Molecular weight dependence of emission intensity and emitting sites distribution within single conjugated polymer molecules
Molecular weight dependence of emission intensity and emitting sites distribution within single conjugated polymer molecules
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DOI：
10.1039/c0cp01729a
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发表时间：
2011-01-01
影响因子：
3.3
通讯作者：
Vacha, Martin
中科院分区：
文献类型：
--
作者：
Habuchi, Satoshi;Onda, Suguru;Vacha, Martin
我们研究了激子迁移，捕获和发射过程发生在一个单一的共轭聚合物分子通过超分辨率荧光定位显微镜。这种方法使我们能够以纳米精度定位单链内发射位点的空间分布。以平均分子量为215000 ~ 1440000，分子量分布较窄的聚[2-甲氧基-5-（2′-乙基-己基氧基）-1,4-苯基乙烯]（MEH-PPV）分子为研究对象。我们发现平均发射强度随聚合物分子量的增加而增加。定位实验表明，发射位点几乎均匀地分布在单链内，并且与聚合物的分子量无关，这些位点的平均间距为10 nm。此外，一条链内所有组合发射位点形成的空间轮廓呈细长形状，与MEH-PPV在坍缩状态下的棒状结构一致。
We investigated exciton migration, trapping and emission processes occurring within a single conjugated polymer molecule by means of superresolution fluorescence localization microscopy. This methodology allowed us to locate the spatial distribution of emitting sites within single chains with nanometre precision. The study was done on individual poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) molecules with average molecular weights ranging from 215 000 to 1 440 000 and with narrow weight distributions. We found that the mean emission intensity increases proportionally to the polymer molecular weight. The localization experiments suggest that the emitting sites are distributed nearly uniformly within a single chain and that the sites are on average 10 nm apart, irrespective of the molecular weight of the polymer. Furthermore, spatial contours formed by all the combined emitting sites within one chain show elongated shapes, in agreement with a rod-like structure of MEH-PPV in a collapsed state.