Scaling Behavior of Entanglement Dynamics in Polyelectrolyte Solutions: Insights from High-Frequency Rheometry

IF 5.1 Q1 POLYMER SCIENCE

ACS Macro Letters Pub Date : 2025-02-13 DOI:10.1021/acsmacrolett.4c00722

Yahya Rharbi

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引用次数: 0

Abstract

Entanglement dynamics in polyelectrolyte solutions remain a challenging topic, particularly in capturing the entire dynamic spectrum, from single entanglement relaxation (τ_e) to reptation time (τ_rep), and aligning these observations with scaling predictions in the semidilute entangled (SE) and fully entangled (FE) neutral regimes. Using piezo compressional and classic rotational rheometry, we investigate the scaling behaviors of key viscoelastic properties over several decades of time scales in ten million Mw cationic polyacrylamide solutions. Specific viscosity (η_sp) and τ_rep scale as predicted within Fuoss, SE, and FE regimes, defining crossover concentrations between these regimes (C_e and C_D). More importantly, τ_e, the rubbery plateau width (τ_rep/τ_e), and the high-frequency modulus (G_e) scale as C^{–1.14±0.02}, C^1.25±0.07, and C^1.32±0.05, aligning with SE prediction in the early SE regime before transitioning to neutral scaling of C^–2.7±0.14, C^3.1±0.15, and C^2.35±0.07 at an intermediate concentration between C_e and C_D labeled C_D^e. These results indicate that electrostatic interactions affect single entanglements and reptation differently, leading to a transition to neutral behavior at C_D^e for the former and at C_D for the latter.

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来源期刊

ACS Macro Letters 化学-

CiteScore

10.40

自引率

3.40%

发文量

209

审稿时长

1 months

期刊介绍： ACS Macro Letters publishes research in all areas of contemporary soft matter science in which macromolecules play a key role, including nanotechnology, self-assembly, supramolecular chemistry, biomaterials, energy generation and storage, and renewable/sustainable materials. Submissions to ACS Macro Letters should justify clearly the rapid disclosure of the key elements of the study. The scope of the journal includes high-impact research of broad interest in all areas of polymer science and engineering, including cross-disciplinary research that interfaces with polymer science. With the launch of ACS Macro Letters, all Communications that were formerly published in Macromolecules and Biomacromolecules will be published as Letters in ACS Macro Letters.