Dynamic arrest of colloids in porous environments: disentangling crowding and confinement

Details Dynamic arrest of colloids in porous environments: disentangling crowding and confinement Dynamic arrest of colloids in porous environments: disentangling crowding and confinement

2010-12-06

arxiv.org/abs/1012.1267v2

J. Phys.: Condens. Matter 23, 234122 (2011)

Physics

Condensed Matter

Soft Condensed Matter

18 pages, 12 figures, minor changes

Scientific paper

10.1088/0953-8984/23/23/234122

Using numerical simulations we study the slow dynamics of a colloidal hard-sphere fluid adsorbed in a matrix of disordered hard-sphere obstacles. We calculate separately the contributions to the single-particle dynamic correlation functions due to free and trapped particles. The separation is based on a Delaunay tessellation to partition the space accessible to the centres of fluid particles into percolating and disconnected voids. We find that the trapping of particles into disconnected voids of the matrix is responsible for the appearance of a nonzero long-time plateau in the single-particle intermediate scattering functions of the full fluid. The subdiffusive exponent $z$, obtained from the logarithmic derivative of the mean-squared displacement, is observed to be essentially unaffected by the motion of trapped particles: close to the percolation transition, we determined $z \simeq 0.5$ for both the full fluid and the particles moving in the percolating void. Notably, the same value of $z$ is found in single-file diffusion and is also predicted by mode-coupling theory along the diffusion-localisation line. We also reveal subtle effects of dynamic heterogeneity in both the free and the trapped component of the fluid particles, and discuss microscopic mechanisms that contribute to this phenomenon.

Affiliated with

Also associated with

No associations

Rating

Dynamic arrest of colloids in porous environments: disentangling crowding and confinement does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Dynamic arrest of colloids in porous environments: disentangling crowding and confinement, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dynamic arrest of colloids in porous environments: disentangling crowding and confinement will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-168478