Micelles as “Fluorescence Protector” for an Europium Complex in Microcapsules

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• 作者：Cui Wang ; Renjie Zhang ; Helmuth Mhwald
• 刊名：Langmuir
• 出版年：2010
• 出版时间：July 20, 2010
• 年：2010
• 卷：26
• 期：14
• 页码：11987-11990
• 全文大小：753K
• 年卷期：v.26,no.14(July 20, 2010)
• ISSN：1520-5827

文摘

Microcapsules with excellent fluorescence enhancement are assembled by using cetyltrimethylammonium bromide (CTAB) micelles to enrich Eu(DBM)₃Phen (DBM and Phen are dibenzoylmethane and 1,10-phenanthroline, respectively) on CaCO₃ particles by the LbL technique. Compared to microcapsules without micelles, the fluorescence intensity of microcapsules with micelles increases 9 times, larger than the 6 times increase of absorbance. This unexpected fluorescence enhancement is attributed to the “fluorescence protector” effect of CTAB micelles in microcapsules. Energy loss from nonradiative deactivation through energy transfer to high-energy O−H vibrations from the emissive ⁵D₀ state of Eu(III) is greatly prohibited. The new strategy using micelles in this work not only enriches europium complexes during assembly in aqueous solution but also yields a fluorescence enhancement ratio larger than the enrichment ratio.