The alignment of single walled carbon nanotubes in an epoxy resin by applying a DC electric field

The alignment of single walled carbon nanotubes (SWCNTs) in an epoxy monomer liquid medium by the application of a DC electric field has been investigated, taking into account the various transport phenomena involved: the tube rotation in the electric field, the translation of polarized SWCNTs toward each other to form a chain-like structure and the migration of the tubes toward the positive electrode. Moreover, the relaxation mechanism which takes place when the electric field is switched off has also been considered. Experimental tests, performed to verify the effectiveness of the model, are based on the application of an electric field to a liquid epoxy-SWCNT colloid (0.025 wt.%) while measuring the current and observing the system by optical microscopy. As a result of the modeling it is possible to identify the processing conditions that allow the alignment of SWCNTs in an epoxy resin through the short-time application of a DC electric field. Experimental measurements are in agreement with the model's predictions.