New polyaniline/polypyrrole/polythiophene and functionalized multiwalled carbon nanotube-based nanocomposites: Layer-by-layer in situ polymerization

In this endeavor, a new type of nanocomposites has been developed from conducting organic polymers (layer-by-layer in situ polymerization of various monomers) and functionalized multiwalled carbon nanotubes (MWCNTs). Initially, functionalization of MWCNTs was achieved by sulfuric acid (H2SO4):nitric acid (HNO3) and HNO3:hydrogen peroxide treatment. A comparative study regarding the synthetic, morphological, and electrical profiles of raw MWCNTs (R-MWCNTs), pure-MWCNTs (P-MWCNTs), functionalized MWCNTs (F-MWCNTs), and polyaniline/polypyrrole/polythiophene-F-MWCNTs (PANI/PPy/PTh/F-MWCNTs) nanocomposites was successfully carried out. Introduction of functional groups on the surface of MWCNTs was confirmed by Fourier transform infrared spectra. Energy dispersive x-ray spectroscopy and Rutherford back scattering were employed for the elemental analyses. Morphology of the obtained hybrid material was studied via scanning electron microscopy and their thermal stability was investigated using thermogravimetric analysis. The dielectric constant and electrical conductivity were also measured. Result exploration revealed that F-MWCNTs were well functionalized ensuing interfacial entrapment between the carbon nanotubes and the matrix. In addition, the layer-by-layer deposition of PPy/PANI/PTh polymers enhanced the electrical conductivity of material relative to the neat ones. Besides, the improved thermal stability of composite was acquired when compared with the homopolymers.