Toroidal Triblock Copolymer Assemblies

作者：Darrin J. Pochan, Zhiyun Chen, Honggang Cui, Kelly Hales, Kai Qi, Karen L. Wooley · 发表于：Science · 年份：2004 · DOI：10.1126/science.1102866 · 被引用次数：780 · 研究领域：Advanced Polymer Synthesis and Characterization、Polymer Surface Interaction Studies、Surfactants and Colloidal Systems

A stable phase of toroidal, or ringlike, supramolecular assemblies was formed by combining dilute solution characteristics critical for both bundling of like-charged biopolymers and block copolymer micelle formation. The key to toroid versus classic cylinder micelle formation is the interaction of the negatively charged hydrophilic block of an amphiphilic triblock copolymer with a positively charged divalent organic counterion. This produces a self-attraction of cylindrical micelles that leads to toroid formation, a mechanism akin to the toroidal bundling of semiflexible charged biopolymers such as DNA. The toroids can be kinetically trapped or chemically cross-linked. Insight into the mechanism of toroid formation can be gained by observation of intermediate structures kinetically trapped during film casting.