Preparation of transparent alumina film and fiber from a composite of aluminum polynuclear complex/methyl cellulose

Transparent alumina film and fiber were prepared from the inorganic/organic polymer composites as a precursor by heating at 600-1000degreesC in air. The composites were composed of basic aluminum chloride (BAC) and methyl cellulose (MC). The composite films were prepared by a casting method of aqueous solution of BAC and MC. An alumina film (40 mum thick) was obtained by heating at 1000degreesC for 2 h, which exhibited high transmittance of above 85% in the range of 300-1000 nm. The phase of alumina changed from amorphous to gamma-form between 800 and 900 degreesC. Upon heating at 1150degreesC, the alumina transformed to alpha-form, and the appearance of the alumina film changed to opaque. Colored transparent alumina films were found to be prepared easily from the composite by the introduction of transition metal ions such as Au3+ and Co2+. Transparent and continuous alumina fiber was also obtained by heating of the composite fibers made by wet solution spinning of aqueous solution of BAC and MC. (C) 2003 Elsevier B.V. All rights reserved.