کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5182813 | 1380999 | 2012 | 12 صفحه PDF | دانلود رایگان |
We identified the conformational structure, aggregation behavior and photophysical properties of poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) in various toluene/nonane solutions dependent on nonane content. In dilute solution region (e.g., below the overlap concentration, c*), static light scattering (SLS) revealed that the stiffness of MEH-PPV decreased as nonane content was increased, attributed to a stronger interaction force between MEH-PPV backbones. However, MEH-PPV chains presented a more extended-wormlike conformational structure in toluene. Therefore, a looser intermolecular micellelike aggregates occurred easily between the ether side chains of MEH-PPV at the concentration exceeded the overlapping concentration in toluene and toluene/nonane solutions. Nevertheless, at higher nonane content, the micellelike aggregates were became highly compacted by the Ï-Ï complex force between MEH-PPV backbones, dominating the dynamic behaviors and photophysical properties of MEH-PPV in toluene/nonane solution. These results proved that two types of segmental association with distinct stability were identified for the MEH-PPV/toluene/nonane solutions upon prolonged aging. The highly stable, which could not be disrupted by heating, was attributed to the interaction force between ether side chains of MEH-PPV in both solutions. Other type was a weaker affinity force through Ï-Ï complex, which could be disrupted thermally, making the micellelike aggregates more compact to form the network structure in MEH-PPV-enriched at higher nonane content.
Journal: Polymer - Volume 53, Issue 21, 28 September 2012, Pages 4843-4854