Abstract
Charge-carrying species, such as polyelectrolytes, are vital to natural and synthetic processes that rely on their dynamic behavior. Through single-particle tracking techniques, the diffusivity of individual polyelectrolyte chains and overall system viscosity are determined for concentrated polylysine solutions. These studies show scaling dependences of D ∼ c-6.1 and η ∼ c7.2, much stronger than theoretical predictions, drawing the applicability of power law fits into question. Similar trends are observed in concentrated solutions prepared at various pH and counterion conditions. These hindered system dynamics appear universal to polyelectrolyte systems and are attributed to the large effective excluded volumes of polyelectrolyte chains inducing glassy dynamics. The framework of the Vrentas-Duda free-volume theory is used to compare polyelectrolyte and neutral systems. Supported by this theory, excluding counterion mass from total polymer mass results in all environmental conditions collapsing onto a common trendline. These results are applicable to crowded biological systems, such as intracellular environments where protein mobility is strongly inhibited.
| Original language | English (US) |
|---|---|
| Article number | ado4976 |
| Journal | Science Advances |
| Volume | 10 |
| Issue number | 27 |
| DOIs | |
| State | Published - Jul 2024 |
Funding
We are grateful to J. Torkelson, M. Tirrell, A. Neitzel, C. Lopez, J. Richards, K. Patel, and P. Ramos for access to their equipment and useful discussions. We would also like to thank C. Rademacher for his work on the SPT analysis interface. Funding: This work was performed under the financial assistance award 70NANB14H012 from the U.S. Department of Commerce, National Institute of Standards and Technology as part of the Center for Hierarchical Materials Design (CHiMaD). M.W. acknowledges support from the Alfred P. Sloan Foundation and The Camille and Henry Dreyfus Foundation. This work made use of the IMSERC NMR facility at Northwestern University, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECC S-2025633), NSF CHE-1048773, and Northwestern University. Author contributions: Conceptualization: H.L. and M.W. Methodology: H.L. Investigation and Analysis: H.L. and N.K. Supervision: M.W. Writing- original draft: H.L., N.K., and M.W. Writing-review and editing: H.L. and M.W. Competing interests: The authors declare that they have no competing interests. Data and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials.
ASJC Scopus subject areas
- General