Preparation of alumina by sol-gel process,its structures and properties

Alumina monolithic gel has been prepared by ammonia method from anhydrous aluminium chloride and n-butanol using formamide as the solvent. The gel has been made by hydrochloric acid catalysis and using large quantity of water for hydrolysis (molar ratio of water to aluminium-n-butoxide, R>99). Transparent alumina xerogel of size 37.5×20×5 mm approximately has been prepared. The alumina gel has been dried and sintered at 400°C, 1000°C and 1200°C respectively and the powders formed thereby have been examined by XRD, FTIR spectroscopy, SEM and particle size analysis. These studies have confirmed the formation of -alumina at 1200°C having particle size as low as 0.2 m or less along with agglomerates. The density of the powder has increased gradually, where as its particle size has decreased, with the increase of the sintering temperature.