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

The 500 MHz to 5.50 GHz complex permittivity spectra of a thick-film polymer 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 to 35, and the imaginary permittivity by a factor of 1200. The spectral magnitudes 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 cylindrical conductors [A.N. Lagarkov, A.K. Sarychev, Phy. Rev. B 53 (1996) 6318]. (C) 2000 Published by Elsevier Science B.V. All rights reserved.