Center for Supramolecular Optoelectronic Materials, Department of Materials Science and Engineering, Seoul National University , 1 Gwanak-ro, Gwanak-gu, Seoul 08826, Korea.
ACS Appl Mater Interfaces. 2017 Jan 25;9(3):2883-2890. doi: 10.1021/acsami.6b13818. Epub 2017 Jan 13.
We synthesized two different amphiphilic small molecules 1 and 2 by attaching the same oligo(ethylene glycol) (OEG) unit to the same dicyanodistyrylbenzene (DCS) fluorophore but at different positions. These molecules self-assemble into nanoparticles in water and show lower critical solution temperature (LCST) at 26 and 58 °C, respectively. Upon heating, the transition of hydrophilic coils to hydrophobic globules of the OEG unit leads to the change in the stacking structure of the luminescent DCS cores. As a result, it shows significant ratiometric fluorescence color changes from excimeric yellow emission to monomer-dominated green emission. Interestingly, the coassembly of 1 and 2 exhibits single transition temperature between the transition temperatures of the two components. Moreover, it is demonstrated that the transition temperature of the coassembly is delicately tuned over 26-58 °C by varying the molar mixing ratio of them.
我们通过将相同的聚乙二醇（OEG）单元连接到相同的二氰基二苯乙烯（DCS）荧光团但在不同位置，合成了两种不同的两亲性小分子 1 和 2。这些分子在水中自组装成纳米颗粒，并分别在 26 和 58°C 表现出较低的临界溶液温度（LCST）。加热时，亲水性线圈向 OEG 单元的疏水性球的转变导致发光 DCS 核的堆积结构发生变化。结果，它显示出从激基缔合物黄色发射到单体主导的绿色发射的显著比率荧光颜色变化。有趣的是，1 和 2 的共组装表现出两个组分的转变温度之间的单一转变温度。此外，通过改变它们的摩尔混合比，证明共组装的转变温度可以在 26-58°C 之间精细调节。
