Journal des sciences et de l'ingénierie des matériaux

Iron Oxide Nanoparticles Coated with Polymer Derived from Epoxidized Oleic Acid and Cis-1,2-Cyclohexanedicarboxylic Anhydride: Synthesis and Characterization

Abstract

Pereira da Silva S, Costa de Moraes D and Samios D \r\n

This study investigated the use of polymer derived from oleic acid for coating iron oxide nanoparticles. The purpose of this study was to provide the magnetic nanoparticles an appropriate surface for stabilization in organic solution. The magnetic nanoparticles coated were produced by mixing of the polymer solution with the ferromagnetic fluid by mechanical stir, followed by magnetic separation. These nanoparticles generated a core-shell behavior, in which the core provides the magnetic properties and the external layer formed by the polymer. The interaction between iron nanoparticles and oleic acid polymer occurred by the affinity of carboxylic group. This interaction makes the nanoparticles hydrophobic, moving to the organic media. The carbon content of the coated nanoparticles was approximately 14%, when analyzed by scattering electron microscopy (SEM–EDX), and 12%, when analyzed by Elemental Analysis of carbon, hydrogen and nitrogen. This percentage confirms the presence of the polymer on the surface of magnetic nanoparticles. The average diameter of the coated and uncoated nanoparticles obtained by transmission electron microscopy was around 13 nm and 11 nm and the average diameter of crystallite by X-ray diffraction was around 8 nm and 12 nm respectively. Averaging all this values we obtain 11 ± 2 nm. The thermogravimetric analysis showed the degradation temperatures starting from 200°C to 500°C, attributed to the polymer, and another one degradation temperature between 650-750ºC, relative to the polymer-nanoparticles interaction. Furthermore, the vibrating sample magnetometer indicated that coated nanoparticles remain magnetic, with increasing saturation magnetization value, when a magnetic field was applied.

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