Conductive polymer/carbon nanotubes nanocomposites with core-shell structures: preparation and properties

The combination of conductive polymers with carbon nanotubes offers an attractive route to introduce electronic properties based on morphological modification or electronic interaction between the two components. We prepared three different types of conductive polymers, i.e. polyaniline (PANI), polypyrrole (PPy) and poly [p-2,5-bis(n-octyloxy) phenylvinylene] (POPV) by in situ chemical polymerization of conjugate monomers in the presence of multi-walled carbon nanotubes (MWCNTs). TEM images showed that the resulting nanocomposites exhibited tight and uniform core shell structures, which benefited from the use of MWCNTs with less defects as a template. The thickness of polymer shell-layers can be effectively controlled by changing the weight ratio of MWCNTs to conjugate monomers. FTIR spectra indicated that strengthened electron delocalisation and conjugation along the polymer chains appeared by the incorporation of carbon nanotubes. XRD results further showed that the interaction between polymers and MWCNTs gradually weakened with the increase of polymer shell-layer thickness. The nanotubular morphology and strong pi-pi* interaction for the resulting composite as promising electrode materials are responsible for the lower charge transfer impedance, lower internal resistance, and the enhanced electrochemical properties in comparison to that shown for their mixed system.