Determining the Molecular Weight of Polyelectrolytes Using the Rouse Scaling Theory for Salt-Free Semidilute Unentangled Solutions

Chain dynamics in the semidilute unentangled regime can be used to determine the molecular weight of polyelectrolytes based on the Rouse scaling model. Four methods enable determination of the number density of chains via measurements of correlation length (ξ) by small-angle X-ray scattering, specific viscosity (ηsp) and relaxation time (τ) by rheometry, and diffusion coefficient (D) by NMR. Five narrow dispersity cesium polystyrene sulfonate (CsPSS) solutions without salt are studied in water, anhydrous ethylene glycol, and anhydrous glycerol to test all methods. Combining viscosity and correlation length yields the weight-average molecular weight (Mw) from the Rouse model. Combining diffusion coefficient and correlation length in water provides number-average molecular weight (Mn) reliably for chains with N < 2000 repeat units. Glycerol slows relaxation dynamics, and the shear rate dependence of viscosity yields reliable τ for CsPSS with N > 100, which is governed by the product of z-average and z + 1 average molecular weight (MzMz+1) in the Rouse model. Terminal modulus G = (η – ηs)/τ via rheometry correlates with Mw/MzMz+1.

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Work Title Determining the Molecular Weight of Polyelectrolytes Using the Rouse Scaling Theory for Salt-Free Semidilute Unentangled Solutions
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Open Access
Creators
  1. Aijie Han
  2. Veera Venkata Shravan Uppala
  3. Daniele Parisi
  4. Christy George
  5. Benjamin J. Dixon
  6. Camila Denise Ayala
  7. Xiuli Li
  8. Louis A. Madsen
  9. Ralph Colby
Keyword
  1. Rheology
  2. NMR diffusometry
  3. Viscosity
  4. Terminal Modulus
  5. Relaxation Time
License In Copyright (Rights Reserved)
Work Type Article
Publisher
  1. Macromolecules
Publication Date August 8, 2022
Publisher Identifier (DOI)
  1. https://doi.org/10.1021/acs.macromol.2c01007
Deposited June 25, 2023

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Version 1
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  • Created
  • Updated
  • Added Creator Ralph Colby
  • Added Creator 0000-0002-9309-5912
  • Added Creator Ralph Colby
  • Added Creator Aijie Han
  • Added CsPSSMnMw.pdf
  • Updated License Show Changes
    License
    • https://rightsstatements.org/page/InC/1.0/
  • Published
  • Updated Keyword, Publisher, Publisher Identifier (DOI), and 1 more Show Changes
    Keyword
    • Rheology, NMR diffusometry, Viscosity, Terminal Modulus, Relaxation Time
    Publisher
    • Macromolecules
    Publisher Identifier (DOI)
    • https://doi.org/10.1021/acs.macromol.2c01007
    Publication Date
    • 2022
    • 2022-08-08
  • Deleted Creator Ralph Colby
  • Updated Creator 0000-0002-9309-5912
  • Added Creator Veera Venkata Shravan Uppala
  • Added Creator Daniele Parisi
  • Added Creator Christy George
  • Added Creator Benjamin J. Dixon
  • Added Creator Camila Denise Ayala
  • Added Creator Xiuli Li
  • Deleted Creator 0000-0002-9309-5912
  • Updated Creator Ralph Colby
  • Updated Creator Aijie Han
  • Updated Creator Veera Venkata Shravan Uppala
  • Updated Creator Daniele Parisi
  • Updated Creator Christy George
  • Updated Creator Benjamin J. Dixon
  • Updated Creator Camila Denise Ayala
  • Updated Creator Xiuli Li
  • Added Creator Louis A. Madsen
  • Updated