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: 2017 p. 1 - 12

0272-8397

Compositesof cobalt ferrite nanoparticles in a polypyrrole (PPy) matrix have beensynthesized in acid media and characterized by X-ray diffraction studies,scanning and transmission electron microscopy observation, thermogravimetricanalysis, conductivity and infrared spectroscopy measurements. Two types ofcomposites were prepared: one including dodecylbenzenesulphonic acid as aparticle protector, and another one without protection. The magnetic behaviorwas studied through DC magnetization measurements; hysteresis loops wereobserved, showing ferromagnetic behavior for particles and composites. Materialswith particle protection showed magnetic parameters independent of thePPy/ferrite ratio; in absence of protector, both the coercivity and remanenceratio decreased as the PPy/ferrite ratio increased. These results areattributed to conducting polymer effects on the ferrite particles, affectingthe magnetic anisotropy. On the other hand, composites with low PPy/ferriteratio showed positive magnetoresistance of up to 20% at room temperature,indicating an effect of the magnetic particles on polymer conduction.