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

Abstract

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 the 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. POLYM. COMPOS., 39:4617–4627, 2018. © 2017 Society of Plastics Engineers

Composites of Poly(3,4-ethylenedioxythiophene) and CoFe2O4 Nanoparticles: Composition Influence on Structural, Electrical, and Magnetic Properties

“…The morphology of the cobalt ferrite particles obtained here corresponds to a spheric-like shape aggregated in clusters, very similar to those of Antonel et al 3 and Muñoz Resta et al, 45 The morphology of some of the obtained materials, as observed by SEM, is shown in Fig. 2a to e; Fig.…”

Magnetic and conducting composites of cobalt ferrite nanorods in a polyaniline matrix

“…Moreover, in Fig. b–d, the most important band of DBS within the region studied is highlighted within a circle at approximately 1,004–1,029 cm −1 . This proves that this anion is present in the final products.…”

“…In Fig. a, the main lattice band of CoFe 2 O 4 is marked at 588 cm −1 in dashed trace. Figure c shows the spectrum for the composite with r S = 6 ( r P = 0.9), where it is observed the shift of the ferrite main band to lower wavenumbers.…”

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“…Composites formed by magnetic nanoparticles (MNPs) embedded in a conducting polymer matrix are very interesting due to the capability of combine electrical conduction with magnetic properties . MNPs are very interesting materials, due to their many potential applications .…”