ALTERAÇÕES COLORIMÉTRICAS EM COMPOSTO DE BaO-Al2O3-MnO2 A PARTIR DA SÍNTESE POR NANOESCALA

Abstract

The purpose of this work was the synthesis of nanoscaled BaO-Al2O3-MnO2 system and its characterization. The nanoparticulate system was prepared by mixing salts of Ba, Al and Mn in a chamber of low temperature, lyophilizing the solutions of their salts, and followed by calcination in the temperature range from 230 °C to 1190° C.This synthesis was compared with two other systems, prepared using a chemical mixture of oxides, with a particle size of conventional size and also with the phase of nanoscale oxides, followed by calcination in the same temperature conditions. The colorimetric properties of ceramic powders were evaluated by UV-visible spectroscopy and coordinates CIE-L a b and characterized by X-ray diffraction, Xray fluorescence, simultaneous thermal analyisis, scanning electron microscopy and laser scattering technique. This nanoscaled synthesis provides a possible application in the production on ceramic pigments because the resulting powder showed different color in comparison to the other systems. The nanoparticulate system showed the advantage of needing lower calcination temperatures, and, at 1135ºC,showed a different color that was not presented by powders synthetized by other methods.