Decoupling Salt- and Polymer-Dependent Dynamics in Polyelectrolyte Complex Coacervates via Salt Addition

15 June 2020, Version 1
This content is a preprint and has not undergone peer review at the time of posting.

Abstract

In polyelectrolyte complex coacervates, changes in salt concentration and changes in polymer concentration are typically strongly coupled, complicating interpretation of the salt- and polymer concentration-dependent dynamics of these materials. To address this problem, we developed a “salt addition” method for preparation of complex coacervates that allows the salt concentration of a coacervate sample to be varied without changing its polymer concentration. This method was used to prepare coacervates of poly(styrene sulfonate) (PSS) with poly(diallyldimethylammonium chloride) (PDADMAC) with salt concentrations between 1.2 and 2 M and volume fractions of polymer between 0.1 and 0.25. Characterization of these samples by small-amplitude oscillatory shear rheology revealed that the relaxation times scale significantly more strongly with polymer volume fraction than has been previously assumed, highlighting the need to account for both salt and polymer-dependent contributions to the dynamics of these complex materials.

Keywords

complex coacervate
rheology
polyelectrolyte

Supplementary materials

Title
Description
Actions
Title
FJM-2020-saltaddn-SI
Description
Actions

Comments

Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.