Aggregation Behavior of Cyclic Rod-Coil Diblock Copolymers in Selective Solvents  

作　　者：Wen-ping Zhang Xiang-hong Wang 何林李 

机构地区：[1]Department of Physics, Wenzhou University, Wenzhou 325035 China [2]Wenzhou Vocational & Technical College, Wenzhou 325035, China

出　　处：《Chinese Journal of Polymer Science》2016年第4期420-430,共11页高分子科学（英文版）

基　　金：financially supported by the National Natural Science Foundation of China(No.21474076);the Natural Science Foundation of Zhejiang(Nos.Z13F20019 and LY15B040005);the Science and Technology of Wenzhou(No.G20140054)

摘　　要：The aggregation behavior of cyclic rod-coil （RC） diblock copolymers in dilute solutions is investigated through dissipative particle dynamics simulation. By varying the rod length and coil length, cyclic RC copolymers in selective solvents exhibit various morphologies, including spherical miceUe, vesicle, bilayer disc, and ribbon bundle structure. Compared with the equivalent linear RC copolymer, only spherical micelle and barrel bundle phase are observed. Rod length is the major factor that controls the liquid-crystalline behavior of RC copolymer systems, while the coil length has a secondary effect on the aggregate morphology. The size of rod bundle varies with the coil length, especially for the end-to- end ribbon bundle and side-by-side barrel bundle, which are assembled by cyclic and linear RC copolymer solutions. This finding indicates that the ribbon bundle or nanofiber-like structure in cyclic RC copolymers can be obtained by controlling the rod length and coil length, and thus the optical and electrical properties of RC copolymer would be further controlled and optimized. Results illustrate that cyclization of a linear RC copolymer induces remarkable differences in the rod arrangement and aggregation behavior, thereby indicating the competition between interfacial energy, rod orientational entropy, coil stretching entropy, and packing constraints.The aggregation behavior of cyclic rod-coil （RC） diblock copolymers in dilute solutions is investigated through dissipative particle dynamics simulation. By varying the rod length and coil length, cyclic RC copolymers in selective solvents exhibit various morphologies, including spherical miceUe, vesicle, bilayer disc, and ribbon bundle structure. Compared with the equivalent linear RC copolymer, only spherical micelle and barrel bundle phase are observed. Rod length is the major factor that controls the liquid-crystalline behavior of RC copolymer systems, while the coil length has a secondary effect on the aggregate morphology. The size of rod bundle varies with the coil length, especially for the end-to- end ribbon bundle and side-by-side barrel bundle, which are assembled by cyclic and linear RC copolymer solutions. This finding indicates that the ribbon bundle or nanofiber-like structure in cyclic RC copolymers can be obtained by controlling the rod length and coil length, and thus the optical and electrical properties of RC copolymer would be further controlled and optimized. Results illustrate that cyclization of a linear RC copolymer induces remarkable differences in the rod arrangement and aggregation behavior, thereby indicating the competition between interfacial energy, rod orientational entropy, coil stretching entropy, and packing constraints.

关 键 词：Cyclic rod-coil Ribbon bundle Cyclization. 

分 类 号：O631.1[理学—高分子化学]