs due to the manufacture processing.
Article to be published in NDT & E International (C. Bonavolontà, et al., 2008).