Polypyrrole-CoFe2O4 nanocomposites: Polymer influence on magnetic behavior and particle effects on polymer conduction

I. MUÑOZ RESTA; J. M. SELLÉS; M. LANÚS MENDEZ ELIZALDE; P. S. ANTONEL; F. V. MOLINA

POLYMER COMPOSITES

JOHN WILEY & SONS INC

Año: 2018 vol. 39 p. 4617 - 4627

0272-8397

Composites of cobalt ferrite nanoparticles in a polypyrrole (PPy) matrix have been synthesized in acid media and characterized by X-ray diffraction studies, scanning and transmission electron microscopy observation, thermogravimetric analysis, conductivity and infrared spectroscopy measurements. Two types of composites were prepared: one including dodecylbenzenesulphonic acid as a particle protector, and another one without protection. The magnetic behavior was studied through DC magnetization measurements; hysteresis loops were observed, showing ferromagnetic behavior for particles and composites. Materials with particle protection showed magnetic parameters independent of the PPy/ferrite ratio; in absence of protector, both the coercivity and remanence ratio decreased as the PPy/ferrite ratio increased. These results are attributed to conducting polymer effects on the ferrite particles, affecting the magnetic anisotropy. On the other hand, composites with low PPy/ferrite ratio showed positive magnetoresistance of up to 20% at room temperature, indicating an effect of the magnetic particles on polymer conduction.