Polypyrrole‐Fe 3 O 4 Magnetic Nanocomposite Prepared by Ultrasonic Irradiation

Summary: Ultrasonic irradiation was employed to prepare polypyrrole (PPY)/Fe 3 O 4 magnetic nanocomposite by chemical oxidative polymerization of pyrrole in the presence of Fe 3 O 4 nanoparticles. This approach can solve the problem in the dispersion and stabilization of inorganic nanoparticles in polymer. The structure and properties of PPY/Fe 3 O 4 nanocomposite were characterized by TEM, XPS, FT‐IR, TG, and XRD. PPY deposits on the surface of Fe 3 O 4 nanoparticles while Fe 3 O 4 nanoparticles are dispersed at the nanoscale by ultrasonic irradiation, which leads to the formation of polypyrrole‐encapsulated Fe 3 O 4 composite particles. The doping level of PPY in PPY/Fe 3 O 4 nanocomposite is higher than that of neat PPY. The composites possess good electrical and magnetic properties. With the increase in the Fe 3 O 4 content, the magnetization increases and the conductivity first increases and then decreases. When the Fe 3 O 4 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 Fe 3 O 4 nanoparticles enhances the thermal stability of PPY/Fe 3 O 4 composite.Conductivity of PPY/Fe 3 O 4 composite at different Fe 3 O 4 content.