Abstract

COBO QUEZADA, Janeth; VILLAQUIRAN, Claudia F; SCIAN, Alberto  and  RODRIGUEZ-PAEZ, Jorge E. Síntesis de nanopartículas de a-Al₂O₃ a partir de Al₂(SO₄)₃.18H₂O estudio de los mecanismos de formación de las partículas. Rev. LatinAm. Met. Mat. [online]. 2006, vol.26, n.1-2, pp.95-107. ISSN 0255-6952.

Alumina is normally obtained employing the Bayer process, it is employed industrially in order to obtain abrasives, electrical insulators, catalysts supports, refractory materials, filling material for polymers, among other uses, and its properties can be modified by varying its calcination temperature and particle size. Nowadays, several synthetic methods for a-Al2O3 are being analyzed in order to meet the demands of particular applications. These methods have advantages and disadvantages and they have in common a complete description of the method in question but they do not mention the possible formation mechanisms of the particles. In what follows an analysis is made of the Alumina particle production from Al₂(SO₄)₃.18H₂O  by the use of the controlled precipitation method (CPM), placing special interest in the conformation of the complexes and intermediate compounds of Aluminum that are formed throughout the synthesis process. Results obtained by optical microscopy, FTIR, ATD, TG, XRD and TEM indicate that factors such as pH, stirring speed and the nature of the washing solvent influence the conformation of the different intermediate Alumina complexes and the final properties of the a-Al₂O₃ particles.

Keywords : Synthesis; Alumina; Al complexes; Nanoparticles; Controlled precipitation.