P.C.P. Watts, W.K. Hsu, H.W. Kroto, D.R.M. Walton
School of Chemistry, Physics
and Environmental Science
University of Sussex,
Brighton BN1 9QJ, UK
The electrical conduction path within a carbon black-based polymer matrix ( polystyrene) has been established via aggregated carbon particles. However, the conduction is often localized, due to the uneven distribution of carbon particles; discontinuous conduction occurs when the polymer is bent or stretched, due to segregation of particles. The localisation of conduction in the polymer can be minimised by replacing carbon black with carbon nanotubes. The elongated nanotube structure achieves stable electrical contact via cross tube bundles. Boron-doped carbon nanotubes possess a film resistivity of 10-5 W.m, meanwhile the carbon additives become paramagnetic (carbon nanotubes are diamagnetic). In order to enhance the magnetic properties of the polymer composite, ferromagnetic Fe3O4 powder was also added, resulting in an electromagnetic plastic, which responds rapidly to the magnetic field. The purpose of fabricating electromagnetic plastics is to dispense with the conventional Fe-based induction component, i.e. transformer.