Effect of acidity on the glycine-nitrate combustion synthesis of nanocrystalline alumina powder
- Department of Chemistry, Wuhan University, Wuhan 430072 (China) and Centre of Nanoscience and Nanotechnology, Wuhan University, Wuhan 430072 (China)
- Department of Chemistry, Wuhan University, Wuhan 430072 (China)
Nanocrystalline alumina powders were prepared by combustion synthesis using glycine as fuel and nitrate as an oxidizer. The effect of the pH values in the precursor solutions on crystallite sizes, surface areas and morphologies of the synthesized alumina powder has been investigated by X-ray diffractometry, thermal analysis, nitrogen adsorption-desorption, and transmission electron microscopy. With decreasing the pH values in the precursor solutions, the obtained materials could be modified from segregated nanoparticles (pH 10.5) to aggregates of nanoparticles (pH 6.0), and finally to a flaky morphology (pH 2.5). The rates of decomposition, the interaction of coordination as well as the hydrogen bonding of the glycine and the Al-hydroxides species at different pH values were found to be responsible for the generation of flake and/or segregated nanoparticles during auto-ignition reactions. The as-prepared combustion ashes were converted into pure nanocrystalline alumina after calcination at elevated temperatures. The specific surface areas of the products calcined at 800 deg. C ranged from 96 to 39 m{sup 2}/g with the pH decreased from 10.5 to 2.5.
- OSTI ID:
- 20895265
- Journal Information:
- Materials Research Bulletin, Vol. 41, Issue 9; Other Information: DOI: 10.1016/j.materresbull.2006.02.026; PII: S0025-5408(06)00088-2; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
- Country of Publication:
- United States
- Language:
- English
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