A water‐dispersible conducting nanocomposite from suspension polymerisation of thiophene in presence of N‐vinylcarbazole

The polymerisation of a mixture of thiophene and N‐vinylcarbazole was achieved in aqueous suspension in the presence of nanodimensional alumina and FeCl₃ as oxidant. The resultant composite was found to contain both polythiophene (PTP) and poly(N‐vinylcarbazole) (PNVC) components even after reflux in benzene, which would remove any PNVC homopolymer. The presence of the individual polymer components was endorsed by FTIR spectroscopic analyses. Thermogravimetric analyses showed that the overall stabilities of the composite and the corresponding homopolymers were in the order: PTP–Al₂O₃ > PTP > PTP–PNVC–Al₂O₃ > PNVC. Differential thermal analyses studies showed the manifestation of two different exotherms corresponding to the presence of two different polymeric constituents in the PTP–PNVC–Al₂O₃ composite. Differential scanning calorimetry studies revealed two glass‐transition temperatures (T_g) suggesting the presence of two polymeric moieties in the PTP–PNVC composite. Scanning electron micrographs of the PTP–Al₂O₃ and PTP–PNVC–Al₂O₃ composites showed distinctive morphological patterns. Transmission electron microscopic images of the composite revealed that the average particle size varied between 20 and 80 nm. DC conductivities of the composites were of the order of 10^?6 S cm^?1. Copyright © 2003 Society of Chemical Industry