ALUMINUM TITANATE POWDER SYNTHESIS VIA THERMAL-DECOMPOSITION OF TRANSPARENT GELS

Aluminum titanate powder has been prepared through thermal decomposition of a transparent gel formed from a mixture of titanium butoxide and boehmite sol in acetic acid-butanol medium. The thermogravimetric curve of aluminum titanate precursor gel is characterized by a decomposition temperature extending up to 800-degrees-C while the constituent gels of boehmite and hydrous titania independently decompose at lower temperature. The removal of water entrapped in the gel structure heated at the above temperature is further made clear by infrared spectral data. The gel stays in the amorphous state up to 800-degrees-C, as revealed from XRD. The sintered aluminum titanate shows that grains with sizes above 2-mu-m are cracked while smaller ones are intact. When heated for a period of 2 h, the gel decomposes to powders with average particle sizes of 2.7-mu-m at 900-degrees-C and 6.5-mu-m at 1400-degrees-C.