【作者】 雷娜娜； 陈晓；

【Author】 Nana Lei;Xiao Chen;Key Laboratory of Colloid and Interface Chemistry,Shandong University,Ministry of Education;

【机构】 山东大学胶体与界面化学教育部重点实验室；

【摘要】 本文选取两性表面活性剂(十四烷基二甲基氧化胺,C₁₄DMAO)和Na₉EuW₁₀O₃₆·32H₂O(EuW₁₀)阴离子纳米簇,通过调节C₁₄DMAO/EuW₁₀摩尔比（R）,系统考察了二者在水溶液中的共组装行为及荧光性能变化。在R=20时,得到了稳定性能较好且荧光增强的纳米带^[1]。研究表明,纳米带具有沿轴向排列的有序层状结构,这在杂多酸盐自组装体系中是很少见的。而C₁₄DMAO在体系pH值为6.5时的"部分质子化"是纳米带形成的关键。因纳米带中能较好地屏蔽Eu W₁₀周围的水分子,其荧光强度、寿命及绝对量子产率得到极大的提高。此外,C₁₄DMAO随p H可逆质子化的行为赋予了纳米带灵敏的pH刺激响应性。该C₁₄DMAO/EuW₁₀共组装纳米带的成功构筑,不仅丰富了杂多酸盐有序分子聚集体的形态,而且为pH响应智能材料的设计提供了有价值的参考。更多还原

【Abstract】 A commercially available and pH-switchable zwitterionic surfactant,tetradecyldimethylamine oxide (C₁₄DMAO),was chosen to co-assemble with a lanthanide-containing anionic POM,Na₉(EuW₁₀O₃₆)·32H₂O (EuW₁₀),in water.The much improved red-emitting luminescent nanobelts at a C₁₄DMAO/EuW₁₀ molar ratio （R） of 20 were obtained,which exhibited longer luminescence lifetime and higher quantum yield compared with EuW₁₀ aqueous solution.After careful characterization of morphology and structure of nanobelts,an unusual axial lamellar aggregation arrangement mechanism was proposed.It was the partial protonation of C₁₄DMAO at the solution pH of about 6.5 that led to positively charged micelles,being bridged by anionic EuW₁₀ clusters to aggregate into such novel nanobelts under the synergetic effects of appropriate electrostatic,hydrogen bonding and hydrophobic interactions.The resulted pH responsive luminescent nanobelts and their aggregation model should offer attractive references for preparing smart optical supramolecular materials.更多还原