Zhang Liangshun, Lin Jiaping, Lin Shaoliang
Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
J Phys Chem B. 2007 Aug 9;111(31):9209-17. doi: 10.1021/jp068429l. Epub 2007 Jul 17.
Microstructures assembled by amphiphilic graft copolymers in a selective solvent (poor for the backbone chain and good for graft chains or poor for graft chains and good for the backbone chain) were investigated on the basis of a real-space algorithm of self-consistent field theory in two-dimensions. Circle-like micelles, line-like micelles, large compound micelles, and vesicles are obtained by tailoring the architectural parameters and interaction parameter between the graft blocks and solvents. The aggregate morphology stability regions of graft copolymers as functions of the position of first graft point and the number of branches are constructed. It is found that the architectural parameters play a remarkable role in the complex microstructure formation. The interaction between the graft blocks and solvents is also shown to exert an effect on the morphology stability regions. The distributions of the free end and inner blocks of the backbone are found to be different in various aggregate structures. For the circle-like micelles assembled by graft copolymers with a hydrophobic backbone and vesicles assembled by graft copolymers with a hydrophilic backbone, the free end and inner blocks segregate and localize in different parts of the aggregates depending on their length. However, with respect to the large compound micelles and vesicles assembled by graft copolymers with a hydrophobic backbone, the free end and inner blocks uniformly mix in the clusters.
基于二维自洽场理论的实空间算法，研究了两亲性接枝共聚物在选择性溶剂（对主链链段不良而对接枝链段良好，或对接枝链段不良而对主链链段良好）中组装而成的微观结构。通过调整接枝嵌段与溶剂之间的结构参数和相互作用参数，可得到环状胶束、线状胶束、大复合胶束和囊泡。构建了接枝共聚物的聚集体形态稳定性区域与第一接枝点位置和支链数的函数关系。研究发现，结构参数在复杂微观结构的形成中起着显著作用。接枝嵌段与溶剂之间的相互作用也对形态稳定性区域产生影响。在各种聚集体结构中，主链的自由端和内链段的分布各不相同。对于由具有疏水主链的接枝共聚物组装而成的环状胶束和由具有亲水主链的接枝共聚物组装而成的囊泡，自由端和内链段会根据其长度在聚集体的不同部位发生分离和定位。然而，对于由具有疏水主链的接枝共聚物组装而成的大复合胶束和囊泡，自由端和内链段在聚集体中均匀混合。
