Hou Yi, Ye Jing, Gui Zhou, Zhang Guangzhao
Hefei National Laboratory for Physical Sciences at Microscale and State Key Laboratory of Fire Science, Department of Chemical Physics, University of Science and Technology of China.
Langmuir. 2008 Sep 2;24(17):9682-5. doi: 10.1021/la800312u. Epub 2008 Jul 19.
Cadmium sulfide (CdS) quantum dots (QDs) grafted with thermoresponsive poly( N-isopropylacrylamide) chains have been prepared. As the temperature increases, PNIPAM chains shrink and aggregate so that the QDs exhibit enhanced fluorescence emission. At a temperature around the lower critical solution temperature (LCST) of PNIPAM, the fluorescence exhibits a maximum intensity. Our experiments reveal that the fluorescence emission is determined by the interactions between QDs as a function of the interdot distance. The optical interdot distance for the maximum luminescence intensity is approximately 10 nm. The chain length of PNIPAM also has an effect on the luminescence. Short PNIPAM chains are difficult to associate, leading to a large interdot distance, so that the luminescence intensity changes slightly with temperature.
已制备出接枝有热响应性聚（N-异丙基丙烯酰胺）链的硫化镉（CdS）量子点（QDs）。随着温度升高，聚N-异丙基丙烯酰胺链收缩并聚集，从而使量子点表现出增强的荧光发射。在聚N-异丙基丙烯酰胺的较低临界溶液温度（LCST）附近的温度下，荧光呈现最大强度。我们的实验表明，荧光发射取决于量子点之间的相互作用，该相互作用是点间距离的函数。最大发光强度时的光学点间距离约为10 nm。聚N-异丙基丙烯酰胺的链长也对发光有影响。短的聚N-异丙基丙烯酰胺链难以缔合，导致较大的点间距离，因此发光强度随温度变化不大。
