Arrested fluid-fluid phase separation in depletion systems: Implications of the characteristic length on gel formation and rheology.
In: Journal of Rheology, Jg. 54 (2010-03-01), Heft 2, S. 421-438
academicJournal
Zugriff:
We investigate the structural, dynamical, and rheological properties of colloid-polymer mixtures in a volume fraction range of [lowercase_phi_synonym]=0.15–0.35. Our systems are density-matched, residual charges are screened, and the polymer-colloid size ratio is ∼0.37. For these systems, the transition to kinetically arrested states, including disconnected clusters and gels, coincides with the fluid-fluid phase separation boundary. Structural investigations reveal that the characteristic length, L, of the networks is a strong function of the quench depth: for shallow quenches, L is significantly larger than that obtained for deep quenches. By contrast, L is for a given quench depth almost independent of [lowercase_phi_synonym]; this indicates that the strand thickness increases with [lowercase_phi_synonym]. The strand thickness determines the linear rheology: the final relaxation time exhibits a strong dependence on [lowercase_phi_synonym], whereas the high frequency modulus does not. We present a simple model based on estimates of the strand breaking time and shear modulus that semiquantitatively describes the observed behavior. [ABSTRACT FROM AUTHOR]
Titel: |
Arrested fluid-fluid phase separation in depletion systems: Implications of the characteristic length on gel formation and rheology.
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Autor/in / Beteiligte Person: | Conrad, J. C. ; Wyss, H. M. ; Trappe, V. ; Manley, S. ; Miyazaki, K. ; Kaufman, L. J. ; Schofield, A. B. ; Reichman, D. R. ; Weitz, D. A. |
Zeitschrift: | Journal of Rheology, Jg. 54 (2010-03-01), Heft 2, S. 421-438 |
Veröffentlichung: | 2010 |
Medientyp: | academicJournal |
ISSN: | 0148-6055 (print) |
DOI: | 10.1122/1.3314295 |
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