Kim Jung Yong
School of Chemical Engineering and Materials Science and Engineering, Jimma Institute of Technology, Jimma University, Post Office Box 378 Jimma, Ethiopia.
Polymers (Basel). 2021 Mar 23;13(6):983. doi: 10.3390/polym13060983.
Phase diagrams of ternary conjugated polymer solutions were constructed based on Flory-Huggins lattice theory with a constant interaction parameter. For this purpose, the poly(3-hexylthiophene-2,5-diyl) (P3HT) solution as a model system was investigated as a function of temperature, molecular weight (or chain length), solvent species, processing additives, and electron-accepting small molecules. Then, other high-performance conjugated polymers such as PTB7 and PffBT4T-2OD were also studied in the same vein of demixing processes. Herein, the liquid-liquid phase transition is processed through the nucleation and growth of the metastable phase or the spontaneous spinodal decomposition of the unstable phase. Resultantly, the versatile binodal, spinodal, tie line, and critical point were calculated depending on the Flory-Huggins interaction parameter as well as the relative molar volume of each component. These findings may pave the way to rationally understand the phase behavior of solvent-polymer-fullerene (or nonfullerene) systems at the interface of organic photovoltaics and molecular thermodynamics.
基于具有恒定相互作用参数的弗洛里 - 哈金斯晶格理论构建了三元共轭聚合物溶液的相图。为此，研究了作为模型体系的聚（3 - 己基噻吩 - 2,5 - 二基）（P3HT）溶液，考察其作为温度、分子量（或链长）、溶剂种类、加工添加剂和电子接受小分子的函数关系。然后，还以相同的相分离过程思路研究了其他高性能共轭聚合物，如PTB7和PffBT4T - 2OD。在此，液 - 液相转变通过亚稳相的成核和生长或不稳定相的自发旋节线分解来进行。结果，根据弗洛里 - 哈金斯相互作用参数以及各组分的相对摩尔体积计算出了通用的双节线、旋节线、系线和临界点。这些发现可能为合理理解有机光伏与分子热力学界面处溶剂 - 聚合物 - 富勒烯（或非富勒烯）体系的相行为铺平道路。
