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Abstract
Recently, attention has been directed toward understanding the dynamics and relaxation kinetics of block copolymer micelles, including mechanisms such as micelle fragmentation and fusion. The few prior studies on block copolymer micelle fragmentation relied on ensemble averaging techniques such as small-angle X-ray scattering and dynamic light scattering; some individual particles were imaged by ex situ transmission electron microscopy. Here we report the direct observation of fragmentation for three molecular weights of 1,2-polybutadiene-block-poly(ethylene oxide) (PB-PEO) micelles in the ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide using high-temperature liquid-phase transmission electron microscopy (LP-TEM). The use of in situ LP-TEM provides unique insights into the evolution of block copolymer micelles during fragmentation. Specifically, upon heating to 170 °C, a sequence of morphological transitions from a spherical micelle to a prolate ellipsoid, then a "peanut" shape, followed by a two-spherical-compartment micelle was observed, where the last is presumed to be the transition state.
Original language | English (US) |
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Pages (from-to) | 756-761 |
Number of pages | 6 |
Journal | ACS Macro Letters |
Volume | 9 |
Issue number | 5 |
DOIs | |
State | Published - May 19 2020 |
Bibliographical note
Publisher Copyright:© 2020 American Chemical Society.
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Dive into the research topics of 'Direct Observation of Micelle Fragmentation via in Situ Liquid-Phase Transmission Electron Microscopy'. Together they form a unique fingerprint.Projects
- 2 Finished
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MRSEC IRG-3: Hierarchical Multifunctional Macromolecular Materials
Reineke, T. M. (Coordinator), Bates, F. S. (Senior Investigator), Dorfman, K. (Senior Investigator), Dutcher, C. S. (Senior Investigator), Hillmyer, M. A. (Senior Investigator), Lodge, T. P. (Senior Investigator), Morse, D. C. (Senior Investigator), Siepmann, I. (Senior Investigator), Barreda, L. (Researcher) & Ganewatta, M. S. (Researcher)
11/1/14 → 10/31/20
Project: Research project
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University of Minnesota MRSEC (DMR-1420013)
Lodge, T. P. (PI)
11/1/14 → 10/31/20
Project: Research project