Synthesis and Characterization of Polyimide-Cobalt Ferrite Nanocomposites

Magnetic nanocrystals exhibiting outstanding coercivity values can be dispersed in polymer-based composites for use in micro actuators, micro pumps and sensing devices. In the present work, cobalt ferrite nanocrystals were synthesized under size-controlled conditions in aqueous phase and incorporated into a polyimide matrix at various volumetric loads. Synthesized 20nm-cobalt ferrite single crystals, which exhibited a coercivity of 2.9kOe at room-temperature, were dispersed in polyimide precursor (Dupont P12555) and cured to develop the polyimide matrix in the resulting nanocomposites. Produced films were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and vibrating sample magnetometry, which confirmed the formation of the nanocomposite. As expected, the saturation magnetization in the nanocomposites varied according to the Polyimide/Ferrite weight ratio, while coercivity remained at the value corresponding to pure cobalt ferrite nanocrystals.