Next Article in Journal
Densification and Strengthening of Aerogels by Sintering Heat Treatments or Plastic Compression
Next Article in Special Issue
Crystal Crosslinked Gels for the Deposition of Inorganic Salts with Polyhedral Shapes
Previous Article in Journal / Special Issue
Binding of Lysozyme to Spherical Poly(styrenesulfonate) Gels
Article Menu
Issue 1 (March) cover image

Export Article

Open AccessArticle

Relaxation Behavior by Time-Salt and Time-Temperature Superpositions of Polyelectrolyte Complexes from Coacervate to Precipitate

Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899, USA
Author to whom correspondence should be addressed.
Official contribution of the National Institute of Standards and Technology; not subject to copyright in the United States.
Received: 6 December 2017 / Revised: 12 January 2018 / Accepted: 17 January 2018 / Published: 18 January 2018
(This article belongs to the Special Issue Polyelectrolyte Gels)
Full-Text   |   PDF [4558 KB, uploaded 18 January 2018]   |  


Complexation between anionic and cationic polyelectrolytes results in solid-like precipitates or liquid-like coacervate depending on the added salt in the aqueous medium. However, the boundary between these polymer-rich phases is quite broad and the associated changes in the polymer relaxation in the complexes across the transition regime are poorly understood. In this work, the relaxation dynamics of complexes across this transition is probed over a wide timescale by measuring viscoelastic spectra and zero-shear viscosities at varying temperatures and salt concentrations for two different salt types. We find that the complexes exhibit time-temperature superposition (TTS) at all salt concentrations, while the range of overlapped-frequencies for time-temperature-salt superposition (TTSS) strongly depends on the salt concentration (Cs) and gradually shifts to higher frequencies as Cs is decreased. The sticky-Rouse model describes the relaxation behavior at all Cs. However, collective relaxation of polyelectrolyte complexes gradually approaches a rubbery regime and eventually exhibits a gel-like response as Cs is decreased and limits the validity of TTSS. View Full-Text
Keywords: coacervate; polyelectrolyte; rheology; sticky-Rouse; viscosity coacervate; polyelectrolyte; rheology; sticky-Rouse; viscosity

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Ali, S.; Prabhu, V.M. Relaxation Behavior by Time-Salt and Time-Temperature Superpositions of Polyelectrolyte Complexes from Coacervate to Precipitate. Gels 2018, 4, 11.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Gels EISSN 2310-2861 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top