Characterization of the dielectric properties of multiwalled carbon nanotubes (MWCNTs) /PEDOT:PSS nanocomposites

Abstract

Poly (3,4-ethylenedioxythiophene) poly (4-styrene-sulfonate) (PEDOT:PSS) polymer shows remarkable electrical properties which can be enhanced by using multi-walled carbon nanotubes (MWCNTs) as fillers. The MWCNTs/PEDOT:PSS nanocomposites containing 0.025, 0.05, 0.075 and 0.1 wt. % of MWCNTs were prepared and deposited on a flexible thin substrate (Kapton HN) by using the drop casting technique. The dielectric characterization of nanocomposite was conducted by using the electrochemical impedance spectroscopy over a wide range of frequency from 40 Hz to 110 MHz. It was observed that the real part of complex impedance decreases due to generation of more conductive paths in nanocomposite with increasing MWCNTs content and it shows the existence of both frequency dependent and frequency independent regions. The imaginary part of impedance indicates the presence of dipolar relaxation which is considered as a peak in the corresponding frequency. Furthermore, the polarization and the conduction mechanism of PEDOT:PSS nanocomposites of different MWCNTs content has been analyzed by designing an equivalent circuit based on the impedance data of the nanocomposites.