具有扭曲结构的嵌段共聚物。
Block copolymers with a twist.
机构信息
Department of Chemical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan.
出版信息
J Am Chem Soc. 2009 Dec 30;131(51):18533-42. doi: 10.1021/ja9083804.
Chiral block copolymers (BCPs*) comprising chiral entities were designed to fabricate helical architectures (i.e., twisted morphologies) from self-assembly. A new helical phase (H*) with P622 symmetry was discovered in the self-assembly of poly(styrene)-b-poly(l-lactide) (PS-PLLA) BCPs*. Hexagonally packed, interdigitated PLLA helical microdomains in a PS matrix were directly visualized by electron tomography. The phase diagram of the PS-PLLA BCPs* was also established. Phase transitions from the H* phase to the stable cylinder and gyroid phases were found after long-time annealing, suggesting that the H* is a long-lived metastable phase. In contrast to racemic poly(styrene)-b-poly(d,l-lactide) BCPs, chiral interaction significantly enhances the incompatibility between achiral PS and chiral PLLA blocks in the PS-PLLA BCPs* and can be estimated through the determination of the interaction parameter.
手性嵌段共聚物（BCPs*）由手性实体组成，旨在通过自组装来制造螺旋结构（即扭曲形态）。在聚（苯乙烯）-嵌段-聚（L-丙交酯）（PS-PLLA）BCPs的自组装中发现了一种具有 P622 对称性的新螺旋相（H）。通过电子断层扫描可以直接观察到 PS 基质中具有六边形堆积、交错 PLLA 螺旋微区。还建立了 PS-PLLA BCPs的相图。经过长时间退火后，发现从 H相到稳定的圆柱和双轴各向同性相的相转变，表明 H是一种长寿命的亚稳相。与外消旋聚（苯乙烯）-嵌段-聚（D，L-丙交酯）BCPs 相比，手性相互作用显著增强了非手性 PS 和手性 PLLA 嵌段在 PS-PLLA BCPs中的不相容性，并且可以通过确定相互作用参数来估计。
Zotero 插件