Physics Department, Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991, Russian Federation.
Physics Department, Lomonosov Moscow State University, Leninskie Gory 1-2, Moscow 119991, Russian Federation; DWI - Leibniz Institute for Interactive Materials e.V., Forckenbeckstraße 50, Aachen 52056, Germany.
J Colloid Interface Sci. 2022 Jan 15;606(Pt 2):1966-1973. doi: 10.1016/j.jcis.2021.09.196. Epub 2021 Oct 4.
Amphiphilic miktoarm star copolymers with one long solvophobic arm (a "stem") and several short solvophilic arms (the "leaves") were studied in a selective solvent using mesoscopic computer simulations. The conventional morphologies (spherical, cylindrical and vesicular) as well as the mixed ones were obtained. However, the resulting diagram of states appeared to be different from the diagram of the linear diblock copolymer with the analogous composition. Namely, the increase of the number of leaves at fixed solvophobic-solvophilic ratio leads to the transition from the vesicles to the cylinders, while the latter ones eventually transform into spherical micelles in the case of highly branched copolymers. The observed effect appears due to the increase of the interfacial area between the collapsed and swollen blocks per single macromolecule. In turn, the increase of the solvent selectivity shifts the stability region of the cylindrical micelles to the region of more symmetric copolymer composition. Meanwhile, the compatibility between the blocks has a weak effect on the resulting morphology. Finally, it was found that the increase in the number of leaves and the simultaneous decrease in their length results in the localization of higher amount of solvophilic segments near the core-solvent interface, which in the case of cylindrical micelles significantly affects the shape of the aggregates making them thinner and longer.
具有一个长疏溶剂臂（“主干”）和几个短亲溶剂臂（“叶子”）的两亲性星型嵌段共聚物在选择性溶剂中使用介观计算机模拟进行了研究。得到了常规形态（球形、圆柱形和囊泡形）以及混合形态。然而，得到的状态图似乎与具有类似组成的线性两嵌段共聚物的状态图不同。也就是说，在固定的疏溶剂-亲溶剂比下，随着叶子数量的增加，会从囊泡转变为圆柱，而在高度支化共聚物的情况下，圆柱最终转变为球形胶束。观察到的效应是由于每单个大分子的塌陷和溶胀块之间的界面面积增加所致。反过来，溶剂选择性的增加会将圆柱形胶束的稳定性区域转移到更对称的共聚物组成区域。同时，块之间的相容性对所得形态的影响较弱。最后，发现叶子数量的增加和叶子长度的同时减小会导致更多亲溶剂段在核-溶剂界面附近定位，这在圆柱形胶束的情况下会显著影响聚集体的形状，使其更细更长。
