Morphology and properties of core-shell nanocomposites of poly(N/-vinylcarbazole) with multi-walled carbon nanotubes

In this article, we present the morphology and properties of core-shell nanocomposites of poly(N-vinyl carbazole) (PNVC) with multi-walled carbon nanotubes (MWCNTs). Nanocomposites were synthesized by the in situ solid-state polymerization of N-vinylcarbazole (NVC) at an elevated temperature in the presence of MWCNTs. Fourier transform infrared (FTIR) studies confirmed the ability of MWCNTs to initiate the in situ polymerization of NVC monomers and the presence of PNVC polymer in the nanocomposites. X-ray photoelectron spectroscopy (XPS) studies supported the FTIR results. Field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) images showed the homogeneous covering of MWCNTs outer surfaces by PNVC matrix. The Raman spectroscopy studies also revealed the homogeneous wrapping of MWCNTs outer surfaces without disturbing the inherent electronic structure of MWCNTs. Thermogravimetric analyses revealed a significant improvement of thermal stability of the nanocomposites in the higher temperature region. The core-shell nanocomposites showed interesting fluorescence properties. The dc (direct current) electrical conductivity of pure PNVC dramatically improved after nanocomposites formation with MWCNTs and degree of improvement was dependent on the loading of MWCNTs in the nanocomposites. For example, dc electrical conductivity increased from 10 ^-16-10 ^-12 S-cm ^-1 for pure PNVC to ∼12 S-cm ^-1 for nanocomposite containing 50 wt% MWCNTs.