Resumen de Synthesis of iron and iron-manganese colloids and nanoparticles using organic solvents
Galo Cardenas, Viviana Delgado G, Jose Acuña E, Carlos A.s. Lima
Manganese, iron colloids and iron-manganese bicolloids were prepared by cocondensation of the metal at 77K with ethanol, 2-propanol, 1,2-dimethoxyethane, 2-methoxyethanol and acetone. The distribution of particle sizes was determined by transmission electron microscopy of the most stable dispersions. Electrophoretic measurements such as colloid charge and zeta potential were achieved. lt was found that the colloids possess electrical charge, therefore it is postulated that their stability is by simple solvatation. The colloids showed instability at room temperature. In some colloids absorption bands in the UV region were observed. In the visible region no plasma absorption was found. Active solids obtained by evaporation of the solvent contain certain amount of the solvent incorporated, and due to their reactivity they produce a mixture with manganese oxide and iron oxide. The X-ray of the powders of Fe-Mn-2-methoxyethanol does not allow to conclude about the alloyed composition. The presence of solvents can be observed by FT-IR incorporation in the finely divided solids. Characteristic bands for each solvent were measured. By means of thermogravimetric analysis and DSC the thermal stability of the solids and the transition heat give us the carbonaceous residues in the films. The elemental analysis of the powders was carried out
