Simultaneous dispersion and alignment of carbon nanotubes in epoxy resin through chronoamperometry

A novel technique of dispersion, stretching and alignment of carbon nanotubes (CNTs) in an epoxy resin has been developed based on chronoamperometry. The procedure is to apply an electrical field in non-cured CNT/epoxy mixtures, using an electrode of large surface. CNT movements can be promoted by their intrinsic polarisation or by the introduction of electrical charges over their surfaces. The efficiency of the process can be monitored through the electrical current passing through the system as a function of time. Different experimental conditions, such as the applied voltage, have been analysed. The composites have been characterised through their thermal, mechanical and electrical behaviour. They show high dispersion degree of nanotubes, which are found to be stretched and untangled. CNTs show alignment along a preferred direction in the epoxy matrix, which affects to their electrical conductivity. (C) 2012 Elsevier Ltd. All rights reserved.