|Polyelectrolyte Conformation Controlled by a Trivalent-Rich Ion Jacket.
|Year of Publication
|Innes-Gold, Sarah N., Philip A. Pincus, Mark J. Stevens, and Omar A. Saleh
|Phys Rev Lett
|2019 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.
|Phys. Rev. Lett.