Fabrication of carbon nanotube-polyaniline composites via electrostatic adsorption in aqueous colloids

We report that, for the first time, multiwalled carbon nanotube (MWNT)-polyaniline (PANI) nanocomposites were readily prepared via electrostatic adsorption in their mixed aqueous media. The pristine MWNTs were first oxidized to add some negative charges, and the PANI nanofibers, to add some positive charges, were fabricated by aqueous/organic interfacial polymerization, and then the MWNT-PANI composites were prepared by rapidly mixing the negatively charged oxidized MWNT aqueous colloid and the positively charged PANI aqueous colloid. Scanning and transmission electron microscopies (SEM and TEM, respectively) and Raman and Fourier-transform infrared (FTIR) spectroscopies were used to characterize the resulting composites. The results show that the electrostatic adsorptive forces between the positively charged PANI nanofibers and the negatively charged MWNTs enable precipitation of MWNT-PANI composites in the mixed aqueous colloids. This work provides new strategy for fabricating other nanocomposites of carbon nanotubes with conducting polymers.