Institute of Organic and Macromolecular Chemistry and Jena Center for Soft Matter (JCSM), Friedrich-Schiller-University Jena, Humboldtstrasse 10, 07743 Jena, Germany.
Chemistry. 2012 Jan 9;18(2):517-25. doi: 10.1002/chem.201102322. Epub 2011 Dec 9.
We demonstrate the synthesis and characterization of star-shaped crystalline-coil block copolymers with four arms consisting of an inner block of poly(ethylene oxide) and an outer semicrystalline compartment of poly(ferrocenyldimethylsilane), PEO(50) -b-PFDMS(35). The materials were synthesized by transition-metal-catalyzed ring-opening polymerization of dimethylsila[1]ferrocenophane in the presence of silane-functionalized four-arm PEO stars as macroinitiators and they exhibited a moderate polydispersity (PDI≅1.4). Self-assembly in mixtures of THF and different alcohols as selective solvents for the PEO block resulted in the formation of semicrystalline vesicles (ethanol, 1-butanol) or large, rather ill-defined, spherical structures (methanol). Further, both the rate of addition of the selective co-solvent and the overall solvent/non-solvent ratio drastically affected the size and stability of the self-assembled particles. We could also show that a photoacid generator, as a model for an active substance, can be encapsulated and the UV-induced generation of HCl resulted in a straightforward degradation of the organometallic vesicles.
我们展示了具有四个臂的星形晶状-螺旋嵌段共聚物的合成和表征,这些臂由聚(氧化乙烯)的内部嵌段和聚(二茂铁基二甲基硅烷)的外部半结晶隔室组成,[PEO(50)-b-PFDMS(35)](4)。这些材料是通过二茂铁基二甲基硅烷在硅烷官能化的四臂 PEO 星作为大分子引发剂存在下的过渡金属催化开环聚合合成的,它们表现出中等的多分散性(PDI≅1.4)。在 THF 和不同醇作为 PEO 嵌段选择性溶剂的混合物中的自组装导致半结晶囊泡(乙醇,1-丁醇)或大的、相当不规则的球形结构(甲醇)的形成。此外,选择性共溶剂的添加速率和整体溶剂/非溶剂比都极大地影响了自组装颗粒的大小和稳定性。我们还表明,可以封装光酸产生剂作为活性物质的模型,并且 UV 诱导的 HCl 的生成导致有机金属囊泡的直接降解。