Polypyrrole-Fe3O4 magnetic nanocomposite prepared by ultrasonic irradiation

Ultrasonic irradiation was employed to prepare polypyrrole (PPY)/Fe3O4 magnetic nanocomposite by chemical oxidative polymerization of pyrrole in the presence of Fe3O4 nanoparticles. This approach can solve the problem in the dispersion and stabilization of inorganic nanoparticles in polymer. The structure and properties of PPY/Fe3O4 nanocomposite were characterized by TEM, XPS, FT-IR, TG, and XRD. PPY deposits on the surface of Fe3O4 nanoparticles while Fe3O4 nanoparticles are dispersed at the nanoscale by ultrasonic irradiation, which leads to the formation of polypyrrole-encapsulated Fe3O4 composite particles. The doping level of PPY in PPY/Fe3O4 nanocomposite is higher than that of neat PPY The composites possess good electrical and magnetic properties. With the increase in the Fe3O4 content, the magnetization increases and the conductivity first increases and then decreases. When the Fe3O4 content is 40 wt.-%, the conductivity reaches a maximum value of 11.26 S(.)cm(-1), about nine times higher than that of neat PPY, and the saturation magnetization is 23 emu(.)g(-1). Also, the introduction of Fe3O4 nanoparticles enhances the thermal stability of PPY/Fe3O4 composite.