School of Chemistry, University of Bristol , Bristol BS8 1TS, United Kingdom.
Department of Chemistry, University of Toronto , Toronto, Ontario M5S 3H6, Canada.
J Am Chem Soc. 2016 Oct 5;138(39):12902-12912. doi: 10.1021/jacs.6b05973. Epub 2016 Sep 20.
Hydrogen bonds are among the most common interactions used by nature for the creation of hierarchical structures from smaller building blocks. Herein, we describe an in-depth study of the hierarchical assembly of cylindrical block comicelles with a crystallizable poly(ferrocenyldimethylsilane) (PFS) core via H-bonding interactions to form complex supermicellar structures. Well-defined block comicelles bearing H-bond donor (H) segments (M(PFS-b-PMVSOH)), or H-bond acceptor (H) segments (M(PFS-b-P2VP)), and non-interacting (N) segments (M(PFS-b-PtBA)) were created by the living crystallization-driven self-assembly (CDSA) method [PMVSOH = hydroxyl-functionalized poly(methylvinylsiloxane), P2VP = poly(2-vinylpyridine), PtBA = poly(tert-butyl acrylate), M = micelle segment]. Due to the control provided by the living CDSA approach, both the block comicelles and the individual segments were virtually monodisperse in length, which facilitated their predictable hierarchical assembly into higher-level structures. Two cases were investigated in detail: first, the interaction of N-H-N triblock comicelles with the H homopolymer PMVSOH, and second, the interaction of N-H-N triblock comicelles with very short H cylinders (seeds). By manipulation of several factors, namely coronal steric effects (via the PtBA corona chain) and attractive interaction strength (via the H-bonding interaction between P2VP and PMVSOH), the aggregation of the triblock comicelles could be controlled, and well-defined multi-micrometer-size structures such as "shish-kebab"-shaped supermicelles were prepared. The ability of the seeds adsorbed on the block comicelles to function as initiators for living CDSA to generate fence-like "shish-kebab" superstructures was also explored.
氢键是自然界中最常用的相互作用之一，用于从小的构建块创建层次结构。在此，我们描述了通过氢键相互作用深入研究具有结晶性聚（二茂铁基二甲基硅烷）（PFS）核的圆柱形嵌段胶束的分级组装，以形成复杂的超胶束结构。通过活的结晶驱动自组装（CDSA）方法[PMVSOH=羟基官能化聚（甲基乙烯基硅氧烷），P2VP=聚（2-乙烯基吡啶），PtBA=聚（叔丁基丙烯酰胺），M=胶束段]制备了具有氢键给体（H）段（M（PFS-b-PMVSOH））、氢键受体（H）段（M（PFS-b-P2VP））和非相互作用（N）段（M（PFS-b-PtBA））的嵌段胶束。由于活的 CDSA 方法提供的控制，嵌段胶束和各个段在长度上几乎都是单分散的，这便于它们可预测地分层组装成更高层次的结构。详细研究了两种情况：首先，N-H-N 三嵌段胶束与 H 均聚物 PMVSOH 的相互作用，其次，N-H-N 三嵌段胶束与非常短的 H 圆柱（种子）的相互作用。通过操纵几个因素，即冠冕位阻效应（通过 PtBA 冠冕链）和吸引力相互作用强度（通过 P2VP 和 PMVSOH 之间的氢键相互作用），可以控制三嵌段胶束的聚集，并制备了具有良好定义的多微米尺寸结构，例如“串珠”形超胶束。还探索了吸附在嵌段胶束上的种子作为活 CDSA 的引发剂生成围栏状“串珠”超结构的能力。
