Department of Chemistry and Chemical Biology, University of New Mexico, Albuquerque, New Mexico 87131, USA.
Langmuir. 2012 Nov 27;28(47):16401-7. doi: 10.1021/la3034337. Epub 2012 Nov 14.
Poly(3-hexylthiophene) (P3HT) nanofibers (NF) displaying J-aggregate exciton coupling behavior are encapsulated with the amphiphilic block copolymer (BCP), poly(3-hexyl-thiophene)-block-poly(ethylene-glycol), (PHT(20)-b-PEG(108)). Encapsulation results in the formation of hierarchical superstructures, and the BCP coating is expected to exert a mild chemical pressure on the periphery of the NFs. Photoluminescence from encapsulated NF superstructures show line shape distortions due to self-absorption of the 0-0 transition which is consistent with preservation of J-aggregate character (intrachain order). Detailed resonance Raman spectra of encapsulated BCP-NF structures show no discernible changes in the P3HT aggregation state, and overtone and combination bands involving the symmetric stretching C═C (1450 cm(-1)) and C-C (1380 cm(-1)) backbone modes are observed. These features permit quantitative estimates of vibrational mode-specific excited state structural displacements using a time-dependent Raman intensity analysis which is not possible from conventional vibronic analysis of optical lineshapes.
聚（3-己基噻吩）（P3HT）纳米纤维（NF）显示 J-聚集体激子耦合行为，用两亲嵌段共聚物（BCP）聚（3-己基噻吩）-嵌段-聚（乙二醇）（PHT（20）-b-PEG（108））封装。封装导致分级超结构的形成，并且预期 BCP 涂层对 NF 的外围施加温和的化学压力。封装 NF 超结构的光致发光显示由于 0-0 跃迁的自吸收而导致线形状失真，这与 J-聚集体特征（链内有序）的保留一致。封装的 BCP-NF 结构的详细共振拉曼光谱显示 P3HT 聚集态没有明显变化，并且观察到涉及对称拉伸 C═C（1450 cm(-1)) 和 C-C（1380 cm(-1)) 骨架模式的倍频和组合带。这些特征允许使用时间相关的拉曼强度分析对振动模式特异性激发态结构位移进行定量估计，而这是从光学线形状的常规振子分析中不可能的。
