Role of Urea in the Preparation of Highly Porous Nanocomposite Aerogels

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• 作者：Maria F. Casula ; Danilo Loche ; Sergio Marras ; Giorgio Paschina ; Anna Corrias
• 刊名：Langmuir
• 出版年：2007
• 出版时间：March 27, 2007
• 年：2007
• 卷：23
• 期：7
• 页码：3509 - 3512
• 全文大小：307K
• 年卷期：v.23,no.7(March 27, 2007)
• ISSN：1520-5827

文摘

The preparation of highly porous CoFe₂O₄-SiO₂ nanocomposite aerogels was successfully achieved by a novelsol-gel procedure involving urea-assisted co-gelation of the precursor phases. This method allows fast gelation, givingrise to an aerogel with 97% porosity. The formation of CoFe₂O₄ nanocrystals homogeneously distributed within thematrix occurs after calcination at 750 C and is complete at 900 C. Despite the high temperature required for theformation of the CoFe₂O₄ nanocrystals, the high porosity typical of aerogels is still retained.