Synthesis and electrical properties of polyaniline/polyaniline grafted multiwalled carbon nanotube mixture via in situ static interfacial polymerization

The mixture of polyaniline (PANi) and PANi grafted multiwalled carbon nanotube (PANi‐g‐MWNT) was prepared by a two‐step reaction sequence. MWNT was first functionalized with 4‐aminobenzoic acid via “direct” Firedel‐Crafts acylation in polyphosphoric acid (PPA)/phosphorous pentoxide (P₂O₅) medium to afford 4‐aminobenzoyl‐functionalized MWNT (AF‐MWNT). Then, aniline was polymerized via an in situ static interfacial polymerization in H₂O/CH₂Cl₂ in the presence of AF‐MWNT in organic phase to yield the mixture of PANi and PANi‐g‐MWNT. The mixture was characterized with a various analytical techniques such as elemental analysis (EA), Fourier transform infrared spectroscopy (FTIR), wide angle X‐ray diffraction (WAXD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), cyclic voltammogram (CV), UV‐vis and fluorescence spectroscopies, and electrical conductivity measurement. On the basis of TGA analysis, the thermo‐oxidative stability of the mixture was markably improved compared to that of PANi homopolymer. Even after dedoping, in alkaline solution, the mixture would still display semimetallic conductivity (4.9 S/cm). The capacitance of the mixture was also greatly enhanced and its capacitance decay with respect to cycle times was significantly reduced. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1962–1972, 2010