# Tracer diffusion in colloidal gels

Abstract : Computer simulations were done of the mean square displacement (MSD) of tracer particles in colloidal gels formed by diffusion or reaction limited aggregation of hard spheres. The diffusion coefficient was found to be determined by the volume fraction accessible to the spherical tracers ($\phi_a$) independent of the gel structure or the tracer size. In all cases, critical slowing down was observed at $\phi_a\approx 0.03$ and was characterized by the same scaling laws reported earlier for tracer diffusion in a Lorentz gas. Strong heterogeneity of the MSD was observed at small $\phi_a$ and was related to the size distribution of pores.
Document type :
Journal articles
Domain :

https://hal.archives-ouvertes.fr/hal-00206247
Contributor : Jean-Christophe Gimel <>
Submitted on : Wednesday, January 16, 2008 - 6:03:19 PM
Last modification on : Wednesday, May 6, 2020 - 5:48:03 PM

### Citation

Sujin Babu, Jean-Christophe Gimel, Taco Nicolai. Tracer diffusion in colloidal gels. Journal of Physical Chemistry B, American Chemical Society, 2008, 112 (3), pp.743-748. ⟨10.1021/jp076342+⟩. ⟨hal-00206247⟩

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