Estudio preliminar de la síntesis de ferrita de hierro por el método de combustión en solución con el solvente eutéctico profundo relina (cloruro de colina y urea).

Abstract

This study focused on the synthesis of magnetite by the solution combustion method (SCS), using the deep eutectic solvent (DES) reline as fuel. The SCS method is fast, simple and economical, and it is based on the exothermic reaction between metal oxide precursors and fuel. The use of reline as fuel in the SCS method offers an efficient and environmentally-friendly alternative for the synthesis of ferrites. This work investigated the influence of the synthesis temperature and the precursor to fuel ratio on the properties of the obtained materials. Several characterization techniques were applied, including X-ray diffraction (XRD), atomic absorption (AA), transmission electron microscopy (TEM) and nitrogen physisorption. The results revealed that the synthesis temperature significantly impacts the composition and properties of the SCS products. Synthesis temperatures between 300-500 °C favor mainly the formation of maghemite and hematite instead of magnetite. Furthermore, the precursor to fuel ratio also affects the composition, size distribution and specific surface area of the synthesized samples. TEM analysis confirmed that the SCS method with reline allows the synthesis of materials smaller than 100 nm in size. The atmosphere control during the magnetite synthesis was crucial since the nitrogen atmosphere prevented partially the oxidation of magnetite to maghemita and hematite.