Anomalous diffusion of symmetric and asymmetric active colloids.

The stochastic dynamics of colloidal particles with surface activity-in the form of catalytic reaction or particle release-and self-phoretic effects are studied analytically. Three different time scales corresponding to inertial effects, solute redistribution, and rotational diffusion are identified...

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Bibliographic Details
Main Author: Golestanian, R
Format: Journal article
Language:English
Published: 2009
Description
Summary:The stochastic dynamics of colloidal particles with surface activity-in the form of catalytic reaction or particle release-and self-phoretic effects are studied analytically. Three different time scales corresponding to inertial effects, solute redistribution, and rotational diffusion are identified and shown to lead to a plethora of different regimes involving inertial, propulsive, anomalous, and diffusive behaviors. For symmetric active colloids, a regime is found where the mean-squared displacement has a superdiffusive t;{3/2} behavior. At the longest time scales, an effective diffusion coefficient is found which has a nonmonotonic dependence on the size of the colloid.