SYNTHESIS OF SHORT FIBROUS BOEHMITE SUITABLE FOR THERMALLY STABILIZEDTRANSITION ALUMINAS FORMATION

Transmission electron microscopy showed that xerogel of long and short fibrous boehmite samples, AlO(OH), were respectively produced via hyd rolysis of aluminium alkoxide at slow and high stirring rates. Thermog ravimetry, differential scanning calorimetry, and X-ray diffractometry , showed the two xerogels to produce similar calcination products, at 400 degrees C and up to 1000 degrees C, for the chemical and phase com position of the material bulk. In contrast, nitrogen adsorption measur ement revealed different surface textural consequences of the boehmite fiber length. It has been concluded that the short fiber boehmite pro duces on calcination aluminas that are more resistant to particle sint ering (thermally stabilized) than the long fiber boehmite. (C) 1998 Ac ademic Press.