TY - JOUR
T1 - Electric-field-induced displacement of a charged spherical colloid embedded in an elastic Brinkman medium
AU - Hill, Reghan J.
AU - Ostoja-Starzewski, M.
N1 - The authors of this paper like to acknowledge the technical assistance of Koen Chielens and Patrick De Pue. The research was carried out in the framework of two Ph.D.'s funded by grants (SB-81139 and SB-141289) of the Institute for the Promotion of Innovation through Science and Technology in Flanders (IWT-Vlaanderen). The experimental equipment was funded by a Research Grant (1.5.147.10N) of the Research Foundation Flanders (FWO). These financial supports are gratefully acknowledged.
PY - 2008/1/25
Y1 - 2008/1/25
N2 - When an electric field is applied to an electrolyte-saturated polymer gel embedded with charged colloidal particles, the force that must be exerted by the hydrogel on each particle reflects a delicate balance of electrical, hydrodynamic, and elastic stresses. This paper examines the displacement of a single charged spherical inclusion embedded in an uncharged hydrogel. We present numerically exact solutions of coupled electrokinetic transport and elastic-deformation equations, where the gel is treated as an incompressible, elastic Brinkman medium. This model problem demonstrates how the displacement depends on the particle size and charge, the electrolyte ionic strength, and Young's modulus of the polymer skeleton. The numerics are verified, in part, with an analytical (boundary-layer) theory valid when the Debye length is much smaller than the particle radius. Finally, we identify a close connection between the displacement when a colloid is immobilized in a gel and its velocity (electrophoretic mobility) when dispersed in a Newtonian electrolyte.
AB - When an electric field is applied to an electrolyte-saturated polymer gel embedded with charged colloidal particles, the force that must be exerted by the hydrogel on each particle reflects a delicate balance of electrical, hydrodynamic, and elastic stresses. This paper examines the displacement of a single charged spherical inclusion embedded in an uncharged hydrogel. We present numerically exact solutions of coupled electrokinetic transport and elastic-deformation equations, where the gel is treated as an incompressible, elastic Brinkman medium. This model problem demonstrates how the displacement depends on the particle size and charge, the electrolyte ionic strength, and Young's modulus of the polymer skeleton. The numerics are verified, in part, with an analytical (boundary-layer) theory valid when the Debye length is much smaller than the particle radius. Finally, we identify a close connection between the displacement when a colloid is immobilized in a gel and its velocity (electrophoretic mobility) when dispersed in a Newtonian electrolyte.
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U2 - 10.1103/PhysRevE.77.011404
DO - 10.1103/PhysRevE.77.011404
M3 - Article
AN - SCOPUS:38749096636
SN - 1539-3755
VL - 77
JO - Physical Review E - Statistical, Nonlinear, and Soft Matter Physics
JF - Physical Review E - Statistical, Nonlinear, and Soft Matter Physics
IS - 1
M1 - 011404
ER -