Orange II (O-II), a water-soluble ionic azo dye, aggregates and eventually forms needle-like crystals at concentrations greater than 0.15 M. However, when equimolar amounts of γ-cyclodextrin (γ-CD) are added to solutions containing O-II at 0.025 M or higher, the solution’s appearance rapidly changes presenting a viscous, birefringent liquid, a lyotropic liquid crystalline solution. Birefringence is absent when viewing aqueous solutions of only O-II or γ-CD at concentrations greater than 0.03 M. Using ultraviolet–visible (UV–vis) and fluorescence spectroscopy, coupled with conductivity measurements, we postulate a structure for the basic “building block” of the self-assembly that eventually gives rise to a rodlike superstructure, leading to the formation of a lyotropic liquid crystalline phase.

中文翻译：

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不同种类的纳米管：水中橙 II/γ-环糊精复合物的化学计量和几何结构


Orange II (O-II) 是一种水溶性离子偶氮染料，浓度大于 0.15 M 时会聚集并最终形成针状晶体。然而，当将等摩尔量的 γ-环糊精 (γ-CD) 添加到含有O-II 在 0.025 M 或更高时，溶液的外观迅速变化，呈现粘稠、双折射液体、溶致液晶溶液。当观察浓度大于 0.03 M 的 O-II 或 γ-CD 水溶液时，不存在双折射。使用紫外可见 (UV-vis) 和荧光光谱，再加上电导率测量，我们假设了一种基本“建筑”结构自组装的“块”最终产生棒状上部结构，导致溶致液晶相的形成。