The production of a carbon-coated alumina foam

✍ Scribed by Prasanta Jana; V. Ganesan

• Book ID: 104009548
• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 880 KB
• Volume: 49
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/j.carbon.2011.04.005

✦ Synopsis

A method for producing ultra light carbon-coated alumina foam with a density of 0.04 g cm À3 and 99% porosity has been developed. It was synthesised from an aqueous aluminum nitrate-sucrose solution. The resin formed by heating this solution underwent foaming and set into solid green foam, which was sintered in the temperature range 1073-1873 K. The thermogram obtained by heating the green foam in argon showed 62 wt% mass loss occurring in three stages. The sintered foam constituted 81 wt% of c-alumina in three-dimensional network and 19 wt% of carbon present as coating over the alumina framework. Phase analysis by X-ray diffraction revealed that carbon is in outer phase and c-alumina is in the inner phase. Surface morphology of this foam, examined by scanning electron microscope showed open, fully interconnected and near spherical pores held together by hexagonal edges with a 300 lm average pore size. Energy dispersive X-ray spectroscopy revealed peaks corresponding to carbon, oxygen and aluminum indicating that the foam is free from nitrogen impurity. The surface concentration of carbon is nearly 85 wt% while it coating thickness is about 10 lm.