Polyelectrolyte Conformation Controlled by a Trivalent-Rich Ion Jacket.

TitlePolyelectrolyte Conformation Controlled by a Trivalent-Rich Ion Jacket.
Publication TypeJournal Article
Year of Publication2019
AuthorsInnes-Gold, Sarah N., Philip A. Pincus, Mark J. Stevens, and Omar A. Saleh
JournalPhys Rev Lett
Date Published2019 Nov 01

The configuration of charged polymers is heavily dependent on interactions with surrounding salt ions, typically manifesting as a sensitivity to the bulk ionic strength. Here, we use single-molecule mechanical measurements to show that a charged polysaccharide, hyaluronic acid, shows a surprising regime of insensitivity to ionic strength in the presence of trivalent ions. Using simulations and theory, we propose that this is caused by the formation of a "jacket" of ions, tightly associated with the polymer, whose charge (and thus effect on configuration) is robust against changes in solution composition.

Alternate JournalPhys. Rev. Lett.
PubMed ID31763890