No abstract

No abstract

Nanocomposites of iron oxide (Fe 3 O 4 ) with a sulfonated polyaniline, poly(aniline-co-aminonaphthalenesulfonic acid) [SPAN(ANSA)], were synthesized through chemical oxidative copolymerization of aniline and 5-amino-2-naphthalenesulfonic acid/1-amino-5-naphthalenesulfonic acid in the presence of Fe 3 O 4 nanoparticles. The nanocomposites [Fe 3 O 4 /SPAN(ANSA)-NCs] were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, elemental analysis, UV-visible spectroscopy, thermogravimetric analysis (TGA), superconductor quantum interference device (SQUID), and electrical conductivity measurements. The TEM images reveal that nanocrystalline Fe 3 O 4 particles were homogeneously incorporated within the polymer matrix with the sizes in the range of 10-15 nm. XRD pattern reveals that pure Fe 3 O 4 particles are having spinel structure, and nanocomposites are more crystalline in comparison to pristine polymers. Differen-tial thermogravimetric (DTG) curves obtained through TGA informs that polymer chains in the composites have better thermal stability than that of the pristine copolymers. FTIR spectra provide information on the structure of the composites. The conductivity of the nanocomposites ($ 0.5 S cm 21 ) is higher than that of pristine PANI ($ 10 23 S cm 21 ). The charge transport behavior of the composites is explained through temperature difference of conductivity. The temperature dependence of conductivity fits with the quasi-1D variable range hopping (quasi-1D VRH) model. SQUID analysis reveals that the composites show ferromagnetic behavior at room temperature. The maximum saturation magnetization of the composite is 9.7 emu g 21 .