How a Small Modification of the Corona-Forming Block Redirects the Self-Assembly of Crystalline-Coil Block Copolymers in Solution

Maria Jose Gonzalez-Alvarez, Lin Jia, Gerald Guerin, Kris Sanghyun Kim, Van Du, Gilbert Walker, Ian Manners, Mitchell Winnik

Research output: Contribution to journalArticle (Academic Journal)peer-review

12 Citations (Scopus)
261 Downloads (Pure)

Abstract

In this study, we examine how the self-assembly of crystalline-coil block copolymers in solution can be influenced by small changes in the chemical structure of the corona-forming block. Three samples of poly(ferrocenyldimethylsilane)-block-poly(2-vinylpyridine) that form long fiber-like micelles uniform in width in 2-propanol, were treated with methyl iodide to convert a small fraction (0.1% to 6%) of the pyridines to methylpyridinium groups. When these partially quaternized samples (PFS-b-P2VPQ) were subjected to the same self-assembly protocol, very different structures were obtained. For PFS36-b-P2VP502Q, the presence of positive charges led to the formation of much shorter rod-like micelles. In contrast, for PFS17-b-P2VP170Q and PFS30-b-P2VP300Q, complex platelet structures were obtained. We explain the complexity of these structures in terms of a distribution of compositions, in which the polymer chains with the highest extent of methylation are the least soluble in 2-PrOH and the first to associate, leading to two-dimensional aggregates. The less quaternized polymer chains remaining in solution have a stronger tendency to form elongated fiber-like micelles that grow from the ends of the initially formed planar structures. In this way, we show that small extents of chemical modification of the corona forming chains can modify the self-assembly process and that simple one-pot protocols can lead to diverse hierarchical structures.
Original languageEnglish
Pages (from-to)7975-7984
Number of pages10
JournalMacromolecules
Volume49
Early online date12 Oct 2016
DOIs
Publication statusPublished - 25 Oct 2016

Fingerprint

Dive into the research topics of 'How a Small Modification of the Corona-Forming Block Redirects the Self-Assembly of Crystalline-Coil Block Copolymers in Solution'. Together they form a unique fingerprint.

Cite this