G. Cardenas et J. Acuna, Synthesis and characterization of manganese colloids and active solids prepared with organics solvents, BOL SOC CH, 45(3), 2000, pp. 499-507
Manganese colloids were prepared by cocondensation cf the metal at 77K with
ethanol, 2-propanol, 1,2-dimethoxyethane, 2-methoxyethanol and acetone. Th
e distribution of particle sizes was determined by transmission electron mi
croscopy of the most stable dispersions.
Electrophoretic measurements such as: colloid load and zeta potential were
achieved. It was found that the colloids do not possess electrical charge,
therefore it is postulated that their stability is by simple solvation. The
colloids showed instability at room temperature.
In some colloids absorption bands in the UV region were observed. In the vi
sible region no plasma absorption was found. Active solids obtained by evap
oration of the solvent contain certain amount of the solvent incorporated,
and due to their reactivity they produce a mixture with manganese oxide.
The presence of solvents can be observed and their incorporation in the fin
ely divided solids can be observed by FT-IR. Characteristic bands for each
solvent were measured. The TGA - FTIR shows the presence of the C = O and C
- H bands indicating the acetone in the solid. By means of thermogravimetr
ic analysis and DSC the thermal stability of the solids and the transition
heat from the thermal analysis can be determined.