Water‐dispersible conducting nanocomposites of binary polymer systems. I. Poly( N ‐vinylcarbazole)–polyaniline–Al 2 O 3 nanocomposite system

The chemical oxidative polymerization of a mixture of N ‐vinylcarbazole (NVC) and aniline (ANI), by FeCl 3 in aqueous medium, produced an insoluble polymer that contained polyaniline (PANI), along with some residual poly‐ N ‐vinylcarbazole (PNVC) not extractable with benzene. This insoluble PNVC–PANI composite could be obtained as a stable suspension in water when the above polymerization was conducted in the presence of nanodimensional Al 2 O 3 . Alternatively, PNVC–(PANI–Al 2 O 3 ) composite could also be produced by precipitating a THF solution of preformed PNVC onto a PANI–Al 2 O 3 suspension. Likewise PANI–(PNVC–Al 2 O 3 ) could be obtained by polymerizing ANI onto an aqueous suspension of PNVC–Al 2 O 3 . The inclusion of either of these monomer units in the resultant polymer was confirmed by FTIR analysis. SEM analyses revealed formation of a lumpy aggregate, and TEM analyses confirmed particle sizes of the PNVC–PANI–Al 2 O 3 composite to be in the 52–200 nm range. Thermogravimetric stability was in the order: PANI–Al 2 O 3 < PNVC–PANI–Al 2 O 3 < PNVC–Al 2 O 3 . The dc conductivity values (S/cm) followed the trend: PNVC–Al 2 O 3 (10 −7 ) < PNVC–PANI–Al 2 O 3 (1.5 × 10 −4 ) ≈ PANI–Al 2 O 3 (1.1 × 10 −4 ) < PNVC–PANI (1 × 10 −3 ) at ambient temperature. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 803–811, 2004