SÍNTESE E CARACTERIZAÇÃO DE ÓXIDO DE ALUMÍNIO E ALUMINATOS (Fe, Co e Ni) A PARTIR DE NITRATOS E PECTINA CÍTRICA

Abstract

The aluminium oxide or alumina is a material widely used in industry, due to their thermal properties, mechanical and refractory. When mixed with other metal oxides originates aluminate species, which have important applications in the field of pigments. This work we present the preparation and characterization of aluminium oxide and aluminate obtained by gelation of the suspension of citrus pectin and nitrates. Aluminates are characterized by the presence of the group oxyanion aluminate (AlO2-). When combined in the form of a mixed oxide of spinel structure has the general formula [A²+B23+O42-] containing aluminium as Al3 +. We chose species as A²+ ions iron (III), cobalt (II) and nickel (II), possibly forming [Fe(Al2O4)], [Co(Al2O4)] and [Ni(Al2O4)]. The solids were characterized by thermal analysis, X-ray diffraction, scanning electron microscopy with quantitative analysis by energy dispersive, electronic and vibrational spectroscopy. The diffractograms showed the formation of non-crystalline phases, characterized by the absence of diffraction peaks that can be attributed to the calcination temperature applied. Waste organic matter was identified by the TG curves and the Raman spectrum. MEV images showed materials with diverse morphology, with the presence of pores, a fact that was confirmed by BET analysis. The characterization results demonstrate the feasibility of preparing new oxide with morphology and composition induced by the polysaccharide, with application as pigments.