Synthesis and representation of a new structure for polypyrrole–chitosan nanocomposite and investigation of effect of intermolecular interaction

This study describes the preparation of polypyrrole/chitosan nanocomposite (PPC) in aqueous media by chemical polymerization of pyrrole in presence of ferric chloride (FeCl3) as an oxidant. The products were investigated in terms of morphology and chemical structure with scanning electron microscope (SEM), transmission electron microscope (TEM) and Fourier transform infrared (FTIR) spectroscopy, respectively. The observable experimental IR spectra were compared with the calculated spectra. In theoretical calculations, different models of polypyrrole (PPy), chitosan and PCC were established. All models geometry were optimized without any geometrical constraint by different methods and IR vibrational wavenumbers of these models were calculated using DFT-B3LYP/6-31G and they were compared with experimental FTIR spectrum. By analyzing the results, the actual configurations of PCC were found that have moderate internal hydrogen bonds (IHB).