Kong Weixin, Li Baohui, Jin Qinghua, Ding Datong, Shi An-Chang
College of Physics and Key Laboratory of Functional Polymer Materials of Ministry of Education, Nankai University, Tianjin, 300071, China.
J Am Chem Soc. 2009 Jun 24;131(24):8503-12. doi: 10.1021/ja900405r.
Multicompartment micelles, especially nanostructured vesicles, offer tremendous potential as delivery vehicles of therapeutic agents and nanoreactors. Solution-state self-assembly of miktoarm star terpolymers provides a versatile and powerful route to obtain multicompartment micelles. Here we report simulations of solution-state self-assembly of ABC star terpolymers composed of a solvophilic A arm and two solvophobic B and C arms. A variety of multicompartment micelles are predicted from the simulations. Phase diagrams for typical star terpolymers are constructed. It is discovered that the overall micelle morphology is largely controlled by the volume fraction of the solvophilic A arms, whereas the internal compartmented and/or segregated structures depend on the ratio between the volume fractions of the two solvophobic arms. The polymer-solvent and polymer-polymer interactions can be used to tune the effective volume fraction of the A-arm and, thereby, induce morphological transitions. For terpolymers with equal or nearly equal length of B and C arms, several previously unknown structures, including vesicles with novel lateral structures (helices or stacked donuts), segmented semivesicles, and elliptic or triangular bilayer sheets, are discovered. When the lengths of B and C arms are not equal, novel micelles such as multicompartment disks and onions are observed.
多隔室胶束，尤其是纳米结构囊泡，作为治疗剂的递送载体和纳米反应器具有巨大潜力。米克托臂星形三嵌段共聚物的溶液态自组装为获得多隔室胶束提供了一条通用且强大的途径。在此，我们报道了由亲溶剂性A臂和两个疏溶剂性B臂及C臂组成的ABC星形三嵌段共聚物溶液态自组装的模拟。模拟预测了多种多隔室胶束。构建了典型星形三嵌段共聚物的相图。研究发现，胶束的整体形态在很大程度上受亲溶剂性A臂的体积分数控制，而内部隔室和/或分离结构则取决于两个疏溶剂性臂的体积分数之比。聚合物 - 溶剂和聚合物 - 聚合物相互作用可用于调节A臂的有效体积分数，从而诱导形态转变。对于B臂和C臂长度相等或近乎相等的三嵌段共聚物，发现了几种先前未知的结构，包括具有新型侧向结构（螺旋或堆叠环面）的囊泡、分段半囊泡以及椭圆形或三角形双层片。当B臂和C臂长度不相等时，会观察到新型胶束，如多隔室盘状和洋葱状胶束。
