Influence of molecular weight on the aggregation-induced emission enhancement and spectral stability of vinyl polymers containing the fluorescent 2,4,6-triphenylpyridine pendant groups
作者:Chung Tin Lai、Jin Long Hong
DOI:10.1039/c2jm30455d
日期:——
The effect of molecular weight on the aggregation-induced emission enhancement (AIEE) and the spectral stability of vinyl polymers containing fluorescent 2,4,6-triphenylpyridine (TP) pendant groups was evaluated in this study. The high and low molecular weight (MW) vinyl polymers of PDMPS-H and -L are deep-blue emitters with the respective high quantum yields of 82.5 and 84.1% in the solid film state. With high MW (Mn = 525,400 g mol−1), PDMPS-H also possesses high spectral stability without reduction in the emission intensity upon heating to temperatures above 200 °C. Solutions of the low MW (Mn = 37,300 g mol−1) PDMPS-L exhibited the normal AIEE effect with continuous emission gains with increasing aggregation upon nonsolvent inclusion. In contrast, the high MW PDMPS-H solutions emitted with constant intensity on all solutions with different extent of aggregation. The emission behavior was then explained by the conformational difference between the PDMPS-L and -H chains and was theoretically approached by computer simulation.
本研究评估了分子量对聚集诱导发光增强(AIEE)的影响,以及含荧光2,4,6-三苯基吡啶(TP)侧基的乙烯基聚合物的光谱稳定性。PDMPS-H和-L的高分子量和低分子量(MW)乙烯基聚合物是深蓝色发光体,在固态薄膜状态下,其量子产率分别为82.5%和84.1%。PDMPS-H具有高分子量(Mn = 525,400 g mol−1),因此具有高光谱稳定性,在加热到200°C以上时,发光强度不会降低。低分子量(Mn = 37,300 g mol−1)PDMPS-L的溶液在非溶剂包合时,随着聚集的增加,发光强度持续增加,表现出正常的AIEE效应。相比之下,高分子量PDMPS-H溶液在所有不同聚集程度的溶液中,发光强度保持恒定。然后,通过PDMPS-L和-H链之间的