Vena M Paula, de Moor Demi, Ianiro Alessandro, Tuinier Remco, Patterson Joseph P
Laboratory of Physical Chemistry, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands.
Soft Matter. 2021 Jan 28;17(4):1084-1090. doi: 10.1039/d0sm01596b. Epub 2020 Dec 8.
Polymer self-assembly is used to form nanomaterials with a wide range of structures. While self-assembly of polymers in bulk has been thoroughly explored, the same process in solution remains widely used but partially unresolved, due to the formation of structures which are often kinetically trapped. In this paper we report kinetic state diagrams of polystyrene-b-poly(ethylene oxide) block copolymer in water by changing the solvent-switch assembly conditions. We study 36 different conditions for a single block copolymer, exploring three parameters: polymer concentration, temperature and rate addition of selective solvent. The data shows that polymer concentration plays an important role in determining which morphologies are accessible within a given set of experimental parameters and provides evidence that vesicles can evolve into particles with complex internal structures, supportive of recent mechanistic studies. Most importantly, the data shows a complex relationship between all parameters and the resulting kinetically trapped morphologies indicating that combined in situ and ex situ studies are required to gain a fundamental understanding of kinetically controlled block copolymer assembly processes.
聚合物自组装用于形成具有多种结构的纳米材料。虽然本体中聚合物的自组装已得到充分研究，但溶液中的相同过程仍被广泛使用，但由于经常形成动力学捕获的结构，该过程仍部分未得到解决。在本文中，我们通过改变溶剂切换组装条件，报告了聚苯乙烯-b-聚环氧乙烷嵌段共聚物在水中的动力学状态图。我们研究了单一嵌段共聚物的36种不同条件，探索了三个参数：聚合物浓度、温度和选择性溶剂的添加速率。数据表明，聚合物浓度在确定给定实验参数集内可获得的形态方面起着重要作用，并提供了囊泡可演变成具有复杂内部结构的颗粒的证据，这支持了最近的机理研究。最重要的是，数据显示了所有参数与所得动力学捕获形态之间的复杂关系，表明需要结合原位和非原位研究，才能对动力学控制的嵌段共聚物组装过程有基本的了解。
