Morphological Control of Anisotropic Self-Assemblies from Alternating Poly(p?dioxanone)-poly(ethylene glycol) Multiblock Copolymer Depending on the Combination Effect of Crystallization and Micellization
writer：Mei-Jia Wang, Hao Wang, Si-Chong Chen,* Cheng Chen, and Ya Liu*
keywords：Crystallization induced self-assembly
source：期刊
specific source：Langmuir
Issue time：2015年
A novel and facile method was developed for morphological controlling of self-assemblies prepared by crystallization induced self-assembly of crystalline-coil copolymer depending on the combination effect of crystallization and micellization. The morphological evolution of the selfassemblies of alternating poly(p-dioxanone)-block-poly-(ethylene glycol) (PPDO.PEG) multiblock copolymer prepared by different solvent mixing methods in aqueous solution were investigated. “Chrysanthemum”-like and “star anise”-like self-assemblies were obtained at different rates of solvent mixing. The results suggested gradually change in solvent quality (slowly dropping water into DMF solution) leaded to a hierarchical micellization-crystallization process of core-forming PPDO blocks, and flake-like particles were formed at the initial stage of crystallization. Meanwhile, crystallization induced micellization process occurred when solvent quality changed drastically. Shuttle-like particles, which have much smaller size than those of flake-like particles, were formed at the initial stage of crystallization when quickly injecting water into DMF solution of the copolymer. Therefore, owing to the different changing rate of solvent quality, which may result in different combination effect of crystallization and micellization during self assembly of the copolymer, PPDO.PEG self-assemblies with different hierarchical morphology in nano scale could be obtained