Effect of functionalization of iron oxide nanoparticles on the physical properties of poly (aniline-co-pyrrole) based nanocomposites: Experimental and theoretical studies

Abstract

Poly(aniline-co-pyrrole)@functionalized Fe3O4 (PACP@f-Fe3O4) nanocomposites were prepared by a two-step method. In the first step, the Fe3O4-OH and Fe3O4-NH2 nanoparticles were synthesized by the solvothermal and co-precipitation techniques, respectively. In the second step, the PACP@f-Fe3O4 nanocomposites were synthesized by an in-situ microemulsion polymerization technique. The synthesized materials were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Based on the SEM, the iron oxide changed the morphology of the PACP copolymer from being completely nanospheres. The TGA showed the higher thermal stability of the PACP@Fe3O4-OH nanocomposite in comparison to the PACP@Fe3O4-NH2, and the density functional theory (DFT) successfully confirmed this fact by calculating the binding energies between the PACP copolymer and functionalized nanoparticles. Also, the HOMO − LUMO energy gap (Eg) values were determined by the DFT to investigate the electrical conductivities, which are in accord with the experimental electrical conductivities in the order PACP@Fe3O4-OH > PACP@Fe3O4-NH2 > PACP. Keywords: Poly(aniline-co-pyrrole), Functionalized Fe3O4, Nanocomposite, Electrical conductivity, Density functional theory