Publication Date

2017

Journal or Book Title

Soft Matter

Abstract

Polyelectrolyte complexation has long been known to result in both liquid and solid complexes. However, the exact nature of the liquid-to-solid transition remains an open question. We have used rheology to explain this phenomenon for the model system of poly(4-styrenesulfonic acid, sodium salt) (PSS) and poly(diallyldimethyl ammonium chloride) (PDADMAC) in the presence of potassium bromide (KBr). The use of a time-salt superposition allows for a detailed analysis of changes in the linear viscoelastic response for both liquid complex coacervates and solid polyelectrolyte complexes as a function of salt concentration, and facilitates unambiguous determination of the mechanism for this phase transition. Decreasing salt concentration, and the commensurate decrease in the water content of PSS/PDADMAC/KBr complexes is shown to lead to the formation of a physical gel due to the development of a network with trapped electrostatic crosslinks that percolates the sample at a critical salt concentration.

DOI

10.1039/C7SM01285C

Comments

This article can be cited before page numbers have been issued, to do this please use: Y. Liu, B. Momani, H. H. Winter and S. L. Perry, Soft Matter, 2017, DOI: 10.1039/C7SM01285C.

License

UMass Amherst Open Access Policy

Funder

Acknowledgment is made to the Donors of the American Chemical Society Petroleum Research Fund for support of this research.

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