Volume 71, Number 3, August 2005
|Page(s)||480 - 486|
|Section||Interdisciplinary physics and related areas of science and technology|
|Published online||13 July 2005|
The sediment of mixtures of charged colloids: Segregation and inhomogeneous electric fields
Institute for Theoretical Physics, Utrecht University Leuvenlaan 4, 3584 CE Utrecht, The Netherlands
Accepted: 6 June 2005
We theoretically study sedimentation-diffusion equilibrium of dilute binary, ternary, and polydisperse mixtures of colloidal particles with different buoyant masses and/or charges. We focus on the low-salt regime, where the entropy of the screening ions drives spontaneous charge separation and the formation of an inhomogeneous macroscopic electric field. The resulting electric force lifts the colloids against gravity, yielding highly nonbarometric and even nonmonotonic colloidal density profiles. The most profound effect is the phenomenon of segregation into layers of colloids with equal mass-per-charge, including the possibility that heavy colloidal species float onto lighter ones.
PACS: 82.70.Dd – Colloids / 05.20.Jj – Statistical mechanics of classical fluids
© EDP Sciences, 2005
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.