The 500 MHz to 5.50 GHz complex permittivity spectra of single-wall carbonnanotube-loaded polymer composites

The 500 MHz to 5.50 GHz complex permittivity spectra of a thick-film polyme r loaded with 0-23 wt% single-wall carbon nanotubes is measured. At 500 MHz , as the weight percentage loading of the carbon nanotubes increases from 0 to 23% the real permittivity is found to increase by a factor of similar t o 35, and the imaginary permittivity by a factor of 1200. The spectral magn itudes decrease rapidly from the 500 MHz value over the measured frequency range. Experimental data are in qualitative agreement with values predicted using an effective medium theory for materials comprised of elongated cyli ndrical conductors [A.N. Lagarkov, A.K. Sarychev, Phy. Rev. B 53 (1996) 631 8]. (C) 2000 Published by Elsevier Science B.V. All rights reserved.