Electrical properties of solution cast films of polystyrene/polyaniline-multiwalled carbon nanotube nanocomposites

Self-standing films of camphor sulphonic acid doped polyaniline (PANI) and polystyrene (PS) with different multiwalled carbon nanotube (MWNT) loadings are successfully prepared by solution casting method. The presence of MWNT is characterized by X-ray diffraction and Raman spectroscopy. Raman modes confirm the presence of PANI and MWNTs. Transmission electron microscope images confirm the presence and dispersion of MWNTs in the film. The temperature-dependent electrical conductivity of the films is measured in the temperature range 10-300 K for different loadings of MWNTs. The nanocomposite films show a very low percolation threshold with nearly three order enhancement of electrical conductivity with MWNT loadings. The electrical conductivity variation with temperature follows the fluctuation induced tunnelling model. The films show two order increases in mobility with 1.45 wt% MWNT loadings. Hall Effect study confirms that the PANI-PS blend films switched from p-type to n-type behaviour with the addition of MWNT.