Emergence of Multiscale Dynamics in Colloidal Gels.
Phys Rev Lett
; 124(8): 088005, 2020 Feb 28.
Article
en En
| MEDLINE
| ID: mdl-32167319
ABSTRACT
To gain insight into the kinetics of colloidal gel evolution at low particle volume fractions Ï, we utilize differential dynamic microscopy to investigate particle aggregation, geometric percolation, and the subsequent transition to nonergodic dynamics. We report the emergence of unexpectedly rich multiscale dynamics upon the onset of nonergodicity, which separates the wave vectors q into three different regimes. In the high-q domain, the gel exhibits Ï-independent internal vibrations of fractal clusters. The intermediate-q domain is dominated by density fluctuations at the length scale of the clusters, as evidenced by the q independence of the relaxation time τ. In the low-q domain, the scaling of τ as q^{-3} suggests that the network appears homogeneous. The transitions between these three regimes introduce two characteristic length scales, distinct from the cluster size.
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Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Phys Rev Lett
Año:
2020
Tipo del documento:
Article
País de afiliación:
Estados Unidos