Temperature-dependent electrical properties of dilute suspensions of carbon nanotubes in nematic liquid crystals

Dielectric spectroscopy was used in a frequency-dependent study of pristine nematic liquid crystals (E7) and E7 doped with multi-walled carbon nanotubes. The experiment was carried out in the frequency range of 10–1–105 Hz and temperature range of 303–353 K. The low-frequency (1–102 Hz) data reflect the electrode polarization due to space-charge polarization dictated by both the concentration and diffusion constant of impurity ions and, thus, are particularly useful for interpretation of the dopant effect on the ion transport. It was found that the activation energy for ionic diffusion is slightly higher and the diffusion constant significantly smaller in the suspensions.

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► CNTs as a dopant reduce impurity-ion concentration in pure E7 in the mesophase.
► The activation energy for ionic diffusion is slightly higher in E7-CNT suspensions.
► The ionic diffusion constant is significantly smaller in the suspensions.