Polymer polymerization is the process of converting low molecular weight monomers into high molecular weight polymers. With the development of polymer science, various polymerization mechanisms came into being. Among them, living polymerization has greatly promoted the accurate design and preparation of polymers and has gradually become one of the important cores of polymer synthetic chemistry due to the characteristics of high precision and narrow distribution.
At a higher level, self-assembly based on ordered polymer aggregates, such as micelles, is also considered a supramolecular reaction in which the reaction primitives are micelles. In recent years, the research group of Jiaping Lin, School of Materials Science and Engineering, has extended the concept of polymer polymerization to the field of supramolecular reactions based on micelles and discovered a variety of supramolecular reactions such as polymerization, cyclization, ring chain competition and living polymerization of micelles (Chem. Rev. 2020, 120, 4111). For example, the intermicellar polymerization and intramicellar cyclization of polypeptide rod-like micelles can produce chain-like and ring-like supramolecular reaction products respectively, and there is supramolecular ring-chain competitive reaction between the two behaviors (Macromolecules 2021, 54, 5196).
Recently, the group discovered the "lying flat" living growth of polymer micelles on substrates, which is a new type of supramolecular polymerization mechanism. It was found that the liquid crystal block copolymer first formed micelles in solution, some of which were adsorbed to the surface of the substrate to nucleate and act as seeds. These micelle seeds have living ends, and induce the living growth of 1D cylindrical micelles on the substrate by fusing with the remaining micelles in the solution. Theoretical simulations further reveal that this process is related to the anchoring of the micelles by the substrate and the rearrangement of the liquid crystal blocks within the micellar core, which is a novel anchorage-dependent living supramolecular reaction on the substrate.
Figure 1. "lying flat" living growth behavior of polymer micelles
Our group discovered the living supramolecular mechansim of "lying flat" similar to the formation and deposition of amyloid fibrin and could provide useful information for the study of the etiology, mechanism, and treatment of Alzheimer's disease, Parkinson's disease, and other related diseases.
The work was completed by Zhengmin Tang, a doctoral student in the School of Materials Science and Engineering, and Liang Gao, a young scholar, under the guidance of Professor Jiaping Lin, Professor Chunhua Cai, and Professor Gerald Guerin. The relevant work was published in J. Am. Chem. Soc. (DOI: 10.1021/jacs.1c06020). Under the title of Anchorage-Dependent Living Supramolecular Self-Assembly of Polymeric Micelles.
Original link:https://pubs.acs.org/doi/10.1021/jacs.1c06020