These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
3 files

Spatiotemporal Formation Kinetics of Polyelectrolyte Complex Micelles with Millisecond Resolution

revised on 25.07.2020, 18:55 and posted on 27.07.2020, 07:40 by Hao Wu, Jeffrey Ting, Boyuan Yu, Nicholas Jackson, Siqi Meng, Juan de Pablo, Matthew Tirrell
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) and aggregation number (N) with complementary molecular dynamics simulations, we develop new information on 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 occur on ultrafast timescales.


Email Address of Submitting Author


University of Chicago


United States

ORCID For Submitting Author


Declaration of Conflict of Interest

The authors declare no competing financial interest.

Version Notes

Version 2, added additional analysis and simulations.


Logo branding