open access

https://hdl.handle.net/2115/90762

Microrheological study of single chain dynamics in semidilute entangled flexible polymer solutions : Crossover from Rouse to Zimm modes

英語

Zimm mode

2022-11-01

The Society of Rheology

Journal of rheology

66(6)

1165-1179

The dynamics of polymer chains in entangled semidilute solution have been of theoretical and experimental interest. Among a number of characteristic lengths and times of the polymer in solution, those of the correlation blob are the key to understand the applicability of the Rouse and Zimm models to rheology of the semidilute solution. Direct rheological measurements of Rouse and Zimm modes are limited as the corresponding time scale is out of the range of classical rheological techniques. We investigated the single chain dynamics of entangled poly(ethylene oxide) in semidilute aqueous solutions by high-frequency micro-rheology based on diffusing-wave spectroscopy compared to classical shear macro-rheology. Concentration dependence of the three characteristic times of the entangled polymer chains, reptation time, entanglement time, and correlation time, was studied with the help of the time-concentration superposition. At the low frequency range, dynamic moduli measured by macro-rheology and micro-rheology showed a good agreement without adjustable parameters. At the higher frequency range, we found the Rouse regime in the mean square displacement of the probe particles and in the magnitude of the complex specific viscosity of the solution. We propose a simple method to estimate the boundary of the Rouse regime. Finally, at the high frequency range, we demonstrate that the contribution of the solvent to the solution viscosity needs to be subtracted to observe the power-law behavior of the Zimm mode.

学術雑誌論文

Accepted Manuscript

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Journal of Rheology 66, 1165-1179 (2022) and may be found at https://doi.org/10.1122/8.0000402

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