(683g) Rheology and Dynamics of Slit-Confined Charged Suspensions with Different Dielectrics | AIChE

(683g) Rheology and Dynamics of Slit-Confined Charged Suspensions with Different Dielectrics

Authors 

Hernandez-Ortiz, J. P. - Presenter, Universidad Nacional de Colombia
de Pablo, J. J. - Presenter, University of Wisconsin-Madison

A Stokesian-dynamics approach and an accelerated boundary integral formulation are de- veloped to study the rheology and dynamics of slit-confined charged spherical suspensions. Far-field interactions, for the hydrodynamics and electrostatics, are included through a Green’s function formalism. The mobility problem for the hydrodynamic forces is solved following an accelerated Stokesian-dynamic method. The far-field interactions, including higher moments of Stokes’ singular solution, are calculated including non-slip conditions at walls using an efficient General geometry Ewald-like (GgEm) approach. On the other hand, near-field lubri- cation forces are resolved by direct construction of the pairwise particle-particle and particle- wall resistance matrix. Indirect and direct boundary integral formulations are used to account for the electrostatic interactions considering different dielectrics between the fluid and the charged spheres. The electrostatic integral formulation is also resolved efficiently following a GgEm approach. The effects of confinement, charge, dielectric ratio and concentration are studied. Delicate balance between hydrodynamic and electrostatic forces determine the struc- ture, rheology and dynamics of the flowing suspension.