Cylindrical Block Copolymer Micelles and Co-Micelles of Controlled Length and Architecture

Abstract

Block copolymers consist of two or more chemically different polymers connected by covalent linkages. In solution, repulsion between the blocks leads to a variety of morphologies, which are thermodynamically driven. Polyferrocenyldimethylsilane block copolymers show an unusual propensity to forming cylindrical micelles in solution. We found that the micelle structure grows epitaxially through the addition of more polymer, producing micelles with a narrow size dispersity, in a process analogous to the growth of living polymer. By adding a different block copolymer, we could form co-micelles. We were also able to selectively functionalize different parts of the micelle. Potential applications for these materials include their use in lithographic etch resists, in redox-active templates, and as catalytically active metal nanoparticle precursors.

Two-dimensional assemblies from crystallizable homopolymers with charged termini

“…Seeded-growth of crystallizable BCPs from 1D cylindrical seeds prepared by sonication of long, polydisperse cylinders with a crystalline core provides a recently established route to low dispersity cylindrical micelles of controlled length [18][19][20] and also complex architectures such as block comicelles, [21][22][23] branched cylindrical micelles, 24 and multi-armed micelles. 25 The key to this approach is that the core termini of the seeds remain active to the addition of further BCP unimer, leading to a process that is analogous to a living covalent polymerization of molecular monomers.…”

Synthesis and Solution Self‐Assembly of Polyisoprene‐block‐poly(ferrocenylmethylsilane): A Diblock Copolymer with an Atactic but Semicrystalline Core‐Forming Metalloblock

“…Significantly, it was found that addition of further unimer to these short micelles resulted in longer cylinders, with the preformed micelles essentially acting as "seeds" for further unimer nucleation. 323 The length of the micelles depended linearly on the unimer-to-seed ratio and was also found to be of low polydispersity. This demonstrated an analogy with a living covalent polymerisation of molecular monomers.…”

“…324 Cylindrical micelles with length dispersities of 1.01 and overall length greater than 2 µm have been prepared by this protocol (see Figure 37). 323,324 Reproduced with permission from reference 324.…”

“…47 This subsequently led to the discovery that the crystalline cores at the micelle termini were able to elongate by the addition of further BCP. 323 The use of small seed micelles (generated by sonication of longer cylinders) as "initiators" led to a process that is analogous to a living covalent polymerisation of molecular monomers. 324 This process, termed "Living…”

Supramolecular Interfacial Polymerization: A Controllable Method of Fabricating Supramolecular Polymeric Materials

“…Owing to the dynamic nature of the noncovalent interactions, supramolecular polymers exhibit unique properties such as reversibility, stimuli‐responsiveness, self‐healing, and good processability 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30. Over the past decades, significant advances have been made in developing methods of supramolecular polymerization, from spontaneous to controllable and living supramolecular polymerization 31, 32, 33, 34, 35, 36, 37, 38. Furthermore, supramolecular polymers have displayed potential applications in many interdisciplinary fields, such as molecular muscles,39, 40, 41 self‐healing materials,42, 43, 44 self‐healing organic electronics,45, 46 heterogeneous catalysis,47 degradable drug nanocarriers,48 and stimuli‐responsive supramolecular gels 49, 50, 51…”