Collapse Transition‐Assisted Crystallization in P3HT Solution
Collapse Transition‐Assisted Crystallization in P3HT Solution
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DOI：
10.1002/polb.24865
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发表时间：
2019-07
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影响因子：
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通讯作者：
Lei Sun;Jingnan Zhao;Weiheng Huang;Xiaowei Chen;Wenhua Zhang;Yanwei Ding;Liangbin Li
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文献类型：
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作者：
Lei Sun;Jingnan Zhao;Weiheng Huang;Xiaowei Chen;Wenhua Zhang;Yanwei Ding;Liangbin Li
了解溶液中的多重相变，如塌缩转变、相分离和结晶，对于在器件加工中控制共轭聚合物的溶液结构至关重要。结合原位同步辐射小角和广角X射线散射、超灵敏差示扫描量热法、紫外-可见吸收光谱和偏光显微镜，我们研究了聚（3-己基噻吩）/甲苯溶液在冷却和加热过程中的有序-无序转变。我们证明了在溶液中冷却过程中，在结晶开始之前，聚合物链从无规卷曲状态到低维网络的塌陷过渡的发生。这种构象预序可以导致溶致液晶相的形成，这对聚合物薄膜的结晶和有序化以及进一步提高其电性能具有重要意义。研究表明，从链塌缩溶液中浇铸的膜的迁移率可以比从具有随机卷曲构象的各向同性溶液中浇铸的膜的迁移率高一个数量级。因此，在溶液中的构象预排序被认为是一个更有效的方式比后退火的薄膜，以提高共轭聚合物薄膜的电性能。© 2019 Wiley Periodicals，Inc. J.波利姆科学，部分B：聚合物物理2019，57，1105-1114
Understanding the multiple phase transitions such as collapse transition, phase separation, and crystallization in solutions is of fundamental importance to control the solution structure of conjugated polymers in device processing. Combiningin situsynchrotron radiation small and wide‐angle X‐ray scattering, ultrasensitive differential scanning calorimetry, ultraviolet–visible absorption spectroscopy, and polarized optical microscopy, we investigate the order–disorder transitions in poly(3‐hexylthiophene)/toluene solutions during cooling and heating processes. We demonstrate the occurrence of collapse transition of polymer chains from a random coil state to a lower dimensional network prior to the onset of crystallization during cooling in solution. This conformational preordering can lead to the formation of a lyotropic liquid crystalline phase, which is of great significance to the crystallization and ordering in polymer films, and further to promote its electric performance. It is examined that the mobility of films cast from chain‐collapsed solutions can be one order of magnitude higher than that from isotropic solutions with random‐coiled conformations. Thus, the conformational preordering in solutions is proposed to be a more efficient way than the postannealing of films to improve the electric performance of conjugated polymer films. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys.2019,57, 1105–1114