国产一级a毛一级a看免费视频,久久久久久国产一级AV片,免费一级做a爰片久久毛片潮,国产精品女人精品久久久天天,99久久久无码国产精品免费了

 

作者： Kai Wang, Yimin Luo, Shuo Huang, Hongbin Yang, Bin Liu andMingfeng Wang

School of Chemical and Biomedical Engineering, Nanyang Technological University, Singapore, Singapore

 

摘要：Well-defined 1,4-diketo-3,6-di(thiophen-2-yl)pyrrolo[3,4-c]pyrrole (DTDPP) labeled polycaprolactones (PCL) with different chain lengths were synthesized and characterized. The effect of polymer chain lengths on the optical properties of DTDPP in solid states was studied by UV-Vis absorption spectroscopy as well as steady-state and dynamic fluorescence spectroscopies. Our results indicate that when the PCL side chain is extended to a certain length, the intermolecular aggregation of DTDPP units can be reduced significantly due to segregation effect of PCL. This approach offers a new facile strategy to address the common problem of aggregation-caused quenching existing in organic fluorophores. These highly fluorescent biodegradable PCL polymers may find broad biomedical applications such as fluorescence-based bioimaging and tissue engineering.

 

關鍵詞：aggregation; biodegradable;diketopyrrolopyrrole;fluorescence;polycaprolactone;ring-opening polymerization