A record nine different phases (four cubic, two hexagonal, and one lamellar lyotropic liquid crystalline and two micellar solutions) in a ternary isothermal system of an amphiphilic block copolymer and selective solvents (water and oil)
A record nine different phases (four cubic, two hexagonal, and one lamellar lyotropic liquid crystalline and two micellar solutions) in a ternary isothermal system of an amphiphilic block copolymer and selective solvents (water and oil)
复制标题
DOI：
10.1021/la971117c
复制
发表时间：
1998-05-12
期刊：
影响因子：
3.9
通讯作者：
Lindman, B
中科院分区：
文献类型：
--
作者：
Alexandridis, P;Olsson, U;Lindman, B
我们报告的三元等温系统组成的聚（环氧乙烷）/聚（环氧丙烷）（PEO/PPO）的两亲性嵌段共聚物，“水”，和“油”（其中“水”和“油”是选择性溶剂的不同块），表现出最丰富的结构多态性以往任何时候都观察到（平衡）在含有两亲物的混合物（如嵌段共聚物，表面活性剂，或脂质）。由PEO/PPO嵌段共聚物的自组装产生的微结构可以不同于正常的微结构。（水包油）胶束在溶液中，通过所有类型的正常和反向（油包水）溶致液晶（正胶束立方体、正六边形、正双连续立方体、层状、反双连续立方体、反六边形、反胶束立方体），反胶束，因为非极性（“油”状）组分的相对体积分数增加超过极性（“水”状）组分的相对体积分数。在液晶相的结构已经建立与小角X-射线散射;正常和反向双连续立方结构是一致的Ia 3d晶体空间群（和Gyroid最小表面），而正常和反向胶束立方结构是一致的Im 3 m和FdSm空间群，分别。本文所述的两亲性嵌段共聚物在选择性溶剂中的自组装提供了表面活性剂在水（和油/助表面活性剂）中的自组装与嵌段共聚物在不存在任何溶剂的情况下的自组装之间的联系。此外，PEO/PPO两亲性嵌段共聚物获得不同微结构的能力对于许多实际应用是非常重要的，特别是因为这样的共聚物是可商购的（作为泊洛沙姆、普朗尼克或Synperonics）。
We report on a ternary isothermal system consisting of a poly(ethylene oxide)/poly(propylene oxide) (PEO/PPO) amphiphilic block copolymer, "water", and "oil" (where "water" and "oil" are selective solvents for the different blocks), which exhibits the richest structural polymorphism ever observed (in equilibrium) in mixtures containing amphiphiles (such as block copolymers, surfactants, or lipids). The microstructure resulting from the self-assembly of the PEO/PPO block copolymer can vary from normal (oil-in-water) micelles in solution, through all types of normal and reverse (water-in-oil) lyotropic liquid crystals (normal micellar cubic, normal hexagonal, normal bicontinuous cubic, lamellar, reverse bicontinuous cubic, reverse hexagonal, reverse micellar cubic), to reverse micelles, as the relative volume fraction of the apolar ("oil"-like) components increases over that of the polar ("water"-like) components. The structure in the liquid crystalline phases has been established with small-angle X-ray scattering; both the normal and the reverse bicontinuous cubic structures are consistent with the Ia3d crystallographic space group (and the Gyroid minimal surface), while the normal and reverse micellar cubic structures are consistent with the Im3m and FdSm space groups, respectively. The self-assembly of amphiphilic block copolymer in selective solvents described here provides a link between the self-assembly of surfactants in water (and oil/cosurfactant) and the self-assembly of block copolymers in the absence of any solvent. Furthermore, the ability of the PEO/PPO amphiphilic block copolymers to attain diverse microstructures is of great importance to numerous practical applications, especially since such copolymers are commercially available (as poloxamers, Pluronics, or Synperonics).