Formation of parallel aligned nano-fibrils of a donor–acceptor conjugated copolymer via controlling J-aggregates and post treatment
Formation of parallel aligned nano-fibrils of a donor–acceptor conjugated copolymer via controlling J-aggregates and post treatment
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DOI：
10.1039/c3sm51986d
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发表时间：
2013-10
期刊：
影响因子：
3.4
通讯作者：
Yao Xu;Jiangang Liu;Haiyang Wang;Xinhong Yu;Rubo Xing;Yanchun Han
中科院分区：
文献类型：
--
作者：
Yao Xu;Jiangang Liu;Haiyang Wang;Xinhong Yu;Rubo Xing;Yanchun Han
通过选择合适的溶剂，提高了聚[2，5-双（2-辛基十二烷基）吡咯并[3，4-c]吡咯-1，4（2 H，5 H）-二酮-alt-2，2 ′：5′，2 ′′：5′′，2 ′-四噻吩]（PDQT）溶液中J-聚集体的含量。发现在良溶剂（即CF）中的溶液中较高含量的J-聚集体导致平行排列的纳米原纤的形成。这种从无序域到有序域的形态转变也可以在热处理或溶剂蒸气退火后发生。通过在200 °C下退火20分钟或在具有相对低的蒸气压的CF气氛中溶剂蒸气退火24小时，在膜中形成平行排列的PDQT原纤维。在平行排列的原纤维填充的薄膜中，PDQT分子采用侧边取向，分子的π-π堆积方向垂直于原纤维的生长方向。由于PDQT链的骨架刚性很强，所以它更倾向于采用不折叠的伸展构象。具有扩展构象的刚性PDQT链的完整共轭平面允许平行排列的原纤维的进一步生长，这增强了结晶域之间的连接性。本工作的结果被认为有助于改善PDQT薄膜的载流子输运。
We increased the content of J-aggregates in poly[2,5-bis(2-octyldodecyl)pyrrolo[3,4-c]pyrrole-1,4(2H,5H)-dione-alt-2,2′ : 5′,2′′ : 5′′,2′′′-quaterthiophene](PDQT) solution by choosing appropriate solvents. It was found that the higher content of J-aggregates in solution in good solvents (i.e. CF) led to the formation of parallel aligned nano-fibrils. This morphological transition from the disordered domains to ordered ones could also occur after thermal treatment or solvent vapor annealing. Parallel aligned fibrils of PDQT formed in films via annealing at 200 °C for 20 min or solvent vapor annealing in a CF atmosphere with a relatively low vapor pressure for 24 hours. In the films filled with parallel aligned fibrils, the PDQT molecules adopted an edge-on orientation and the π–π stacking direction of molecules was perpendicular to the growth direction of fibrils. PDQT chains preferred to adopt the extended conformations without chain-folding due to the extremely rigid backbones. The intact conjugation planes of rigid PDQT chains with extended conformations allow the further growth of parallel aligned fibrils, which enhanced the connectivity between crystalline domains. The results in this work are thought to be helpful to improve the charge-carrier transport in PDQT films.