@article{5a55a6cbd6ce4c4ca0a38575f1a7f8d1,
title = "Spatiotemporal Formation and Growth Kinetics of Polyelectrolyte Complex Micelles with Millisecond Resolution",
abstract = "We have directly observed the in situ self-assembly kinetics of polyelectrolyte complex (PEC) micelles by synchrotron time-resolved small-angle X-ray scattering, equipped with a stopped-flow device that provides millisecond temporal resolution. A synthesized neutral-charged diblock polycation and homopolyanion that we have previously investigated as a model charge-matched, core-shell micelle system were selected for this work. The initial micellization of the oppositely charged polyelectrolytes was completed within the dead time of mixing of 100 ms, followed by micelle growth and equilibration up to several seconds. By combining the structural evolution of the radius of gyration (Rg) with complementary molecular dynamics simulations, we show how the self-assemblies evolve incrementally in size over time through a two-step kinetic process: first, oppositely charged polyelectrolyte chains pair to form nascent aggregates that immediately assemble into spherical micelles, and second, these PEC micelles grow into larger micellar entities. This work has determined one possible kinetic pathway for the initial formation of PEC micelles, which provides useful physical insights for increasing fundamental understanding self-assembly dynamics, driven by polyelectrolyte complexation that occurs on ultrafast time scales. ",
author = "Hao Wu and Ting, {Jeffrey M.} and Boyuan Yu and Jackson, {Nicholas E.} and Siqi Meng and {De Pablo}, {Juan J.} and Tirrell, {Matthew V.}",
note = "Funding Information: This work was performed under the following financial assistant award 70NANB19H005 from U.S. Department of Commerce, National Institute of Standards and Technology (NIST) as part of the Center for Hierarchical Materials Design (CHiMaD). Funding Information: We gratefully thank Artem M. Rumyantsev, Ph.D., for helpful discussions. J.M.T. acknowledges support from the NIST-CHiMaD Postdoctoral Fellowship. Parts of this work were carried out at the Soft Matter Characterization Facility of the University of Chicago. The simulations reported here were carried out on the GPU cluster supported by the NSF through grant DMR-1828629. The authors also thank Thomas Weiss, Ph.D., Ivan Rajkovic, Ph.D., and Tsutomu Matsui, Ph.D. at the Stanford National Accelerator Laboratory for their assistance in scattering experiments and insightful discussions. Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515. The SSRL Structural Molecular Biology Program is supported by the DOE Office of Biological and Environmental Research and by the National Institutes of Health, National Institute of General Medical Sciences (including P41GM103393). The contents of this publication are solely the responsibility of the authors and do not necessarily represent the official views of NIGMS or NIH. Publisher Copyright: {\textcopyright} Copyright: Copyright 2020 Elsevier B.V., All rights reserved.",
year = "2020",
month = nov,
day = "17",
doi = "10.1021/acsmacrolett.0c00543",
language = "English (US)",
volume = "9",
pages = "1674--1680",
journal = "ACS Macro Letters",
issn = "2161-1653",
publisher = "American Chemical Society",
number = "11",
}