"Raft" Formation by Two‐Dimensional Self‐Assembly of Block Copolymer Rod Micelles in Aqueous Solution1. Issue 34 (2nd July 2014)

• Record Type: Journal Article
• Authors: Rizis, Georgios; van de Ven, Theo G. M.; Eisenberg, Adi
• Is Part Of: Angewandte Chemie international edition. Volume 53:Issue 34(2014)
• Page Start: 9000
• Page End: 9003
• Publication Date: 2014-07-02
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201404089
• Languages: English
• ISSNs: 1433-7851

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Block copolymers can form a broad range of self‐assembled aggregates. In solution, planar assemblies usually form closed structures such as vesicles; thus, free‐standing sheet formation can be challenging. While most polymer single crystals are planar, their growth usually occurs by uptake of individual chains. Here we report a novel lamella formation mechanism: core‐crystalline spherical micelles link up to form rods in solution, which then associate to yield planar arrays. For the system of poly(ethylene oxide)‐block‐polycaprolactone in water, co‐assembly with homopolycaprolactone can induce a series of morphological changes that yield either rods or lamellae. The underlying lamella formation mechanism was elucidated by electron microscopy, while light scattering was used to probe the kinetics. The hierarchical growth of lamellae from one‐dimensional rod subunits, which had been formed from spherical assemblies, is novel and controllable in terms of product size and aspect ratio.</p> </abstract>