Poly(N-vinyl carbazole) (PNVCz)-based composite materials: Electrical properties, morphologic, and thermal characterization of PNVCz/MWCNTs and PNVCz/o-GLs systems

Poly(N-vinylcarbazole)/oxidized-graphite layers (PNVCz/o-GLs) and PNVCz/multiwalled carbon nanotubes (MWCNTs) composites were prepared by both solution blending and in situ polymerization methods. Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), and polarized optical microscope (POM) were used for their structural and morphologic characterization. Thermal stabilities and glass transition temperatures (T _gs) were measured by thermogravimetry (TG) and differential scanning calorimetry (DSC), respectively. The synthesis and characterization results showed that the in situ polymerization of NVCz could be initiated without cerium ammonium nitrate, CAN as oxidant in the presence of the o-GLs and o-MWCNTs dispersed and activated by sonication in acetonitrile (ACN)/sodium dodecyl sulfate (SDS)/water mixture and in ACN, respectively. It was discussed that the PNVCz chains were interacted with the conducting surfaces of fillers by hydrogen bonds and/or by coating, depending on the synthesis conditions, preparation process and the structure of organic matrix. Further, the electrical conductivity of PNVCz was improved from insulating to semiconducting state in the presence of both o-GLs and MWCNTs.